PREFACE 

EPA’s Response to the Petitions to Reconsider the Endangerment and Cause or Contribute 

Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act 

 

This is the Response to Petitions (RTP) document that accompanies the Environmental 

Protection Agency’s (EPA’s) Notice of Denial of Petitions to Reconsider the Endangerment and 

Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act 

(“Denial” or “Decision”). The Endangerment and Cause or Contribute Findings for Greenhouse 

Gases under Section 202(a) of the Clean Air Act (“Findings” or “Endangerment Finding”) were 

signed by the Administrator on December 7, 2009, appeared in the Federal Register December 

15, 2009, and became effective January 14, 2010. The Administrator’s Endangerment Finding 

concluded that six greenhouse gases (GHGs) taken in combination endanger both the public 

health and public welfare of current and future generations. The Findings were supported by a 

Technical Support Document (TSD), containing the underlying GHG emissions data and climate 

change science, as well as an 11-volume Response to Comments (RTC) document that provided 

EPA’s responses to all significant public comments received during the comment period 

following the Administrator’s proposed Findings, signed April 17, 2009. 

Since issuing the December 2009 Findings, EPA has received 10 petitions requesting that EPA 

reconsider the Findings. 

This RTP document provides additional information, often more technical information, in 

response to the arguments, claims and assertions by the petitioners in their petitions to reconsider 

the Endangerment Finding. EPA has thoroughly reviewed all of the petitions, the arguments 

presented in the petitions, and the supplemental information provided by the petitioners intended 

to show evidence of the petitioners’ claims. EPA also revisited the scientific record and the 

Administrator’s decision process underlying the Endangerment Finding in light of the petitions. 

All of the petitioners’ arguments are addressed in the Denial and/or this RTP document. 

Within this document, the petitioners’ arguments and assertions are grouped together and 

responded to in three volumes: 1) climate science and data issues raised by the petitioners; 2) 

issues raised by petitioners on EPA’s use of information from the Intergovernmental Panel on 

Climate Change; and 3) process issues raised by the petitioners. 

 

The Administrator’s Findings and its supporting material (the TSD and RTC), as well as all ten 

petitions, including amendments to some of those petitions, can be found at: 

http://epa.gov/climatechange/endangerment.html. All documents and materials that are 

referenced in the Denial and this RTP document can be found in the docket for this action 

(Docket ID No. EPA-HQ-OAR-2009-0171 at www.regulations.gov). 

Throughout the Denial and the three volumes of this RTP document, EPA references the 

conclusions of five recent inquiries and investigations regarding the Climatic Research Unit 
(CRU) e-mails and the IPCC’s Fourth Assessment Report (AR4). These five reports have been 

placed in the docket for this action (Docket ID No. EPA-HQ-OAR-2009-0171 at 

www.regulations.gov) under the document title “Recent Inquiries and Investigations of the CRU 

E-mails and the IPCC Fourth Assessment Report”. We provide a brief overview of the purpose 

of each investigation below: 

1. The disclosure of climate data from the Climatic Research Unit at the University of East 

Anglia 

 UK House of Commons, Science and Technology Committee 

 Published on March 31, 2010 

 Referred to in the volumes as: “the UK House of Commons Science and Technology 

 Committee investigation” 

This investigation assessed the accuracy and availability of CRU’s data, datasets and 

computer programming, whether CRU scientists withheld access to this information, and 

implications for the UK Freedom of Information Act 2000. The report also included the 

Science and Technology Committee’s comments on the independent reviews that 

University of East Anglia announced. 

2. Report of the International Panel set up by the University of East Anglia to examine the 

research of the Climatic Research Unit 

 University of East Anglia, Oxburgh Panel 

 Published on April 14, 2010 

 Referred to in the volumes as: “the Scientific Appraisal Panel review” 

The Panel was set up by the University of East Anglia in consultation with the Royal 

Society to assess the integrity of the research published by CRU in light of various 

external assertions. The Panel was asked to address criticisms regarding whether climatic 

data had been dishonestly selected, manipulated and/or presented to arrive at predetermined conclusions. 

3. RA-10 Final Investigation Report Involving Dr. Michael E. Mann 

 The Pennsylvania State University 

 Published on June 4, 2010 

 Referred to in the volumes as: “the Pennsylvania State University investigation” 

The University initiated an investigation to examine whether accusations that Michael 

Mann had manipulated data, destroyed records and colluded to hamper the progress of 

scientific discourse, when placed in an academic context, could be construed as 

allegations of research misconduct, which would constitute a violation of Pennsylvania 

State University policy. 

4. Assessing an IPCC assessment – An analysis of statements on projected regional impact 

in the 2007 report 

2
 Netherlands Environmental Assessment Agency (PBL) 

 Published on July 5, 2010 

 Referred to in the volumes as: “Assessing an IPCC Assessment” 

 On January 28, 2010, the Dutch Parliament asked the Ministry for the Environment and 

the Netherlands Environmental Assessment Agency for an investigation into the 

reliability of the regional chapters 9-16 of the IPCC Working Group II Report, and to 

assess the effects of any errors on the summary conclusions drawn by the IPCC Working 

Group II. 

5. The Independent Climate Change E-mails Review 

 University of East Anglia, Russell Panel 

 Published on July 7, 2010 

 Referred to in the volumes as: “the Independent Climate Change E-mails Review” 

This report examines the conduct of the scientists involved in the CRU email issue and 

makes recommendations to the University of East Anglia. The inquiry addressed a 

number of important allegations that were made following the e-mail release, including: 

a) the behavior of the CRU scientists, such as their handling and release of data, their 

approach to peer review, and their role in the public presentation of results, b) the 

assertion that actions were taken to promote a particular view of climate change by 

improperly influencing the process of advising policy makers, and c) the honesty, rigor 

and openness with which the CRU scientists have acted. 

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Table of Contents 

Volume 1: Climate Science and Data Issues Raised by Petitioners 

1.1. Validity of Paleoclimate Temperature Reconstructions and Related Issues 

1.1.1 The “Divergence Issue” in Paleoclimate Reconstructions 

1.1.2 Background 

1.1.3 Assessment of the Evidence Provided by Petitioners Regarding the 

Climate Reconstructions 

1.1.4 Assessment of the Evidence Provided by the Petitioners of 

Intentional Data Manipulation Regarding Tree Ring Data and the 

MWP 

1.1.5 Assessment of Petitioners’ Argument That the MWP May Have 

Been Warmer Than Present Temperatures 

1.1.6 Assessment of the Petitioners’ Argument that Questions About the 

MWP and Paleoclimate Reconstructions Limit Current Ability to 

Attribute Present Warming to Humans 

1.1.7 Summary 

1.2 Attribution of Recent Temperature Trends and Models 

1.2.1 The Validity of the Human “Fingerprint” in the Vertical 

Temperature Structure of the Atmosphere Over the Tropics 

1.2.1.1 Background 

1.2.1.2 Assessment of the Arguments Regarding the Vertical 

Temperature Structure Over the Tropics 

1.2.2 Global Temperature Trends Over the Last Decade and Implications 

for Attribution of These Trends to GHGs 

1.2.2.1 Background 

1.2.2.2 Assessment of Arguments Regarding Global 

Temperature Trends Over the Last Decade and 

Implications for Attribution of These Trends to GHGs 

1.2.3 Climate Model Issues Raised by Petitions 

1.2.4 Summary 

1.3. Validity of the HadCRUT Temperature Record 

1.3.1 Overview 

1.3.2 Scientific Background on Surface Temperature Records and 

Underlying Datasets 

1.3.3 Responses to Petitioners’ Arguments Regarding the Validity of 

CRU Data 

1.3.3.1 Alleged Destruction of Raw Data 

1.3.3.2 Alleged Data Manipulation 

1.3.3.3 “Harry Read Me” file and other code 

1.3.3.4 Claims of Selective Use of Data From Russian Weather 

Stations 

1.3.4 Claims of Flawed Approach to Correct for Urban Heat Island 

(UHI) Effects 

4
1.3.5 Alleged Dependence of IPCC Conclusions on the HadCRUT 

temperature record 

1.3.6 Summary 

1.4 Validity of NOAA and NASA Temperature Records 

1.4.1 Overview 

1.4.2 Background on the Collection and Analysis of Surface 

Temperature Data 

1.4.3 The Petitioners’ Arguments and EPA Responses 

1.4.3.1 Assessment of Issues Related to Alleged Station 

Dropout and Inappropriate Extrapolation 

1.4.3.2 Issues Raised With Respect to Adjustments for the UHI 

Effect 

1.4.3.3 Issues Raised in Additional Literature Provided by 

Petitioners 

1.4.3.4 Petitioners’ Allegations Regarding Data Adjustments at 

Specific Stations 

1.4.3.5 Allegations Regarding the Independence of NOAA, 

NASA, and HadCRUT Temperature Records 

1.4.3.6 Additional Issues Regarding Allegations of 

Manipulation of Data 

1.4.4 Summary 

1.5 Implications of New Studies and Data Submitted by the Petitioners 

1.5.1 Overview 

1.5.2 Implications of a New Study on Stratospheric Water Vapor 

1.5.3 Implications of Material Indicating That CO2 Is Not Well Mixed 

in the Atmosphere and That the Airborne Fraction of CO2 Has Not 

Changed 

1.5.4 Implications of New Tropical Cyclone Studies 

1.5.5 Implications of New Studies on the Statistical Significance of 

Increases in Antarctic Sea Ice 

1.5.6 Implications of Recent Data on Observational Snow Cover Trends 

1.5.7 Petitioners Claim That EPA Ignored a Satellite Dataset 

1.5.8 Summary 

References 

Volume 2: Issues Raised by Petitioners on EPA’s Use of IPCC 

2.1 Claims That IPCC Errors Undermine IPCC Findings and Technical Support 

for Endangerment 

2.1.1 Overview 

2.1.2 Accuracy of Statement on Percent of the Netherlands Below Sea 

 Level 

2.1.3 Validity of Himalayan Glacier Projection 

2.1.4 Characterization of Climate Change and Disaster Losses 

2.1.5 Validity of Alps, Andes, and African Mountain Snow Impacts 

2.1.6 Validity of Amazon Rainforest Dieback Projection 

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2.1.7 Validity of African Rain-Fed Agriculture Projection 

2.1.8 Summary 

2.2 Claims That the IPCC Has a Policy Agenda and Is Not Objective and 

Impartial 

2.2.1 Overview 

2.2.2 Background 

2.2.3 Responses to Arguably New Objections Raised by the Petitioners 

2.2.3.1 Allegations of Inappropriate Authorship and Reviewer 

Roles Among IPCC Personnel 

2.2.3.2 Allegations That Citing One’s Own Papers 

Compromises Objectivity 

2.2.3.3 Allegations That IPCC Is Biased 

2.2.3.4 Allegations That IPCC Lead Authors Forced Consensus 

and Suppressed Dissenting Views 

2.2.4 Responses to Allegations Based on Information That Is Not New 

2.2.4.1 Allegations of Inappropriate Collaborations Among 

IPCC Authors 

2.2.4.2 Allegations Regarding Insufficient Peer Review 

Processes for the IPCC 

2.2.4.3 Allegations That IPCC Authors Manipulated Deadlines 

for New Literature 

2.2.4.4 Allegations Regarding the IPCC’s Use of Gray 

Literature 

2.2.5 Summary 

References 

Volume 3: Process Issues Raised by Petitioners 

3.1 Approaches and Processes Used to Develop the Scientific Support for the 

Findings 

3.1.1 Overview 

3.1.2 Issues Regarding Consideration of the CRU E-mails 

3.1.3 Assessment of Issues Raised in Public Comments and Re-Raised 

in Petitions for Reconsideration 

3.1.4 Summary 

3.2 Response to Claims That the Assessments by the USGCRP and NRC Are Not 

Separate and Independent Assessments 

3.2.1 Overview 

3.2.2 EPA’s Response to Petitioners’ Arguments 

3.2.3 Summary 

3.3 Issues Concerning the Integrity of Peer-Reviewed Literature 

3.3.1 Overview 

3.3.2 Allegations Regarding Reviews of Manuscripts 

3.3.3 Allegations Regarding Journal Publication Practices 

3.3.4 Allegations Regarding Efforts to Remove Editors and Boycott 

Journals 

6
7

3.3.5 Allegations Regarding Objectivity of the Peer-Reviewed Literature 

3.3.6 Allegations of Intimidating Scientists and Those With Dissenting 

Views 

3.3.7 Summary 

3.4 Issues Concerning Freedom of Information Act Requests 

3.4.1 Overview 

3.4.2 Allegations of Withholding Key Data and Information 

3.4.3 Allegations of Improper Conduct With Regard to UK FOI and U.S. 

FOIA Laws 

3.4.3.1 General Allegations 

3.4.3.2 Specific FOI Request Regarding the IPCC’s Fourth 

Assessment Report 

3.4.3.3 Allegations of Improperly Influencing University FOIA 

Officials 

3.4.4 Summary 

References 
EPA’s Response to the Petitions 

to Reconsider the Endangerment 

and Cause or Contribute 

Findings for Greenhouse Gases 

under Section 202(a) of the Clean 

Air Act 

Volume 1: Climate Science and 

Data Issues Raised by 

Petitioners 

U.S. Environmental Protection Agency 

Office of Atmospheric Programs 

Climate Change Division 

Washington, D.C.

1
TABLE OF CONTENTS 

Page

1.0 Climate Science and Data Issues Raised by Petitioners ...................................................6 

1.1. Validity of Paleoclimate Temperature Reconstructions and Related Issues ....................6 

1.1.1 The “Divergence Issue” in Paleoclimate Reconstructions .....................................6 

1.1.2 Background..............................................................................................................7 

1.1.3 Assessment of the Evidence Provided by Petitioners Regarding the 

Climate Reconstructions..........................................................................................9 

1.1.4 Assessment of the Evidence Provided by the Petitioners of Intentional 

Data Manipulation Regarding Tree Ring Data and the MWP..............................22 

1.1.5 Assessment of Petitioners’ Argument That the MWP May Have Been 

Warmer Than Present Temperatures.....................................................................24 

1.1.6 Assessment of the Petitioners’ Argument that Questions About the MWP 

and Paleoclimate Reconstructions Limit Current Ability to Attribute 

Present Warming to Humans.................................................................................26 

1.1.7 Summary .............................................................................................................31 

1.2 Attribution of Recent Temperature Trends and Models.................................................32 

1.2.1 The Validity of the Human “Fingerprint” in the Vertical Temperature 

Structure of the Atmosphere Over the Tropics...............................................................32 

1.2.1.1 Background............................................................................................................32 

1.2.1.2 Assessment of the Arguments Regarding the Vertical Temperature 

Structure Over the Tropics.........................................................................33 

1.2.2 Global Temperature Trends Over the Last Decade and Implications for 

Attribution of These Trends to GHGs....................................................................35 

1.2.2.1 Background................................................................................................35 

1.2.2.2 Assessment of Arguments Regarding Global Temperature Trends 

Over the Last Decade and Implications for Attribution of These 

Trends to GHGs.........................................................................................36 

1.2.3 Climate Model Issues Raised by Petitions.............................................................50 

1.2.4 Summary ................................................................................................................58 

1.3. Validity of the HadCRUT Temperature Record.............................................................59 

1.3.1 Overview................................................................................................................59 

1.3.2 Scientific Background on Surface Temperature Records and Underlying 

Datasets..................................................................................................................60 

1.3.3 Responses to Petitioners’ Arguments Regarding the Validity of CRU Data.........65 

1.3.3.1 Alleged Destruction of Raw Data ..............................................................66 

1.3.3.2 Alleged Data Manipulation.......................................................................70 

1.3.3.3 “Harry Read Me” file and other code.......................................................73 

1.3.3.4 Claims of Selective Use of Data From Russian Weather Stations.............89 

1.3.4 Claims of Flawed Approach to Correct for Urban Heat Island (UHI) 

Effects.....................................................................................................................90 

1.3.5 Alleged Dependence of IPCC Conclusions on the HadCRUT temperature 

record.....................................................................................................................92 

1.3.6 Summary ................................................................................................................96 

2
1.4 Validity of NOAA and NASA Temperature Records ....................................................97 

1.4.1 Overview................................................................................................................97 

1.4.2 Background on the Collection and Analysis of Surface Temperature Data..........97 

1.4.3 The Petitioners’ Arguments and EPA Responses..................................................99 

1.4.3.1 Assessment of Issues Related to Alleged Station Dropout and 

Inappropriate Extrapolation......................................................................99 

1.4.3.2 Issues Raised With Respect to Adjustments for the UHI Effect ...............106 

1.4.3.3 Issues Raised in Additional Literature Provided by Petitioners..............116 

1.4.3.4 Petitioners’ Allegations Regarding Data Adjustments at Specific 

Stations.....................................................................................................118 

1.4.3.5 Allegations Regarding the Independence of NOAA, NASA, and 

HadCRUT Temperature Records.............................................................127 

1.4.3.6 Additional Issues Regarding Allegations of Manipulation of Data........131 

1.4.4 Summary ..............................................................................................................133 

1.5 Implications of New Studies and Data Submitted by the Petitioners ...........................135 

1.5.1 Overview..............................................................................................................135 

1.5.2 Implications of a New Study on Stratospheric Water Vapor............................135 

1.5.3 Implications of Material Indicating That CO2 Is Not Well Mixed in the 

Atmosphere and That the Airborne Fraction of CO2 Has Not Changed .............136 

1.5.4 Implications of New Tropical Cyclone Studies....................................................142 

1.5.5 Implications of New Studies on the Statistical Significance of Increases in 

Antarctic Sea Ice..................................................................................................144 

1.5.6 Implications of Recent Data on Observational Snow Cover Trends...................146 

1.5.7 Petitioners Claim That EPA Ignored a Satellite Dataset ....................................151 

1.5.8 Summary ..............................................................................................................152 

References....................................................................................................................................153 

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ACRONYMS 

°C degrees Celsius 

°F degrees Fahrenheit 

AIRS Atmospheric Infrared Sounder 

AMS American Meteorological Society 

AOGCM Atmosphere-Ocean General Circulation Models 

AR4 IPCC Fourth Assessment Report 

BOM Australian Bureau of Meteorology 

CCSP U.S. Climate Change Science Program 

CH4 methane 

cm centimeter 

CDIAC Carbon Dioxide Information Analysis Center 

CMIP Coupled Model Intercomparison Project 

CO2 carbon dioxide 

CRU Climatic Research Unit 

EPA U.S. Environmental Protection Agency 

FOIA Freedom of Information Act 

GHCN Global Historical Climatology Network 

GHG greenhouse gases 

GISS Goddard Institute for Space Studies (NASA) 

GSL Global Snow Laboratory (Rutgers Universitry) 

IAC InterAcademy Council 

IEA Institute of Economic Analysis 

IISD International Institute for Sustainable Development 

IJC International Journal of Climatology 

IPCC Intergovernmental Panel on Climate Change 

IQA Information Quality Act 

LIA Little Ice Age 

MET United Kingdom Meteorological Office 

MWP Medieval Warm Period 

NASA National Aeronautics and Space Administration 

NCAR National Center for Atmospheric Research 

NCDC National Climatic Data Center 

NIWA National Institute of Water & Atmospheric Research 

NMS National Meteorological Station 

NOAA National Oceanic and Atmospheric Administration 

NRC National Research Council 

NSIDC U.S. National and Snow and Ice Data Center 

ORNL Oak Ridge National Laboratory 

PBL Netherlands Environmental Assessment Agency 

RTC Response to Comments 

RTP Response to Petitions 

SAB Scientific Advisory Board 

SALR saturated adiabatic lapse rate 

TSD Technical Support Document 

4
UAH University of Alabama–Huntsville 

UCAR University Corporation for Atmospheric Research 

UHI urban heat island 

UK United Kingdom 

USGCRP U.S. Global Change Research Program 

USHCN United States Historical Climatology Network 

W/m2 watts per meter squared 

WMO World Meteorological Organization 

WWR World Weather Reports 

5
1.0 Climate Science and Data Issues Raised by Petitioners

1.1. Validity of Paleoclimate Temperature Reconstructions and Related 

Issues 

1.1.1 The “Divergence Issue” in Paleoclimate Reconstructions 

A number of petitioners (the Coalition for Responsible Regulation, Peabody Energy, the 

Southeastern Legal Foundation, the State of Texas, and the Competitive Enterprise 

Institute) challenge the validity of the paleoclimate reconstructions of the temperatures of 

the past 1,000 and 10,000 years, as summarized in the assessment literature.1

 Many of 

the issues they raise are similar to comments EPA received on the proposed 

Endangerment Finding, although in some cases the petitioners draw additional support 

from more recent information released in the media. In particular, several petitioners use 

e-mails involving scientists at the Climatic Research Unit (CRU) of the University of 

East Anglia in the United Kingdom that were made public in November 2009. Based on 

statements in these e-mails, along with other sources, petitioners specifically raise the 

possibility that the Medieval Warm Period (MWP) or the early Holocene (about 10,000 

to 8,000 years ago) may have been warmer than the present. Additionally, they claim 

that the e-mails demonstrate deliberate, inappropriate manipulation of the data. 

Petitioners claim that by showing that recent warmth may not have been 

“unprecedented,” that the attribution of recent warming to human causes is undermined, 

and therefore, the Findings are flawed. 

EPA’s review of the arguments raised by the petitioners, as well as EPA’s review of the 

totality of the CRU e-mails and other documents, finds that the uncertainties about 

paleoclimate reconstructions highlighted by the petitioners were recognized and 

appropriately discussed in the Intergovernmental Panel on Climate Change (IPCC) and 

other assessment documents, as well as in the EPA Technical Support Document (TSD). 

EPA addressed the uncertainties involved in historical temperature reconstructions in the 

Response to Comments (RTC) document, as this was an issue raised by a number of 

commenters. Petitioners fail to acknowledge or engage substantively with the scope and 

comprehensiveness of the discussion of this issue, both in the assessment literature and 

by EPA. Further, they fail to recognize or discuss the other evidence relied on in 

assessing the conclusions drawn from the entire body of paleoclimate evidence. As a 

result, the petitioners’ arguments rely on innuendo and speculation with little scientific 

support or argumentation. 

When viewed as a whole, the paleoclimate analysis contributes to our understanding of 

the climate system. These analyses provide supporting evidence that current warming is 

attributable to anthropogenic greenhouse gases (GHGs). The uncertainties concerning 

the precise temperature and climatic influences in the paleoclimate reconstructions are 

clearly recognized, acknowledged, and taken into account in the conclusions of the 

 

1

 Paleoclimatology is the study of climates of time periods prior to the widespread use of direct 

measurement instruments. 

6
assessment literature and in EPA’s Endangerment Finding. Contrary to petitioners’ 

claims, EPA has not treated this evidence as “compelling” but has instead weighed it 

appropriately given the uncertainties involved. Whether previous warm historical 

episodes were possibly slightly warmer globally than the present or, as the majority of the 

science suggests, slightly cooler on a global average than the present, does not materially 

change the understanding of the climate provided by the paleoclimate evidence. 

We respond to petitioners’ arguments in the following subsections. Subsection 1.1.2 

provides background on paleoclimate temperature reconstructions as context for the more 

technical responses that follow. Subsection 1.1.3 addresses issues including the 

“divergence issue” concerning recent tree ring data. Subsection 1.1.4 addresses the 

arguments over manipulation of data including tree ring data. Section 1.1.5 addresses 

arguments regarding the relative warmth of the MWP and the present day. Section 1.1.6 

addresses arguments on the issue of the role of paleoclimate reconstructions in attribution 

of observed temperature changes to GHGs. Subsection 1.1.7 summarizes EPA’s 

conclusions on the petitioners’ arguments 

1.1.2 Background 

To evaluate the technical details of the petitioners’ arguments, it is useful to describe 

what paleoclimate temperature reconstructions are and how they are used to improve 

understanding of past and present climate change. Direct observation of surface 

temperature records have global coverage over approximately the last 130 to 150 years. 

To determine temperatures in time periods before the instrumental record, climate 

scientists need to use indirect methods (“proxies”). These indirect methods include 

examining tree rings; sediment cores for pollen and plankton records; atomic isotope and 

chemical compound ratios in corals and other marine organisms; glacier extent and 

oxygen isotope ratios in the glacial ice; and subsurface ground temperatures. 

Determining temperatures from these proxies is not always straightforward. For 

example, tree growth is dependent not only on temperature but also water availability, 

CO2 concentrations in the air, and pollution exposure. Marine organism records can be 

influenced by salinity changes, glacier records can be influenced by precipitation 

changes, and so forth. Many of these proxies (including tree rings) are calibrated against 

the instrumental temperature record for the period where datasets overlap. The statistical 

relationship found between the proxy and regional temperatures over the past 150 years is 

then used to extrapolate over the hundreds or thousands of years before instrumental 

records. Examining more data sources and more proxies provides more certainty in the 

reconstructions than would be achieved using a single proxy study with fewer data 

sources, even if some of the included proxies have only a weak relationship with 

temperature. 

Researchers combine a number of different proxies from around the world to develop 

their temperature reconstructions of the past. Different researchers use different subsets 

of data—some rely on only one proxy, others use multi-proxy reconstructions. Fewer 

proxies are available for examination as scientists extend their research further back in 

the past, and the uncertainty of conclusions about past surface temperatures becomes 

7
larger. These reconstructions contribute to our understanding of historical temperatures 

and variability and enable comparison of present day changes to changes in the past 

1,000 years, as well as allowing testing of climate models and our understanding of how 

the climate system responded to historical conditions. 

The “divergence” issue refers to a certain subset of the tree ring records whose growth 

has not correlated with temperature change in recent decades. Basically, in recent years, 

where the regional instrumental record shows warming, some tree ring proxies do not 

show a corresponding growth rate. This is not a new issue; one of the earliest papers on 

divergence was published by CRU researchers in 1998 in the journal Nature (Briffa et al., 

1998). More recently, reports of the IPCC (Jansen et al., 2007) and National Research 

Council (NRC) (2006) cite a number of studies that have explored this topic, assessing 

potential explanations ranging from ozone depletion to specific regional changes in 

drought and precipitation. EPA’s TSD discusses this issue and includes the NRC (2006) 

multiproxy reconstruction in Figure 4.3. As discussed in the TSD, and in more detail in 

Volume 2 in the RTC document, NRC (2006) found divergence in some trees north of 55 

degrees latitude. The TSD summarizes the NRC (2006) and IPCC conclusions on 

paleoclimate, including important discussions of the uncertainty in the reconstructions, 

stating on page 32, “Considering this study and additional research, the IPCC (2007d) 

concluded: “Paleoclimatic information supports the interpretation that the warmth of the 

last half century is unusual in at least the previous 1,300 years.” However, like NRC 

(2006b), IPCC cautions that uncertainty is significant prior to 1600 (Jansen et al., 2007).” 

Some researchers are concerned about the implications of this divergence in the use of 

tree rings for reconstructing historical warm periods; other researchers note that because 

the divergence only applies to trees north of 55 degrees latitude, and a similar difference 

in behavior between northern and southern trees was not seen before the last few decades, 

it is reasonable to conclude that the divergence is a unique phenomenon of the last few 

decades. 

Placing the paleoclimate work into the broader climate science context, the TSD cites the 

U.S. Global Change Research Program (USGCRP) statement that “The second line of 

evidence arises from indirect, historical estimates of past climate changes that suggest 

that the changes in global surface temperature over the last several decades are unusual 

(Karl et al, 2009).” The phrase in Karl et al. regarding “indirect historical estimates” 

refers to the paleoclimate reconstructions based on proxies. Following Karl’s statement, 

the unusual nature of the current warming in the context of the past 1,000 years 

contributes to one of the lines of evidence supporting the attribution of current warming 

to human activities. Note that “unusual” does not mean unprecedented, and past 

warming must be considered in the light of what we know about past climatic forcings 

such as solar and volcanic activity. Additionally, in the IPCC chapter on attribution, 

Hegerl et al. (2007) states that “[a]nalyses of palaeoclimate data have increased 

confidence in the role of external influences on climate.” Hegerl et al. are stating that 

paleoclimate information improves our understanding of the difference between how the 

climate responds to external changes, such as changes in solar radiation, orbital 

8
characteristics, GHG concentrations, or atmospheric loadings of aerosols (such as from 

volcanic eruptions), compared to internal changes such as el Niño events. 

1.1.3 Assessment of the Evidence Provided by Petitioners Regarding the 

Climate Reconstructions 

Comment (1-1): 

Several petitioners (the Coalition for Responsible Regulation, Peabody Energy, the 

Southeastern Legal Foundation, the State of Texas, and Competitive Enterprise Institute) 

argue that the “divergence” issue in the tree ring records “makes comparing the 

temperatures during the MWP [Medieval Warm Period] with recent observed 

temperatures virtually impossible” and that these concerns were suppressed in IPCC 

reports. 

Response (1-1): 

As noted in the background on paleoclimate above, the divergence issue (between certain 

tree rings and recent temperature changes) is not yet a fully explained phenomenon, and 

the e-mails quoted by the petitioners recognize these uncertainties. However, these 

uncertainties are not new. The science community has long been aware of the tree ring 

divergence issue, as well as other issues on the certainty of proxy reconstructions. After 

thorough evaluations, both the IPCC and NRC properly recognized these issues and 

appropriately reflected the uncertainty in their scientific conclusions, as did EPA. Thus, 

these uncertainties were fully presented in the assessment literature. In Response 2-64 

and 2-67 of the RTC document, EPA addressed divergence and uncertainty in 

paleoclimate reconstructions, stating: 

Some temperature reconstructions end in 1980 or earlier because of a well-recognized (in 

the assessment literature) “divergence” problem, where some tree ring records present 

temperature trends that do not correlate well with the instrumental (thermometer) records. 

Explanations for the divergence discussed in NRC (2006b) include water (i.e., drought 

stress) becoming a limiting factor, increasing winter precipitation (leading to delaying 

snowmelt), greater ultraviolet radiation (resulting from ozone depletion) or bias in 

instrumental temperature. However, NRC (2006b) notes a number of tree-ring records 

have not been impacted by divergence, and it is primarily concentrated north of 55° 

latitude. The IPCC (Jansen et al., 2007) notes it is not even ubiquitous in that region. 

Specifically, the NRC also found that “Elevational treeline sites in Mongolia (D’Arrigo et 

al., 2001) and the European Alps (Büntgen et al., 2005) are not affected by “divergence.” 

This geographic separation was confirmed by Cook et al. (2004)” (NRC, 2006). The 

significance of these studies is that they demonstrate that divergence is not an issue with 

all tree ring proxies, much less the many non-tree ring proxies, such as retreating glaciers, 

sediment cores, corals, and other data sources. 

It is important to recognize that the assessment reports looked at all of the proxy evidence 

(e.g., see Fig 4.3 in the TSD [U.S. EPA, 2009]) as well as other paleoclimate evidence, 

such as the clear record that warmer periods in the past coincide with periods with higher 

levels of CO2. The assessment reports rely on this entire body of evidence to support 

9
their conclusions, correctly reflecting any uncertainty expressed in the literature, while 

petitioners discuss only one part of this evidence—the tree ring divergence for trees in 

some locations—and do not contest any of the other parts of the entire body of evidence. 

Petitioners also do not attempt to show that the entire body of evidence supports a 

different conclusion than that drawn by the assessment reports and by EPA. 

Comment (1-2): 

Peabody Energy cites papers by D’Arrigo et al. (2008), Esper and Frank (2009), and 

Loehle (2009) on the subject of divergence. Loehle (2009) presents an analysis on the 

implications of divergence being a result of non-linear responses to temperature. 

Peabody Energy quotes D’Arrigo’s paper as stating that the divergence issues impede “a 

robust comparison of recent warming during the anthropogenic period with past natural 

climate episodes such as the Medieval Warm Period,” and states that the Esper and Frank 

paper “concluded that the divergence problem ‘is of importance...’” 

Response (1-2): 

EPA has reviewed the petitioners’ submission of D’Arrigo et al. (2008), Esper and Frank 

(2009), and Loehle (2009) and finds that it was not impracticable to raise the objection 

during the public comment period and that the reasons for the objection did not arise 

between June 24, 2009, and February 16, 2010. Petitioners could have submitted these 

studies during the comment period on the proposed Endangerment Finding. Although, in 

most cases, the petitioners provide excerpts from the CRU e-mails in support of their 

assertions, EPA’s review has determined that this evidence does not support their 

allegations, and that the information submitted by petitioners on these topics was 

available before the comment period for the Endangerment Finding. Petitioners have not 

shown why it would have been impractical for them to have submitted these studies then. 

Indeed, similar points were already raised, and responded to, in the RTC. Despite the 

fact that these objections fail to meet the statutory timeframe for evidence supporting a 

petition for reconsideration, we briefly explain why, contrary to petitioners’ allegation, 

they fail to call into question the Finding. 

Though the petitioners cite D’Arrigo et al. (2008) to support their contention that the 

divergence problem undermines paleoclimate reconstructions, D’Arrigo et al. (2008) 

recognize the possibility that divergence is a uniquely modern phenomena, though they 

do include caveats on that conclusion: “Although limited evidence suggests that the 

divergence may be anthropogenic in nature and restricted to the recent decades of the 20th

century, more research is needed to confirm these observations.” Similarly, the quote 

from Esper and Frank (2009) that the petitioners select comes from a context-setting 

paragraph and is not a conclusion of the paper, despite the contention of the petitioner. 

Esper and Frank also note that the divergence phenomena is “widely perceived” and the 

“potential consequences discussed (e.g., IPCC, 2007),” providing confirmation that the 

researchers in the field approve of the assessment literature conclusions. Indeed, more 

recent work by Esper (Esper et al., 2010) may have found that some analysis methods do 

not show the same divergence phenomena when used with high latitude Siberian trees. 

10
Loehle (2009) is a more theoretical study examining the implications for reconstructions 

if the reason for “divergence” results from a non-linear response of trees to warming. He 

shows that if the trees respond quadratically to warming rather than linearly, then it is 

possible that reconstructions using these trees would not reproduce some historical warm 

periods. However, these questions are not new: the possibility of such non-linear 

response was addressed in a qualitative form by the NRC (2006). Additionally, some 

reconstructions have examined the effect of not including any tree rings whatsoever and 

still find that modern warming is slightly larger than other events in the past millenium 

(Mann et al., 2008). 

This is an area of ongoing research, but petitioners present no evidence that demonstrates 

that the treatment of this issue by EPA failed to address the uncertainties involved in 

these reconstructions. 

Comment (1-3): 

Peabody Energy raises objections to the IPCC Fourth Assessment Report (AR4) treatment 

of Holocene temperature variation, to the sentence in the TSD referring to reconstructions 

of this period, and to the discussion in the RTC document on the subject. Peabody Energy 

claims that certain e-mails raise doubts about IPCC conclusions regarding the early 

Holocene (about 10,000 to 8,000 years ago). Peabody Energy states that “Obviously, 

warmer temperatures in the early Holocene when GHG concentrations were lower than 

those today would seem to further undermine the conclusion that today’s temperatures 

are unprecedented and, therefore, must be the result of anthropogenic GHG emissions.” 

Peabody Energy quotes several e-mails from IPCC authors discussing two papers (Porter, 

2000 and Thompson et al., 2006) that were not included in the AR4. Peabody Energy 

states that these e-mails support its claims that the IPCC omitted references and skewed the 

discussion of this issue in the AR4, and that the two papers demonstrate that there was 

simultaneous warmth in the tropics and the Southern Hemisphere during the early 

Holocene, in contrast to the IPCC conclusions. 

For example, a petitioner quotes the following from Olga Solomina from July 2006: 

I attach here a version of glacier box and suggestions (in red) how to include there the 

reference to the new Thompson et al., 2006 paper. 

In this relation - I am getting more and more concern about our statement that the Early 

Holocene was cool in the tropics - this paper shows that it was, actually, warm - ice core 

evidences+glaciers were smaller than now in the tropical Andes. The glaciers in the 

Southern Hemisphere (Porter, 2000, review paper) were also smaller than at least in the 

Neoglacial. We do not cite Porter’s paper for the reason that we actually do not know how 

to explain this - orbital reason does not work for the SH, but if we do cite it (which is fair) 

we have to say that during the Early to Mid Holocene glaciers were smaller than later in 

both Northern, and Southern Hemisphere, including the tropics, which would contradict 

11
to our statement in the Holocene chapter and the bullet. It is probably too late to rise these 

questions, but still just to draw your attention.2

The petitioner further quotes Valerie Masson-Delmotte on uncertainties in Holocene land 

reconstructions: 

It seems to me that there is still a large uncertainty about the temperature versus 

precipitation effect on these tropical glaciers. Other indications from South America are 

related to lake levels with contrasted views in the low versus highlands. 

Several references suggest that there is the end of a wet period after the early Holocene in 

tropical south America; this is expected to induce an increase of 18O signals. One review 

was conducted several years ago within the PEPI project 

(http://wwwpaztcn.wr.usgs.gov/pcaw/ and references herein). 

I think that the state of the art is that we have no reliable proxy record that is sensivite to 

temperature only on the tropical lands for the Holocene; therefore the statement that was 

written for the Holocene was based on areas of the tropical oceans where SST 

reconstructions were published. 

Do we have to write more explicitely about the uncertainty?3

The petitioner objects that “Ultimately, the Coordinating Lead Author of Chapter 6, 

Eystein Jansen, decided, contrary to the contentions of Thompson et al. and Foster, that 

the early Holocene evidence from the tropics and Southern Hemisphere is not a reliable 

temperature indicator, and to just leave the text the way it was – that is, without including 

the published evidence from Thompson et al. (2006), Foster (2000), or any discussion 

surrounding these studies that runs contrary to the orbital hypothesis,” including Jansen’s 

e-mail: 

I agree with Valerie that the ice core evidence is ambiguous. I would personally place 

more weight on the alkenone data, which is a reasonable well calibrated SST proxy. 

Foraminifer transfer function based SSTs and some Mg/Ca results that are available 

suggest a similar picture as far as I know. Of course it is possible and plausible that the 

tropical oceans are behaving in a non consistent manner and not all areas are showing the 

same signal, but a sizeable portion appear to do so in order to conclude as we do in the 

chapter in my opinion. Some signals may be due to changes in in trade wind induced 

coastal upwelling strength, but there are enough cores with alkenone data outside of these 

areas. If we were to say more about the uncertainties it may be the fact that proxies are 

seasonally skewed. 

My conclusion is to let the chapter say what we say at the moment.4

 

2

 E-mail file 1154353922.txt, (July 31, 2006), page 1189, lines 9-19 of PDF version entitled: CRU Emails 

1996-2009.pdf 

3

 E-mail file 1154353922.txt, (July 31, 2006), page 1188, lines 35-45 of PDF version entitled: CRU Emails 

1996-2009.pdf 

4

 E-mail file 1154353922.txt, (July 31, 2006), page 1188, lines 25-34 of PDF version entitled: CRU Emails 

1996-2009.pdf 

12
Response (1-3): 

The petitioner raises three main claims: that the e-mails demonstrate bias in writing the 

IPCC chapters, that the omitted references demonstrate global early Holocene warmth, 

and that early Holocene warmth raises doubt about attribution of current warming. On 

the first claim, our analysis finds that the e-mails are examples of legitimate scientific 

discussion between the authors trying to determine what is appropriate for inclusion in a 

chapter and that several of the issues discussed in these e-mails were indeed included in 

the final chapter even if the two papers in question were not directly referenced. On the 

second claim, we note that there is uncertainty regarding early Holocene warmth, that this 

is still an area of ongoing research, and that EPA made no claims about Holocene warmth 

in the TSD or the Finding. On the third claim, early Holocene temperature 

reconstructions are not central to arguments regarding attribution. Additionally, the 

Thompson paper in question makes statements consistent with the EPA TSD regarding 

the effects of human activities. 

With regard to Peabody Energy’s assertions about the Holocene based on glacier 

literature from Porter (2000) and Thompson et al (2006), the final version of the IPCC 

chapter (Jansen et al., 2007) discusses early Holocene reconstructions without referring to 

either paper. Thompson et al. (2006) finds that glacier data suggests tropical Pacific 

warmth between 11,000 and 8,000 years ago, in apparent contrast to Figure 6.9 in the 

IPCC chapter, which shows a cooler tropical Pacific in that time period. The e-mail 

discussion between Eystein Jansen (Professor of Marine Biology, University of Bergen, 

Norway), Olga Solomina (Senior Scientist, Institute of Geology, Russian Academy of 

Sciences), and Valérie Masson-Delmotte (Laboratoire des Sciences du Climat et de 

l’Environnement, France) cited by the petitioners includes the reasoning of the e-mail 

authors that there is more confidence in using marine sediment and shell data for 

determining ocean temperatures than there is using glacier oxygen isotope data relied 

upon in the Thompson paper, because the glacier data can also be influenced by changes 

in precipitation. This kind of ongoing discussion regarding which data best reflects past 

temperatures is appropriate for lead authors of a scientific assessment, and reflects 

scientific dialogue attempting to determine the most appropriate answer. 

A very recent paper (Leduc et al., 2010) finds cool early Holocene tropical oceans based 

on alkenone data but an apparently contradictory result based on Mg/Ca data. A possible 

explanation suggested by this paper was that one proxy was capturing winter trends, and 

the other proxy summer trends, and there are orbital reasons to think that the trends might 

be different. Interestingly, this is consistent with Jansen’s statement in the quoted e-mail 

that the proxies may be seasonally skewed. This is clearly an area of ongoing research. 

Contrary to the assertion of the petitioners that there was no discussion included in the 

chapter that “runs contrary to the orbital hypothesis,” Chapter 6 of Working Group I 

(Jansen et al., 2007) discusses that there are some Holocene results that are not fully 

explained by the orbital hypothesis, stating: “At high southern latitudes, the early warm 

period cannot be explained by a linear response to local summer insolation changes (see 

Box 6.1), suggesting large-scale reorganization of latitudinal heat transport.” Similarly, 

13
Box 6.3 discusses tropical glacier retreat stating “tropics indicate short, or in places even 

absent, glaciers between 11 and 5 ka,” consistent with both Porter and Thompson. 

Therefore, the quoted e-mails demonstrate that the authors were appropriately attempting 

to explore this issue and use their best scientific reasoning to determine which proxies 

were most appropriate for use in their assessment. One of the e-mails even presciently 

identified a possible source of seasonal skew which was a core finding of a paper 

published four years later. Evidence that “runs contrary to the orbital hypothesis” was in 

fact included in the final version of the chapter, as was the issue about absent glaciers. 

The Endangerment Finding does not directly address the early Holocene. The TSD 

statement that “current data limitations limit the ability to determine if there were multidecadal periods of global warmth compared to the last half of the 20th century prior to 

about 1,000 years ago” remains accurate after considering these two papers on Holocene 

glaciers. The RTC document (RTC Response 3-55) also quotes this statement from the 

TSD in response to a comment regarding early Holocene temperatures. The TSD also 

stated (quoting the NRC report) that “Very little confidence can be assigned to statements 

concerning the hemispheric mean or global mean surface temperature prior to about 900 

A.D. because of sparse data coverage and because the uncertainties associated with proxy 

data and the methods used to analyze and combine them are larger than during more 

recent time periods.” Again, nothing that the petitioner has provided suggests that this 

statement about uncertainty regarding early Holocene data is incorrect. Therefore, the 

issues raised by the petitioner do not cast doubt on or change any of the reasoning or the 

scientific basis for the Administrator’s Findings. 

With regard to the implications of early Holocene temperature reconstructions to 

attribution of recent temperature changes to human influences, we quote the NRC again: 

Surface temperature reconstructions have the potential to provide independent 

information about climate sensitivity and about the natural variability of the climate 

system that can be compared with estimates based on theoretical calculations and climate 

models, as well as other empirical data. However, large-scale surface temperature 

reconstructions for the last 2,000 years are not the primary evidence for the widely 

accepted views that global warming is occurring, that human activities are contributing, 

at least in part, to this warming, and that the Earth will continue to warm over the next 

century. (NRC, 2006) 

Just as temperature reconstructions of the last 2,000 years are not the primary evidence 

for anthropogenic climate change, neither are temperature reconstructions of 8,000 years 

ago. Because climate forcings in the early Holocene were very different from present, 

whether the early Holocene was slightly warmer or cooler than today (an uncertainty 

recognized in the TSD and assessment literature) does not prove or disprove the 

anthropogenic nature of recent warming. Additionally, the major conclusions of 

Thompson et al. (2006) are consistent with those of the TSD on attribution. In fact, with 

regard to recent glacier retreat, the conclusion of the paper states: 

14
“These observations suggest that within a century human activities may have nudged 

global-scale climate conditions closer to those that prevailed before 5,000 yr ago, during 

the early Holocene. If this is the case, then Earth’s currently retreating glaciers may 

signal that the climate system has exceeded a critical threshold...” 

Therefore, the e-mails quoted by the petitioners demonstrate that the authors were 

making deliberate and appropriate choices in writing their chapter that reflected their 

ongoing dialogue over the best understanding of the science. Several of the issues 

identified by petitioners were indeed included in the chapter. While there is continuing 

uncertainty in reconstructions of early Holocene temperatures, as reflected even in the 

most recent papers, the EPA TSD makes no statements inconsistent with this uncertainty. 

Finally, early Holocene reconstructions are not central to the determination of attribution. 

Comment (1-4): 

Referring to previous discussions about Holocene temperatures, the petitioner states 

“Thus, it is clear that the IPCC AR4 is not an accurate assessment of the scientific 

literature, but instead includes only a selection of the literature that supports a particular 

viewpoint – one either held by the chapter IPCC authors, or which had been dictated to 

them by more influential IPCC authorities. This is perhaps the type of behavior that 

Chapter 6 Lead Author Briffa was referring to when he told a colleague ‘I tried hard to 

balance the needs of the science and the IPCC, which were not always the same.’” 

Response (1-4): 

Response 1-3 above demonstrates that the e-mail authors were engaging in a dialogue 

over the best understanding of the science, and that the chapter did include uncertainties 

and conclusions consistent with the omitted papers. Response 2-30 in Subsection 2.2 of 

this Response to Petitions (RTP) document shows how the quote on the “needs of the 

science” was taken out of context by the petitioners, and that the work by Briffa was 

complimented on how it managed to “convey the the science accurately”. 

Comment (1-5): 

The Competitive Enterprise Institute refers to a presentation by Don Easterbrook at the 

Geological Society of America (Easterbrook, 2009), stating Professor Easterbrook 

“demonstrated how tree ring data from Russia, which show a cooling after 1961, were 

artfully truncated in graphs presented in IPCC publications.” The petitioner claims “This 

truncation gave the false impression that the tree ring data agree with reported late 20th 

Century surface temperature data, when in fact they did not. This artful deceit, now 

exposed, indicates that the IPCC Assessment Report 4 (AR4) is scientifically 

questionable. The CRU e-mails leaked in November confirmed that this deception was 

deliberate.” 

Response (1-5): 

EPA has reviewed the petitioner’s information and has determined that the graph 

provided by the petitioner from Professor Easterbrook’s talk is not from the AR4, but 

rather from the Third Assessment Report, which was published in 2001 and is no longer 

the most recent IPCC assessment report. In the AR4, the latest data on this issue was 

assessed and depicted in Figure 6.10. In this figure, three out of the 12 reconstructions 

15
terminate in 1960 (as noted in Table 6.1 in the same chapter), because the reconstructions 

in the underlying papers also terminate in 1960. Six of the 12 reconstructions extend to 

1990 or later, again based on the time period covered by the relevant dataset. 

EPA’s TSD actually uses a figure from the NRC (2006), which shows six 

reconstructions, one of which terminates in 1960. Because these assessment reports are 

showing the entirety of the data represented in the underlying literature, there is no 

evidence of any “artful deceit,” nor is this evidence that the AR4 is “scientifically 

questionable.” 

Comment (1-6): 

Peabody Energy also quotes e-mail exchanges by Richard Alley and by John Mitchell 

before the release of the NRC (2006) report regarding divergence. For example, Peabody 

Energy cites the following excerpt from an e-mail by Richard Alley of Penn State to 

Jonathan Overpeck of the University of Arizona, written on March 11, 2006: 

My impression is that, for good reasons, the US NRC panel looking at the record of 

temperatures over the last millennium or two is not going to strongly endorse the ability 

of proxies to detect warming above the level of a millennium ago, and that a careful reexamination of the Chapter 6 wording and its representation in the TS and SPM would be 

wise. . . 

These considerations do somewhat affect the confidence that can be attached to the best 

estimate of recent warmth versus that of a millennium ago. If the paleoclimatic data could 

be confidently be interpreted as paleotemperatures, then joining the paleoclimatic and 

instrumental records would be appropriate, and the recent warmth would clearly be 

anomalous over the last millennium and beyond. By demonstrating that some tree-ring 

series chosen for temperature sensitivity are not fully reflecting temperature changes, the 

divergence issue widens the error bars and so reduces confidence in the comparison 

between recent and earlier warmth5

Peabody Energy also quotes Professor John Mitchell from the UK Met Office as stating: 

There needs to be a clear statement of why the instrumental and proxy data are shown on 

the same graph. The issue of why we dont show the proxy data for the last few decades 

(they dont show continued warming) but assume that they are valid for early warm 

periods needs to be explained 

and

I have not had time to check the original chapter, but the comments give the impression 

that the recent 50 yr warming is unprecedented over the last 500years (seems reasonable) 

and elsewhere over the last 1000years (less clear).6

 

5

 E-mail file 1142108839.txt, (March 11, 2006), pages 1103-1104, lines 9-13 and 37-44 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

6

 E-mail file 1150923423.txt, (March 11, 2006), pages 1141-1142, lines 45-46 and 16-17 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

16
Finally, Peabody Energy quotes an e-mail by Keith Briffa which stated “I know there is 

pressure to present a nice tidy story as regards 'apparent unprecedented warming in a 

thousand years or more in the proxy data' but in reality the situation is not quite so 

simple.”7

Peabody Energy claims that “Taken together, the foregoing emails present a record of 

serious and sustained doubt about the validity of the proxy record, and particularly, as 

developed from tree rings. The divergence problem plainly concerned a number of 

respected researchers leading them to question not only the continued use of tree ring data 

in the science of paleoclimatology, but also the key theory based on that data: that recent 

warming of the 20th century is truly unprecedented and unmatched over a period of at least 

1000 years.”

Response (1-6): 

The petitioner’s arguments are flawed for several reasons, previously discussed. First, 

not all tree ring records demonstrate divergence, only a subset mainly in far northern 

latitudes. Second, while this divergence does raise potential issues about the applicability 

of those trees for reconstructions of warm eras, there are also a number of potential 

reasons for this divergence that are due to anthropogenic influences and that therefore 

would not reduce the value of these tree rings for reconstructions. Third, the TAR and 

AR4 do not solely rely on tree ring records in their assessment of temperatures in the past 

1000 years. There are a number of other proxies that have been used. Mann et al. (2008) 

shows proxy reconstructions that do not use any tree rings at all. 

Finally, the EPA TSD quotes both the NRC and the AR4 on the significant uncertainties 

involved in reconstructions before 1600. The TSD never claims that the current warming 

is “truly unprecedented in 1000 years,” and neither does the AR4. What the IPCC AR4 

says (Jansen et al., 2007) is: 

The TAR pointed to the ‘exceptional warmth of the late 20th century, relative to the past 

1,000 years’. Subsequent evidence has strengthened this conclusion. It is very likely that 

average Northern Hemisphere temperatures during the second half of the 20th century 

were higher than for any other 50-year period in the last 500 years. It is also likely that 

this 50-year period was the warmest Northern Hemisphere period in the last 1.3 kyr, and 

that this warmth was more widespread than during any other 50-year period in the last 1.3 

kyr. These conclusions are most robust for summer in extratropical land areas, and for 

more recent periods because of poor early data coverage. 

The AR4 does not use the term “unprecedented” in this statement, nor with respect to 

temperature in its Summary for Policymakers, and discusses that there is increased 

uncertainty before the “more recent periods”. 

In addition to these issues, the petitioners do not quote the full context of the e-mails and 

instead cherry-pick only segments. For example, in the above e-mail quoted from 

 

7

 E-mail files 0938018124.txt, (September 22, 1999), page 205, line 22 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

17
Richard Alley, he provides a long and detailed assessment of many of the issues involved 

in divergence. The petitioners do not, for example, quote his statement that “[t]hese 

considerations do not affect the best estimate that recent warmth is greater than that of a 

millennium ago; the central estimate from proxy data of latter-twentieth-century warmth 

is still above that of a millennium ago, with greater spatial coherence recently in the 

signal.”8 John Mitchell and Jonathan Overpeck are discussing how to address issues of 

uncertainty: Jonathan Overpeck forwarded these concerns from Mitchell to Keith Briffa 

and Tim Osborn so that they would be addressed in the IPCC chapter, and as noted 

above, the IPCC chapter includes a discussion of the relevant uncertainties and the 

divergence issue. Michael Mann’s response to Briffa’s arguments was that “Keith and 

Phil have both raised some very good points” 9, and many of Briffa’s arguments were 

included in the final version of the IPCC AR4 chapter. For example, Keith Briffa argues 

in his e-mail that “I prefer a Figure that shows a multitude of reconstructions”, and the 

figure in the chapter includes a multitude of reconstructions. The discussion of the MWP 

in the IPCC AR4 chapter (Jansen et al. 2007) heavily referenced and was consistent with 

Briffa’s own research, concluding that: 

The evidence currently available indicates that NH mean temperatures during medieval 

times (950–1100) were indeed warm in a 2-kyr context and even warmer in relation to 

the less sparse but still limited evidence of widespread average cool conditions in the 

17th century (Osborn and Briffa, 2006). However, the evidence is not sufficient to 

support a conclusion that hemispheric mean temperatures were as warm, or the extent of 

warm regions as expansive, as those in the 20th century as a whole, during any period in 

medieval times (Jones et al., 2001; Bradley et al., 2003a,b; Osborn and Briffa, 2006). 

Therefore, the petitioners do not appropriately characterize the e-mails which they are 

excerpting, and the fundamental issues of uncertainty related to historical reconstructions 

were properly reflected in the EPA TSD and the Endangerment Findings. 

Comment (1-7):

Peabody Energy quotes a 1999 e-mail in which Cook (Professor at the Lamont-Dohert 

Earth Observatory) asks Briffa (Professor at CRU), “Also, there is no evidence for a 

decline or loss of temperature response in your data in the post-1950s (I assume that you 

didn’t apply a bodge here)”10 in relation to a discrepancy between a Nature paper 

published at that time by Vaganov (1999) and an earlier Nature paper by Briffa (1998). 

Peabody Energy states that “By saying he assumed Briffa had not applied a “bodge,” he 

seemed to be asking Briffa to confirm that Briffa had not masked divergence in the data 

through statistical legerdemain.” 

 

8

 E-mail file 1142108839.txt, (March 11, 2006), page 1104, lines 34-37 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

9

 E-mail files 0938018124.txt, (September 22, 1999), page 205, line 22 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

10 E-mail file 0932158667.txt, (July 16, 1999), page 180, lines 27-29 of PDF version entitled: CRU Emails 

1996-2009.pdf 

18
Response (1-7): 

In this 1999 e-mail, two scientists are discussing the results of papers that are now more 

than a decade old. The earlier Nature paper by Briffa (1998) (on which Vaganov was 

also a co-author) clearly stated in its abstract, “During the second half of the twentieth 

century, the decadal-scale trends in wood density and summer temperatures have 

increasingly diverged as wood density has progressively fallen.” This statement is 

clearly flagging the divergence issue and rebuts the petitioner’s claim that Briffa et al. 

“masked divergence” in their paper. 

The paper by Vaganov explores the possibility that later spring snowmelt due to 

increased winter precipitation might explain the divergence observed in the data. In the 

e-mail discussion with Cook, Briffa is doubtful that this is the answer (though he does 

not rule it out) because his data do not show an effect of high precipitation and because 

the precipitation data in the region is “dubious.” Cook notes that Vaganov used a 

different, more distant city from the tree ring site for the meteorological data for his 

paper than Briffa had used in the original, which may explain this difference. 

This e-mail chain is clearly a professional discussion between colleagues attempting to 

understand the implications of newer literature. There is no evidence of any 

inappropriate behavior on the part of the scientists involved. 

The Independent Climate Change E-Mail Review (The Independent Climate Change 

Email Inquiry, 2010) discussed the term “bodge” in their report, finding that the term 

referred to an ad hoc adjustment that was later validated: 

The term “bodging” has been used, including by Briffa himself, to refer to a procedure he 

adopted in 1992. The ‘bodge’ refers to the upward adjustment of the low-frequency 

behaviour of the density signal after 1750, to make it agree with the width signal. This 

ad hoc process was based on the conjecture that the width signal was correct. There is 

nothing whatsoever underhand or unusual with this type of procedure, and it was fully 

described in the paper. The interpretation of the results is simply subject to this caveat. 

The conjecture was later validated when it was shown to be an effect due to the 

standardisation technique adopted in 1992. Briffa referred to it as a “bodge” in a private 

e-mail in the way that many researchers might have done when corresponding with 

colleagues. We find it unreasonable that this issue, pertaining to a publication in 1992, 

should continue to be misrepresented widely to imply some sort of wrongdoing or sloppy 

science. 

Comment (1-8):

Peabody Energy quotes from a July 2000 discussion between Bradley (Professor at 

UMass Amherst) and Frank Oldfield (Executive Director of the International GeosphereBiosphere Programme Past Global Changes Core Project), in which they express 

concern that the divergence issue could “become a foothold for climate change 

skeptics.” 

The petitioner highlights part of the e-mail from Bradley, “Indeed, in the verification 

period, the biggest ‘miss‘ was an apparently very warm year in the late 19th century that 

19
we did not get right at all. This makes criticisms of the ‘antis‘ difficult to respond to 

(they have not yet risen to this level of sophistication, but they are ‘on the scent‘). 

Furthermore, it may be that Mann et al simply don’t have the long-term trend right, due 

to underestimation of low frequency info.”11

The petitioner states that this quote shows “complete disregard of objective science in 

Bradley’s statement that the ‘antis’ had not yet realized a possible flaw in the 

reconstructions but were ‘on the scent.’ Bradley appears much more interested in 

preserving the views of himself and his colleagues than in an objective and transparent 

scientific process.” 

Additionally, the petitioner highlights another July 2000 quote from Bradley that stated 

“The results were good, giving me confidence that if we had a comparable proxy data set 

for post-1980 (we don’t!) our proxy-based reconstruction would capture that period well. 

Unfortunately, the proxy network we used has not been updated, and furthermore there 

are many/some/tree ring sites where there has been a ‘decoupling’ between the longterm relationship between climate and tree growth, so that things fall apart in recent 

decades.... this makes it very difficult to demonstrate what I just claimed.”12 

Response (1-8): 

As noted in the latter quote provided by the petitioner, Bradley postulated that if more data 

for the period post-1980 existed, it would support his existing conclusions. This suggests 

that he believed that his conclusions are sound, though he recognized that the divergence 

issue limits the number of useable sites where his theory could be tested. Regarding 

discussion of the “antis,” there is no evidence of any attempt to hide or ignore uncertainties 

by Bradley or his colleagues. 

To the contrary, the quote from the petitioner is embedded in a larger paragraph that 

begins, “But there are real questions to be asked of the paleo reconstruction.” Furthermore, 

the e-mail ends, “In Ch 7 we will try to discuss some of these issues, in the limited space 

available. Perhaps the best thing at this stage is to simply point out the inherent 

uncertainties and point the way towards how these uncertainties can be reduced.”13 Neither 

of these statements suggests that Bradley was merely “interested in preserving the views of 

himself and his colleagues,” and both support the contention that he was indeed interested 

in “an objective and transparent scientific process.” The petitioner selectively lifts words 

or phrases from e-mail correspondence to make unsupported, discrediting accusations. 

Comment (1-9): 

Peabody Energy claims that “The bona fides of McIntyre and McKitrick should have 

become evident after their 2003 paper and follow-up papers were published in peer-

 

11E-mail file 0963233839.txt, (July 10, 2000), page 263, line 9-13 of PDF version entitled: CRU Emails 

1996-2009.pdf 

12 E-mail file 0963233839.txt, (July 10, 2000), page 262-263, line 43-46 and 1-3 of PDF version entitled: 

CRU Emails 1996-2009.pdf 

13 E-mail file 0963233839.txt, (July 10, 2000), page 262-263, lines 41-42 and 24-27 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

20
reviewed scientific journals. Moreover, the independent Wegman Report subsequently 

confirmed the validity of their critiques of the hockey stick analysis and the 

methodological errors in that analysis that they brought to light, and the NRC report also 

confirmed that it was not confident of the central conclusions of the hockey stick paper.” 

The Southeastern Legal Foundation also cites McIntyre, McKitrick, and the Wegman 

Report in order to criticize the “hockey stick affair”. 

Response (1-9): 

The petitioners are critiquing a 1998 paper by Michael Mann (“the hockey stick paper”). 

This paper broke new ground in terms of temperature reconstructions of the past several 

hundred years and therefore attracted a lot of attention. Indeed, the petitioners focus on 

this 1998 paper despite the fact that many other reconstructions have been published in 

the decade since the original paper and several additional assessments have been 

conducted (including NRC [2006], which focused specifically on the divergence issue 

and new literature since Mann’s paper). The TSD relied on the NRC (2006) report and 

the IPCC AR4, which were comprehensive assessments of the published literature, not 

only the early papers examined by the ad hoc Wegman report (2006) and McIntyre and 

McKitrick (2003). 

We also note that there have been a number of peer-reviewed critiques and discussions of 

the McIntyre and McKitrick analyses (e.g., Rutherford et al. 2005, Juckes et al. 2007, von 

Storch and Zorita 2005, Huybers 2005, Wahl and Amman 2007). These papers question 

the validity of some aspects of the McIntyre and McKitrick critiques and find that 

correcting for other valid aspects of the critiques have “no significant effects on the 

reconstruction itself” (Wahl and Amman, 2007). 

Therefore, the petitioners have overstated the implications of the “hockey stick” critiques, 

in terms of both the validity of the critiques and the reliance of EPA on the original 

“hockey stick” papers. 

Comment (1-10):

Peabody Energy states that “In the fall of last year [2009], as a result of McIntyre’s 

requests for data, the authors of a paper published in Science were forced to admit that 

they had flipped a data set upside down,” referring to Kaufman et al. (2009). 

Response (1-10): 

A correction to Kaufman et al. (2009) was recently published in Science (Kaufman, 

2010). This correction updated some of the proxies to “conform to the interpretations of 

the original authors” and acknowledged the contributions of “H. McCulloch and others 

who have pointed out errors and have offered suggestions.” 

However, the correction also stated that “[t]he original conclusions of the paper have 

been strengthened as a result,” and “[t]he primary trends of the Arctic temperature 

reconstruction, however, are not changed, including the millennial-scale summer cooling 

that was reversed by strong warming during the 20th century and (on the basis of the 

instrumental record) continued through the last decade.” 

21
1.1.4 Assessment of the Evidence Provided by the Petitioners of Intentional 

Data Manipulation Regarding Tree Ring Data and the MWP 

 

Comment (1-11): 

Petitioners cite a statement in an e-mail written in November 1999 by Dr. Phil Jones 

(then co-director of the CRU), which states: 

“I’ve just completed Mike’s Nature trick of adding in the real temps to each series for the 

last 20 years (ie from 1981 onwards) and from 1961 for Keith’s to hide the decline.”14 

The petitioners claim that this e-mail “evidences CRU staff’s effort to deliberately 

manipulate data to yield desired results.” The Southeastern Legal Foundation states that 

some responses to this text reached the conclusion that the statement shows “an attempt 

to cook the books to conceal the fact that the famous ‘hockey stick’ is a manipulated, 

misleading barrel of scientific nonsense.” 

Response (1-11): 

Based on our review of this string of e-mails, it appears that the quote citing “Mike’s 

Nature Trick” referred to a graph prepared for the front cover of a WMO report, “WMO 

Statement on the Status of the Global Climate in 1999,” which was under development at 

the time (WMO, 2000). While few details were provided about the cover graphic, the 

caption and text box referring to it discussed the uncertainties involved in historical 

temperature reconstructions. The figure developed for this WMO report is unrelated to 

the IPCC process. While it would have been clearer about its sources if the graph had 

overlaid the instrumental record using a separate color rather than merging the 

instrumental and proxy records together, this is an issue for WMO to address, considering 

the purpose of the report and the role of the graph on the cover. However, the graph and 

the method used to prepare the graph bear no relationship to the detailed technical 

discussion found in the assessment reports which EPA relied upon in the development of 

the TSD, which addressed all of the evidence and discussed the issue of tree ring data in 

the context of the entire body of paleoclimate evidence.

In fact, the evidence shows that the research community was fully aware of these issues 

and was not hiding or concealing them. The figure as developed for the WMO report 

was not used by the IPCC. Rather, the Third Assessment Report, published in 2001 

(IPCC, 2001), had a full paragraph on “important caveats to be kept in mind” regarding 

paleoclimate reconstructions that use tree rings. The paragraph included a discussion of 

the divergence and concluded that tree rings were best used as one of multiple proxies 

rather than being the sole source for a climate reconstruction. The AR4, published in 

2007, addressed the divergence issue in a paragraph that began “Several analyses of ring 

width and ring density chronologies, with otherwise well established sensitivity to 

temperature, have shown that they do not emulate the general warming trend evident in 

instrumental temperature records over recent decades....” Figure 6.10 in the AR4 and 

 

14 E-mail file 0942777075.txt, (November 16, 1999), page 243, lines 39-41 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

22
Figure S-1 in the NRC report (which was replicated in Figure 4.3 in the EPA TSD) both 

clearly show a separate line for the instrumental temperature record and the lines 

provided by proxy reconstructions, unlike the WMO figure. Hence, the IPCC and 

additional assessment literature relied on by EPA transparently document, illustrate, and 

discuss the divergence issue, as did EPA in Volume 2 of the RTC document. The 

evidence (the CRU e-mails) the petitioners cite on this issue have no relevance on the 

Administrator’s Findings. 

The petitioners highlight the use of the word “trick.” Contrary to the responses described 

by the Southeastern Legal Foundation, more formal reviews did not find that this phrase 

indicated an “attempt to cook the books”. The UK Science & Technology Committee 

(2010) reviewed this specific e-mail in its investigation of the disclosure of climate data 

from the CRU. This investigation concluded: “We are content that the phrases such as 

‘trick’ or ‘hiding the decline’ were colloquial terms used in private e-mails, and the 

balance of evidence is that they were not part of a systematic attempt to mislead.” 

Comment (1-12): 

As part of a set of e-mails that purportedly “confirm certain scientists’ efforts to 

‘artificially adjust’ data,” the Coalition for Responsible Regulation quotes from a 1996 email by Gary Funkhouser of the University of Arizona: “I really wish I could be more 

positive about the Kyrgyzstan material, but I swear I pulled every trick out of my sleeve 

trying to milk something out of that.” 

Response (1-12): 

The Funkhouser quote regarding “trying to milk something out of that” does not appear 

to be an example of an effort to “artificially adjust” data. The full e-mail contains quotes 

such as “The data’s tempting but there’s too much variation even within stands” and “Not 

having seen the sites I can only speculate, but I’d be optimistic if someone could get back 

there and spend more time collecting samples, particularly at the upper elevations.”15 

Thus, this e-mail is most likely an example of a researcher being who is aware of the 

limits of the data, is committed to data that are of high quality, and did not draw stronger 

conclusions than the data warranted. We further note that this email is almost 14 years 

old, and has no relevance to the literature assessed in the reports upon which EPA relied 

or the Finding. 

Comment (1-13): 

As part of a set of e-mails that purportedly “confirm certain scientists’ efforts to 

‘artificially adjust’ data,” the Coalition for Responsible Regulation quotes from a 2006 email from Keith Briffa (a scientist at CRU) noting that “the PC1 time series in the Mann 

et al. analysis was adjusted to reduce the positive slope in the last 150 years,” and that 

“this adjustment was arbitrary and the link between Bristlecone pine growth and CO2 is, 

at the very least, arguable.”16 

 

15 E-mail file 0843161829.txt, (September 19, 1996), page 11, lines 13-14,16, and 19-21 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

16 E-mail file 1163715685.txt, (November 16, 2006), page 1239, lines 9-10 and 15-16 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

23
Response (1-13): 

The Briffa e-mail does not appear to raise questions about artificially adjusting the data in 

the analysis. While Briffa appears to disagree with the adjustments used by Mann, he 

does note that the Mann adjustment was “following an earlier paper by Lamarche et al.”17

based on CO2 fertilization estimates and therefore is consistent with the literature. 

Disagreement among scientists is part of the normal scientific process and is not evidence 

of deceit. 

Comment (1-14): 

As part of a set of e-mails that purportedly “confirm certain scientists’ efforts to 

‘artificially adjust’ data,” the Coalition for Responsible Regulation quotes from a 2003 email from Michael Mann (then of the University of Virginia) stating that “it would be 

nice to try to ‘contain’ the putative ‘MWP’ [Medieval Warm Period].”18 

Response (1-14): 

With regard to the Mann quote about containing the MWP, petitioners do not explain 

why the word “contain” is not a reference to timeframe rather than, as they imply, data 

manipulation. The full quote is: “I think that trying to adopt a timeframe of 2K [2000 

years], rather than the usual 1K [1000 years], addresses a good earlier point that Peck 

made w/ regard to the memo, that it would be nice to try to ‘contain’ the putative 

‘MWP.’”19 A 1,000-year-long reconstruction would only cover (i.e., “contain”) part of 

the MWP, whereas 2,000 years would contain the entire MWP. In sum, although 

petitioners read into the quotes evidence of artificial adjustment of data, when examined 

in their entirety the quotes do not support this conclusion. 

1.1.5 Assessment of Petitioners’ Argument That the MWP May Have Been 

Warmer Than Present Temperatures 

Comment (1-15): 

Petitioners make a number of arguments claiming that the MWP may have been warmer 

than present temperatures. For example, petitioners claim that the divergence issue 

undermines our understanding of climate change, because “if tree rings missed the 

warming of the latter half of the 20th century, they may also have missed the warming in 

the MWP.” They claim that all proxy data are unreliable for use in any time period. For 

example, Peabody Energy states that the effect of the divergence between tree ring proxy 

data and recent temperature data is to “reduce the mean and range of reconstructed values 

compared to what they actually were,” thereby making comparisons between the MWP 

and recent observed temperatures “virtually impossible.” 

 

17 E-mail file 1163715685.txt, (November 16, 2006), page 1239, lines 10-11 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

18 E-mail file 1054736277.txt, (June 4, 2003), page 510, lines 26-27 of PDF version entitled: CRU Emails 

1996-2009.pdf 

19 E-mail file 1054736277.txt, (June 4, 2003), page 510, lines 25-27 of PDF version entitled: CRU Emails 

1996-2009.pdf 

24
Petitioners ascribe great significance to the reconstructions of paleoclimate and their 

importance to our understanding of anthropogenic global warming and claim this 

evidence was misused by the IPCC. For example, Peabody Energy states that because 

both the IPCC Third and Fourth Assessment Reports relied on tree rings “to significantly 

downplay the MWP and LIA [Little Ice Age],” this casts doubt on “their conclusions that 

current warming is likely unprecedented in 1000 years.” Southeastern Legal Foundation 

claims that “[p]rior naturally occurring episodes of warming and cooling present a 

problem of proof for the promoters of catastrophic anthropogenic global warming 

(“AGW”), namely how to explain that modern warming is caused by man when prior 

episodes of equal or greater warming self-evidently were not.” 

Response (1-15): 

The Finding states that “We agree there was a Medieval Warm Period in many regions 

but find the evidence is insufficient to assess whether it was globally coherent. Our 

review of the available evidence suggests that Northern Hemisphere temperatures in the 

MWP were probably between 0.1°C and 0.2°C below the 1961–1990 mean and 

significantly below the level shown by instrumental data after 1980. However, we note 

significant uncertainty in the temperature record prior to 1600 A.D.” 

The TSD addresses paleoclimate in more depth, finding that “Less confidence can be 

placed in large-scale surface temperature reconstructions for the period from 900 to 1600 

A.D” based on the NRC (2006) report, and further stating that “Considering this study 

and additional research, the IPCC (2007c) concluded: ‘Paleoclimatic information 

supports the interpretation that the warmth of the last half century is unusual in at least 

the previous 1,300 years.’ However, like NRC (2006), IPCC cautions that uncertainty is 

significant prior to 1600 (Jansen et al., 2007).” 

With regard to the claim that the IPCC AR4 “downplays” the MWP and LIA, Jansen et 

al. (2007) clearly acknowledge the existence of and analyze the best estimates of the 

magnitude of both periods, noting the uncertainty due to limitations of past data, and 

conclude that 

The evidence currently available indicates that NH mean temperatures during medieval 

times (950–1100) were indeed warm in a 2-kyr context and even warmer in relation to 

the less sparse but still limited evidence of widespread average cool conditions in the 

17th century (Osborn and Briffa, 2006). However, the evidence is not sufficient to 

support a conclusion that hemispheric mean temperatures were as warm, or the extent of 

warm regions as expansive, as those in the 20th century as a whole, during any period in 

medieval times (Jones et al., 2001; Bradley et al., 2003a,b; Osborn and Briffa, 2006). 

Therefore, the TSD appropriately highlighted the uncertainty that was reflected in both 

the NRC report and the IPCC statements. The NRC and IPCC assessed the best available 

science and came to conclusions that appropriately reflected the underlying literature. 

The petitioners raise nothing new that was not already addressed by existing 

characterizations of the uncertainties involved in paleoclimate reconstructions made by 

the IPCC, NRC, and EPA in the TSD. 

25
Comment (1-16): 

Petitioners present a study by Loehle and McCulloch (2008) that calculated a 2,000-year 

reconstruction without using tree rings. Petitioners claim that this study shows that the 

MWP was as warm as the late 20th century. 

Response (1-16): 

EPA has reviewed the petitioners’ submission of Loehle and McCulloch (2008) and finds 

that it was not impracticable to raise the objection during the public comment period and 

that the reasons for the objection did not arise between June 24, 2009, and February 16, 

2010. Petitioners could have submitted this study during the comment period on the 

proposed Endangerment Finding. Although, in most cases, the petitioners provide 

excerpts from the CRU e-mails in support of their assertions, EPA’s review has 

determined that this evidence does not support their allegations, and that the information 

submitted by petitioners on these topics was available well before the comment period for 

the Endangerment Finding. Petitioners have not shown why it would have been 

impractical for them to have submitted this study then. Indeed, similar points were 

already raised, and responded to, in the RTC. Despite the fact that these objections fail to 

meet the statutory timeframe for evidence supporting a petition for reconsideration, we 

briefly explain why, contrary to petitioners’ allegation, they fail to call into question the 

Finding. 

The petitioners presented a reconstruction from Loehle and McCulloch (2008) that 

claimed that without using tree rings they could show that the average of the warmest 

three decades of the MWP was a little warmer (though not in a statistically significant 

sense) than the three decades ending in 2006. The paper uses the straight average of 18 

proxies, apparently with no attempt to weight the proxies to take into account the 

geographic distribution of the sites or the strength of their ability to detect temperature 

changes. In contrast, Mann et al. (2008) presented reconstructions both with and without 

tree rings, using geographic and other weighting corrections, and unlike Loehle (2008), 

they found that “Recent warmth appears anomalous for at least the past 1,300 years 

whether or not tree-ring data are used.” We acknowledge that this is an area of ongoing 

research and that disagreements among researchers are to be expected, and as noted, the 

assessment literature and the TSD appropriately characterize the Medieval Warm Period 

and the uncertainties associated with reconstructing temperatures prior to 1600. 

1.1.6 Assessment of the Petitioners’ Argument that Questions About the MWP 

and Paleoclimate Reconstructions Limit Current Ability to Attribute 

Present Warming to Humans

Comment (1-17): 

The Southeastern Legal Foundation claims that “The importance of these proxy 

reconstructions to the AGW conjecture can hardly be overstated. Since the Climategate 

documents gravely impeach the validity and reliability of these reconstructions, they are 

obviously of central relevance to the Endangerment Finding.” Peabody Energy claims 

that the doubts raised in the CRU e-mails would make it harder to attribute recent warmth 

to human activity. The petitioners claim that if the current warming is not unprecedented, 

26
this undermines our ability to determine that the recent warming is due to human 

influences. 

Peabody Energy suggests that EPA relies on reconstructions of historic temperatures over 

the last 1,000 to 2,000 years as one of the three lines of evidence supporting the statement 

that GHGs are the root cause of recently observed climate change, but that neither the 

IPCC nor NRC provide “compelling” evidence that the temperatures of the last several 

decades are unusual in that context. Peabody Energy further refers to the CRU e-mails 

discussing uncertainties in historic temperatures, including the divergence in the tree-ring 

temperature reconstruction in the late part of the 20th century. 

Response (1-17): 

The assertions that proxy reconstructions are of “central relevance to the Endangerment 

Finding” and that the importance of these reconstructions “can hardly be overstated” are 

inconsistent with the scientific literature on attribution. On this issue, the TSD states that 

the unusual nature of global surface temperature changes in the past decades are one line 

of evidence contributing to the confidence in statements about attribution (pg. 47), 

relying on Karl et al. (2009). The Finding makes the same argument (page 66523). The 

TSD also notes in Box 5.1 that the IPCC AR4 found that paleoclimate analyses increased 

confidence in the role of external influences on climate, relying on Hegerl et al. (2007). 

However, the relative warmth of the MWP and Holocene are just part of the paleoclimate 

data referred to by Karl et al. and Hegerl et al., and historical paleoclimate data is only 

one line, and not the primary line, of evidence supporting attribution. 

According to Hegerl et al. (2007), paleoclimate data is used to “test understanding of the 

climate response to external forcings” (where external forcings include volcanic 

eruptions, solar variability, and changes in GHGs, but not internal variability such as El 

Niño events). Hegerl et al. note that the past 1,000 years of analyses focus on responses 

to changes in solar radiation and volcanism. The other time periods mentioned in the 

chapter are the mid-Holocene (6,000 years ago) and the last glacial maximum (21,000 

years ago). Hegerl et al. state that the similarity between modeled and reconstructed 

temperatures over the past 1,000 years increases confidence that the inability to simulate 

modern warming without anthropogenic forcing shows the impact of human activity. 

However, they also note that the uncertainty in both temperature reconstructions and the 

solar and volcanic forcings makes it difficult to fully assess models in this way. For 

example, a reconstruction that showed a colder MWP simultaneous with a warmer sun 

would be harder to explain than a warmer MWP. 

The NRC (2006) explicitly addressed this issue at length: 

Surface temperature reconstructions have the potential to provide independent 

information about climate sensitivity and about the natural variability of the climate 

system that can be compared with estimates based on theoretical calculations and climate 

models, as well as other empirical data. However, large-scale surface temperature 

reconstructions for the last 2,000 years are not the primary evidence for the widely 

accepted views that global warming is occurring, that human activities are contributing, 

27
at least in part, to this warming, and that the Earth will continue to warm over the next 

century. The primary evidence for these conclusions (see, e.g., NRC 2001) includes: 

 Measurements showing large increases in carbon dioxide and other greenhouse gases 

beginning in the middle of the 19th century, instrumental measurements of upward 

temperature trends and concomitant changes in a host of proxy indicators over the 

last century. 

 Simple radiative transfer calculations of the forcing associated with increasing 

greenhouse gas concentrations together with reasonable assumptions about the sign 

and magnitude of climate feedbacks. 

 Numerical experiments performed with state-of-the-art climate models. 

Supporting evidence includes: 

 The observed global cooling in response to volcanic eruptions is consistent with 

sensitivity estimates based on climate models. 

 Proxy evidence concerning the atmospheric cooling in response to the increased ice 

cover and the decreased atmospheric carbon dioxide concentrations at the time of the 

last glacial maximum is consistent with sensitivity estimates based on climate 

models. 

 Documentation that the recent warming has been a nearly worldwide phenomenon. 

 The stratosphere has cooled and the oceans have warmed in a manner that is 

consistent with the predicted spatial and temporal pattern of greenhouse warming. 

Surface temperature reconstructions for the last 2,000 years are consistent with other 

evidence of global climate change and can be considered as additional supporting 

evidence. In particular, the numerous indications that recent warmth is unprecedented for 

at least the last 400 years and potentially the last several millennia, in combination with 

estimates of external climate forcing variations over the same period, support the 

conclusion that human activities are responsible for much of the recent warming. 

However, the uncertainties in the reconstructions of surface temperature and external 

forcings for the period prior to the instrumental record render this evidence less 

conclusive than the other lines of evidence cited above. It should also be noted that the 

scientific consensus regarding human-induced global warming would not be 

substantively altered if, for example, the global mean surface temperature 1,000 years 

ago was found to be as warm as it is today. 

It is important to point out that, in drawing the conclusion that multiple lines of evidence 

indicate GHGs are the root cause of recently observed climate change, EPA does not 

claim that any individual line of evidence by itself necessarily forms the “compelling” 

evidence of human-induced climate change. Rather, the multiple lines of evidence 

collectively form the compelling evidence. 

28
EPA did not state that the reconstructions of prior temperatures alone provide evidence 

that the recent warming is unusual, nor that the evidence that recent warming is unusual 

is “compelling” as stated by the petitioners. Instead, EPA appropriately reflected the 

uncertainty raised in the scientific literature in its statements, as described in Subsection 

1.1.2 and many responses to comments in Subsection 1.1.3 of this Response to Petitions 

(RTP) document. The TSD appropriately highlighted the uncertainty that was in both the 

NRC report and the IPCC statements. EPA properly found that this evidence “supports” 

the interpretation that the recent warming is unusual. The arguments raised by Petitioners 

about the MWP and about other issues related to temperature reconstructions do not 

change or undermine the basis for this conclusion. 

 In addition, even if the global mean temperature was as warm or warmer during the 

MWP as it is today (which is not consistent with the best estimates of the scientific 

assessments, nor supported by petitioners’ arguments), recent warming would still be 

“unusual,” even if not “unprecedented”. EPA never stated that recent warming was 

“unprecedented.” In fact, the TSD reserved the use of the term “unprecedented” for the 

rate of increase of radiative forcing in the past 10,000 years and for the likely impacts on 

ecosystems due to a combination of changes in climate and other global change drivers 

over the next 100 years, should GHG emissions continue at or above current rates. 

Additionally, uncertainty over the exact temperatures in the MWP does not change the 

fact that other critical lines of evidence strongly support the view that GHGs are the root 

cause of recent warming, such as our basic physical understanding of how GHGs trap 

heat, how the climate system responds to an increase in GHGs, and how other human and 

natural factors influence climate and the broad, qualitative consistency between observed 

changes in climate and the computer model simulations of how climate would be 

expected to change in response to human activities. The NRC report “Advancing the 

Science of Climate Change” (NRC, 2010) summarizes the many lines of evidence that 

support the conclusion that most of the observed warming over at least the last several 

decades is due to human activities: 

 Both the basic physics of the greenhouse effect and more detailed calculations 

using sophisticated models of atmospheric radiative transfer indicate that 

increase in atmospheric GHGs should lead to warming of the Earth’s surface 

and lower atmosphere. 

 Earth’s surface temperature has unequivocally risen over the past 100 years, to 

levels not seen in at least several hundred years and possibly much longer, at 

the same time that human activities have resulted in sharp increases in CO2

and other GHGs [as discussed above]. 

 Detailed observations of temperatures, GHG increases, and other climate 

forcing factors from an array of instruments, including Earth-orbiting 

satellites, reveal an unambiguous correspondence between human-induced 

GHG increases and planetary warming over at least the past three decades, in 

addition to substantial year-to-year climate variability. 

29
 The vertical pattern of atmospheric temperature change over the past few 

decades, with warming in the lower atmosphere and cooling in the 

stratosphere, is consistent with the pattern expected due to GHG increases and 

inconsistent with the pattern expected if other climate forcing agents (e.g., 

changes in solar activity) were responsible. 

 Estimates of changes in temperature and forcing factors over the first seven 

decades of the 20th century are slightly more uncertain and also reveal 

significant decadal-scale variability, but nonetheless indicate a consistent 

relationship between long-term temperature trends and estimated forcing by 

human activities. 

 The horizontal pattern of observed temperature change over the past century, 

with stronger warming over land areas and higher latitudes, is consistent with 

the pattern of change expected from a persistent positive climate forcing. 

 Detailed numerical model simulations of the climate system are able to 

reproduce the observed spatial and temporal pattern of warming when 

anthropogenic GHG emissions and aerosols are included in the simulation, but 

not when only natural climate forcing factors are included. 

 Both climate model simulations and reconstructions of temperature variations 

over the past several centuries indicate that the current warming trend cannot 

be attributed to natural variability in the climate system 

 Estimates of the climate forcing and temperature changes on a range of 

timescales, from the several years following volcanic eruptions to the 

100,000+ year Ice Age cycles, yield estimates of climate sensitivity that are 

consistent with the observed magnitude of observed climate change and 

estimated climate forcing. 

 Finally, there is not any compelling evidence for other possible explanations 

of the observed warming, such as changes in solar activity, changes in cosmic 

ray flux, natural climate variability, or release of heat stored in the deep ocean 

or their climate system components. 

Another example of evidence supporting human influence on recent warming given by 

the TSD is that observations of natural influences such as solar variability and historical 

volcanism over the past century are not consistent with the pattern of observed 

temperature trends. In general, Karl et al. (2009) found that a number of aspects of 

modeled and theoretically predicted responses to human-induced climate change were 

consistent with observations. As Karl et al. state: 

This conclusion rests on multiple lines of evidence. Like the warming “signal” that has 

gradually emerged from the “noise” of natural climate variability, the scientific evidence 

for a human influence on global climate has accumulated over the past several decades, 

30
from many hundreds of studies. No single study is a “smoking gun.” Nor has any single 

study or combination of studies undermined the large body of evidence supporting the 

conclusion that human activity is the primary driver of recent warming. 

1.1.7 Summary 

The IPCC, NRC, and TSD appropriately reflected the uncertainty involved in 

temperature reconstructions, including those for the MWP and the early Holocene. This 

involved considering the entire body of evidence, including the kinds of evidence and 

arguments presented by petitioners. Petitioners’ evidence and arguments do not warrant 

any revisions to these conclusions and their related caveats on degree of certainty. In 

general, petitioners have not considered the breadth of evidence on these issues and the 

clear recognition and documentation of the uncertainty concerning temperature 

reconstructions of the past. They have instead relied upon a limited selection of e-mails, 

studies, and other evidence that does not warrant the broad conclusions they have drawn. 

The issue of divergence of some tree ring records was discussed in depth in the 

assessment literature and in the RTC document, and the petitioners have not shown that 

these discussions were incorrect or incomplete. While the graph used for the cover of a 

1999 World Meteorological Organization (WMO) report did not disclose this divergence, 

the graph is both outdated and unrelated to any of the assessment reports or the Findings. 

The quotes provided by the petitioners as examples of “deliberate manipulation” or 

“artificial adjustments” are taken out of context and do not support this view. 

The petitioners have not shown that the uncertainty concerning the temperature during 

historical time periods is any different or higher than the degree of uncertainty clearly 

recognized in the assessment reports and considered by the Administrator in the 

Endangerment Finding. EPA stated that “We agree there was a Medieval Warm Period 

in many regions but find the evidence is insufficient to assess whether it was globally 

coherent. Our review of the available evidence suggests that Northern Hemisphere 

temperatures in the MWP were probably between 0.1°C and 0.2°C below the 1961–1990 

mean and significantly below the level shown by instrumental data after 1980. However, 

we note significant uncertainty in the temperature record prior to 1600 A.D.” The 

assessment literature did not conclude that the current warming is definitively unique or 

unprecedented, but that it is unusual, properly accounting for the uncertainty associated 

with temperature reconstructions. The petitioners have provided no evidence that 

indicates a different conclusion is appropriate in light of all of the scientific evidence, or 

that the Administrator failed to properly account for this uncertainty. The broad 

conclusions drawn by petitioners are not warranted by the limited evidence they rely 

upon. 

The CRU e-mails and other evidence do not materially change or warrant any less 

reliance on the paleoclimate temperature reconstructions. Petitioners’ objections to 

certain aspects of the science behind paleoclimate reconstructions are without merit, as 

discussed above. Petitioners fail to consider or contest the other scientific bases for the 

temperature reconstructions, and fail to provide arguments that take into consideration the 

entire body of evidence. Petitioners also mischaracterize the limited role that 

31
paleoclimate temperature reconstructions play in attributing recent warming to 

atmospheric concentrations of GHGs. EPA and the assessment literature consider this 

one of three lines of evidence, and largely as supporting evidence, in light of the 

recognized uncertainties in this area of science. Petitioners' arguments do not support 

changing the degree of reliance EPA properly placed on this one line of evidence. 

The CRU e-mails and other evidence also do not materially change or warrant any less 

reliance on the other important lines of evidence linking GHGs and climate change: our 

basic physical understanding of the effects of changing GHG concentrations and other 

factors; the broad, qualitative consistency between observed changes in climate and the 

computer model simulations of how climate would be expected to change in response to 

human activities; and other important evidence of an anthropogenic fingerprint in the 

observed warming. All of the lines of evidence cited in the TSD concerning attribution, 

including paleolcimate temperature reconstructions, properly reflect the literature as far 

as the degree of certainty involved in each, and the scientific conclusion on attribution 

that is drawn from them is based on consideration of the entire body of evidence and not 

from any single element. Petitioners do not attempt to assess this entire body of evidence 

and do not show that when considered as a whole, it leads to a different conclusion on 

attribution from that found by EPA. 

1.2 Attribution of Recent Temperature Trends and Models 

1.2.1 The Validity of the Human “Fingerprint” in the Vertical 

Temperature Structure of the Atmosphere Over the Tropics 

1.2.1.1 Background 

Supporting the attribution of GHGs to climate change is the vertical pattern of 

temperature change that has been observed in recent decades, as briefly described in 

Subsection 1.1.2.5 and discussed in Section 5 of the TSD. “Fingerprint studies” are often 

used to assess and identify the human contribution to observed changes in the vertical 

temperature structure of the atmosphere. Fingerprint studies compare the patterns of 

observed temperature changes with results from models that account for GHG levels and 

determine whether or not similarities could have occurred by chance. The assessment 

literature documents the identification of these fingerprints—where observations and 

models match and similarities are not expected to have occurred by chance—which the 

TSD summarizes as follows:

Fingerprint studies have identified GHG and sulfate aerosol signals in observed surface 

temperature records, a stratospheric ozone depletion signal in stratospheric temperatures, 

and the combined effects of these forcing agents in the vertical structure of atmospheric 

temperature changes (Karl et al., 2006). 

In many parts of the world, the anthropogenic fingerprint has been unambiguous. 

However, the fingerprint in the tropics only recently has become apparent, as the TSD 

explains: 

32
... However, an important inconsistency may have been identified in the tropics. In the 

tropics, most observational data sets show more warming at the surface than in the 

troposphere, while almost all model simulations have larger warming aloft than at the 

surface (Karl et al., 2006). Karl et al. (2009) state that when uncertainties in models and 

observations are properly accounted for, newer observational data sets are in agreement 

with climate model results. 

EPA references Karl et al. (2009) (the USGCRP 2009 assessment), which synthesizes the 

results of several new studies to conclude that models are in general agreement with 

observations in the tropical troposphere. EPA referred to these same studies in Volume 3 

of the RTC document, in response to public comment. 

1.2.1.2 Assessment of the Arguments Regarding the Vertical Temperature 

Structure Over the Tropics 

Comment (1-18): 

Peabody Energy asserts that the CRU e-mails call into question the reliability of studies 

supporting the existence of a human (i.e., anthropogenic GHG) “fingerprint” in the 

vertical temperature structure of the atmosphere (i.e., in the troposphere) over the tropics. 

Peabody Energy claims that the CRU e-mails reveal that the authors of fingerprint studies 

published their results in an “inappropriate and indeed unethical way.” Peabody Energy 

also suggests that the lack of an anthropogenic fingerprint in the tropics would challenge 

the assessment literature finding of consistency between models and observations, which 

supports a primary line of evidence linking GHGs and climate change. 

Specifically, Peabody Energy claims the authors of a significant article—Santer et al., 

2008—supporting the existence of an anthropogenic tropical fingerprint, along with some 

other scientists with whom Santer corresponded, exerted improper influence to delay the 

print publication of a paper by Douglass et al. (2007) that did not identify a tropical 

fingerprint. Peabody Energy’s chief allegation is that the print publication of Douglass et 

al. in the International Journal of Climatology (IJC), a paper which was originally 

published online in December 2007, was stalled until November 2008 to coincide with 

publication of Santer et al. (2008), a paper which rebutted the Douglass et al. findings. 

According to Peabody Energy, the simultaneous print publication of Santer et al. (2008) 

and Douglass et al. (2007) prevented Douglass et al. from having an opportunity for a 

simultaneous response to Santer’s paper. The petitioner claims, “The gamesmanship 

behind this strategy diverted the process of scientific inquiry from its proper path and 

tainted the material on which the Agency now seeks to rely.” Peabody Energy claims that 

dozens of e-mails document inappropriate conduct on the part of the authors and editors 

of the journals that published the studies supporting the presence of a tropical fingerprint. 

Response (1-18): 

Peabody Energy does not offer any substantive basis for questioning the technical 

validity of the studies cited by EPA (and USGCRP), which rebut Douglass et al. The 

Santer et al. study convincingly detailed a number of errors in the Douglass et al. study, 

the most blatant of which was the inappropriate calculation of uncertainty range of model 

33
estimates, which was off by a factor of almost five in Douglas et al. (2007). Peabody’s 

claims of lack of reliability of the studies at issue are without scientific basis. 

We also note that more than 18 months have passed since publication of Santer et al. 

(2008). Certainly, Douglass et al. have had ample opportunity to publish a rebuttal and 

defend their analysis during this time, either as a reply to Santer et al. in the IJC or as a 

new analysis in a different journal. Such a step is common in areas of active scientific 

discourse, where scientists go back and forth in the literature until the issues are resolved. 

However, to our knowledge, Douglass et al. have not responded with a scientific response 

that has been accepted for publication in a peer-reviewed journal. 

Peabody instead relies upon an assertion of lack of scientific credibility because of the 

timing of the article, not the substance of the article. The timing of the study’s 

publication bears no relationship to its scientific or technical validity. At most, Peabody 

is concerned that the paper publication of an article already available online occurred at 

the same time as a rebuttal. The lack of an opportunity for a simultaneous response is 

unrelated to the scientific merit of the study, especially when it appears no response has 

been forthcoming. There is no scientific merit to Peabody’s argument. 

Furthermore, Peabody Energy is incorrect in asserting that EPA relied solely on Santer et 

al. to rebut Douglass et al. (2007). In response to public comment, RTC (3-7) also cites 

studies by Haimberger et al. (2008) and Allen and Sherwood (2008), which were 

published in other journals (Journal of Climate and Nature Geoscience, respectively) and 

assessed by USGCRP. 

Peabody Energy attempts to implicate several of the authors of the Haimberger et al. and 

Allen and Sherwood studies by linking them to the IJC dispute, because several of the 

authors were copied on some of the CRU e-mails in which the Douglass et al. (2007) 

results are discussed. However, Peabody Energy provides no evidence these authors 

were in any way involved in the publication timing of either the Douglass et al. or Santer 

et al. paper in the IJC. 

In summary, questions raised by petitioners concerning the timing of the paper 

publication of papers in IJC do not provide any substantive basis for questioning the 

validity of the scientific conclusions of the studies at issue or the assessment literature 

(i.e., Karl et al., 2009) and EPA on this issue. For more detailed discussion of the CRU 

e-mails pertaining to the publication of studies on the existence of a human fingerprint in 

the vertical temperature structure of the atmosphere over the tropics and what the e-mails 

signify, refer to Subsection 3.3.3 in Volume 3 of this RTP document. . 

Comment (1-19):

Peabody Energy suggests that Ben Santer, a research scientist at Lawrence Livermore 

Laboratory and lead author of the Santer et al. (2008) study discussed above, improperly 

accuses Douglass et al. of neglecting datasets that do not suggest a discrepancy between 

observations and models in the vertical structure of the atmosphere in the tropics. The 

petitioner quotes an e-mail from Melissa Free, co-author of a paper acknowledging the 

34
existence of a discrepancy between observations and models, which was also the basic 

conclusion of Douglass et al. (2007). Free’s e-mail states: “What about the implications 

of a real model-observation difference for upper-air trends? Is this really so dire?”20

Peabody Energy quotes Santer’s response: “What is dire is Douglass et al.’s willful 

neglect of any observational datasets that do not support their arguments.”21 According 

to Peabody Energy, Santer was referring to two radiosonde datasets—RAOBCORE v1.3 

and v1.4—that were excluded from the analysis in Douglass et al. (2007). Peabody 

Energy states that Douglass et al. (2007) explained in an addendum that these datasets are 

faulty. 

Response (1-19):

The comment by Santer about Douglass’ neglect of datasets was an informal 

communication with colleagues, which was written in December 2007, before Douglass 

et al. submitted the addendum to which Peabody Energy refers; the addendum was 

submitted in January 2008. We note that this addendum was not accepted for publication 

and seems to be available only via the author’s personal website. The formal rebuttal to 

Douglass et al. remains the peer-reviewed paper by Santer et al., which states: 

Our results contradict a recent claim that all simulated temperature trends in the tropical 

troposphere and in tropical lapse rates are inconsistent with observations. This claim was 

based on use of older radiosonde and satellite datasets, and on two methodological errors: 

the neglect of observational trend uncertainties introduced by interannual climate 

variability, and application of an inappropriate statistical “consistency test.” 

As stated in the preceding response, to date, Douglass et al. have not published a rebuttal 

to Santer et al.’s formal critique. Furthermore, the quote from Melissa Free does not 

acknowledge the existence of a discrepancy between observations and models; it is 

raising the possibility as a hypothetical. 

1.2.2 Global Temperature Trends Over the Last Decade and Implications for 

Attribution of These Trends to GHGs 

1.2.2.1 Background 

According to the latest National Oceanic and Atmospheric Administration (NOAA) data 

(NOAA, 2010a), the decade spanning 2000–2009 was substantially warmer than the prior 

decade (1990–1999). Every year from 2000 to 2009 was warmer than the 1990–1999 

average. Using data available through 2008, the TSD in Box 4.1 states that “the warming 

rate in the last 10 30-year periods (averaging about 0.30°F [0.17°C] per decade) is the 

greatest in the observed record...” However, depending on one’s choice of temperature 

record and the start and stop date chosen for computing a trend in that record, it is 

 

20 E-mail file 1196956362.txt, (December 6, 2007), page 1371, line 10-11 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

21 E-mail file 1196956362.txt, (December 6, 2007), page 1371, line 5-6 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

35
possible to demonstrate a slowdown in the rate of warming over the last 10 years or so 

relative to the rate of warming observed over the last several decades. 

The assessment literature, as summarized in the TSD, emphasizes that “that year-to-year 

fluctuations in natural weather and climate patterns can produce a period that does not 

follow the long-term trend” (Karl et al., 2009). More recent assessment literature, not 

available for inclusion in the Endangerment TSD, states (NRC, 2010), “it is not 

appropriate to look at only a short period of the overall record (such as changes over just 

the last five or ten years) to infer major changes in the trajectory of global warming.” 

The responses in this section address petitioners’ arguments about the meaning and 

implications of a possible slowdown in the rate of warming. 

1.2.2.2 Assessment of Arguments Regarding Global Temperature Trends Over the 

Last Decade and Implications for Attribution of These Trends to GHGs 

Comment (1-20): 

Peabody Energy alleges that the “CRU material ... contradicts EPA’s assertion that the 

results of climate models constitute a third line of evidence that can be relied on to 

attribute climate change to anthropogenic GHG emissions.” To support this conclusion, 

Peabody Energy refers to CRU e-mails in which scientists discuss the possible slowdown 

in warming over the last 10 years or so. 

Response (1-20): 

This issue is not new and was the subject of public comment during development of 

EPA’s Findings. As discussed in the TSD, analysis of surface and lower tropospheric 

temperature data over the last 10 or so years indicates that the rate of warming may have 

temporarily slowed, although the magnitude of the slowdown varies depending on dataset 

analyzed and choice of start date. Contrary to the argument of the petitioner, such a 

possible slowdown does not “eviscerate” the scientific support for climate change, which 

is a long-term process. As explained in Box 4.1 of the TSD: 

It is important to recognize that year-to-year fluctuations in natural weather and climate 

patterns can produce a period that does not follow the long-term trend (Karl et al., 2009). 

Thus, each year will not necessarily be warmer than every year before it, though the longterm warming trend continues (Karl et al., 2009). 

In addition, the recent NRC (2010) states: “Individual years, or even individual decades, 

can deviate from the long term trend due to natural climate variability. Thus, it is not 

appropriate to look at only a short period of the overall record (such as changes over just 

the last five or ten years) to infer major changes in the trajectory of global warming.” 

As demonstrated by the detailed responses below, the petitioner’s evidence does not 

warrant the conclusion that current explanations for the possible slowdown in warming 

are invalid, or that this slowdown undermines our confidence in the utility of climate 

models for either attributing or projecting climate change over appropriately long 

timescales. 

36
Comment (1-21): 

In support of the argument that the short-term slowdown in warming undermines the 

science supporting the Findings, Peabody Energy specifically highlights an e-mail from 

climate scientist Kevin Trenberth (Head of the Climate Analysis Section at the National 

Center for Atmospheric Research) stating, “The fact is that we can’t account for the lack 

of warming at the moment and it is a travesty that we can’t.”22 On this basis, Peabody 

Energy asserts that “Trenberth was unconvinced that the recent lack of warming was 

consistent with the scientific understanding of the climate system on which the models 

are based.” Peabody Energy concludes that “Trenberth’s statement eviscerates the 

grounds for EPA’s Endangerment Finding” and posits that “...if, as Trenberth says, the 

science is too uncertain to determine whether GHG reductions will produce a measurable 

climate response, then there is no basis to regulate and no basis to express confidence that 

anthropogenic GHG emissions are primarily responsible for the warming of the last 

several decades.” 

Response (1-21): 

Peabody Energy’s interpretation of the Trenberth e-mail is a profound misinterpretation 

of the context and meaning of his statement. It is not in any sense an admission that the 

science underlying the climate models is compromised. In response to questions about 

the context of the quote, Trenberth provided the following clarification on the website of 

his employer, the University Center for Atmospheric Research (Trenberth, 2010): 

It is amazing to see this particular quote lambasted so often. It stems from a paper I 

published this year bemoaning our inability to effectively monitor the energy flows 

associated with short-term climate variability. It is quite clear from the paper that I was 

not questioning the link between anthropogenic greenhouse gas emissions and warming, 

or even suggesting that recent temperatures are unusual in the context of short-term 

natural variability. 

This paper tracks the effects of the changing Sun, how much heat went into the land, 

ocean, melting Arctic sea ice, melting Greenland and Antarctica, and changes in clouds, 

along with changes in greenhouse gases. We can track this well for 1993 to 2003, but not 

for 2004 to 2008. It does NOT mean that global warming is not happening... 

Furthermore, the paper Trenberth references in this clarification states the following 

(Trenberth, 2009): 

The present-day climate is changing mainly in response to human-induced changes in the 

composition of the atmosphere as increases in greenhouse gases promote warming... 

Peabody Energy’s assertion that Trenberth was implying that the “science is too uncertain 

to determine whether GHG reductions will produce a measurable climate response,” is a 

gross mischaracterization of the meaning and significance of both the quote and 

 

22 E-mail file 1255352257.txt, (October 12, 2009), page 1801, lines 26-27 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

37
Trenberth’s position. Trenberth was not implying or questioning the validity of climate 

models used for attribution and projections. He was identifying a gap in the Earthobserving system, which if filled, would improve our understanding of short-term 

variations in climate. 

Comment (1-22): 

Petitioners (Competitive Enterprise Institute and Southeastern Legal Foundation) refer to 

a recent interview between CRU scientist Phil Jones and the BBC in which temperature 

trends are discussed, with an emphasis on the last seven to 15 years (Harribin, 2010). 

They highlight a question for CRU scientist Phil Jones - “Do you agree that from 1995 to 

the present there has been no statistically-significant global warming?” - to which he 

responds “Yes.” The Competitive Enterprise Institute parenthetically mentions that Jones 

states that there had indeed been warming during the period but that it was not 

statistically significant. Based on this statement from Phil Jones, Southeastern Legal 

Foundation concludes: “Under the circumstances, it is apparent that there is no need to 

rush headlong into a potentially irrational and arbitrary decision [a reference to the need 

to regulate GHGs].” Additionally, the Competitive Enterprise Institute notes that, in this 

interview, Jones indicates that there has been statistically insignificant cooling since 

2002, appearing to contradict a statement (Reuters, 200823) he made on how the 2001–

2007 period was warmer than the previous decade. 

Response (1-22): 

The Competitive Enterprise Institute and Southeastern Legal Foundation are not 

presenting new information or making a new argument. The Jones statement does not 

substantively add to what we have already responded to in the RTC (e.g., see RTC 2-41). 

The TSD is very clear that some datasets show a possible slowdown in the warming trend 

in the last decade or so. Box 4.1 of the TSD states: 

Though most of the warmest years on record have occurred in the last decade in 

all available datasets, according to an analysis of the HadCRUT dataset in the 

“State of the Climate in 2008” report (Peterson and Baringer, 2009), the rate of 

warming has, for a short time, slowed. The temperature trend calculated for 

January 1999 to December 2008 was about +0.13 ± 0.13°F (+0.07 ± 0.07°C) per 

decade, which is less than the 0.32°F (0.18°C) per decade trend recorded between 

1979 and 2005 (or 0.30°F [0.17C] per decade for 1980 to 2008 as stated above). 

However, NOAA [the National Oceanic and Atmospheric Administration] 

(NOAA, 2009a) and NASA [the National Aeronautics and Space Administration] 

(NASA, 2009) trends do not show the same marked slowdown for the 1999-2008 

period. The NOAA trend was ~0.21°F (0.12C) per decade while the NASA 

trend was ~0.34°F (0.19C) per decade. The variability among datasets is a 

reflection of fewer data points and some differences in dataset methodologies. 

Analysis of trends for the years 2000, 2001, and 2002 through 2008 indicate a 

rather flat trend, with slight warming or cooling depending on choice of dataset 

 

23 CEI provided the following link in its petition, but this link does not seem to work: 

http://www.news24.com/Content/SciTech/News/1132/ 1249c274c6df42cca1302d82e4236ef6/11-01-2008-

06-57/Earth_still_warming#. We believe an active link for the article cited is 

http://www.news24.com/SciTech/News/Earth-still-warming-20080111. 

38
and start date. It is important to recognize that year-to-year fluctuations in natural 

weather and climate patterns can produce a period that does not follow the longterm trend (Karl et al., 2009). Thus, each year will not necessarily be warmer 

than every year before it, though the long-term warming trend continues (Karl et 

al., 2009). 

In other words, the fact that the warming rate may have temporarily slowed was 

recognized and taken into full account in the endangerment record. 

In addition, the petitioner only includes part of Jones’ full response to BBC’s interview 

question. Here is the question and complete response (Harribin, 2010): 

[BBC] - Do you agree that from 1995 to the present there has been no 

statistically-significant global warming

[Jones] Yes, but only just. I also calculated the trend for the period 1995 to 2009. 

This trend (0.12C per decade) is positive, but not significant at the 95% 

significance level. The positive trend is quite close to the significance level. 

Achieving statistical significance in scientific terms is much more likely for 

longer periods, and much less likely for shorter periods. 

As the complete response indicates, the Competitive Enterprise Institute and Southeastern 

Legal Foundation fail to mention that Jones found the warming nearly statistically 

significant and that he explains the limitations of analyzing temperature trends over short 

time periods. The petitioners’ implication that the lack of statistically significant 

warming over a few years somehow negates the rationale for action is not supported by 

the science or Dr. Jones’ statements. 

Regarding the “cooling” Jones mentions since 2002, as the Competitive Enterprise 

Institute itself notes, it is statistically insignificant. Furthermore, it is analyzed over a 

completely inappropriate time period for discerning long-term trends, as stated in both 

the scientific literature and the endangerment record. The fact that Jones computed a 

negative temperature trend over this very short period does not contradict the statement 

he had made the year before (in 2008) about the 2001–2007 period, described by the 

news service Reuters accordingly (Reuters, 2008): 

Underscoring an underlying rise in temperatures, British forecaster Phil Jones 

said 2001-07, with an average of 0.44 Celsius above the 1961-90 world average 

of 14 degrees, was 0.21 degrees warmer than the corresponding values for 1991-

2000. 

In this Reuters article, Jones was referring to absolute temperature levels in 2001–2007 

compared to absolute temperatures in 1991–2000, rather than the 2002–2009 time series 

discussed in the BBC interview. Further, a very recent analysis by NOAA’s National 

Climatic Data Center (NCDC) (NOAA, 2010b)—using its own temperature record—

corroborates Jones’ statement. The NOAA analysis indicates that the 2000–2009 period 

was substantially warmer than the prior decade. Importantly, every year from 2000 to 

2009 was warmer than the 1990–1999 average, as shown in the figure below. 

39
To summarize, the TSD and endangerment record address short-term trends in the 

temperature record in a manner that is entirely consistent with the statements in Jones’ 

BBC interview. The petitioners have not provided any new information that alters our 

understanding of temperatures over the last 10 to 15 years—when temperatures have 

been the warmest in the instrumental record. 

Comment (1-23): 

From the BBC interview discussed in Response 1-22, the Competitive Enterprise Institute 

and Southeastern Legal Foundation also refer to Jones’ statement that for the periods 

1860 to 1880, 1910 to 1940, 1975 to 1998, and 1975 to 2009 “the warming rates ... are 

similar and not statistically significantly different from each other.” The Competitive 

Enterprise Institute concludes: 

If there has been no change in warming rates, this contradicts one of EPA’s basic 

contentions. During this same period, atmospheric levels of carbon dioxide and 

other greenhouse gases levels dramatically increased-according to EPA, to 

“essentially unprecedented levels.” 74 FR 66, 517. Yet if increasing levels of 

these gases did not produce a clear acceleration of warming, then the role of 

these gases as a major driver of temperature becomes even more dubious. 

Response (1-23): 

The warming rates for those four periods are similar, but it is important to note that these 

four periods are of different lengths (21, 31, 24, and 35 years), making trend comparisons 

incongruent. The TSD, comparing periods of equal lengths, notes that the recent 

warming rates are the greatest on record, though we note they are closely followed by 

(and therefore similar to) earlier periods (TSD Box 4.1): 

40
The warming rate in the last 10 30-year periods (averaging about 0.30°F [0.17C] 

per decade) is the greatest in the observed record, followed closely by the 

warming rate (averaging about 0.25°F [0.14C] per decade) observed during a 

number of 30-year periods spanning the 1910s to the 1940s. 

The Competitive Enterprise Institute’s assertion that similarity in warming rates between 

the present and past contradicts attribution of recent warming to anthropogenic GHGs is 

not supported by scientific analysis and ignores the scientific assessments on which EPA 

relied. In contrast to petitioners, the TSD accurately characterizes current scientific 

understanding, which does not look at GHGs in isolation but considers them in the 

context of other drivers of warming or cooling. For example, Section 5(a) of the TSD 

states: 

The IPCC (Hegerl et al., 2007) finds that anthropogenic GHG emissions were 

one of the influences contributing to temperature rise during the early part of the 

20th century along with increasing solar output and a relative lack of volcanic 

activity. During the 1950s and 1960s, when temperature leveled off, increases in 

aerosols from fossil fuels and other sources are thought to have cooled the planet. 

For example, the eruption of Mt. Agung in 1963 put large quantities of reflective 

dust into the atmosphere. The rapid warming since the 1970s has occurred in a 

period when the increase in GHGs has dominated over all other factors (Hegerl et 

al., 2007). 

Section 5 of the TSD provides substantial additional information to support this 

statement. Multiples responses (e.g., 1-24, 1-25, 1-27, 1-28, and 1-29) in this RTP 

discuss the possible slowing of the warming rate in the last decade and implications for 

attribution to anthropogenic GHGs. 

Thus, the Competitive Enterprise Institute provides no new information to support its 

conclusion that the role of GHGs in temperature change is “dubious.” The issues they 

raise are not new, their argument improperly looks at GHGs in isolation, and these issues 

were fully addressed in the Endangerment Finding, TSD, and RTC document. 

Comment (1-24): 

Peabody Energy contends that EPA’s understanding of the causes of the warming in the 

latter part of the 20th century is contradicted by the lack of warming over the 1998–2008 

period. They assert that EPA did not cite any natural forces (such as a volcanic eruption) 

that might explain the lack of warming during this period, a period when atmospheric 

GHG concentrations continued to increase. 

Response (1-24): 

The possible slowdown in warming from 1998 to 2008 does not contradict understanding 

of the causes of warming over the latter part of the 20th century. EPA is very clear about 

the well-known scientific limitations of taking a short snapshot of the temperature record 

and attempting to draw any conclusion from it—with respect to either natural variability 

or the human influence on climate. As stated in the RTC 3-4: 

41
... drawing conclusions from short time-scales is of limited value. Directly comparing 

global GHG emissions with global temperatures on decadal or shorter time-scales must 

consider all plausible variations and other existing non-linear inter-relationships. 

We note there are other 10-year periods in the temperature record that when extracted 

show no trend even though these periods are embedded within a longer period showing 

substantial overall warming (Easterling and Wehner, 2009). Therefore, it is clear that 

temperatures do not rise monotonically despite the continuing increase of GHG 

concentrations. Observations over such short periods examined in isolation may be 

misleading in the interpretation of the longer-term trend in temperatures. 

 

In spite of the possible slowdown in warming over the last 10 or so years, TSD Box 4.1 

documents that the overall rate of warming is about 0.29–0.30°F per decade over the last 

30 years and 0.24–0.25°F per decade over the last 50 years. 

Peabody Energy correctly states that EPA does not cite specific natural factors that might 

explain temperature trends over the last decade. This is because attribution of trends over 

short timescales is more difficult and is an emerging area of research. The paper by 

Solomon et al. (2009) discussed in Response 1-81 of this volume provides a plausible 

explanation related to changes in stratospheric water vapor to explain at least some of the 

trend, but concludes that more research is required for understanding temperature 

changes on short time scales. Additionally, in Response 1-27 for example, we 

acknowledge gaps in describing the causes of short-term variability but emphasize that 

these gaps do not undermine the case for linking longer term changes in temperature to 

GHGs. 

The TSD—citing the assessment literature—summarizes the significant advances in 

scientific understanding that have been made in linking long-term temperature trends to 

GHGs in Section 5(a): 

The increased confidence in the GHG contribution to the observed warming 

results from (Hegerl. et al., 2007): 

 An expanded and improved range of observations allowing attribution of 

warming to be more fully addressed jointly with other changes in the climate 

system. 

 Improvements in the simulation of many aspects of present mean climate and 

its variability on seasonal to inter-decadal time scales. 

 More detailed representations of processes related to aerosol and other 

forcings in models. 

 Simulations of 20th-century climate change that use many more models and 

much more complete anthropogenic and natural forcings. 

 Multi-model ensembles that increase confidence in attribution results by 

providing an improved representation of model uncertainty. 

To summarize, the possible slowdown in warming over the last decade or so does not 

undermine the linkage between GHGs and temperature over sufficiently long timescales. 

42
Comment (1-25): 

Peabody Energy asserts that EPA’s explanation for the slowdown in warming—that there 

is enough natural variability in the climate system to accommodate the lack of warming 

over a short time period—is not consistent with the following statement from the 

Academies of Science for the G8+5 countries, which EPA cites in RTC 1-43: 

... climate change is happening even faster than previously estimated; global CO2 

emissions since 2000 have been higher than even the highest predictions, Arctic 

sea ice has been melting at rates much faster than predicted, and the rise in the 

sea level has become more rapid. (National Academies, 2009) 

Peabody Energy states: 

EPA cannot have it both ways. It cannot insist that the cessation of warming over 

the last eleven years must be the result of poorly understood natural variability; 

whereas, other climate phenomena during that period conclusively demonstrate 

man’s impact on the climate and are not explained by the same variability. 

Moreover, EPA’s discussion of the period over which warming must be sustained 

to provide confidence that the warming is not natural is confusing. According to 

EPA, “[b]oth the IPCC and the TSD note that ‘difficulties remain in attributing 

temperature changes on smaller than continental scales and over time scales of 

less than fifty years,’ and that with limited exceptions attribution at these scales 

has not yet been established.” Since the warming of the second period lasted only 

about thirty years before it ceased, and since the plus-fifty year warming trend of 

the 20th century includes a period in which the warming did not result primarily 

from anthropogenic GHGs, it would appear that EPA cannot justify its conclusion 

that the warming of the last thirty years can be definitively attributed to 

anthropogenic GHGs. 

Response (1-25): 

The above statement from the Academies of Science for the G8+5 countries cited by EPA 

in RTC 1-43 (National Academies, 2009) describes trends in GHG emissions, Arctic sea 

ice, and sea level but does not address attribution, whether over a short time period or a 

longer time period. The statement is provided in the context of listing many major 

national and international scientific societies and academies that have endorsed or 

expressed support for the findings and conclusions of the assessment literature. It is not 

scientific information synthesized for the TSD or the Findings. 

This Academies of Science statement does not address attribution and was not used to 

support arguments pertaining to attribution, and EPA is not “having it both ways”. 

Peabody Energy correctly articulates our characterization of the attribution issue when it 

states: 

According to EPA, “[b]oth the IPCC and the TSD note that ‘difficulties remain in 

attributing temperature changes on smaller than continental scales and over time 

scales of less than fifty years,’ and that with limited exceptions attribution at 

these scales has not yet been established.”

43
There is no contradiction or inconsistency in the view that the warming rate may have 

slowed in the last decade or so and the fact that the long-term warming trend has been 

attributed to anthropogenic GHGs—as described in Response 1-24. Our statements about 

temperature trends and their relationship to the observed increases in GHGs are internally 

consistent within the endangerment record, and consistent with the assessment literature. 

Comment (1-26): 

Peabody Energy refers to the following CRU e-mail, written by climate scientist Kevin 

Trenberth in October 2009, to suggest that the climate community could never 

demonstrate that reducing GHG emissions will reduce warming: 

[t]he fact that we can not account for what is happening in the climate system 

[the lack of warming] makes any consideration of geoengineering quite hopeless 

as we will never be able to tell if it is successful or not!24

Peabody Energy asserts that Trenberth’s reference to “geoengineering” includes reducing 

GHG emissions, citing a letter Trenberth wrote in Physics Today in February 2009 

(Trenberth, 2009), stating: 

The ethical questions associated with climate manipulation loom so large that 

some forms of geoengineering are simply unacceptable. The forms that are 

acceptable include those that reduce emissions and mitigate the rates of change or 

reduce the amount of carbon dioxide in the atmosphere. 

Based on Trenberth’s expressed doubts about the ability to evaluate geoengineering, 

Peabody Energy claims: 

...Trenberth stated that the flaws in the climate community’s understanding of 

climatic forces that are exposed by the lack of warming is so fundamental – and 

the extent of natural variability must be so great – that it could never be 

demonstrated that reducing GHG emissions will reduce warming. 

Response (1-26): 

Peabody Energy’s conclusions are speculative and unsupportable, and are based on 

selectively linking disparate statements made at different times by Trenberth. Examining 

each statement in context makes clear that he does not agree with the views Peabody 

Energy ascribes to him. 

 

Although Trenberth included GHG emissions reductions as an example of a 

geoengineering method in the Physics Today letter, that does not mean he is referring to 

GHG reductions as “geoengineering” within the context of the statement, “we will never 

be able to tell if it is successful or not,” from the CRU material. 

 

24 E-mail file 1255523796.txt, (October 14, 2009), page 1810, lines 9-11 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

44
Generally, “geoengineering” does not refer to GHG emissions reductions achieved by 

lowering anthropogenic emissions, but rather, alternative options to counter the warming 

effects of GHGs. The IPCC’s discussion (Barker et al., 2007) of geoengineering 

discusses options such as iron and nitrogen fertilization of the oceans (to take up CO2) 

and deployment of technologies that reduce the amount of sunlight accepted by the 

Earth’s system (e.g. injecting reflective aerosols into the stratosphere and installing a 

deflector system in space to block sunlight). In fact, in a recent paper in Science authored 

by Trenberth and a colleague (Trenberth and Fasullo, 2010), Trenberth describes 

geoengineering accordingly: 

Proposals for addressing global warming now include geoengineering, whereby 

tiny particles are injected into the stratosphere to emulate the cooling effects of 

stratospheric aerosol of a volcanic eruption. 

Furthermore, as discussed in Response 1-21, Trenberth makes clear that his comments in 

this context are in reference to his frustration about gaps in the observing system that 

make it difficult to understand the Earth’s energy balance, and hence climate variability, 

on short timescales. Trenberth and Fasullo (2010) specifically mention the importance of 

understanding the flow of energy in the Earth’s system for tracking the effectiveness of 

potential geoengineering projects: 

Implicitly, such proposals assume understanding and control of the energy flow, 

which requires detailed tracking of energy within the climate system. 

Thus, EPA finds no evidence to suggest that Trenberth intended to imply that reducing 

GHG emissions will not reduce warming. In fact, Trenberth’s July 2008 testimony 

(Trenberth, 2008) before the U.S. Senate Committee on Environment and Public Works 

suggests the opposite: 

I believe that mitigation actions are certainly needed to significantly reduce the 

build-up of greenhouse gases in the atmosphere and lessen the magnitude and 

rate of climate change. Action taken now to reduce significantly the build-up of 

greenhouse gases in the atmosphere will lessen the magnitude and rates of 

climate change. In fact I believe there is a crisis of lack of adequate action in this 

regard. 

Trenberth’s public statements and recent published work very strongly suggest that the 

Trenberth statement cited by Peabody Energy does not mean it is impossible to know if 

GHG reductions will reduce warming, but simply that better understanding of the energy 

budget is needed if we are to track potential geoengineering projects (where 

“geoengineering” is referring to injecting particles into the atmosphere). 

Comment (1-27): 

Peabody Energy raises a number of methodological concerns with the Easterling and 

Wehner (2009) and Knight et al. (2009) analyses and concludes that “the models 

demonstrably do not take account of the current no-warming trend.” 

45
Response (1-27): 

As discussed in Response 1-20, the NRC (2010) states “it is not appropriate to look at 

only a short period of the overall record (such as changes over just the last five or ten 

years) to infer major changes in the trajectory of global warming.” See other prior 

discussions (e.g., Response 1-22) concerning whether there is a slowdown in the rate of 

warming over a limited number of recent years. Furthermore, in the TSD, EPA cites the 

NOAA “State of the Climate in 2008” report (Knight et al., 200925), which finds that 

climate models possess internal mechanisms of variability capable of reproducing the 

possible current slowdown in global temperature rise. Further, in a response to public 

comments on the issue (2-41), we refer to Easterling and Wehner (2009), who find that 

short-term trends in long-term time series occasionally run counter to the overall trend. 

As a general matter, the assessment literature is clear that the ability (or lack of ability) of 

climate models to reproduce a short-term slowdown in warming in no way invalidates or 

changes their reliability for attributing or projecting long-term changes in global climate 

variables resulting from sustained anthropogenic forcing of the climate system. The 

analysis of long-term trends is their primary purpose, rather than projecting year-to-year 

changes over a period of a decade or so or less. As the NRC (2010) states: “Robust 

analyses of global climate change thus tend to focus on trends of at least several 

decades.” Our responses to the specific issues raised by Peabody Energy regarding 

Easterling and Wehner (2009), Knight et al. (2009), and related issues are discussed 

below. 

Comment (1-28): 

Peabody Energy contends that the failure of the planet to warm over the last 11 years 

raises serious questions about the accuracy of computer models, specifically challenging 

the reliance on the studies of Easterling and Wehner (2009) and Knight et al. (2009),26

which support the notion that climate models can produce short periods of temperature 

trends that run counter to the overall long-term warming trend. 

Peabody Energy expresses several concerns about Easterling and Wehner (2009), 

asserting that: 

 The examples of pauses from warming in the past (running counter to the longterm trend) from 1977 to 1985 and from 1981 to 1989 are shorter than the pause 

in warming from 1998 to 2008. Peabody Energy writes that “no global warming 

during the eleven-year period 1998-2008 is a much more unlikely event than no 

global warming during the nine-year periods, 1975-1983 and 1981-1989.” 

 The period of no warming from 1977 to 1985 was driven by the eruption of El 

Chichon in 1981. 

 

25 In the TSD, we cite Knight et al. (2009) as Peterson and Baringer (2009)—the overarching report 

containing Knight et al. 

26 Knight et al. (2009) was cited as Peterson and Baringer, 2009 in EPA’s TSD. 

46
 Easterling and Wehner make a factual error, stating there was no warming from 

1981 to 1989 because the Goddard Institute for Space Studies (GISS) and CRU 

datasets indicate warming of +0.08°C per decade. 

 “...[T]he probability of a ten-year period of no warming, as determined by 

Easterling and Wehner from climate model projections as 10%, is too large. If the 

actual emissions were used to drive the climate models, the probability of 

occurrence of a ten year period of no trend would be smaller, and the mismatch 

between model expectations and observations would be higher.” 

 The distribution of models used in the study disproportionately included models 

that were more likely to simulate a pause in the warming, biasing the results. 

Regarding Knight et al., Peabody Energy then contends that: 

 Knight et al. did not compare observed trends with the results of the model when 

run with an emissions scenario that is closest to observed emissions. 

 Knight et al. changed various parameters within the climate model that do not 

occur in nature; the actual variability is only produced by a single set of physics. 

Peabody Energy concludes that these two studies were designed and conducted in such a 

way as to lead to an artificially inflated probability of occurrence of low (or no) trends in 

global temperatures over short time periods and thus, provide false confidence in the 

ability of the climate models to replicate temperature trends over such short time periods. 

Response (1-28): 

As we have discussed in previous responses (e.g., 1-24 and 1-25), the ability to project 

and attribute global trends in temperature over short time periods is limited, but this does 

not undermine their reliability in longer-term projection and attribution of temperature 

trends to GHGs. It is well recognized that climate models do a better job of simulating 

global changes over longer time scales, when short-term “noise” in the climate system 

due to year-to-year climate variability (e.g., El Niño or La Niña events27) tends to 

become smoothed. 

 

However, some of the limitations of modeling short-term variations in global climate can 

be overcome by running multiple simulations in which the input parameters are altered 

slightly to produce a range of plausible results. This is exactly what Easterling and 

Wehner and Knight et al., relatively new studies published during and after the Proposed 

Endangerment Finding public comment period (refer to Response 1-29 for discussion on 

the timing of the publication of these studies), did to test whether models could simulate 

periods of no warming under a range of conditions. 

27 El Niño is characterized by unusually warm ocean temperatures in the Equatorial Pacific, as opposed to 

La Niña, which characterized by unusually cold ocean temperatures in the Equatorial Pacific. El Niño is an 

oscillation of the ocean-atmosphere system in the tropical Pacific having important consequences for 

weather around the globe. 

47
With respect to Peabody Energy’s criticisms of Easterling and Wehner, we note the 

following: 

 When Peabody Energy asserts that an 11-year pause in warming (from 1998 to 

2008) is much less likely than 9-year pauses in warming (from 1977 to 1985 and 

1981 to 1989), Peabody Energy fails to mention that Easterling and Wehner 

indicate that the lack of warming from 1998 to 2008 is largely related to the start 

and end date chosen. Easterling and Wehner write: “if we drop 1998 and fit the 

trend to the period 1999-2008 we indeed get a strong, statistically significant 

positive trend.” 

 When Peabody Energy notes that the pause in warming from 1977 to 1985 was 

affected by the 1981 volcanic eruption of Mt. Chichon, it is well recognized that 

volcanoes are one kind of natural variability that can temporarily slow the rate of 

warming. Just as the 1981 eruption caused a slow down in warming, there are 

other drivers of variability within the Earth system such as La Niña (or El Niño) 

events that may slow (or steepen) GHG-induced warming over short time periods. 

Peabody Energy does not explain why this specific example of temporary 

slowdown in warming embedded within a longer-term warming trend is 

significant or why it represents any sort of flaw in the Easterling and Wehner 

study. 

 Though Peabody Energy claims that Easterling and Wehner make a factual error 

in computing no warming from 1981 to 1989, Easterling and Wehner do not say 

there was no warming—just that there was no statistically significant warming 

(i.e., “no trend”). 

 In indicating that Easterling and Wehner did not use a sufficiently aggressive 

emissions scenario in its simulations, Peabody Energy fails to mention that 

Easterling and Wehner defend their choice of emissions scenario accordingly: 

“The A2 scenario postulates a ‘business as usual’ future with little reduction in 

anthropogenic emissions resulting in large greenhouse gas concentrations by the 

end of the 21st century.” In other words, Easterling and Wehner chose an 

aggressive emissions scenario. While it may be true that the current rate of 

increase in GHG emissions is higher than that scenario, as discussed in Section 6 

of the TSD, a range of future emissions scenarios are plausible and will depend on 

assumptions regarding population and economic growth, implementation of 

policies, technology change and adoption, and other factors. 

 Peabody Energy’s assertion that the models chosen by Easterling and Wehner 

disproportionately included models more likely to simulate a slowdown is not 

substantiated. Easterling and Wehner state that they used all available simulations 

in the Climate Model Intercomparison Project (CMIP) database. Peabody Energy 

states that “the models with the greater number of runs [in the database] – 

particularly those models with a large degree of internal noise – had a greater 

influence on the overall distribution” but provides no additional evidence to 

support this assertion. 

48
With respect to Peabody Energy’s criticisms of Knight et al., we note the following: 

 Just as in the Easterling and Wehner study, Peabody Energy criticizes the choice 

of the emissions scenario in the Knight et al. study as being too conservative. 

However, Knight et al. indicate that they use “several” scenarios from the IPCC 

Special Report on Emissions Scenarios, which is appropriate to reflect the range 

of plausible futures. 

 Peabody Energy’s claim that Knight et al.’s technique of varying model 

parameters is inappropriate because only a single set of physics applies in nature 

is based on the flawed assumption that modelers can perfectly replicate nature in 

its model settings. Modelers vary these parameters to capture the uncertainty in 

their modeling of the science. Through multiple model runs with these varying 

parameters, the model output can reflect the whole range of plausible results 

rather than a single value for which there would be limited confidence. 

Furthermore, Peabody Energy’s assertion that producing multiple simulations 

artificially inflates the probability of the occurrence of low trends in global 

temperatures is false. Randomly increasing the number of simulations should 

equally increase the number of results that show both large and small trends. 

To summarize, we find Peabody Energy’s criticisms of the Easterling and Wehner and 

Knight et al. studies misplaced, unsubstantiated, and/or flawed. These studies 

demonstrate temporary slowdowns in the rate of warming have occurred in the recent 

past during a period of sustained long-term warming and conduct legitimate modeling 

experiments showing that models can and do produce sustained multi-year periods of 

reduced warming, no trend, and/or even slight cooling embedded within the longer term 

warming projected in the next century. 

Comment (1-29): 

Peabody Energy notes that the Easterling and Wehner study (discussed in Response 1-28) 

was published just before the public comment deadline, such that the public did not have 

an opportunity to fully comment on it. The petitioner also notes that the Knight et al. 

paper was published after the public comment deadline, so the public did not have an 

opportunity to comment on it. Finally, the petitioner notes that the Easterling and 

Wehner and Knight et al. studies were published too recently to have matured to the point 

that the issue has received extensive analysis. 

Response (1-29): 

Peabody Energy’s fundamental concern about these studies—that they allegedly may 

overstate how well models simulate or explain short-term changes in temperature – does 

not undermine the basis for the Findings or justify their reconsideration. We have 

discussed above why EPA concluded that the Easterling and Wehner and Knight et al. 

results are legitimate. However, these studies are not materially important to the 

Findings. The TSD acknowledges there are “difficulties” in explaining the causes of 

short-term temperature change, stating in Section 5(a): “The IPCC (Hegerl et al., 2007) 

cautions that difficulties remain in attributing temperature changes ... over time scales of 

less than 50 years.” Thus, the amount of time the public had to comment on these studies 

49
as well as the concerns raised about them are insignificant. The issue of the ability of the 

models to project temperatures over short time periods was in fact highlighted in the TSD 

and subject to public comment. EPA’s response to comments included an appropriate 

discussion of studies that are relevant to these issues. 

Finally, while the Easterling and Wehner and Knight et al. studies are relatively recent, 

they have been highly visible and subject to significant scrutiny. The Easterling and 

Wehner study was cited in the 2009 report, Global Climate Change Impacts in the United 

States (published in June 2009)—a major assessment report of the USGCRP (Karl et al, 

2009). The Knight et al. study was incorporated into NOAA’s peer-reviewed State of the 

Climate 2008 report (issued in August 2009), published as a special supplement to the 

Bulletin of the American Meteorological Society (AMS) and disseminated to all AMS 

members (NOAA, 2009). Most recently, Easterling and Wehner and Knight et al. were 

cited in the NRC assessment, “Advancing the Science of Climate Change” (NRC, 2010). 

We are not aware of any published criticisms of these studies. 

These studies, and the petitioner’s criticisms of them, do not change the degree of 

uncertainty expressed in the assessment reports and identified by EPA as associated with 

the use of temperature data over these kinds of short time periods. Confidence in linking 

observed climate change to GHGs is not based on modeling analysis of short-term 

temperature trends but rather modeling analysis of longer-term temperature trends and 

additional lines of evidence. In summary, the results of these studies are not central to 

the Findings, and do not change the scientific position expressed in both the proposed and 

final Findings that temperatures over time periods as short as those at issue have only 

limited relevance to determining the existence of long-term temperature trends or 

attributing such trends to their causes. 

1.2.3 Climate Model Issues Raised by Petitions 

Comment (1-30): 

Petitioner Arthur Randol states that the CRU e-mails “reveal serious questions about the 

validity of the IPCC models and the modelers,” and therefore, EPA’s reliance upon 

models. Arthur Randol also quotes a number of EPA and IPCC sources discussing model 

uncertainties (e.g., “What does the accuracy of a climate model’s simulation of past or 

contemporary climate say about the accuracy of its projections of climate change? This 

question is just beginning to be addressed...”) (Randall, 2007).

Response (1-30): 

EPA responded to comments on computer modeling issues at length in the RTC 

document (Volume 4.1), in terms of both their uses and limitations. Response 4-1 of the 

RTC is provided here, as it is the general response to the petitioner’s issues already 

contained within the RTC document. Responses to specific information provided by the 

petitioner are provided below. Response 4-1 stated: 

First, models are not the foundation of climate science, rather they are the tools used to 

better understand information and data from multiple sources and disciplines. 

Paleoclimate data, basic theory, observations of climate changes, and other branches of 

50
climate science together have provided (and continue to provide) the basis for key 

findings in the assessment literature. Indeed, research long before the advent of the 

computer found that the climate should respond to increased CO2 concentrations. 

Recently, scientists have used paleoclimate data about historical analogues such as the 

last interglacial and glacial maximum to estimate climate sensitivity, sea level response to 

temperature change, and other important climatic variables (Jansen et al., 2007, Hegerl et 

al., 2007). Computer modeling is, of course, important because it improves refinement of 

predictions, attributions, and analysis of non-linear interactions of a complex system, and 

thus climate models will continue to play a major role in understanding and projecting the 

future of the climate system. However, the characterization of a number of commenters 

that the projection and attribution findings of the IPCC, the U.S. Global Change Research 

Program (USGCRP), and others are supported only by the output of models is not 

accurate. 

With respect to the issues commenters raised concerning flaws in the models used for 

projections and attribution studies, it is well recognized that models are representations of 

complex systems and may not be able to perfectly represent all interactions in the system 

being modeled. For example, clouds are too difficult to model computationally because 

the physics involved in cloud formation occurs at scales smaller than the resolution of 

most climate models. Although model-based results are subject to some degree of 

inherent uncertainty, as reflected in the assessment literature and in the TSD, these 

uncertainties are acknowledged; uncertainties do not mean that the models are fatally 

flawed or unreliable representations of the climate system. Climate models have been 

demonstrated to successfully simulate a number of climatic properties, as documented in 

the IPCC, CCSP, NRC, and USGCRP reports on which the TSD primarily relies. 

Absolute certainty is not required, and in fact, the TSD summarizes both the important 

role and the limitations of models in Section 6(b), quoting Meehl et al. (2007): 

[C]onfidence in models comes from their physical basis, and their skill in 

representing observed climate and past climate changes. Models have proven to 

be extremely important tools for simulating and understanding climate, and there 

is considerable confidence that they are able to provide credible quantitative 

estimates of future climate change, particularly at larger scales. Models continue 

to have significant limitations, such as in their representation of clouds, which 

lead to uncertainties in the magnitude and timing, as well as regional details, of 

predicted climate change. Nevertheless, over several decades of model 

development, they have consistently provided a robust and unambiguous picture 

of significant climate warming in response to increasing greenhouse gases. 

Karl et al. (2009) reaches a similar conclusion, stating: 

All of the models used in this work [Karl et al., 2009] have imperfections in their 

representation of the complexities of the “real world” climate system. These are 

due to both limits in our understanding of the climate system, and in our ability to 

represent its complex behavior with available computer resources. Despite this, 

models are extremely useful, for a number of reasons. 

First, despite remaining imperfections, the current generation of climate models 

accurately portrays many important aspects of today’s weather patterns and 

51
climate. Models are constantly being improved, and are routinely tested against 

many observations of Earth’s climate system. Second, the fingerprint work 

shows that models capture not only our present-day climate, but also key features 

of the observed climate changes over the past century. Third, many of the largescale observed climate changes (such as the warming of the surface and 

troposphere, and the increase in the amount of moisture in the atmosphere) are 

driven by very basic physics, which is well-represented in models. Fourth, 

climate models can be used to predict changes in climate that can be verified in 

the real world. Examples include the short-term global cooling subsequent to the 

eruption of Mount Pinatubo and the stratospheric cooling with increasing carbon 

dioxide. Finally, models are the only tools that exist for trying to understand the 

climate changes likely to be experienced over the course of this century. No 

period in Earth’s geological history provides an exact analogue for the climate 

conditions that will unfold in the coming decades. 

A CCSP report (2008a) assessed model strengths and limitations in detail, and the 

introduction states: 

Scientists extensively use mathematical models of Earth’s climate, executed on 

the most powerful computers available, to examine hypotheses about past and 

present-day climates. Development of climate models is fully consistent with 

approaches being taken in many other fields of science dealing with very 

complex systems. These climate simulations provide a framework within which 

enhanced understanding of climate relevant processes, along with improved 

observations, are merged into coherent projections of future climate change... 

The science of climate modeling has matured through finer spatial resolution, the 

inclusion of a greater number of physical processes, and comparison to a rapidly 

expanding array of observations. These models have important strengths and 

limitations. They successfully simulate a growing set of processes and 

phenomena; this set intersects with, but does not fully cover, the set of processes 

and phenomena of central importance for attribution of past climate changes and 

the projection of future changes. 

The consensus of the assessment literature is that models serve a useful purpose within 

the field of climate science, successfully modeling a number of processes. This is true 

despite the complexity of the system that was mentioned by one commenter. Although 

there are a number of limitations and uncertainties, they are accounted for, on a global 

scale, by providing a range of global mean temperature estimations for any given 

emission scenario (e.g., Figure 10.26, Meehl et al., 2007). This range, though important, 

still enables robust conclusions about the impact of GHGs on temperature. 

A number of specific comments on model flaws are addressed by responses within this 

volume. It is EPA’s conclusion that the models have demonstrated the ability to 

accurately simulate many key aspects of climate, and in light of the key conclusions of 

the IPCC, CCSP, and USGCRP in regard to model skill and limitations, we have 

determined that it is fully appropriate to report model-based projections and attribution 

studies in the TSD. 

52
Comment (1-31): 

Arthur Randol quotes an e-mail from Tom Wigley to support his contention that the CRU 

e-mails “reveal serious questions about the validity of the IPCC models and 

the modelers”: 

 

Mike[Mann], 

The Figure you sent is very deceptive. As an example, historical runs with PCM look as 

though they match observation—but the match is a fluke. PCM has no indirect aerosol 

forcing and a low climate sensitivity—compensating errors. In my (perhaps too harsh) 

view, there have been a number of dishonest presentations of model results by 

individual authors and by IPCC. This is why I still use results from MAGICC to 

compare with observed temperatures. At least here I can assess how sensitive matches 

are to sensitivity and forcing assumptions/uncertainties. Tom[Wigley].28

Response (1-31): 

The figure referred to in this e-mail is an informal figure developed by Gavin Schmidt for 

posting at the blog “realclimate” and is related to the perception that the climate was 

warming more slowly than the models had predicted. This figure does not appear in the 

IPCC or even the published literature. Gavin Schmidt replies later in the e-mail chain 

that the reason for using the full CMIP3 archive (including the PCM historical runs 

referred to by Wigley) as the basis for the figure, rather than the MAGICC model 

developed by Wigley, is because the behavior being explored by this figure is related to 

unforced variability, which requires the more complex models. MAGICC, a simpler 

model, does not display unforced variability. This is a normal discussion between 

scientists about how best to explore a given question. While Wigley objects to one 

specific model (PCM), the reasoning behind using the full ensemble of different models 

(including PCM) is that the ensemble often demonstrates better attributes overall than any 

of the individual models within the ensemble (each of which have their own strengths and 

weaknesses). This feature of model ensembles was discussed in the paper “How well do 

coupled model simulate today’s climate?” (Reichler and Kim, 2008). The paper 

concluded, based on the authors’ analysis of the CMIP3 model ensemble compared to 

earlier efforts, that “Both improved performance and more physical formulation suggest 

that an increasing level of confidence can be placed in model-based predictions of 

climate.” 

In the e-mail discussion, Wigley also promotes a couple of different methods of his own 

to explain the observed variability in the rate of warming. One method used by Wigley 

involves comparing an artificial distribution of unforced variability to the difference 

between the observed trend and the best estimate of a trend without variability, rather 

than using the CMIP3 archive to determine the variability. Another method involves 

using known sources of variability like the solar cycle, ENSO, or volcanoes to explain 

recent temperature trends. Using both these methods, Wigley also finds that the recent 

rate of warming is consistent with the models: 

 

28 E-mail file 1255553034.txt, (October 14, 2009), page 1824, lines 39-45 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

53
At the risk of overload, here are some notes of mine on the recent lack of warming. I 

look at this in two ways. The first is to look at the difference between the observed and 

expected anthropogenic trend relative to the pdf for unforced variability. The second is 

to remove ENSO, volcanoes and TSI variations from the observed data. Both methods 

show that what we are seeing is not unusual. The second method leaves a significant 

warming over the past decade. These sums complement Kevin‘s energy work. Kevin 

[Trenberth] says ... "The fact is that we can‘t account for the lack of warming at the 

moment and it is a travesty that we can’t". I do not agree with this.29 

This e-mail from Tom Wigley does not reveal serious questions about the validity of 

models as a whole, nor does it demonstrate that the PCM model should not be used. It 

reflects a discussion over alternate ways to analyze one specific question. 

Comment (1-32): 

Arthur Randol quotes one of the CRU e-mails from Susan Solomon, claiming that the 

questions raised regarding the use of models are “enough to seriously challenge the IPCC 

results.” 

The question I want to raise is not related to the very important dialogue on how to 

handle the errors and the statistics, but rather how to think about the models. The 

attached paper by Forster et al. appeared recently in GRL. It taught me something I 

didn’t realize, namely that ozone losses and accompanying temperature trends at higher 

altitudes can strongly affect low altitudes, through the influence of downwelling 

longwave. 

No global general circulation model can possibly be expected to simulate this correctly 

unless it has interactive ozone, or prescribes an observed tropical ozone trend. The AR4 

models did not include this, and any “discrepancies” are not relevant at all to the issue of 

the fidelity of those models for global warming.30

Response (1-32): 

We note, with respect to this e-mail from Susan Solomon, that she specifically stated that 

the issues raised were “not relevant at all to the issue of the fidelity of those models for 

global warming.”31 This means that this issue does not raise doubts about conclusions 

based on using these models for long-term global warming studies. In addition, the fact 

that there are phenomena not captured by the models should not be surprising, as 

described above. The question is, how much will the inclusion of these phenomena alter 

the conclusions reached from using the model? The particular phenomena described by 

Solomon is the possibility that cooling of the stratosphere due to ozone depletion may 

also lead to cooling of some parts of the troposphere: Solomon suggests that this could 

further explain any discrepancies between the observed warming in the tropical 

 

29 E-mail file 1255496484.txt, (October 14, 2009), page 1807, lines 37-43 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

30 E-mail file 1199027884.txt, (December 30, 2007), page 1397-1398, lines 35-40 and 18-22 of PDF 

version entitled: CRU Emails 1996-2009.pdf 

31 E-mail file 1199027884.txt, (December 30, 2007), page 1398, lines 21-22 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

54
troposphere and theoretically predicted warming (the “hot spot”). The comment at the 

start of this e-mail fragment about “the errors and the statistics” is a reference to the 

Douglass (2007) paper on the “hot spot”. The errors in the Douglass paper were the 

subject of a paper (Santer, 2008) that is discussed in Responses 1-18 and 1-19 of this 

RTP document. Our review finds that the petitioner may have misunderstood the e-mail. 

The e-mail does not challenge the IPCC results; if anything, it suggests a way in which 

some existing discrepancies might be further narrowed.

Comment (1-33): 

Arthur Randol quotes an e-mail from Peter Thorne in support of his contention that 

models are flawed: 

Maybe we need to step back and rephrase the question in terms of the physics rather than 

aiming solely to rebutt Douglass et al? In this case the key physical questions in my view 

would be: 

Is there really a stratospheric radiative influence? If so, how low does it go? What is the 

cause? Are the numbers consistent with the underlying governing physics or simply an 

artifact of residual obs errors? 

Can any models show trend behaviour that deviates from a SALR on multi-decadal 

timescales? If so, what is it about the model that causes this effect? Physics? Forcings? 

Phasing of natural variability? Is it also true on shorter timescales in this model? 

I think in the future the Forster et al paper may be seen as the more scientifically 

significant result when Douglass et al is no longer cared about ...32

Response (1-33): 

This quote is also related to discussion about the “hot spot” in the troposphere, as was the 

quote discussed in Response 1-32. The e-mail’s author indicates that there are more 

significant scientific questions involved on this topic than would be addressed merely by 

rebutting Douglass et al. (2007). The discrepancy that scientists are interested in is the 

possible difference between the theory of saturated adiabatic lapse rate (SALR) and the 

observations of the tropical tropospheric temperatures. While the Santer (2008) rebuttal 

of the Douglass et al. study resolved this discrepancy in large part, there is still the 

interesting question of whether a model could demonstrate a way in which the 

troposphere would not warm as much as the surface, in contradiction to the basic theory. 

The Santer (2008) paper is discussed in Responses 1-18 and 1-19 of this RTP document. 

This quote is not about flawed models, but rather, about determining whether models can 

be used to explore potentially interesting behavior about the vertical temperature 

structure of the troposphere. 

 

32 E-mail file 1199286511.txt, (January 2, 2008), page 1400, lines 13-15, 18-23 and 27-29 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

55
Comment (1-34): 

Arthur Randol quotes a 2008 e-mail from Jagadish Shukla critiquing some aspects of 

regional climate change projections. The petitioner underlines two portions of this email: 

For example, we can not advise the policymakers about re-building the city of New 

Orleans - or more generally about the habitability of the Gulf-Coast - using climate 

models which have serious deficiencies in simulating the strength, frequency and tracks 

of hurricanes. 

and 

It is not without precedent that quite deficient climate models are used by large 

communities simply because it is convenient to use them. It is self-evident that if a 

coarse resolution IPCC model does not correctly capture the large-scale mean and 

transient response, a high-resolution regional model, forced by the lateral boundary 

conditions from the coarse model, can not improve the response. Considering the 

important role of multi-scale interactions and feedbacks in the climate system, it is 

essential that the IPCC-class global models themselves be run at sufficiently high 

resolution.33

The petitioner also quotes the EPA TSD, underlining, among other 

statements, the following sentence: 

Uncertainty also increases as the temporal scales move away from present, either 

backward, but more importantly forward in time. 

Response (1-34): 

In the e-mail from Shukla quoted by the petitioner there is also the statement “in fact 

many of us were arguing for stronger language with a higher level of confidence at the 

last meetings of the Las [i.e. at the previous IPCC AR4 lead author meeting],”34 and a 

note that Shukla was not objecting to the use of model results for discussions of 

mitigation, but rather for providing information that is useful for adaptation. The 

statement on hurricanes is consistent with the assessment of hurricane projections in 

Section 6(e) of the TSD. Moreover, that the “chaotic variability” of weather (required for 

predicting hurricane tracks) is different from climatic changes is well understood (see 

Response 4-2 of the RTC document). The uncertainties in regional modeling are well 

understood and summarized in the TSD (as quoted by the petitioner). 

The TSD does not rely on downscaled modeling (where a high resolution model is run 

for a small area within a larger lower resolution model), including the kind critiqued in 

the e-mail. However, we note that within the quote provided by the petitioner, there is no 

 

33 E-mail file 1202939193.txt, (February 13, 2008), page 1460, lines 3-6 and 28-34 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

34 E-mail file 1202939193.txt, (February 13, 2008), page 1459, lines 44-45 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

56
statement that downscaling cannot work, merely that the global models in which the 

downscaled models are embedded should be run at an appropriate resolution. 

The quoted e-mail argued for stronger language with a higher level of confidence, the 

uncertainties involved with regional modeling were well represented in the TSD, and 

specific issues highlighted in the e-mail by the petitioner were both consistent with the 

TSD and not germane to the Findings. Therefore we find that the petitioner has not 

raised any issues that would result in a change of any conclusions in the TSD or the 

RTCs. 

Comment (1-35): 

Arthur Randol claims that “the CRU email reveal serious questions about the validity of 

the IPCC models and the modelers,” based on the e-mails discussed above and also on an 

e-mail from Ben Santer. The Santer e-mail discusses using a subset of models to 

examine certain climatic features, stating: 

We’ve had fun computing a whole range of metrics that might be used to define such a 

subset of “better” models. The ultimate goal is to determine the sensitivity of our water 

vapor D&A results to model quality. I think that this kind of analysis will be unavoidable 

in the multi-model world in which we now live. Given substantial inter-model 

differences in simulation quality, “one model, one vote” is probably not the best policy 

for D&A work!35

The e-mail concludes with “The results are fascinating, and show (at least for water vapor 

and SST) that every model has its own individual strengths and weaknesses. It is difficult 

to identify a subset of models that CONSISTENTLY does well in many different regions 

and over a range of different timescales.”36

Response (1-35): 

That different models have different strengths and weaknesses is well-understood and as 

described above was discussed in the assessment reports and the Findings. This is why 

conclusions in the literature are considered more robust when multiple models exhibit 

similar behavior and the conclusions don’t rely on just one model or one line of evidence. 

Parallel to the conclusions of Santer in this e-mail, Reichler and Kim (2008) published a 

paper which showed that it is often difficult to identify one best model, and that using the 

average of multiple models often produces better results than any model individually over 

a range of metrics. Therefore, the issue that models have differential abilities to simulate 

different processes is well documented in the literature and the assessment reports, and 

was taken into consideration when considering model results for purposes of developing 

an Endangerment Finding. The commenter does not explain how these recognized 

differences between models impacts the validity of the conclusions drawn in the 

 

35 E-mail file 1196882357.txt, (December 5, 2007), page 1368, lines 36-41 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

36 E-mail file 1196882357.txt, (December 5, 2007), page 1369, lines 16-19 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

57
assessment reports and in EPA’s Endangerment Finding, which recognized and took into 

account the differences, strengths, and weaknesses of the various climate models. 

1.2.4 Summary 

Petitioners attempt to challenge key scientific information supporting the Endangerment 

Finding pertaining to temperature trends in the vertical structure of the atmosphere, the 

rate of warming over the last 10 or so years at the surface, the ability to attribute observed 

temperature trends (both in the vertical structure of the atmosphere and at the surface) to 

increasing GHG concentrations, and the general ability of models to replicate what has 

been observed and then make valid projections. Petitioners refer to material in the CRU 

e-mails in some cases to support their assertions. 

We find the following: 

 The claim that the CRU e-mails provide evidence that there is no human 

fingerprint in the vertical structure of the atmosphere in the tropics is not 

supported by scientific evidence but rather speculative assertions pertaining the 

timing of the publication of a journal article. 

 Petitioners’ overstate the significance of a possible slowdown in the rate of 

warming in the last 10 or so years; misinterpret statements on the issue from 

prominent scientists, as well as published literature; and rely upon an 

inappropriate examination of a short period of the temperature record to draw 

broad, conclusive statements about global warming and the ability to attribute it to 

human activities, an issue which requires analysis of data over several decades 

and consideration of a wide body of evidence. 

 The discussions among scientists in the CRU e-mails do not undermine the 

validity of climate models or raise any new issues of their reliability. The 

discussions revolve around the strengths and weaknesses of individual models, 

which have been long understood by the scientific community and were reflected 

in and taken into account in the assessment literature and in EPA’s endangerment 

record. The e-mails do not change the appropriate degree of certainty that should 

be associated with the results obtained from such models, including the increased 

degree of certainty when multiple different models are used to evaluate an issue, 

as reflected in the assessment reports and EPA’s Endangerment Finding. 

58
1.3. Validity of the HadCRUT Temperature Record 

1.3.1 Overview 

A number of petitioners challenge the validity of the surface temperature record 

developed by scientists at CRU. Many of their issues were raised during notice and 

comment on the Endangerment Findings, although in some cases the petitioners claim 

additional support from more recent information released in the media. In particular, 

several petitioners reference the CRU e-mails that were made public in November 2009. 

Based on statements in the e-mails, petitioners question the validity of the HadCRUT 

temperature record and other associated temperature records. 

As described in more detail in this section, the petitioners make a number of claims 

involving the HadCRUT temperature record, including alleged destruction of data; 

inappropriate data manipulation; selective use of data from Russian weather stations to 

create a biased global temperature record; and inappropriate corrections for urban heat 

island (UHI) effect, particularly in China. 

The petitioners argue that these errors demonstrate that the CRU datasets in general, and 

the HadCRUT temperature record in particular, are flawed and unreliable. In some cases, 

they argue that errors in unrelated datasets maintained by CRU also undermine the 

HadCRUT temperature record. They then argue that these datasets and temperature 

records are a critical underpinning of the IPCC assessment reports, and that questions 

about the quality of the CRU datasets must inevitably raise questions about the validity of 

the IPCC’s conclusions. Finally, they argue that EPA’s Endangerment Finding must be 

reconsidered as a result of these questions, because EPA relied on the IPCC findings in 

reaching its conclusions. 

EPA’s analysis indicates that the issues and evidence presented by the petitioners do not 

support the conclusions they draw. First, we note that many of the issues raised by 

petitioners were already addressed in EPA’s RTC document, such as the alleged 

destruction of data and the alleged problems involving Chinese UHI analyses. As 

explained in more detail below, other issues identified by the petitioners involve codes 

that have not been shown to be used in a public product; speculative analyses of Russian 

data that do not have any effect on modern temperature trends;, and objections to logs of 

quality control efforts (related to another CRU dataset, but not the HadCRUT 

temperature record that is the main issue in the petitioners’ allegations), with no showing 

of any bias of the final products. 

We note that the HadCRUT temperature record is one of three surface temperature 

records relied on by the AR4 or the EPA Findings. There are also many other records of 

warming, such as satellite and other records of atmospheric temperatures, as well as 

evidence of warming in many aspects of the environment. These multiple and 

independent sources of physical evidence of warming provide a comprehensive and 

consistent picture of warming. Petitioners fail to address this body of evidence, and 

59
instead, as discussed below, make inappropriate and exaggerated claims concerning one 

of the three surface temperature records. 

For all of the temperature records referenced in the IPCC’s AR4 and the TSD, including 

the HadCRUT temperature record, there are known to be both strengths and uncertainties 

with respect to data coverage, instrumental error, and other issues. There is no assertion 

that historical temperatures are precisely known. The size of the error ranges shown in 

one paper (Brohan et al. 2006) on the HadCRUT temperature record, for example, 

appropriately indicates the certainty of that temperature reconstruction. The petitioners 

have not shown that the existing error range was too small, nor have the petitioners 

presented any analysis indicating these error bounds should be adjusted. In addition, as 

described in responses throughout this section, their accusations of bias are unfounded. 

In reaching the Endangerment Finding, the Administrator took the recognized degree of 

certainty of the underlying scientific evidence into consideration when making her 

decision. For many reasons that we discuss below, EPA strongly disputes the arguments 

that the HadCRUT temperature record or the CRU datasets serve as “the only” or “the 

most important” basis for 1) determinations pertaining to warming in recent decades, 2) 

all analyses of anthropogenic global warming, and 3) IPCC’s models of future warming. 

EPA’s review indicates that neither the claims of error or bias nor their broad and 

unfounded conclusions about the validity of EPA scientific findings are supported by the 

evidence that they present. 

Note: petitioners’ arguments regarding the three surface temperature records together are 

addressed in Section 1.4 of this document. 

1.3.2 Scientific Background on Surface Temperature Records and Underlying

Datasets

Before the detailed response to petitioners’ arguments, we provide some background on 

the development and use of the major surface temperature records and datasets. We list 

the records and datasets in the following text boxes. The CRU temperature record and 

datasets are described in this section, and the NOAA and NASA temperature records and 

datasets are described in Section 1.4 of this document. 

60
At CRU (University of East Anglia) 

CRUTEM3 Temperature record; land only, based on multiple sources 

including unadjusted GHCN (see below) 

HadCRUT Temperature record: land and ocean, based on CRUTEM3 

plus ocean data 

CRU TS2.1 and 

TS3.0

Multiple climate elements (temperature, rainfall, cloudiness) 

at a high resolution 

At NOAA (NCDC) 

GHCN (Global 

Historical Climate 

Network) 

Unadjusted: Data collected from a number of 

weather stations, used by NASA and CRU in developing 

their temperature record. 

Adjusted: Uses various techniques to correct for 

station moves and other issues in the raw data. This is the 

temperature record most commonly presented by NOAA. 

USHCN (U.S. 

Historical Climate 

Network) 

Adjusted: Uses various techniques to correct for 

time of observation and corrections based on neighboring 

stations. 

At NASA GISS 

NASA temperature 

record 

Referred to in other documents as the GISS temperature 

record, or GISTEMP. Available as a land only temperature 

record or as land plus ocean. Based on unadjusted GHCN, 

adjusted USHCN, and Antarctic station records. 

Other data sources

CLIMAT Monthly reports from national meteorological stations 

organized through WMO 

World Weather 

Records (WWR) 

Station data from around the world, published decadally for 

most of the century. WWR was originally published by the 

Smithsonian Institution, later by the U.S. Weather Bureau 

and other organizations, and was digitized by the National 

Center for Atmospheric Research (NCAR). 

Monitoring the changes in the surface temperature of the Earth is one of several key 

components of studying climate change. Surface temperature is not the only metric of a 

changing climate. Receding glaciers, sea level rise, changes in Arctic ice, tropospheric 

and stratospheric temperatures, ocean heat content, changes in precipitation and 

hurricanes, movement of plants, and a number of other indicators are also valuable 

physical parameters to monitor and evaluate observed changes of the Earth’s climate. 

The surface temperature record is but one of many sources of evidence leading to the 

conclusion that global warming is occurring. 

61
Surface temperature records are built on the data collected from thousands of weather 

stations around the globe, as well as sea surface temperature records taken by ships 

crossing the ocean on different routes. Some of this data goes back for well over 100 

years. These weather stations and the data collected by the stations were not originally 

intended to be used for climate monitoring, and therefore, a number of adjustments often 

have to be made to the data they have collected over time. Typical adjustments include 

corrections for the introduction of artificial biases, such as changes in the time of day that 

observations were made, changes in station locations, changes in the type of 

measurement instrument or temperature recording method, and addressing the effects of 

UHIs (the increased temperature observed within cities compared to rural locations). For 

example, sea surface temperatures used to be recorded by dipping a canvas or wooden 

bucket into the sea and checking the temperature after the bucket had been brought on 

board the ship. More recently, these temperatures are recorded in intake valves of ships. 

Studies have shown that these two methods result in different temperatures for 

measurements made at the same time and place. Thus, a long-term climate record that 

includes a transition from one method to the other requires an adjustment so that the 

whole time series consistently reflects the actual changes in temperature trends, rather 

than artifacts of different data collection methodologies. 

We note that the petitioners have raised no objections concerning the sea surface 

temperature record, despite the fact that the oceans cover about 70% of the Earth’s 

surface, and therefore, ocean surface temperature trends are the dominant component of 

any global temperature trend analyses. The corrections described above to adjust for the 

bucket to intake valve transition (documented in Rayner et al., 2005 and Folland and 

Parker, 1995) result in a dataset that shows less warming than the raw data would 

suggest. Folland and Parker noted that the first, crude attempts to correct for this bias in 

the 1980s involved adding 0.3 degrees to all data before 1940; this is the largest single 

source of bias correction involved in the global surface temperature record. Even after 

this correction, the sea surface temperature record shows a clear warming signal over 

both the past several decades and the past century. Petitioners ignore this aspect of the 

surface temperature record. 

Other routine quality control measures involve checking for and deleting data that are 

shown to be duplicative. This can occur, for example, when data are obtained from 

different sources, and some stations are included in both datasets. Often, such duplicate 

stations are identified because two records have the same WMO identifier. In some 

cases, weather stations in different countries, or at different points in time, will have 

inconsistent measurement methodologies or formats for reporting data. When this 

occurs, the data must be adjusted to ensure that the observed results reflect actual 

temperature change and not methodological differences. Further, the recording stations 

are not evenly distributed around the planet. The methodology for building up a global 

average temperature record must ensure that areas with many stations are not 

overrepresented in the record and areas with few stations are not underrepresented. In 

this case, available data from existing recording stations need to be averaged in areas 

with high station coverage and extrapolated for areas with poorer coverage. Overall, the 

62
kinds of adjustments made to the underlying raw data are designed so that the results of 

analyses of the dataset reflect as much as possible the actual direction and magnitude of 

any change in surface temperature and do not reflect other changes, such as in 

measurement devices or in the location of stations, as if they were changes in surface 

temperature. 

In general, the method for estimating temperature trends does not attempt to determine 

the average surface temperature of the Earth, but rather, to determine if temperatures 

have changed over time, both regionally and globally. The difference between the 

temperatures at a given time period compared to a reference period is known as the 

temperature “anomaly.” Anomalies or equivalent methods are used for long-term trend 

analyses that combine multiple stations. Temperature anomalies are superior to absolute 

temperatures for climate analysis because absolute temperatures can vary significantly 

over small distances, whereas anomalies are better correlated with large regional changes. 

For example, two nearby stations—one on top of a mountain and one in the neighboring 

valley—will likely have different absolute temperatures but similar anomalies (changes 

in temperature) over time, as a shift in climate will cause both temperatures to drop or 

both temperatures to rise in concert. Additionally, use of anomalies, rather than absolute 

temperatures, allows for determination of temperature trends, even when the data 

availability changes (see Subsection 1.4.3.1 on “station drop-out” for an explanation of 

why this matters). 

The process by which the HadCRUT global surface temperature record is collected and 

computed is described in a series of publications from CRU scientists, such as Jones 

(1988), Jones (1994), Jones and Moberg (2003), and Brohan et al. (2006). The earliest 

versions of these temperature records primarily relied on the World Weather Records. 

The Jones (1988) work included 1,873 stations (mostly in the Northern Hemisphere), plus 

16 stations in Antarctica. The 1994 update added a number of additional stations that had 

been collected through the efforts of Karl et al. (1993) and incorporated some 

methodological improvements. Even with these improvements in spatial coverage and 

accuracy, the hemispheric averages were nearly unchanged. Jones attributed this to the 

robustness of the hemispheric mean temperature series and the high correlation of 

anomaly measurements over large areas. He estimated that for a hemispheric average, 

only 100 well-placed stations would be necessary to give a robust result. However, for 

estimating continental or smaller regional-scale temperature trends, more temperature 

records would be necessary. 

The Jones and Moberg (2003) paper reported the inclusion of the GHCN dataset 

(described in Subsection 1.4.2 of this document on NOAA and NCDC data); improved 

18th and 19th century records; and integrated data from individual National 

Meteorological Services (NMSs) in countries around the world, data exchanged over the 

WMO CLIMAT network and other global datasets covering the years after 1981, and 

data from Antarctica. The 2003 temperature record was based on data from 5,159 

stations. Jones and Moberg (2003) describes the “laborious and time consuming” 

analysis that was required when certain stations existed in both the original Jones 

temperature record and in the new data that was acquired from other sources, and the 

63
approach taken in such cases to determine how to appropriately “homogenize” the data. 

This “homogenization” involves adjusting data to correct for discontinuities in the data 

due to nonclimatic effects. For example, in 1994 the Australian NMS switched from 

reporting a “daily mean” temperature, which was the average of the maximum and 

minimum temperature each day, to a “daily mean” temperature, which was the average of 

every temperature recorded over the day on a three-hour basis. These two methods yield 

different results for the same date, and without an adjustment to correct for the change in 

average temperature before and after the switch, the apparent temperature trends would 

reflect the change in methodology in addition to any actual climatic change. Other 

quality control methods involved examining every outlier (defined as five standard 

deviations from the mean) and determining if there was a reason that the data point was 

so far off from the other data from that station. Jones and Moberg (2003) compared the 

CRU analysis to the NOAA and NASA analyses as well as the older Jones study (1994), 

and found that the Northern Hemisphere patterns remained remarkably similar in all four 

series. There were some larger differences in the Southern Hemisphere because fewer 

stations were located there, and therefore, differences in methodologies used for the 

different temperature records (in terms of how to include Antarctica and South Pacific 

islands) could lead to more differences in the Southern Hemispheric record than were 

seen in the Northern Hemisphere. 

The final published update (Brohan et al., 2006) added a few more stations, deleted some 

stations where there were duplicates, and performed additional quality control checks. 

This update also describes three kinds of errors that are incorporated into an error 

analysis: station error due to bad measurements or adjustments to an individual station, 

sampling error because of too little coverage, and large-scale bias error due to changes in 

methodologies (like the Australian NMS switch or the bucket to ship intake switch) (see 

Brohan et al. Figure). We 

note that while bad 

measurements or 

adjustments to an 

individual station can lead 

to incorrect assessments of 

very local trends, on a large 

scale, these kinds of 

random errors will, on 

average, cancel out. Largescale bias errors have the 

potential to be more important 

for large-scale trends, but the 

major sources of biases have all 

been examined, and corrections 

for these biases have been 

incorporated into the temperature records and uncertainty estimations. Petitioners have 

not identified new sources of large-scale bias that are not already considered and 

addressed by the scientific literature. 

Brohan et al. (2006) Figure: Land component of HadCRUT3: 

The solid black line is the best estimate value, the red band 

gives the 95% uncertainty range caused by station, sampling 

and measurement errors; the green band adds the 95% error 

range due to limited coverage; and the blue band adds the 95% 

error range due to bias errors. 

64
Another graph is included in Brohan et al. (2006) that summarizes all the homogenization 

adjustments that were made to the data, showing a fairly symmetric distribution, although 

with slightly more adjustments that cooled older data (attributed to a number of stations 

moving from inside a city to an out of town airport). The paper also discusses how the 

uncertainty estimates take into account the potential magnitude of the effects of 

urbanization (UHIs) and changes in thermometer methodologies. Continued updates to 

the HadCRUT methodology, along with links to the data, are reported on the UK Met 

office website (UK Met Office, 2010a). 

These data, along with a number of other temperature records (such as the NOAA and 

NCDC temperature records), are used to analyze long-term trends to compare to both 

model simulations and satellite trends. The recent warming shown in HadCRUT and 

other temperature records has contributed to statements by the IPCC that “warming in the 

climate system is unequivocal” (IPCC 2007a), among other statements. 

In addition to the HadCRUT temperature record, CRU also maintains a dataset whose 

current version is known as TS3.0. TS2.1, also referred to in some of the CRU e-mails, is 

the older version of this dataset. The TS datasets include various temperature metrics and 

data on precipitation, wet-day frequency, frost-day frequency, vapour pressure, and cloud 

cover. The gridding of these data is at a high resolution (half a degree) compared to the 

5-degree resolution of the HadCRUT temperature record, and is described in Mitchell 

and Jones (2005). These data have been used by many researchers, in combination with 

other datasets that measure the same variables, to analyze long-term trends and compare 

to model simulations. The TS2.1 dataset is referred to twice in the IPCC AR4 in relation 

to historical precipitation data. However, almost all of the references to global 

temperatures over time that refer to CRU data refer to the HadCRUT temperature record. 

The HadCRUT temperature record is distinct from the TS datasets. Compared to 

HadCRUT, the TS datasets include many more climatic variables than temperature, are 

gridded at a finer resolution, and are updated only once every several years rather than 

every month. While the TS2.1 dataset did use the CRUTEM dataset from Jones and 

Moberg (2003) for temperature data, it also included temperature data from five other 

sources. Arguments made by petitioners about the TS datasets are not relevant to the 

HadCRUT temperature record. 

1.3.3 Responses to Petitioners’ Arguments Regarding the Validity of CRU 

Data 

Petitioners, including the Competitive Enterprise Institute, the Pacific Legal Foundation, 

Peabody Energy, the Southeastern Legal Foundation, the State of Texas, and the 

Coalition for Responsible Regulation, raise a number of concerns regarding the data held 

and analyzed by CRU. The petitioners present five major arguments regarding the 

validity of the CRU data. The first argument is that alleged destruction of raw data for 

the HadCRUT temperature record renders the scientific data on surface temperature 

worthless and makes replication of temperature trends impossible. The second argument 

alleges that comments within code and log files are evidence of manipulation that 

“undercuts the credibility of CRU databases.” The third argument refers to a report from 

the Moscow-based Institute of Economic Analysis (IEA) (Pivovarova, 2009) that claims 

65
to show that the Russian stations used in the HadCRUT temperature record were 

selectively chosen to show increased warming. The fourth argument refers to a dispute 

about a 1990 paper coauthored by Phil Jones (Jones et. al, 1990) and claims that the IPCC 

improperly relied on this study for its conclusions about the magnitude of the UHI effect. 

Finally, petitioners argue that the CRU data is the primary basis for the conclusion of 

“unprecedented” warming and the foundation of anthropogenic global warming analyses. 

The following subsections address each of these five arguments. The alleged data 

destruction was addressed in the RTC document. No original raw data were destroyed, 

the original raw data are and remain the property of the NMS that collected them and can 

be obtained from the original stations (or national meteorological offices), subject to their 

procedures. With respect to the code and log files, the quotes selected by the petitioners 

are not evidence of deliberate data manipulation and are mainly the result of quality 

control processes determining how to best address the vast quantities of data collected 

from different sources. The IEA analysis of Russian temperature stations shows little 

divergence between the HadCRUT dataset and its own analysis after 1950, and while 

there is some divergence in the pre-1950 timeframe, the IEA analysis is not credible 

because it uses improper methodologies to do the comparison. Jones et al. (1990) was 

addressed in the RTC document and is not a central component of the IPCC analysis of 

UHI effects. Finally, the HadCRUT temperature record does not serve as the only or 

most important basis for recent warming or other anthropogenic global warming 

analyses. It is one of several temperature records used in analyses of global warming, 

along with numerous other analyses of physical evidence of warming. 

1.3.3.1 Alleged Destruction of Raw Data 

Comment (1-36): 

Several petitioners claim that CRU has not kept raw data collected from the surface 

weather stations, only the homogenized and value-added data (e.g., the data corrected for 

station moves and measurement changes), and that therefore, the evidence for warming in 

the past century is questionable. For example, the Competitive Enterprise Institute 

objects that CRU has been involved in “data dumping” the original raw data for its 

datasets and claims that this action “renders independent review and verification of the 

150-plus year temperature trends published by the Hadley Center-CRU impossible - a 

clear violation of basic principles of science and was found by the British Information 

Commissioner’s Office to be a violation of the British Freedom of Information Act.” 

Along similar lines, the State of Texas argues that “revelations that CRU data was 

destroyed, lost, or simply withheld indicate a different, but equally serious, problem: that 

the data can neither confirm nor deny how quickly, how far, for how long, or even, in 

some cases, whether, temperatures have risen.” The Southeastern Legal Foundation cited 

a newspaper article claiming that “Shortly after the Climategate documents became 

public, CRU was forced to admit on or about November 29, 2009 that much of their 

original data has been destroyed...” (Leake, 2009). 

66
Petitioners assert that these alleged actions by CRU make EPA’s “claim of warming 

trends scientifically indefensible” (Competitive Enterprise Institute) and render the CRU 

data “scientifically worthless” (State of Texas). 

Peabody Energy states: 

EPA was aware at the time it published the Endangerment Finding that some of the raw 

data used in HadCRUT3 had been destroyed but dismissed concerns about the reliability of 

these records on essentially three grounds. First, it uncritically adopted CRU’s public 

position that since (a) ninety-five percent of the raw data has long been available to 

researchers on the Global Historical Climatology Network (“GHCN”) and (b) CRU’s 

adjustment methodology is available, then (c) researchers could independently replicate 

and confirm the appropriateness of CRU’s adjustments.243 But as shown in section VI(E) 

below, the reason CRU and independent researchers cannot replicate CRU’s adjustments 

is because CRU can no longer determine which data from the GHCN it used. EPA’s 

unwillingness to make its own assessment of this issue further illustrates that EPA has 

ceded its own judgment to third parties. 

Response (1-36): 

CRU has not retained all of the raw weather station data collected during development of 

the HadCRUT temperature record, and CRU has openly acknowledged this point and 

provided a detailed explanation for its handling of the data. In fact, this issue was raised 

in public comment on the proposed Endangerment Finding and is addressed at length in 

Volume 2 (Response 2-39) of the EPA RTC document. In that response, we explained 

that: 

CRU has stated (see Appendix B) that they do not hold the original raw data but only the 

value added (i.e., quality-controlled and homogenized) data for ”some sites,” and refers 

readers to a long list of peer-reviewed references that describe how the value-added data 

were generated. To the extent possible, CRU has made all data for the HadCRUT record 

available (see Appendix A). In certain instances, data may be unavailable to the public 

due to constraints of the arrangements made in obtaining the data between CRU and other 

governments/organizations, as described in Appendix B. 

CRU’s statement on this issue is available on their website (CRU, 2010). 

The fact that CRU has not retained all the raw data does not interfere in any way with 

replication of or development of independent estimates of global or regional surface 

temperature history. The vast majority of the raw global weather station data is available 

from the GHCN and other public data sources. It is therefore possible to generate an 

independent estimate of global temperatures, as GISS, NCDC, and other groups have 

done. While attempting an exact replication of a particular analysis could be useful in 

understanding how it works and possibly identify minor bugs, this kind of exact 

replication is certainly not necessary. Indeed, for a result to be robust, it should yield a 

very similar answer, even if there are differences in the method of the underlying 

analysis. As discussed in Section 1.4 of this document, NOAA and NASA analyses of 

global surface temperature records provide such evidence. These analyses find 

temperature increases of similar magnitude and thus, strongly support the conclusion that 

the CRU analysis is robust. Similarly, as described in the background above, the major 

67
conclusions about warming based on the HadCRUT temperature record have remained 

robust, even as more data were integrated and methodologies refined over a period of two 

decades. Additionally, CRU has posted a graph showing that there is very little 

difference in global average surface temperatures resulting from using the 80% of the 

station data that is publicly available compared to the full dataset (MetOffice Data Subset 

Figure; UK Met Office, 2010c). At smaller spatial scales there may be differences 

between the full and partial datasets, but at the global scale, this confirms the trend is 

very robust and reliable. 

UK Met Office Data Subset Figure: The temperature reconstruction from the full dataset 

is in black, and the temperature reconstruction from the publically available dataset is in 

red. (UK Met Office, 2010c) 

Petitioners have not conducted an independent analysis to determine global temperature 

trends, although the data are available, and they do not provide any global analysis that 

yields a different result. They have provided no evidence that an additional or different 

analysis using the publicly available temperature data would yield a result that differs 

substantively from the warming over the century reflected in the HadCRUT and other 

analyses of global surface temperature. 

In contrast, the recent Independent Climate Change E-mails Review (2010) managed to 

write computer code from scratch in a space of two days that produced results similar to 

the HadCRUT temperature record and other independent analyses, working with publicly 

accessible data. This independent effort included the two key characteristics of any 

global temperature analysis: use of anomalies (or equivalent method) in order to focus on 

the change in temperature rather than the absolute temperature, and use of gridding (or 

68
equivalent method) to take into account the spatial distribution of the data. In the 

process, the Review determined that: 

The exercise and comparison of all figures demonstrates that: 

1. Any independent researcher may freely obtain the primary station data. It is 

impossible for any group to withhold data. 

2. It is impossible for any group to tamper improperly with data unless they have 

done so to the GHCN and NCAR (and presumably the NMO [National 

Meteorological Office]) sources themselves. 

3. The steps needed to create a temperature trend are straightforward to 

implement. 

4. The computer code necessary is straightforward to write from scratch and could 

easily be done by any competent programmer. 

5. The shape obtained in all cases is very similar; in other words, if one does the 

same thing with the same data one gets very similar results. 

6. The result does not depend significantly on the exact list of stations. 

7. Adjustments make little difference. 

Studies that use consistent methods for determining annual anomalies and spatial 

interpolation weighting factors produce results broadly consistent with the HadCRUT 

temperature record. Contrary to the assertions of petitioners, EPA has not ceded its 

judgment to third parties or uncritically adopted positions by other organizations; it has 

assessed the major surface temperature records and the methodologies of creating them 

and determined that the global trends found in these temperature records are robust. 

Contrary to the implications by the petitioners, it is not necessary to perfectly duplicate 

the HadCRUT temperature record to the precise decimal point in order to make 

scientifically useful conclusions from replication exercises. 

In addition, the limited amount of raw data that is no longer in CRU’s possession does 

not adversely affect the scientific usefulness of the surface temperature analyses and 

results prepared by CRU. There is a long record of peer-reviewed publications 

explaining the process of preparing the raw data for analysis, presenting the results of the 

analyses, and evaluating the magnitude of various possible sources of error. It is an 

unwarranted leap in logic to assume these analyses have no merit just because a small 

percentage of the underlying raw data is no longer in CRU’s possession. 

In summary, we find that the petitioners arguments were previously addressed in EPA’s 

RTC document, and they have shown no evidence that CRU’s lack of a small portion of 

the raw temperature data impedes the ability to check if the publicly available data give 

results consistent with the HadCRUT temperature record, or that it changes the scientific 

validity of the analyses performed by CRU. 

69
1.3.3.2 Alleged Data Manipulation 

 

Comment (1-37):

The Coalition for Responsible Regulation claims that “According to CRU’s own 

programming staff, the CRU temperature data were ‘fudged,’” noting that “the file 

BRIFFA_SEPT98_E.PRO reveals that the programmer ‘Appl[ied] a VERYARTIFICIAL 

correction for decline!!,’ and literally labeled several of the adjustments as ‘fudge 

factors.’” 

Response (1-37):

Based on the comments in the code, BRIFFA_SEPT98_E.PRO appears to be a 

provisional test program, with comments in capital letters to remind the programmer to 

replace the temporary fudge factors with more valid adjustments before the code is used 

for public products. Additionally, although the petitioners claim that this code shows that 

“CRU temperature data were ‘fudged,’” it appears that the fudge factor in question is 

related to the divergence issue discussed in Section 1.1 of this document, and therefore 

the fudge factor is not related to the HadCRUT temperature record. There is no evidence 

or reason to believe that the BRIFFA_SEPT98_E.PRO code was actually used for any 

public final product. On its face the “Artificial Correction” was designed as a temporary 

adjustment. 

Comment (1-38): 

The State of Texas refers to “one notable email” in which “a CRU staff member discuss a 

‘trick’ to ‘hide the decline’ in CRU temperature data sets from 1981-2000”, and 

concludes that “Such emails show that the CRU did not simply gather raw temperature 

data, enter it into computer programs, and produce conclusions based on collated raw 

data. Instead, the CRU gathered temperature data and manipulated it to produce a result 

that was sometimes different from the result that the raw data would have produced.” 

The State of Texas states that “Consequently, the British Meteorological Office (the 

‘MET’

) has announced that it will reexamine 160 years of climate data, attributing the 

need to reexamine the data to a ‘lack of public confidence based on the leaked emails.’” The Southeastern Legal Foundation also brought up the MET reexamination in 

its petition. 

Response (1-38):

The State of Texas is referring to an e-mail that addressed paleoclimate temperature 

reconstructions, not the modern surface temperature record. As discussed in Subsection 

1.1.4, the “decline” referenced in this e-mail was a reference to the divergence between 

some tree ring records and the instrumental record. This divergence was recognized in 

the published literature, and in some cases the authors of these publications were the 

same people who were the authors of the e-mails. This is unrelated to the HadCRUT 

temperature record. 

In addition, the petitioner objects to the “manipulation” of raw temperature data but has 

produced no evidence or argument that CRU made any inappropriate adjustments to the 

data in the process of producing the HadCRUT temperature record. The adjustments to 

70
the raw data are made in order to make the resulting temperature record a more accurate 

representation of the actual large-scale historical temperature changes. There is no 

scientific merit to petitioners’ allegations that the adjusted data is faulty because it gives 

different results than the unadjusted data. That ignores the scientific basis for making the 

adjustments. EPA addresses these issues in Subsection 1.3.2 on the Scientific 

Background on the HadCRUT Temperature Record. 

 

The MET announced a reexamination of climate data, but creating an investigative body 

to reexamine the data is not evidence that the original conclusions are in error. Indeed, 

the proposal from the MET (UK Met Office, 2010b) stated, “[i]t is important to 

emphasize that we do not anticipate any substantial changes in the resulting global and 

continental-scale multi-decadal trends. This effort will ensure that the datasets are 

completely robust and that all methods are transparent.” There have been several 

investigations of CRU and other climate researchers, and to date, none of the released 

conclusions of these investigations have found evidence of inappropriate data 

manipulation, nor has any evidence been shown that the HadCRUT temperature record is 

not robust. The existence of similar trends in the NASA and NOAA records, along with 

other physical signs of warming, such as glacial melt, satellite records, and ocean heating, 

strongly supports the robustness of the HadCRUT temperature record, and it is all of 

these sources that provide the comprehensive evidence that has led to the conclusion that 

warming in the climate system is unequivocal. 

Comment (1-39): 

The State of Texas also references the investigation into CRU by the British House of 

Commons, stating “On December 2, 2009, Science and Technology Committee 

Chairman Phil Willis wrote to the Vice Chancellor of East Anglia University asking for 

an explanation of CRU’s conduct and expressing concern about allegations that CRU 

‘data may have been manipulated or deleted in order to produce evidence on global 

warming.’” 

Response (1-39): 

The UK House of Commons Science and Technology Committee has released the report 

(2010) from its independent investigation and found no evidence of manipulations or 

deletions to produce evidence on global warming. See the Decision Document, as well as 

Subsections 1.3.5 and 1.4.3.5. 

Additionally, the “Report of the International Panel set up by the University of East 

Anglia to examine the research of the Climatic Research Unit” was issued recently 

(University of East Anglia, 2010a), and found that: 

We saw no evidence of any deliberate scientific malpractice in any of the work of the 

Climatic Research Unit and had it been there we believe that it is likely that we would have 

detected it. Rather we found a small group of dedicated if slightly disorganised researchers 

who were ill-prepared for being the focus of public attention. As with many small research 

groups their internal procedures were rather informal. 

71
Comment (1-40): 

The Pacific Legal Foundation claims that “The e-mails may suggest that the authors 

manipulated and “massaged” the data to strengthen the case in favor of unprecedented 

global warming, and to suppress their own data if it called global warming into question. 

See e-mails 0938018124, 0843161829, 0939154709, 0942777075, and 1059664704.”37

Response (1-40): 

The petitioners do not state what portions of these selected e-mails are evidence for their 

claim of manipulation. All of these e-mails were written in 1999. The first e-mail 

(0938018124)38, for example, is from Michael Mann to Keith Briffa, Chris Folland, and 

Phil Jones and includes in the first paragraph a statement that is directly contrary to the 

assertion of the petitioners. This paragraph demonstrates appropriate acknowledgment of 

limitations and avoidance of overconfidence: 

And I should point out that Chris, through no fault of his own, but probably through ME 

not conveying my thoughts very clearly to the others, definitely overstates any singular 

confidence I have in my own (Mann et al) series. I believe strongly that the strength in 

our discussion will be the fact that certain key features of past climate estimates are 

robust among a number of quasi-independent and truly independent estimates, each of 

which is not without its own limitations and potential biases. And I certainly don’t want 

to abuse my lead authorship by advocating my own work.39

E-mail 084316182940 is from Gary Funkhouser, about a certain Kyrgyzstan tree ring 

dataset from which he was unable to make robust conclusions. We respond to the issues 

in this e-mail in Response 1-12 in Subsection 1.1.4 of this RTP document, and find that 

the scientist is following proper procedures and not using data unless the data meets 

statistical requirements. The e-mail ends with Funkhouser hoping that someone will take 

some more data from the site to get better statistics. 

E-mail 093915470941 contains data from a temperature reconstruction from Tim Osborn 

to Mike Mann and others. This e-mail contains a discussion of the post-1960 nontemperature signal that has been discussed in Section 1.1 on “divergence”, but again this 

e-mail contains no evidence of improperly massaging data: 

Keith has asked me to send you a timeseries for the IPCC multi-proxy reconstruction 

figure, to replace the one you currently have. The data are attached to this e-mail. They 

 

37 E-mail files 0938018124.txt (September 22, 1999) page 203 line 12, 0843161829.txt (September 19, 

2006) page 11 line 4, 0939154709.txt (October 5, 1999) page 229 line 32, 0942777075.txt (November 16, 

1999) page 243 line 31, and 1059664704.txt (July 31, 2003) page 558 line 6 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

38 E-mail files 0938018124.txt, (September 22, 1999), page 203, line 12 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

39 E-mail file 0938018124.txt, (September 22, 1999), page 203, lines 21-27 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

40 E-mail files 0843161829.txt, (September 19, 2006), page 11, line 4 of PDF version entitled: CRU Emails 

1996-2009.pdf 

41 E-mail files 0939154709.txt, (October 5, 1999), page 229, line 32 of PDF version entitled: CRU Emails 

1996-2009.pdf 

72
go from 1402 to 1995, although we usually stop the series in 1960 because of the recent 

non-temperature signal that is superimposed on the tree-ring data that we use. I haven’t 

put a 40-yr smoothing through them - I thought it best if you were to do this to ensure the 

same filter was used for all curves.42

E-mail 094277707543 is from 1999 and similarly refers to the divergence issue, and has 

been quoted extensively because it used the term “Mike’s Nature trick”. We address this 

e-mail in Response 1-11 in Subsection 1.1.4 of this document, and find that this e-mail 

refers to a graph used in a 1999 WMO report which is unrelated to the IPCC and that the 

word “trick” does not imply deceit. The underlying issues involved with divergence are 

addressed in Section 1.1 of this document. 

E-mail 105966470444 is the e-mail from Mike Mann discussing “calibration residuals.” 

We respond to these issues in Response 1-80 in Section 1.3.3.6 where it is shown that the 

uncertainties arising from these residuals were discussed in the published papers by Dr. 

Mann. 

None of these e-mails provide evidence of or support the conclusion that the e-mail 

authors conducted inappropriate “massaging” or manipulating of the data or suppressed 

their own data. 

1.3.3.3 “Harry Read Me” file and other code 

The petitioners submitted a large number of quotes from a 300 page, 90,000 word 

document named HARRY_READ_ME.txt45. The HARRY_READ_ME.txt debugging 

notes are a record of “Harry’s”46 attempt to update the CRU TS2.1 product to TS3.0 

during the years 2006 to 2009 by merging six years of additional data (covering 2003 to 

2008) to an old dataset running until 2002, and migrating the code to a new computer 

system at the same time. As noted in the science background in Subsection 1.3.2 of this 

document, CRU TS2.1 and 3.0 are different from the HadCRUT temperature record that 

is referred to in the EPA TSD. Arguments made by petitioners about the TS datasets are 

not relevant to the HadCRUT temperature record. 

These quotes mainly fall into the following categories: 

1) Expressions of frustration with documentation or system processes that do 

not indicate any problems in the underlying data. 

 

42 E-mail file 0939141116.txt, (October 5, 1999), page 226, lines 32-37 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

43 E-mail files 0942777075.txt, (November 16, 1999), page 243, line 31 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

44 E-mail files 1059664704.txt, (July 31, 2003), page 558, line 6 of PDF version entitled: CRU Emails 

1996-2009.pdf

45 The complete text of this document has been placed in the docket for this action. See Docket ID No. 

EPA-HQ-OAR-2009-0171 at www.regulations.gov. 

46 “Harry” is a researcher at CRU. 

73
2) Notes about imperfections in the data received from various organizations 

that make it difficult to integrate the new data with the old database. The 

problems that arise from this integration are resolved one by one throughout 

the time period covered by the file. 

3) Expressions of frustration based on introducing errors into code which then 

have to be fixed. Bugs are almost always introduced in the coding process, 

and the key is to find them and fix them. The file includes evidence that this 

is being done. 

4) A few unresolved data issues arise at the end of the log file, and there is no 

indication in the log file of how these imperfections were fixed. This does 

not mean that these issues were not fixed between the version of the log file 

that was released with the CRU e-mails and the final TS3.0 version. 

Additionally, none of these issues appear to involve large-scale errors that 

would introduce bias, but rather unresolved inconsistencies in the data of one 

or two stations for a subset of the climate variables being recorded. 

In sum, the HARRY_READ_ME.txt is a long, multi-year log of expressed frustrations 

with old codes, merging datasets from different sources, changing computer systems, and 

the arduous process of performing quality control. This file reflects both specific 

technical terminology and the personality of the researcher. Taken out of context, as 

done by petitioners, the quotes from the file can provide misleading impressions. As the 

files show, the datasets are not perfect, but that is not a surprise. As exemplified by the 

Brohan et al. (2006) uncertainty analysis discussed in Subsection 1.3.2 (Background), it 

is well known that there are a number of reasons for there to be errors and uncertainties in 

the underlying raw data set. Importantly, the petitioners have not identified any errors 

that are likely to bias that would affect the large-scale trends analyzed with the TS 

dataset. As discussed, measurement or other errors at individual stations matter for very 

local trends but tend to cancel out when averaged over large scales. Importantly, EPA 

was unable to identify any quotes among the many dozens submitted that indicated any 

deliberate attempt to bias the data (nor did EPA find any such evidence in its analysis of 

the underlying HARRY_READ_ME document). 

The evidence shows that “Harry” was working on identifying and solving these errors in 

order to improve on the CRU TS2.1 dataset, much like the HadCRUT temperature record 

has gone through multiple iterations and improvements. Again, the petitioners have 

shown no evidence of bias or of errors that are of sufficient magnitude to compromise the 

climate signals in the various climate variables included in the TS dataset. 

The CRU TS2.1 dataset was not used in the IPCC for evaluating the trends in surface 

temperature. The HadCRUT temperature record was used for that, and it is a separate 

and distinct dataset from TS2.1. The TS2.1 products are only directly cited in Working 

Group I of the IPCC AR4 in two places: in Figure 3.12/Table 3.4 as one example out of 

several of a global land precipitation dataset (Trenberth et al., 2007), and in Figure 9.19 

for comparing Sahel precipitation trends to model simulations (Hegerl et al., 2007). 

Therefore, in addition to a lack of evidence that the contents of the 

HARRY_READ_ME.txt file materially change any large-scale trends, analyses of TS2.1 

74
data in most cases are presented alongside other independent data that support the same 

conclusions. 

The TS datasets in particular involved up to nine different climate variables collected 

from thousands of weather stations from dozens of different countries covering a century 

of time. One problem in particular involving WMO codes that appears in many of the 

quotes highlighted by petitioners was explicitly highlighted in the paper published about 

TS2.1, as well as in other papers in the literature as discussed in Response 1-46. None of 

the quotes highlighted indicated any problems that are outside the bounds of the known 

uncertainties and imperfections in the data that are discussed in the literature. 

Comment (1-41): 

One petitioner provides a quote: “As far as I can see, this renders the (weather) station 

counts totally meaningless.” 

Response (1-41):

This quote is followed, a long time later, by a discussion from “Harry” of trying to get 

this code working on the computer system of a client (the British Atmospheric Data 

Center): “Next problem - station counts. I had this working fine in CRU - here it’s 

insisting on stopping indefinitely at January 1957.” The first part of the quote shows that 

“Harry” did fix the station count problem. The last part of this quote refers to additional 

frustrations involved in getting the code to work on an unfamiliar computer system, 

which is a fairly typical occurrence when moving from one system to another. 

Comment (1-42):

The quote “COBAR AIRPORT AWS (data from an Australian weather station) cannot 

start in 1962, it didn’t open until 1993!” is provided by Peabody Energy as an example of 

false data. 

Response (1-42): 

The paragraphs preceding and following the quote clearly indicate that this problem was 

identified by an automated quality control routine, that “Harry” followed up by e-mailing 

the Australia Bureau of Meteorology, and that he was able to resolve the problem by 

determining that the 1962 to 1993 portion of the COBAR AIRPORT AWS station was 

actually from the Cobar MO station. 

Comment (1-43):

Southeastern Legal Foundation provides a quote: “Well, dtr2cld is not the world’s most 

complicated program. Wheras cloudreg is, and I immediately found a mistake! Scanning 

forward to 1951 was done with a loop that, for completely unfathomable reasons, didn’t 

include months! So we read 50 grids instead of 600!!!” 

Response (1-43):

Examination of this file shows that this quote refers to a piece of code that “Harry” had 

just written, and the quote was immediately followed by the comment, “Running with 

those bits fixed improved matters somewhat...,” showing that the goal of the exercise 

75
was to identify and address issues with the merging/updating of the data system, and that 

the problems were addressed. 

Comment (1-44):

Another quote Southeastern Legal Foundation provides is: “I was expecting that maybe 

the latter contained 94-00 normals, what I wasn’t expecting was that they are in % x10 

not %! Unbelievable - even here the conventions have not been followed. It’s botch after 

botch after botch. Modified the conversion program to process either kind of normals 

line.” 

Response (1-44):

In this case, the problem was merely that some input data had different units than other 

input data, and that “Harry” developed a routine to address this. The resolution of the 

problem (modifying the conversion program) is included within the quote provided by 

the petitioner. 

Comment (1-45): 

Peabody Energy claims that if adjustments are made to a methodology of developing a 

temperature record after peer review, then the resulting temperature record no longer 

qualifies as peer-reviewed itself, stating “If CRU cannot replicate its adjustments (as in 

the case with their HadCRUT3 data), or if adjustments were made after the publication 

of peer-reviewed methodology (as in the case with their TS2.1/3.0 data), there is no 

basis to say that the adjustments, in fact, were properly applied. CRU—and EPA—in 

essence are saying “trust me,” but any basis to do so seems to have collapsed with the 

Harry_Read_Me files.” Peabody Energy further argues that any dataset that is updated 

or changed cannot count as peer reviewed, stating “Moreover, as is evident in several 

emails, the CRU temperature data set is in a constant state of flux, with the data set 

constantly being modified both in terms of the inclusion/exclusion of data as well as the 

methods employed. Thus, the datasets now available have not been directly peerreviewed.” 

Response (1-45):

The petitioner misunderstands how the peer-review process is applied to the creation of 

temperature records and similar datasets. The papers published by CRU over the years 

detail the sources and methods used to generate the temperature record (as summarized in 

Subsection 1.3.2). It is expected that as new data become available, they will be 

incorporated, and as minor errors or updates are made that those too will be incorporated, 

without triggering any need for a new peer review. If any of this new data or updates 

resulted in substantial changes to the final output or the methodology, then that might call 

for further review. However, as has been noted repeatedly, the HadCRUT temperature 

record is both reliable and robust, with similar trends resulting from the analyses of 

NOAA, NASA, and other groups. The evidence suggests that these temperature records 

and other datasets are being produced in accordance with the peer-reviewed papers in 

which they are described, where these peer-reviewed papers discuss the limitations of the 

underlying data records and other uncertainties. The petitioner has not shown evidence 

of any changes that are substantial enough to warrant a new peer-review process. 

76
The Harry_Read_Me file is not related to the HadCRUT temperature record, but rather to 

the creation of TS3.0, as explained in Subsection 1.3.2. TS3.0 (or Time-Series 3.0) is a 

separate dataset produced by CRU, with different stations, spatial resolution, and set of 

variables. Regardless, the notion that CRU and EPA are saying “trust me” with regard to 

the surface temperature record is flawed; the GHCN data is publicly available for any 

individual or researcher to use to generate his or her own global temperature record. The 

petitioners have not provided or referenced any credible analysis of the GHCN data that 

reaches a different conclusion than those of NOAA, NASA, and the CRU. 

Comment (1-46): 

The Coalition for Responsible Regulation, Peabody Energy, and Pacific Legal 

Foundation all provide sections of a quote from the HARRY_READ_ME file: “What 

the hell is supposed to happen here? Oh yeah - there is no ‘supposed’, I can make it 

up. So I have :-)” The Coalition for Responsible Regulation claims that “The 

programmer asserts in the HARRY READ ME.txt file that, in the absence of data 

from the period 1990 through 2003, he made up what to do” and states “EPA cannot 

support a scientific judgment premised on ‘very artificial,’ ‘fudged,’ and ‘made up’ 

data. Because these Disclosures demonstrate that at least some of the temperature 

data managed and maintained by CRU were ‘fudged’ or ‘made up,’ EPA must 

reconsider its Finding and demonstrate that the data upon which it relied are valid and 

not corrupted.” 

Related quotes about WMO codes are provided by the above petitioners and the 

Southeastern Legal Foundation: “You can’t imagine what this has cost me - to actually 

allow the operator to assign false WMO codes!! But what else is there [in] such 

situations? Especially when dealing with a ‘Master‘ database of dubious provenance 

(which, er, they all are and always will be),” “So with a somewhat cynical shrug, I added 

the nuclear option - to match every WMO possible, and turn the rest into new stations ... 

In other words, what CRU usually do. It will allow bad databases to pass unnoticed, and 

good databases to become bad, but I really don’t think people care enough to fix `em, and 

it’s the main reason the project is nearly a year late,” and “False codes will be obtained 

by multiplying the legitimate code (5 digits) by 100, then adding 1 at a time until a 

number is found with no matches in the database. THIS IS NOT PERFECT but as there 

is no central repository for WMO codes - especially made-up ones – we’ll have to chance 

duplicating one that’s present in one of the other databases. In any case, anyone 

comparing WMO codes between databases - something I’ve studiously avoided doing 

except for tmin/tmax where I had to - will be treating the false codes with suspicion 

anyway. Hopefully.” 

The Coalition for Responsible Regulation claims that these quotes are evidence of 

“deliberately fabricating non-existent temperature-recording stations” and that “This kind 

of data manipulation, including creation of false temperature stations, undercuts the 

credibility of the CRU databases and requires EPA to reconsider its Endangerment 

Finding.” 

77
Response (1-46): 

Petitioners mischaracterize the emails by ignoring the context of the legitimate quality 

control process that they reflect. The problems encountered in merging WMO station 

data from different countries and time periods has been recognized and discussed in the 

peer reviewed literature (two examples are quoted in this response), and the quality 

control measures taken here are consistent with those discussed in the literature. 

These quotes address a specific issue where the programmer had written an automatic 

quality control routine to be used when merging incoming data provided by national 

weather organizations to the existing data in the database. As mentioned in the 

background discussion above, data are assumed to be from the same weather station if 

their WMO codes match, but sometimes issues arise that cast doubt on this assumption. 

To address these situations, the programmer developed a routine that ran prior to merging 

the data that checked for sufficient correlation (e.g., seasonal patterns) between the new 

and the old data. If the data were correlated, the merge would proceed. However, in 

cases where the correlation routine finds something anomalous, the program warns the 

user that an inconsistency exists and provides the user with three options: 

You have failed a match despite the WMO codes matching. 

This must be resolved!! Please choose one: 

1. Match them after all. 

2. Leave the existing station alone, and discard the update. 

3. Give existing station a false code, and make the update the new WMO station. 

Therefore, this quality control check is ensuring that for any data that seems odd, a user 

will conduct a manual review and determine whether the best option is to assume that 

both datasets are from the same station or whether the new station should be discarded or 

turned into its own station. We note here that the use of “false codes” is not 

“falsification,” as inferred by the Pacific Legal Foundation, but rather a way to address 

the problem that a few stations in the new data set had the same WMO code as stations in 

the old data set, despite the fact that quality control routines determined that the data from 

these stations had different statistical characteristics. 

This is not “making up” data. No data have been created; the only thing “made up” is an 

identification number associated with the data (the WMO code), because the previous 

identification number was already in use. The petitioners did not highlight these 

additional quotes that show the fuller context of the now oft-cited “I can make it up” 

quote. 

Moreover, the problems involved with WMO codes are not new and are well documented 

in the published literature. As explained in the published paper on the CRU TS2.1 

database (e.g., Mitchell and Jones, 2005), there are challenges involved in matching 

WMO codes. 

However, not all sources attach WMO codes to their data, and not all stations have been 

assigned WMO codes, so additional information was used: location, name and country. 

Each additional station was compared with the stations already in the database, both to 

78
avoid unnecessary duplication and to ensure that each station record is as complete as 

possible. 

If an additional station was already present in the database, then the two records were 

compared....The comparison was based on any available overlap between the records; if 

none was available, then an attempt was made to construct a reference series that 

overlapped both records (as in Section 2.4). If an overlap was found, then it was used to 

alter the statistical characteristics of the additional station to match those of the existing 

record, using the method in Section 2.4.4; the two records were then merged. If no 

overlap was found, then the records were assumed to be for different stations, because of 

the possibility of the two records having different normals. 

Where the sources were very recent (CLIMAT and MCDW) the additional station was 

assumed to be the same without the above data check. This was justified because the 

normals from these sources were likely to be the same as the post-adjustment normals 

from other sources. This assumption was necessary for some climate variables (notably 

wet days) for which overlaps with stations from other sources were very rare; without it 

the normals could be calculated for very few recent data. 

As demonstrated by this quote from the published literature, the standard procedure was 

to assume that a new record was a different station if the data did not have sufficient 

overlap to merge the records with confidence. This is what “Harry” was doing when he 

was “making up” a new WMO code. 

Peterson, Daan, and Jones (1997) also addressed some of the challenges involved when 

gathering data from many independent national services based on WMO codes, and the 

well understood imperfections in this procedure: 

These four sources total 15,433 stations. But how many are unique? To answer this 

question, all the stations needed to be merged into a single list, as shown in Fig. 2. This 

was not an easy task: in the four sources, latitudes and longitudes were recorded in 

hundredths of degrees, tenths of degrees, and minutes, depending on the source. 

Therefore, station locations seldom agreed exactly. In addition, stations often move 

slightly over time so data from earlier sources might not have the current location. Not 

only did the spelling of station names change over time, but in many cases, particularly in 

newly independent countries, the entire station name changed. These problems are 

compounded by keypunch errors that occur when keying in hard-to-read metadata from 

handwritten RCS lists. WMO station numbers also change with time, not only for 

individual stations. Sometimes a country will change all their WMO numbers at one 

time. Since most of the metadata flags were keyed to WMO numbers, the final station 

list was merged with the current WMO Volume A station list to tag each station with the 

appropriate WMO number whenever possible. 

The result was a list of 8653 unique stations, but the list is far from perfect. It is very 

likely that some errors in merging remain. An example is the assigning of a WMO 

number from a short-term synoptic reporting airport station to a nearby long-term climate 

station with a similar name. Also, normals stations were treated as if they started in 

1961, which is often erroneous but was the best that could be done with the information 

available. Therefore, the list should be carefully inspected for accuracy by individuals 

from each country that has stations initially selected for the GSN. 

79
This quote from Peterson et al. (1997) is a perfect example of the difficulties involved in 

dealing with data from different time periods and different nations, which results in many 

of the frustrations expressed throughout the HARRY_READ_ME file. These kinds of 

difficulties would not lead to the kind of large-scale bias errors with the potential to 

impact large-scale trends that were discussed in Subsection 1.3.2 of this document. 

As stated before, the “Harry” quality control program gives the user several options of 

how to treat the data. The three options are to merge the new and old data together in one 

station, to discard the new data, or to give the old data a “made-up” station number and 

use the existing WMO code for the new data. “Making up” a station number, and 

assigning it a code that is clearly not a standard WMO code, is a straightforward attempt 

to properly treat imperfect data in the case where the user of the code concludes that this 

is a better solution than either merging the data or throwing away the new data. 

Therefore, this is not a case of “fudged” or “made-up” data as claimed by the petitioners, 

but rather a legitimate attempt to address imperfect input data. 

Comment (1-47): 

The Pacific Legal Foundation claims that “the e-mails suggest that the CRU Data may 

have been falsified,” stating that: 

The scientists referred to "false codes" and running programs to "allow bad databases to 

pass unnoticed, and good data bases to become bad," see Appendix A, 15-16, leading to 

the possible inference that the CRU scientists may have falsified or manipulated the data. 

The fact that the British Information Commissioner’s Office has found that CRU violated 

British law by failing to make disclosures under British freedom of information laws 

lends substantial credence to the proposition that CRU engaged in at least some 

wrongdoing in connection with the CRU Data. See Guy Chazan, U K Says University 

Broke Law on Turning Over Data, Wall St. J., Jan. 29, 2010, at A8. See also David 

Derbyshire, Scientists broke the law by hiding climate change data: But legal loophole 

means they won’t be prosecuted, Daily Mail, Jan. 30, 2010. 

Response (1-47): 

The statement about “false codes” is addressed in Response 1-46 above which 

demonstrates that this statement does not refer to falsification of data. 

 

The issues involved with the British freedom of information laws are unrelated to the 

issues involved in the HARRY_READ_ME file. Freedom of information issues are 

addressed in Volume 3, Section 3.4 of the RTP document. 

Comment (1-48): 

The Coalition for Responsible Regulation provides the following quote from the HARRY 

READ ME.txt file 

OH F[---] THIS. It’s Sunday evening, I’ve worked all weekend, and just when I thought 

it was done I’m hitting yet another problem that’s based on the hopeless state of our 

databases. There is no uniform data integrity, it’s just a catalogue of issues that 

continues to grow as they’re found. 

80
The petitioner claims that this shows that “the CRU programmer admits the CRU data are 

without integrity.” 

Response (1-48): 

The programmer is upset because one dataset has a resolution of 2.5 degrees of latitude 

and longitude, but the programmer wanted to do an analysis comparing this dataset to 

another dataset with a resolution of 0.5 degrees. Data integrity in this case refers to the 

fact that the historical dataset used different procedures for calculating rain days before 

1990 and from 1990 onwards, and therefore, “Harry” needs to add a conditional 

statement to his code to address this difference. “No uniform data integrity” does not 

mean “without integrity,” it just means that different data have been treated in different 

ways. This makes a programmer’s job more difficult, but it is not a major flaw in the 

data. The petitioner clearly misconstrues terminology commonly used by computer 

programmers. In addition, this dataset and analysis is unrelated to the HadCRUT 

temperature record. The petitioner provides no support for the assertion that “the CRU 

data” in general are without integrity. 

 

Comment (1-49):

The Coalition for Responsible Regulation provides the following quote:

But what are all those monthly files? DON’T KNOW, UNDOCUMENTED. Wherever I 

look, there are data files, no info about what they are other than their names. And that’s 

useless... take the above example, the filenames in the _mon and _ann directories are 

identical, but the contents are not. And the only difference is that one directory is 

apparently `monthly’ and the other `annual’ - yet both contain monthly files. 

Response (1-49): 

In this quote, “Harry” is complaining about the way certain intermediate data products 

(monthly files) were stored. There is no evidence that these intermediate data products 

were ever meant to be used again, but “Harry” needed to go back to these because of a 

coefficients file. This coefficients file was eventually reconstructed. Therefore, this 

quote is not evidence of flaws in the output of either the older product (TS2.1) or the 

newer product (TS3.0) produced by CRU. Neither of these products is related to the 

dataset used for the HadCRUT temperature record. 

Comment (1-50): 

The Coalition for Responsible Regulation and Peabody Energy provide portions of the 

following quote: 

Back to the gridding. I am seriously worried that our flagship gridded data product is 

produced by Delaunay triangulation - apparently linear as well. As far as I can see, this 

renders the [weather] station counts totally meaningless. It also means that we cannot say 

exactly how the gridded data is arrived at from a statistical perspective - since we’re 

using an off-the-shelf product that isn’t documented sufficiently to say that. . . . Was too 

much effort expended on homogenisation, that there wasn’t enough time to write a 

gridding procedure? Of course, it’s too late for me to fix it too. Meh. 

81
Response (1-50):

This quote refers to a quality control problem with the CRU TS dataset that is identified 

and later resolved. Delaunay triangulation is an alternate method for determining global 

maps from an uneven distribution of stations. One method used to produce a global map 

is to create a set of square grid cells and average together the stations within each grid 

cell before averaging all the grid cells together. The Delaunay method instead makes 

triangles of different sizes with stations at the vertices and weights the stations by the size 

of the triangles on which they are located. The use of an “off-the-shelf product” means 

that CRU did not have access to the code that was used for the Delauney triangulation 

method, and there might be subtle differences depending on exactly how the method is 

implemented. Petitioners provide no evidence that the “off-the-shelf product” is 

inaccurate or that Delaunay triangulation is an inappropriate method. 

“Harry” does use a different product to determine station counts, because the Delaunay 

triangulation method is inappropriate for that use. He also refers to a functional gridding 

program that he wrote: “Got the gridding working, I think. IDL of course”. 

Comment (1-51):

The Coalition for Responsible Regulation provides the following quote: 

I am seriously close to giving up, again. The history of this is so 

complex that I can’t get far Enough into it before my head hurts and I 

have to stop. Each parameter has a tortuous history of manual and 

semi-automated interventions that I simply cannot just go back to early 

versions and run the update prog.

Response (1-51):

This quote from the HARRY_READ_ME file expresses frustration that CRU TS2.1 was 

built by using both manual and automated procedures, making it more difficult to 

integrate new data. Good programming practice would have standardized the procedures. 

However, there is no evidence that this mix of manual and automated procedures 

produces incorrect results. Therefore, this quote is not evidence of flaws in the output of 

either the older product (TS2.1) or the newer product (TS3.0) produced by CRU. It is 

only evidence of the frustration generated by implementing an arduous quality control 

process. 

Comment (1-52): 

The Southeastern Legal Foundation claims that the “HARRY_READ_ME.txt” file 

reveals “an appalling series of manipulations of the data and the code, with no provisions 

for review, no QA/QC on the data or the code, no double-check on data integrity. As has 

been noted by several commentators, the HARRY_READ_ME.txt file really is the 

‘smoking gun‘ of the AGW argument.” 

Response (1-52): 

As demonstrated by the responses in this section, these arguments by the petitioner are 

gross assertions without scientific merit. Indeed, in contrast to the assertion of the 

petitioner that this file included no QA/QC or double-checks on data integrity, the entire 

82
HARRY_READ_ME file is a massive and comprehensive QA/QC endeavor. There is no 

“appalling series of manipulations.” Instead, there is clear evidence of a researcher 

attempting to do the best job possible of bringing together large disparate databases into 

one product with as much integrity as possible. 

With respect to the “smoking gun” claim, as noted before, nothing in the 

HARRY_READ_ME file deals with issues in the data set used for the HadCRUT 

temperature record. The TS products that are the focus of this file are not related to the 

HadCRUT temperature record. Thus, we conclude that there is no “smoking gun” here. 

Comment (1-53): 

The Pacific Legal Foundation referenced the HARRY_READ_ME file and stated that “A 

complete analysis of the programming routines within this file and their implications 

would reasonably require more than five days, which is the number of days between the 

time EPA received the supplement to the petition to reopen the public comments based 

upon the CRU data, and the time that the Endangerment Finding was finalized.” 

Response (1-53): 

The CRU data were made public on November 19th, which was more than five days 

before the Endangerment Finding was finalized. This was enough time for EPA’s initial 

review to determine that the e-mails and data were not likely to materially change the 

Endangerment Finding. EPA’s Response 11-2 of the RTC document addressed this 

issue: 

On December 2, 2009, another commenter (11537) submitted a supplement to an October 

5th petition asking EPA to reopen the comment period in light of what they alleged was 

new information. This commenter claims that the recent disclosure of hacked e-mail 

messages and documents from the Climate Research Unit (CRU) of East Anglia 

University in the United Kingdom undermines the Intergovernmental Panel on Climate 

Change (IPCC) science and assessment process upon which the Technical Support 

Document (TSD) and the Findings primarily rely. 

From our review, it appears that the scientific issues raised in the e-mails were also raised 

in public comments. In fact, we believe that the public comments submitted on our 

Proposed Findings are more comprehensive than the discussions of the issues in the emails because many commenters expended considerable effort to describe their point of 

view and concerns to us, and several also provided supporting literature and data. In 

preparing the Finding, EPA has addressed many of the issues raised in the hacked emails, among the hundreds of issues raised by commenters. Our responses are fully 

documented, transparent and available to the public. The science on which the 

Administrator has based her determinations regarding the endangerment of both public 

health and welfare, and the process EPA has undertaken, have been fully open and 

transparent. 

Some groups have also used the hacked e-mails to attack the credibility of the IPCC 

process and its findings. We received many comments on the process used to develop, 

review and approve or accept IPCC reports; see our responses on these issues in Volume 

1 of this Response to Comments document. The disclosure of the private communications 

of a few individual scientists, among the hundreds of scientists that have participated in 

83
the development of the IPCC reports and the thousands that have developed the literature 

that was assessed, provides no evidence that contradicts the key conclusions and basic 

science underlying climate change. As IPCC Chairman Rajendra K. Pachauri recently 

stated: 

IPCC relies entirely on peer reviewed literature in carrying out its assessment and follows 

a process that renders it unlikely that any peer reviewed piece of literature, however 

contrary to the views of any individual author, would be left out. The entire report writing 

process of the IPCC is subjected to extensive and repeated review by experts as well as 

governments. Consequently, there is at every stage full opportunity for experts in the 

field to draw attention to any piece of literature and its basic findings that would ensure 

inclusion of a wide range of views. There is, therefore, no possibility of exclusion of any 

contrarian views, if they have been published in established journals or other publications 

which are peer reviewed. 

We note that many of the concerns about the emails appear to be based on a 

misunderstanding of the importance of certain issues and how concerns raised about a 

specific issue or study relate to the fundamental conclusions reached through the 

assessment of hundreds of scientific studies; in other words a misunderstanding that 

results in an exaggeration of the importance of these issues. Our responses on these 

specific issues are provided in the relevant volumes of the Response to Comments 

document. As an example of overstatements regarding the events at CRU, many 

commenters and others have implied that the CRU dataset on global surface temperatures 

is “unique” or “the most important” or even “the basis for virtually all peer-reviewed 

literature.” These statements are incorrect. In fact, as we discuss in detail in Volume 2 of 

the Response to Comments document, the CRU data set is not unique (in fact, the other 

two data sets are developed by NASA and NOAA), and it there are multiple lines of 

evidence that support the conclusions reached in the assessment literature upon which we 

primarily rely. 

Additionally, the HARRY_READ_ME file is entirely concerned with the TS2.1 and 

TS3.0 products, which are not germane to the Endangerment Finding. The in-depth 

analysis of the e-mails and files provided in the Decision and this RTP document 

indicates that EPA was correct in its conclusions, reflected in the response above, that 

there were no issues in the CRU e-mails or the HARRY_READ_ME file that would 

materially change the Endangerment Finding. 

Comment (1-54): 

The Pacific Legal Foundation claims that “The ‘HARRY READ ME’ file may suggest 

that the data selected, used, and analyzed by CRU not only had substantial gaps but was 

also potentially irreparably compromised. See Appendix A, 10-21.” Peabody Energy and 

other petitioners also provided a large number of quotes. 

Response (1-54): 

Appendix A of Pacific Legal Foundation’s petition contains a large number of excerpts 

from HARRY_READ_ME. Most of the substantive excerpts are addressed in this 

section of the RTP. The majority of the comments included in the appendix provided by 

Pacific Legal Foundation are merely expressions of frustration or notes on the 

programming process that do not indicate “substantial gaps” or “irreparably 

84
compromised” data. In addition, as noted previously, this does not relate to the dataset 

used for the HadCRUT temperature record. 

A number of quotes provided by the petitioners are completely innocuous, such as a 

complaint about the number of files involved, a quote about naming two files with the 

same name, and a quote indicating “Harry’s” intention to start work on the final product. 

A large number of quotes bemoan inadequate documentation for the original code, but 

this is not an indication of “substantial gaps” or “irreparably compromised” data. One 

quote addresses a network crash: “The biggest immediate problem was the loss of an 

hour’s edits to the program, when the network died,” which is clearly not a problem 

related to the data produced by CRU. In some cases, the petitioners even quote 

statements that indicate success, such as “So let’s say, anomalies are done. Hurrah. 

Onwards, plenty more to do!” 

A large number of quotes address trivial errors that were quickly addressed. For 

example, one quote is the result of confusion about what number indicates missing data: 

“Harry” had been assuming that “-9999” indicated missing data, but the code for missing 

data was actually “-1999.” Running an analysis using the wrong missing data code 

resulted in “Harry’s” comment “Oh Tim what have you done, man?” But this was 

followed almost immediately by his parenthetical realization about the difference in 

codes. Another quote, “It’s botch after botch after botch,” refers to a file that had 

different units than the programmer had been expecting. Once he corrected his code to 

account for the proper units, this was not a problem. 

One quote provided was “Oh, GOD, if I could start this project again and actually argue 

the case for junking the inherited program suite.” But the very next line of the document 

(notably not highlighted by the petitioners) is “OK.. the .ann file was simply that it 

refuses to overwrite any existing one. Meh.” Again, this quote reflects frustration 

because the programmer was unfamiliar with the code, but this is not a problem with the 

data. The solution to the problem of the program not overwriting files is merely to allow 

overwriting of existing files, and HARRY_READ_ME clearly indicates that “Harry” 

figured out and fixed the problem immediately. 

A series of quotes result from the attempt by “Harry” to work on the precipitation 

database: e.g., “If the latest precipitation database file contained a fatal data error ... then 

surely it has been altered since Tim last used it to produce the precipitation grids?” In 

this case, the fatal data error was that one month of one year of data at one station had 

been corrupted and was providing a non-physical value. When that data point was 

removed, the program was able to read the data file. However, it appears that TS2.1 had 

used a different file without this corrupted data bit, and similarly, “Harry” appears to use 

a different version of the file later. Therefore, these quotes are about an inconsequential 

file (another example of messy, poorly documented code, but no evidence of flaws in the 

TS2.1 or TS3.0 output). 

A large number of quotes result from “Harry’s” work on merging the Australian Bureau 

of Meteorology (BOM) data with the CRU data. Because the Australian BOM changed 

85
formatting and coding for a number of their stations, this was a challenging process. The 

file indicates that “Harry” worked with the Australian BOM to resolve the majority of 

these issues. This is another example showing that the CRU researchers were working on 

quality control to properly merge a set of challenging datasets and succeeding in 

resolving a number of tricky issues. 

A number of quotes refer to an issue with Russian “rain day” data from one or two 

stations, where quality control procedures found indications that there are internal 

inconsistencies between data before a “missing block” in the 1980s and data after that 

missing block. This particular error in the data for these one or two stations may never 

have been resolved (it is unclear from the debugging file). For these stations, “Harry” 

stated, “although I can match WMO codes (or should be able to), I must check that the 

data correlate adequately,” indicating that he was doing the appropriate quality control 

for dealing with data provided by outside organizations. A few imperfect stations in a 

large dataset do not indicate that the data is “irreparably compromised.” Imperfect data is 

accounted for in the uncertainty analyses in the data. As stated in New et al. (1999), 

“Isolated errors and subtle inhomogeneities not detected during quality control do not 

have a significant effect at the regional scale.” 

In sum, petitioners have assembled a lengthy collection of quotes that do not support the 

broad conclusions they drawn. 

Comment (1-55): 

Peabody Energy provides the quote, “... this should all have been rewritten from scratch 

a year ago !” 

Response (1-55):

The programmer is complaining because some of the data is stored with longitudes from 

0 to 360 rather than the more standard longitudes that run from -180 (W) to +180 (E). In 

the next line of the file, the programmer discusses his solution to the formatting issue 

(“So, I wrote ‘revlons.for’”) which changes the data from one format to the other. Again, 

this does not indicate any flaws with the data or the products of this work, and the file 

indicates that the issue “Harry” encountered was solved, as were almost all the other 

problems identified in the HARRY_READ_ME file. In addition, this does not relate to 

the HadCRUT temperature data set used for a long-term temperature record. 

Comment (1-56): 

Peabody Energy provides the quote, “Am I the first person to attempt to get the CRU 

databases in working order?! !” 

Response (1-56): 

This quote appears to be referring to an intermediate database (postdating the CRU TS2.1 

product, as it includes more recent data than what was included in TS2.1), which had 

been assembled without checking for duplicate stations, and which apparently didn’t 

always have the same number of stations recording maximum daily temperatures and 

minimum daily temperatures. The programmer resolved both these problems by 

86
producing TS3.0. Therefore, this problem was not present in TS2.1 and was solved for 

TS3.0. In any case, these problems, if left uncorrected, would have led to missing or 

duplicate data, but there is no evidence that these problems would have led to any kind of 

bias. 

Comment (1-57): 

Peabody Energy states that it “does not have the resources to try to untangle the coder 

notes and the TS2.1/3.0 data files to determine the magnitude of the errors in those files. 

Given the state of the record at this point, the TS2.1/3.0 dataset and the HadCRUT3 cannot 

legitimately be relied on nor can any study or modeling which utilized these data.” 

Response (1-57): 

HadCRUT3 and TS2.1 and 3.0 are two different products. Peabody Energy and other 

commenters have not demonstrated that there are any problems with these databases 

that materially affect any conclusions based on the data. Imperfections with individual 

stations are to be expected when data is being collected from thousands of stations 

throughout dozens of nations, but the large-scale patterns are still robust (especially 

after quality control). While the code used to generate TS2.1 could have been better 

documented and organized, the petitioners have not shown that the output of this code 

was flawed or that the quality control improvements by the programmer “Harry” were 

not successful. The scientific conclusions drawn from use of these datasets by the 

research community are consistent with conclusions drawn from other similar datasets, 

as well as other sources of data on climatic changes over time. Therefore, the 

conclusion by Peabody Energy that these datasets cannot be relied on is not supported 

by our analysis of the underlying files. 

Comment (1-58): 

The Southeastern Legal Foundation claims that “The entire HARRY_READ_ME.txt file 

is so riddled with such damning admissions that there’s really little point in highlighting 

them all. The key conclusion is inescapable: no reasonable person can conclude that the 

models that CRU produced, and the datasets on which they were based, meet basic 

scientific standards for reliability, and therefore the IPCC analyses and projections cannot 

be said to be reliable, and therefore EPA’s incorporation of IPCC’s findings and 

conclusions must be reconsidered. Put differently, there is zero chance that CRU’s work 

could survive a Daubert challenge15 that was armed with the Climategate documents. 

Since CRU’s work would be inadmissible in federal court as junk science, it should not 

be relied upon by the EPA as the foundation of the most far-reaching and consequential 

action in its history.” 

Response (1-58): 

While the petitioner has quoted from HARRY_READ_ME at length, none of the 

statements in this file are “damning.” This file has demonstrated that the first version of 

the code was poorly documented, and that the process of integrating data from a large 

group of datasets provided by a number of different nations and sources is a challenging 

process. It also has demonstrated that CRU put a high value on tracking down and 

resolving inconsistencies in the data and being as complete as possible. The petitioners 

87
have not shown that the issues raised in the internal quality control process documented 

in this README file would have resulted in any major change in the TS2.1 product, or 

that they were not addressed properly in creating the TS3.0 product. Therefore, the 

characterization of this product as “junk science” has no factual backing. 

Moreover, the petitioner is making an unfounded leap to conclude that any problems 

involved with the TS2.1 and 3.0 products are also reflected in other CRU products. The 

TS product upgrade was unrelated to the HadCRUT temperature record. While the 

HadCRUT temperature record and the TS products include the GHCN temperature data 

set in common, there is no evidence that any of the issues discussed in the “Harry” file 

were related to the GHCN data set. CRU does not produce any models, counter to the 

claim of the petitioner. And finally, IPCC analyses and projections are based on a wide 

range of different sources and datasets that have produced consistent results, not just the 

CRU output. Therefore, the petitioner is making an unjustified leap to assume that any 

problems in the TS2.1 and TS3.0 product, or even CRU products as a whole, would 

undermine the conclusions of the IPCC, CCSP, National Academies, and other 

organizations that have all found after extensive assessments that there are robust 

conclusions about a number of aspects of the climate system. These robust conclusions 

are the ones that have formed the basis of EPA’s Findings, and nothing presented by the 

petitioner has materially undermined these conclusions. 

The reference to Daubert is unavailing. As described above, there is no basis to 

characterize this as "junk science." In addition, Daubert discusses the Federal Rule of 

Evidence 702, which establishes a threshold inquiry for introduction of scientific 

evidence at a trial, a formal adjudicatory proceeding. Even if that were applicable here, 

the criteria would be readily met: 

If scientific, technical, or other specialized knowledge will assist the trier of fact to 

understand the evidence or to determine a fact in issue" an expert "may testify thereto." 

(Emphasis added.) The subject of an expert's testimony must be "scientific . . . 

 knowledge." The adjective "scientific" implies a grounding in the methods and 

procedures of science. Similarly, the word "knowledge" connotes more than subjective 

belief or unsupported speculation. The term "applies to any body of known facts or to any 

body of ideas inferred from such facts or accepted as truths on good grounds." Webster's 

Third New International Dictionary 1252 (1986). Of course, it would be unreasonable to 

conclude that the subject of scientific testimony must be "known" to a certainty; 

arguably, there are no certainties in science. See, e.g., Brief for Nicolaas Bloembergen et 

al. as Amici Curiae 9 ("Indeed, scientists do not assert that they know what is immutably 

'true' -- they are committed to searching for new, temporary, theories to explain, as best 

they can, phenomena"); Brief for American Association for the Advancement of Science 

et al. as Amici Curiae 7-8 ("Science is not an encyclopedic body of knowledge about the 

universe. Instead, it represents a process for proposing and refining theoretical 

explanations about the world that are subject to further testing and refinement" (emphasis 

in original)). But, in order to qualify as "scientific knowledge," an inference or assertion 

must be derived by the scientific method. Proposed testimony must be supported by 

appropriate validation -- i.e., "good grounds," based on what is known. In short, the 

requirement that an expert's testimony pertain to "scientific knowledge" establishes a 

standard of evidentiary reliability. 509 U.S. 579, 589-90.. 

88
1.3.3.4 Claims of Selective Use of Data From Russian Weather Stations 

Comment (1-59): 

Petitioners state that the “Moscow-based Institute of Economic Analysis (IEA) claims the 

UK Met Office’s Hadley Center for Climate Change tampered with Russian 

meteorological station data that did not support the anthropogenic global warming 

theory.” The Southeastern Legal Foundation further states 

The Institute for Economic Analysis in Moscow prepared a report showing that selective 

use of only 25% of the available Russian stations in the HadCRUT dataset imparted a 

warming bias of .64 C o greater than the trend calculated using all available data. D’Aleo 

& Watts (2010) at p. 16. This results from the disproportionate use of more southern and 

urban stations, and from interpolating or ‘infilling’ data from these warmer stations to 

colder areas for which actually available data was eschewed. Id. at 16-17. Russia 

represents 11.5% of the Earth’s land mass, so this is a significant issue. 

Petitioners claim that CRU selectively chose Russian data stations to create a biased 

dataset that would show more warming than the full dataset. Petitioners provide a link to 

a translation (hosted at a blog) of the original report written in Russian by the IEA in 

Moscow (Pivovarova, 2009). 

Response (1-59): 

EPA has carefully examined this document and finds that it does not support the 

petitioners’ claims. The Moscow IEA temperature record derived from the full set of 

Russian stations agrees well with the record derived from the set of HadCRUT stations 

after 1955, and the difference between the records derived from the two datasets is 

mainly in the 1850 to 1950 section of the record, with the HadCRUT temperature record 

showing more warming over the period, but a smaller peak in 1940.47 The validity of the 

IEA analysis is suspect, however, due to flaws in the methodology it used. IEA averaged 

together the 90 grid cells containing temperature data from HadCRUT and compared it to 

an average of the 152 cells containing temperature data from the full Russian set. A 

proper comparison would involve using the same kind of geographic infilling used by 

HadCRUT in calculating temperatures across all of Russia on both the 90-cell and 152-

cell datasets. Because HadCRUT extrapolates temperatures from cells with data to some 

cells without data, when computing a regional or global average HadCRUT does not 

necessarily weight cells evenly; a cell with data that is adjacent to a cell without data will 

be used to help “fill” that cell in (along with other cells adjacent to the no-data cell), and 

therefore, this cell will be weighted more heavily than a cell that is surrounded by other 

cells that have their own data. The geographic weighting algorithm is more important 

when data is sparse, as it is in the decades before 1955 where the IEA finds that their 

analysis of the full station set diverges from their analysis using the HadCRUT stations 

(and where the Brohan et al. 2006 figure in Subsection 1.3.2 shows that there is more 

 

47 Figure 8 and Figure 9 in the original document at http://www.iea.ru/article/kioto_order/15.12.2009.pdf or 

in the unofficial English translation at http://climateaudit.files.wordpress.com/2009/12/iea1.pdf. 

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uncertainty in the temperature record). Because of the simplistic and flawed 

methodological approach taken by IEA, its analysis is a faulty “apples and oranges” 

comparison of the two datasets. 

We also note that there has been no evidence provided that the station selectivity was a 

result of choices made by CRU. Because CRU depends on a number of other data 

sources, such as WMO reports, World Weather Records, GHCN, and NMS, it is possible 

that the HadCRUT dataset did not use all available stations because the data sources it 

was relying on also did not include these additional Russian stations. CRU also uses 

several metrics to ensure that data can be used, such as the quantity of data available 

during the baseline period. The petitioners did not assess whether these additional 

Russian stations were provided to CRU, or whether these stations met the criteria laid out 

in published papers. Thus, there is no support for the claim that CRU was biased in its 

use of the Russian data. 

Moreover, in contrast to the petitioners’ assertion that the HadCRUT data show excessive 

warming over Russia, a discussion of a preliminary analysis reported by the MET stated: 

“The ECMWF [European Centre for Medium-Range Weather Forecasts] analysis shows 

that in data-sparse regions such as Russia, Africa and Canada, warming over land is more 

extreme than in regions sampled by HadCRUT” (UK Met Office, 2009). If the datasparse regions actually show a greater warming trend, this means that the approach for 

data infill taken by CRU in developing the HadCRUT temperature record may understate 

the recent warming over Russia, contrary to the assumption of petitioners. 

In summary, petitioners’ evidence does not support the conclusion that HadCRUT 

selectively picked stations. Their analysis comparing the HadCRUT data and the full 

Russian dataset is flawed, and the differences that they show with the flawed analysis 

mainly appear before 1950. Other analysis by the ECMWF suggests that HadCRUT may 

actually be underestimating recent warming in the region. 

1.3.4 Claims of Flawed Approach to Correct for Urban Heat Island (UHI) 

Effects 

Comment (1-60): 

Petitioners take significant issue with UHI corrections in the light of a dispute about the 

possible relocation of certain Chinese weather stations that were used in a study by Jones 

et al. (1990). Petitioners argue that this study was challenged as fraudulent by Doug 

Keenan, an “amateur climate analyst” (as described by the State of Texas). The State of 

Texas asserts: 

“The history of where the weather stations were sited was central to the 1990 paper 

because it concluded that the warmer temperatures in China were caused by climate 

change rather than the heat-island effect of growing cities” and that “[t]he Fourth 

Assessment relied on the Jones-Wang study to support the conclusion that ‘any urbanrelated trend’ in global temperatures was ‘an order of magnitude smaller’ than other 

trends.” 

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The State of Texas further alleges that “Although the university found ‘evidence of the 

alleged fabrication of results,’ it exonerated Wang.” The State of Texas finally notes that 

“Ironically, Phil Jones submitted a report to the Journal of Geophysical Research reexamining temperatures in eastern China. His report concluded that not only was the 

urban heat effect not ‘negligible’ it could account for 40% of the warming shown in the 

study.” 

Response (1-60): 

Petitioners raise the treatment of UHI effects in the HadCRUT dataset as another 

example of alleged data manipulation. EPA has long been aware of the UHI issue and it 

is not new. There is substantial research underway to better determine the scope and 

magnitude of UHI effects and to improve methodologies for minimizing these effects in 

surface temperature records. We addressed UHI issues in responses 2-28 through 2-30 of 

the RTC document. Response 2-30, in particular, addresses the Jones et al. (1990) paper 

to which the petitioners refer, in the context of UHI corrections in the global dataset: 

“Though the assessment literature continues to cite Jones et al. (1990), we dispute that it 

is solely ‘relied upon.’ Many subsequent studies (Peterson et al., 1999; Peterson, 2003; 

Parker, 2004; Peterson and Owen, 2005; Parker, 2006) have found supporting results (as 

discussed in response 2-28). In IPCC (Trenberth et al., 2007), Jones et al. (1990) is 

referenced as just one of a number studies which support the Trenberth et al. (2007) 

conclusion that ‘urban heat island effects are real but local, and have not biased the largescale trends’ which is summarized in the TSD.” 

As noted in Response 2-30, Jones et al. (1990) is referenced, but it is not the only study 

that the IPCC AR4 referenced with respect to UHI adjustments. We also note that 

satellite records are not susceptible to UHI and globally show similar trends to the 

HadCRUT and other records of land-based measurements over their overlapping time 

period. 

There is no merit in the petitioners’ claim that in a later paper Jones et al. (2008) 

published in the Journal of Geophysical Research, Jones found different results than in 

his previous study. This paper actually concluded that “accounting for site moves has no 

impact on the results given by Jones et al. (1990),” which is not supportive of the 

petitioners’ claim regarding the results of the study. Jones et al. (2008) did find that 

changes in UHI effects contributed to measured temperature trends in China over the full 

time period up to 2004, but this was because of data not available for the original study. 

They also found that UHIs did not contribute to measured temperature trends in other 

urban areas such as London and Vienna. So the claim that UHI effects bias the 

temperature record upward in all urban areas is not supported. 

We also note that this issue has been reviewed by other organizations. The University of 

East Anglia has also issued a statement on this controversy (University of East Anglia, 

2010b), stating that the accuracy of the data was confirmed in a later paper and that the 

findings of the 1990 paper with regard to UHI effects were confirmed by other papers 

used by the IPCC. In addition, contrary to the assertion by the State of Texas that “the 

university found ‘evidence of the alleged fabrication of results,’” the statement from the 

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University of Albany (as quoted in the news article used by the State of Texas as a 

reference—Pearce, 2010—and the linked copy of the confidential letter from the 

university) was “it found ‘no evidence of the alleged fabrication of results’ and 

exonerated him.” Therefore, the State of Texas is misquoting its source and asserting the 

exact opposite. 

In sum, contrary to the petitioners’ claims, as discussed in the TSD and the RTC for the 

Finding, UHI effects are not inappropriately treated or masked but instead are 

appropriately accounted for using widely accepted and transparent methods. The 

petitioners’ evidence and arguments do not show that the original Jones paper was 

mistaken or fraudulent, nor have they addressed the many papers on UHI effects in the 

subsequent two decades. We reviewed and responded to these same issues in Volume 2 

of the RTC document, and based on the available literature, we found that the UHI effect 

was small on a global scale 

1.3.5 Alleged Dependence of IPCC Conclusions on the HadCRUT 

temperature record 

Comment (1-61): 

Petitioners ascribe great significance to the alleged issues with the HadCRUT 

temperature record, claiming that it is the primary or core support for IPCC conclusions 

on current warming, attribution, and projections of future warming. For example, the 

Coalition for Responsible Regulation asserts: 

...the CRU data form the primary basis for EPA’s determination that ‘unprecedented’ 

warming has occurred in recent decades. 

Similarly, Southeastern Legal Foundation states: 

The CRU dataset constitutes one of the most important sets of information on which all 

analyses of anthropogenic global warming (“AGW”) are based. In addition, the model 

used by CRU formed the basis for IPCC’s models of future global warming. 

Response (1-61): 

EPA finds no merit in the view that the HadCRUT temperature record is the primary or 

core support on which our understanding of climate change rests. As we have previously 

discussed in the TSD and RTC document, the IPCC and USGCRP have concluded that 

warming of the climate system in recent decades is “unequivocal.” This conclusion is not 

drawn from any one source of data, but is based on a review of multiple sources of data 

and information, including the HadCRUT temperature record as well as additional 

temperature records from other sources and numerous other independent indicators of 

global warming. All of the different elements of this body of scientific evidence have 

their strengths and weaknesses, and these are discussed and explained in the TSD and the 

RTC. However it is this entire body of evidence considered together that is the primary 

and core support for EPA’s conclusions on warming. The overall consistency of the 

evidence of warming across multiple types of evidence is central to this conclusion. 

Petitioners have failed to consider or rebut this body of evidence, and instead have 

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focused on arguments aimed at one source of surface temperature record. As shown 

above, their arguments and evidence concerning the HadCRUT temperature record are 

misplaced and do not warrant any change in the weight placed on this one part of a much 

broader body of evidence. 

This consistency across various kinds of evidence of warming also supports the 

robustness of the evidence at issue here. As documented in Section 4(b) of the TSD, 

NOAA (from NCDC) and NASA temperature records (from GISS) show nearly identical 

warming trends to the HadCRUT temperature record, despite different analysis 

methodologies. As discussed below, satellite data and other methods of determining 

atmospheric temperature trends are also consistent with the HadCRUT and other surface 

temperature records, and the sources of atmospheric data are independent of the datasets 

relied upon for surface temperature records. 

Contrary to the Coalition for Responsible Regulation’s assertion, EPA does not refer to 

the warming observed in recent decades as being “unprecedented.” We do note the 

following facts, which are consistent across the NOAA, NASA, and HadCRUT 

temperature records in the TSD’s Box 4.1: 

 Eight of the 10 warmest years on record have occurred since 2001. 

 The 10 warmest years [on record] have all occurred in the past 12 years. 

 The 20 warmest years [on record] have all occurred since 1981. 

Significantly, entirely independent records of lower tropospheric temperature measured 

by both weather balloons (also known as radiosondes) and satellites (from the University 

of Alabama and Remote Sensing Systems) in recent decades demonstrate strong 

agreement with the HadCRUT surface temperature record as well as NOAA’s and 

NASA’s. Additional independently monitored indicators of global warming discussed in 

the TSD include: 

 Increasing global ocean heat content (Section 4(f) of the TSD) 

 Rising global sea levels (Section 4(f) of the TSD) 

 Shrinking glaciers worldwide (Section 4(i) of the TSD) 

 Changes in biological systems, including poleward and elevational range shifts of 

flora and fauna; the earlier onset of spring events, migration, and lengthening of 

the growing season; and changes in abundance of certain species (Section 4(i) of 

the TSD) 

Reaffirming this evidence, NOAA’s State of the Climate in 2009 report (Kennedy et al., 

2010) states: 

The IPCC conclusion (Alley et al. 2007) that “warming of the climate system is 

unequivocal” does not rest solely upon LSAT [land surface air temperature] records. 

These constitute only one line of evidence among many, for example: uptake of heat by 

the oceans, melting of land ice such as glaciers, the associated rise in sea level, and 

increased atmospheric surface humidity (Figure 2.5) [as shown below]. If the land 

surface records were systematically flawed and the globe had not really warmed, then it 

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would be almost impossible to explain the concurrent changes in this wide range of 

indicators produced by many independent groups. The observed changes in a broad 

range of indicators provide a self-consistent story of a warming world. 

The figure below (Figure 2.5 from Kennedy et al., 2010) illustrates a range of indicators 

that would be expected to correlate strongly with the surface temperature record. Note 

that stratospheric cooling is an expected consequence of GHG increases. 

In this figure, the indicators that we would expect to trend upward with surface 

temperatures (e.g. sea surface temperature, specific humidity) do so, and those that one 

94
would expect to trend downward (e.g., stratospheric ozone, sea-ice extent) also behave as 

the science predicts. It is this large body of evidence that supports the conclusion that 

there is an unambiguous warming trend over the last 100 years, with an increase in the 

rate of warming over the past 30 years. 

The investigation into the CRU e-mails and the validity of the HadCRUT surface 

temperature record conducted by the British Parliament’s House of Commons Science 

and Technology Committee reached a conclusion that is consistent with our own 

assessment of these issues (UK Parliament, 2009): 

We have established to the extent that a limited inquiry of this nature can, that the 

NCDC/NOAA and GISS/NASA datasets measuring temperature changes on land and at 

sea have arrived at similar conclusions using similar data to that used by CRU, but using 

independently devised methodologies. We have further identified that there are two other 

datasets (University of Alabama and Remote Sensing Systems), using satellite 

observations that use entirely different data than that used by CRU. These also confirm 

the findings of the CRU work. We therefore conclude that there is independent 

verification, through the use of other methodologies and other sources of data, of the 

results and conclusions of the Climate Research Unit at the University of East 

Anglia. [emphasis in the original] 

Thus, EPA finds that the Coalition for Responsible Regulation’s claim that the 

HadCRUT temperature record serves as the basis for all anthropogenic warming studies 

is unsubstantiated and unsupportable. Numerous studies cited in the assessment literature 

have been published that rely on data and methods independent of the HadCRUT 

temperature record, many pertaining to the indicators above. Though it is true that many 

studies do, in fact, cite CRU data, there is no reason to question the legitimacy of those 

studies. Petitioners have not provided a basis for changing the weight placed on the 

HadCRUT temperature record, as described above. In addition, the CRU results are 

consistent with other surface temperature records and atmospheric temperature records, 

as well as with all of the other physical evidence of warming. Even if there were a basis 

to place less weight on this one surface temperature record, it would be grossly overbroad 

to conclude that all studies that even reference this dataset would be suspect. 

The claim by Southeastern Legal Foundation and others that the HadCRUT temperature 

record is the foundation for computer modeling of the climate and that all climate models 

are thus suspect is also without merit. The models used to generate projections of future 

warming described in the IPCC AR4 do not use the CRU or other surface temperature 

data as an input. These projections of future temperatures arise from the use of 

Atmospheric-Oceanic General Circulation Models (AOGCM). These models are driven 

by physical equations describing the radiative properties and dynamics of the atmosphere 

and oceans and parameterizations of small-scale processes. They do not use observed 

CRU or other sources of temperature data as inputs. 

The projections of future warming come from the largest coordinated global, coupled 

climate model experiment ever attempted, providing the most comprehensive multimodel perspective of any IPCC climate assessment. A set of coordinated, standard 

95
experiments was performed by 14 AOGCM modeling groups from 10 countries using 23 

models. The HadCRUT and other temperature records may be compared with AOGCM 

output to assess how well the models replicate the observed climate, but temperature data 

are not input to these models. There is no “model” used by CRU that was used as a basis 

for the AOGCM models, and the AOGCM models do not rely on or use CRU analysis of 

historical temperature data. 

1.3.6 Summary 

The observed warming of the climate is an important factor considered in the 

Endangerment Finding. The Finding notes that this warming is observed in surface and 

ocean temperatures, atmospheric temperatures, melting of snow and ice, rising sea levels, 

and other physical indicators of warming. The Finding states, “The global surface 

temperature record relies on three major global temperature datasets, developed by 

NOAA, NASA, and the United Kingdom’s Hadley Center. All three show an 

unambiguous warming trend over the last 100 years, with the greatest warming occurring 

over the past 30 years.” The evidence and arguments relied on by petitioners do not 

show otherwise and do not support their broad assertions and conclusions. 

Petitioners have not presented any additional or different analysis of the underlying 

surface temperature data. They have pointed to computer work that involves work on a 

non-public document with no relationship to the Endangerment Finding, or CRU datasets 

other than the HadCRUT temperature record. The CRU datasets at issue had a tangential 

at best relationship to the TSD supporting the Endangerment Finding. The computer 

quality control on this unrelated dataset appears to be just that— comprehensive and 

successful quality control—and does not provide support for allegations that changes 

made were intended to or did bias the resulting dataset. Petitioners’ objections to the 

analysis of temperature data from Russia or China stations appear unfounded and 

speculative and not supported by the body of evidence. 

Certain reviews of CRU and its scientific work have been completed, and there continues 

to be additional independent investigation. EPA supports and appreciates that these 

reviews and investigations are being conducted and takes the results into consideration as 

they are released. The reviews that have been completed to date are consistent with 

EPA’s conclusions described above. 

EPA and the assessment reports have considered the degree of certainty in the various 

lines of evidence on the existence of warming, including the HadCRUT (Brohan et al., 

2006); NOAA (2009); and NASA (Hansen et al., 2010, submitted) temperature records; 

the satellite temperature records; and the observed changes in the global oceans, glaciers, 

and sea levels. Petitioners’ evidence fails to show that these sources of information are 

not credible and reliable. EPA continues to believe that this body of evidence indicates 

an unambiguous warming trend, when viewed as a whole, and that petitioners have not 

presented evidence that would indicate otherwise. EPA remains confident in the 

appropriateness of its overall scientific conclusion of a warming trend over the last 

100 years, with the greatest warming occurring over the past 30 years. This is based on 

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the multiple sources of consistent information indicating such warming, information 

including the three separate surface temperature datasets, as well as a wide variety of 

other data and information independent of the three surface temperature datasets. This 

broad body of evidence is stronger than any one single source of data. Neither the 

evidence presented by petitioners and reviewed by EPA, nor the existence of an ongoing 

review of the CRU and its work, warrants a change in the scientific conclusion drawn by 

EPA concerning the existence of global warming. 

1.4 Validity of NOAA and NASA Temperature Records 

1.4.1 Overview 

A number of petitioners (e.g., Competitive Enterprise Institute, the Southeastern Legal 

Foundation, Peabody Energy, the State of Texas, Pacific Legal Foundation, 

Commonwealth of Virginia, Coalition for Responsible Regulation) question the validity 

of NOAA and NASA surface temperature records. As discussed in detail below, they 

raise a number of claims, including station “drop-out,” flawed or manipulative 

adjustments to data, improper use of smoothing in data presentations, and a lack of 

independence between the three major surface temperature records. To support their 

arguments, the petitioners reference a number of studies—two peer-reviewed and several 

non-peer-reviewed—and in one case provide a quote from the CRU e-mails. 

Many of the issues raised by the petitioners were also raised in comments and responded 

to in the Endangerment Finding. Several of the petitioners’ arguments have already been 

convincingly rebutted in the peer-reviewed literature or by the organizations in question. 

In these cases, petitioners have failed to acknowledge these rebuttals and have not 

provided any additional explanation for why their concerns remain valid. In addition, 

many of the sources on which petitioners rely are not peer-reviewed and use highly 

flawed methodologies. In some cases, petitioners have provided additional arguments or 

new information, which we have reviewed and evaluated. Upon review, petitioners’ 

evidence and arguments do not support the conclusions they draw, and do not materially 

change the credibility or reliability of the NOAA and NASA global temperature record or 

the conclusions drawn from them. 

The remainder of this section includes background on the scientific issues being 

discussed, a description of the petitioners’ arguments, and EPA’s responses. 

1.4.2 Background on the Collection and Analysis of Surface Temperature 

Data 

There are two steps to creating a global surface temperature record. The first is to collect 

the raw weather data, and the second is to process the data into a useable form. As 

described in Subsection 1.3.2 of this document, the CRU team, over several decades, 

acquired and merged data from a number of different sources and then applied 

corrections and geographical smoothing algorithms as appropriate to generate the 

HadCRUT temperature record. Petitioners’ claims regarding the HadCRUT temperature 

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record are responded to in Section 1.3 of this document. Here, we discuss petitioners’ 

claims related to the NASA and NOAA surface temperature records, including claims 

that alleged problems with the HadCRUT temperature record also undermine the 

reliability and credibility of the work by NASA and NOAA. A list of temperature 

records and underlying datasets are also provided in Subsection 1.3.2 of this document. 

One of the sources of data for the HadCRUT temperature record is the GHCN, which was 

developed and is maintained by NOAA’s National Climatic Data Center (NCDC). The 

GCHN dataset is also used by both NOAA and NASA in their surface temperature 

records. NOAA, NASA, and CRU each have their own algorithms to calculate global 

surface temperature trends from a combination of GHCN data and other data sources, 

with each group applying its own set of adjustments and corrections. Subsection 1.3.2 of 

this volume describes the process used to develop the HadCRUT temperature record and 

algorithms; this section will describes the GHCN and the approaches used by NOAA and 

NASA to develop their temperature records. 

The original version of GHCN is described in Vose et al. (1992). Version 2 is described 

in Peterson and Vose (1997). In this paper, Peterson and Vose describe how they 

collected data from 31 sources by “1) contacting data centers, 2) exploiting personal 

contacts, 3) tapping related projects, 4) conducting literature searches, and 5) distributing 

miscellaneous requests” because of the lack of a central repository of temperature and 

climate data. The raw GHCN dataset underwent quality control, which included merging 

data that was provided by different sources for the same weather station. In many cases, 

however, multiple duplicates of the same station are included in the record where the 

original data was not identical, so as to let users determine the best approach to merging 

these sources. The next quality control step involved rejecting datasets that did not 

include original observations, were derived from unreliable sources, or showed 

significant processing errors. Another step corrected mis-located stations, data that was 

repeated month to month, or unexplained discontinuities. A final stage examined 

outlying data—in cases where the data failed additional tests, they were kept in a separate 

file in case later researchers wanted to reincorporate them. Only three of the 31 sources 

used provide regular updates of additional monthly data. 

NOAA (NCDC) (NOAA, 2009) and NASA (Goddard Institute of Space Studies or GISS, 

or sometimes GISTEMP) (Hansen et al., 2010, submitted) both use GHCN and other data 

(including sea surface temperature data) to calculate surface temperature trends around 

the globe. Each group performs different adjustments to the data in building their 

temperature records, and in some cases uses different subsets of the GHCN data or 

includes other outside datasets. As stated by Hansen et al. (2010, submitted): 

These analyses are not independent, as they must use much of the same input 

observations. However, the multiple analyses provide useful checks because they 

employ different ways of handling data problems such as incomplete spatial and temporal 

coverage and non-climatic influences on measurement station environment. 

For example, the NASA algorithms include an adjustment to urban temperature stations 

based on satellite maps of nighttime lights and uses the fact that temperature anomalies 

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measured at a specific spot are correlated with anomalies up to 1200 kilometers away to 

extrapolate measurements over large areas where the observations are sparse (giving 

greater coverage in certain areas such as the Arctic). The adjustments that NOAA and 

NASA make to the unadjusted GHCN dataset are almost all automated, in contrast to 

some of the adjustment procedures used in the HadCRUT temperature record. In the case 

of NASA, there were two stations (St. Helena Island and Lihue, Hawaii) where manual 

adjustments were made because of detected errors and the lack of neighboring stations 

that could be used by the automated algorithms. In both cases, the raw data shows more 

warming than the adjusted data. 

The U.S. Historical Climate Network (USHCN) temperature record developed by NOAA 

and used by both NOAA and NASA uses a slightly different methodology than the 

adjustments used by NOAA for the global GHCN dataset. The most important difference 

is that NOAA corrects for several systematic changes in the U.S. monitoring system that 

could lead to artificial biases, the most important of which are shifts from afternoon to 

morning temperature data collection at many stations, and shifts from “liquid in glass” 

(LiG) measurement instruments to maximum/minimum temperature systems (MMTS) 

(described in Menne et al. 2009). USHCN2 uses a sophisticated automated methodology 

to detect and correct for discontinuities in the temperature data at specific stations such as 

these shifts in measurement time or instrumentation, and this methodology also corrects 

for station moves (whether documented or not). 

GHCN data are available online, both in the unadjusted (raw) format and in an adjusted 

format that includes the automated corrections by NOAA (NOAA, 2010c). Similarly, the 

NASA-adjusted data is all available online along with the GHCN data used to derive the 

adjusted dataset (NASA, 2010a). 

1.4.3 The Petitioners’ Arguments and EPA Responses 

1.4.3.1 Assessment of Issues Related to Alleged Station Dropout and 

Inappropriate Extrapolation 

Comment (1-62): 

Petitioners raise a number of issues regarding the alleged “drop-out” of stations after 

1990 from surface temperature records, and the extrapolation of data from “warmer” 

areas to “colder” areas due to this drop-out or for other reasons, which the petitioners 

claim leads to bias in the global surface temperature record. The Competitive Enterprise 

Institute cites a non-peer-reviewed report by D’Aleo and Watts (2010), which states: 

“Around 1990, NOAA began weeding out more than three-quarters of the climate 

measuring stations around the world. They may have been working under the auspices of 

the World Meteorological Organization (WMO). It can be shown that they systematically 

and purposefully, country by country, removed higher-latitude, higher-altitude and rural 

locations, all of which had a tendency to be cooler.” 

Petitioners argue that station dropout (from 6,000 in the 1970s to about 1,500 currently) 

“likely contributed to false warming trends over the entire globe”—in part because the 

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dropped stations “are generally in colder climates” or because “remaining stations were 

biased towards lower latitudes, lower elevations, and urban locations.” 

Petitioners also cite the specific example of Bolivia, where they claim that GHCN has no 

data collection but shows interpolated warming there that “is purely an artifact of 

interpolation from distant warmer and lower altitude stations.” The petitioners claim that 

station dropout is also a problem in the United States, stating, “The USHCN has dropped 

90% of its climate stations. Most of the remaining stations are at airports, and in the west 

most of the higher elevation stations are gone. In California, the only remaining stations 

are in San Francisco, Santa Maria, Los Angeles and San Diego.” Finally, the 

Southeastern Legal Foundation states, “Infilling from warmer temperature stations to 

colder grid cells for which no actual data is collected also imparts a spurious warming 

signal.” 

Response (1-62): 

Many of the petitioners’ arguments rest on a non-peer-reviewed document by D’Aleo and 

Watts (2010). D’Aleo and Watts’ (2010) study contains a number of inaccurate 

statements, and relies on a scientifically flawed analysis. 

Peterson and Vose (1997) describe the procedures for updating the GHCN database, and 

explain—in a clear and transparent manner—the reasons why there are fewer measuring 

stations covering the post-1992 period than there were for the 1980s. Namely, Peterson 

and Vose explain that only three out of 31 sources submit regular monthly updates, and 

that the remainder of the data would only be updated on “a highly irregular basis”: 

Thirty-one different sources contributed temperature data to GHCN. Many of these were 

acquired through second-hand contacts and some were digitized by special projects that 

have now ended. Therefore, not all GHCN stations will be able to be updated on a 

regular basis. Of the 31 sources, we are able to perform regular monthly updates with 

only three of them (Fig. 5). These are 1) the U.S. HCN, 1221 high quality, long-term, 

mostly rural stations in the United States; 2) a 371-station subset of the U.S. First Order 

station network (mostly airport stations in the United States and U.S. territories such as 

the Marshall and Caroline Islands in the western Pacific); and 3) 1502 Monthly Climatic 

Data for the World stations (subset of those stations around the world that report 

CLIMAT monthly code over the Global Telecommunications System and/ or mail reports 

to NCDC). Other stations will be updated or added to GHCN when additional data 

become available, but this will be on a highly irregular basis. 

Therefore, the reduction in stations with data after the 1990s is due to the fact that NOAA 

has not completed a major data collection effort since Peterson and Vose (1997). We 

note, however, that such an effort is indeed currently ongoing and will result in a new 

dataset—GHCN Version 3—likely in late 2010. In contrast to this public explanation of 

the GHCN process, D’Aleo and Watts provide no evidence that there was a systematic 

and purposeful “weeding out” process, and do not address the reasoning and process 

described in the public, peer reviewed documentation of the GHCN data set. 

The petitioners, by relying on the flawed methodology used in the D’Aleo and Watts 

study, have assumed that dropping stations that are at higher latitudes and in colder 

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climates would result in a biased, warmer temperature trend. This is an unfounded 

assumption that is based on a misunderstanding of the basic methodology used in 

analyzing surface temperature data. The surface temperature datasets evaluate the change 

in temperature over time at the various stations (the temperature “anomaly”), and do not 

base their evaluation on the absolute temperature level, as discussed in Subsection 1.3.2. 

This use of temperature changes or anomalies minimizes localized differences in absolute 

temperature and makes the resulting temperature record relatively insensitive to addition 

or removal of stations. This is because of the correlation of temperature changes over 

distances. 

In fact, theory predicts that high latitudes and colder climates will warm more rapidly 

than low latitudes and warmer climates. Thus, the change in temperature at higher 

latitude or colder climates should tend to indicate greater warming than elsewhere, and 

dropping those stations would thus tend to lead to underestimating the resulting trend not 

overestimating it (although as long as there are at least a couple of stations in any region, 

the correlation of temperature measurements over hundreds of kilometers should also 

reduce this potential bias). We previously responded to comments on this issue in 

Volume 2 of the RTC document (2-36). The petitioners incorrectly assume and do not 

explain why dropping these stations would bias the trend in the change in temperature 

toward greater warmth. 

An analysis (Clear Climate Code, 

2010) used an emulation of the 

NASA GISTEMP code to only 

output the data from those stations 

that kept reporting data after a 

given year, or only output data

from stations that stopped reporting

data after that year. A graph from 

this analysis is shown here, where

the blue line is a graph of global 

land temperatures (no ocean data) 

from stations that “dropped out” 

before 1992, and the red line is the

same analysis but only from 

stations that were still reporting past that date. As can be seen in the graph, the difference 

between the two groups of stations is very small in modern times. Differences are larg

pre-1945 because there are a smaller number of stations, especially in the southern 

hemisphere, so taking a subset of a small number of stations increases the potential fo

errors due to insufficient coverage of the land surface (the increased uncertainty in early 

20th century temperatures can be seen in the Brohan, 2006 figure reproduced in Section 

1.3.2 of this d

er 

r 

ocument). 

This graph shows that the station drop-out issue which many petitioners raise has not 

imparted any kind of “spurious warming signal.” This analysis and graph were 

produced as part of the Clear Climate Code project, an independent project which 

101
involved the replication the NASA GISTEMP code in Python. We have independently 

verified this analysis. Much like the Independent Climate Change Email Review creation 

of a surface temperature record from public data in two days, the ability of the group 

working on this project to exactly reproduce the NASA temperature record and then 

apply the same code to new analysis demonstrates the overall availability, transparency, 

and utility of public code and data which enable any scientist to examine the issues 

involved in developing temperature records. 

It also appears that D’Aleo and Watts failed to account for the methodologies used by 

NOAA, NASA, and HadCRUT to create a record of the trend in changes in global 

temperature, called anomalies. These methods determine the change in temperature at 

various stations and then average the temperature changes; they do not average the 

absolute temperatures of the stations. Thus, dropping colder stations does not make the 

resulting record of the change in temperature warmer unless the change in temperature at 

colder stations is lower than the change in temperature at warmer stations. As discussed 

previously, this does not appear to be the case, and scientific literature in general 

indicates that the opposite is true (the change in temperature in colder, higher latitude 

regions is generally larger that at warmer, lower latitude regions). 

In contrast, the D’Aleo and Watts analyses use a scientifically improper methodology to 

evaluate the change in temperature over time. They determine simple averages of the 

absolute temperatures at the stations—without, apparently, taking into account their 

geographic distribution, much less calculating the change in temperature at the stations 

(the anomalies). As discussed in the science background in Subsection 1.3.2 on 

HadCRUT, two nearby stations can have very different absolute temperatures but very 

similar anomalies or changes in temperature, which is one reason why using changes in 

temperature is a more correct method than using absolute temperatures. In addition, not 

taking into account the geographic distribution of stations leads to overweighting those 

regions with many temperature records, such as the United States, rather than weighting 

each area of the globe equally in order to determine the global average temperature. 

These are both significant errors that undermine the petitioners’ critique of the 

temperature records. 

With respect to Bolivia, the NASA temperature record does not appear to have any data 

for Bolivia after 1990. The reason is likely because stations in Bolivia have not been 

reporting through the CLIMAT network. However, there is no merit to the argument that 

extrapolating temperature changes or anomalies from bordering countries will create a 

warming bias in Bolivia because those countries are warmer than Bolivia. As already 

explained, the issue is not the absolute temperature, but rather temperature trends that 

have been shown to be correlated over large distances. The petitioners provide no data to 

support that neighboring countries are warming faster than Bolivia, rather than being 

warmer in an absolute sense. 

There is no factual basis for the petitioners’ claim that the USHCN has dropped 90% of 

its stations. As demonstrated in the following Figure (Number of U.S. HCN stations with 

102
temperature records) from Menne et al. (2009), the station coverage in the past few years 

is only slightly lower than the peak coverage: 

Similarly, the claim that only four stations are reporting from California conflicts with the 

NOAA temperature record for California (NOAA, 2010), which shows more than 40 

stations in California with data in 2009. 

Finally, we also note that the station dropout comes during the period when satellite data 

are available. As noted in the TSD, “The satellite tropospheric temperature record is 

broadly consistent with surface temperature trends,” confirming that the reduction in the 

raw data reported from weather stations has not created a warming bias in the surface 

temperature dataset. 

Comment (1-63): 

The Southeastern Legal Foundation, in their Third Amendment to Petition, discussed the 

issue of “station drop-out” at length: 

“Station drop-out” refers here to the precipitous decline in the number of temperature 

records included in the GHCN dataset. In the 1970’s more than 6000 stations were active. 

Today the figure is 1500 or less. D’Aleo & Watts, p. 10, n. 94 The following graph, 

prepared by Ross McKitrick5

 shows the relationship between station drop-out and 

average temperature, where “Average T” is a mean of raw unprocessed temperature data, 

and No. of Stations. 

103
D’Aleo & Watts, p. 11. See http://www.uoguelph.ca/~rmckitri/research/nvst.html (last 

visited Feb. 10, 2010) for a full explanation of this chart, and access to data it represents. 

This chart shows that the station drop out coincides with a sharp and significant increase 

in average raw temperature, and thus suggests that the change in temperature is the result 

of sampling bias and not climate change. 

The stations that were dropped were disproportionately rural. D’Aleo & Watts, p. 11-12. 

Further, the remaining stations were biased towards lower latitudes, lower elevations, and 

urban locations. Id., citing E.M. Smith6

, http://chiefio.wordpress.com/2009/11 /03/ghcnthe-global-analysis/ (last visited Feb. 10, 2010). All of these tendencies away from

random sampling impart a warm bias to the record. D’Aleo & Watts show that station 

drop out has occurred all over the world, but the greatest station drop-out has occurred in 

Siberia and Canada, where these global temperature datasets purport to show the greatest 

warming has occurred. 

Response (1-63): 

In the previous response, EPA addressed petitioners’ allegations that weather station 

dropouts have led to a warming bias in the temperature record. As described above, 

1) petitioners rely on a non-peer-reviewed source that contains a number of inaccurate 

statements and relies on a scientifically flawed analysis; 2) petitioners demonstrate a 

fundamental misunderstanding of how to determine a warming or cooling trend from a 

temperature record and what issues actually would lead to either a warming or cooling 

bias in that record; and 3) petitioners fail to acknowledge that climatic records other than 

land surface temperature records also show clear warming trends consistent with the 

trend shown by the surface temperature data. 

The graph submitted by the petitioner shows the absolute temperature averaged across all 

the stations existing at any given point in time, which has no real physical meaning—

proper analysis averages the changes of station temperatures across a set of stations. 

Additionally, the analysis should take into account station location when making global 

104
average rather than weighting every station equally. Equal weighting tends to introduce a 

bias by overweighting regions with many stations. 

Comment (1-64): 

The Competitive Enterprise Institute states that D’Aleo and Watts found that “NASA 

modified 20% of the historical record 16 times in two and one-half years ending in 2007” 

and that every modification “resulted in temperature trends that appeared to increase 

faster than they did in reality.” 

Response (1-64): 

EPA’s review of the information provided indicates that the Competitive Enterprise 

Institute’ statement that “every instance of manipulation resulted in temperature trends 

that appeared to increase faster than they did in reality” is not supported by D’Aleo and 

Watts (2010) or by Goetz (2010), the source on which D’Aleo and Watts rely. On the 

contrary, D’Aleo and Watts (2010) state: “John Goetz showed that 20% of the historical 

record was modified 16 times in the 21⁄2 years ending in 2007. 1998 and 1934 ping pong 

regularly between first and second warmest year as the fiddling with old data continues.” 

The Web page with the Goetz analysis states, “I will note that the overall trend in 

changes between now and Sep. 24, 2005 is very close to zero” (Goetz, 2010). This 

contrasts with the assertion by the Competitive Enterprise Institute that these changes to 

the temperature record always resulted in a warmer trend. The petitioners evidence does 

not support their claim of manipulation with the intent to bias the temperature record 

inappropriately. 

Comment (1-65): 

The Competitive Enterprise Institute also cites D’Aleo and Watts: 

In late January 2010, the findings of D’Aleo, Watts, and Smith were confirmed by 

investigative journalists. They found, for example, that in the 1980s 600 Canadian 

monitoring stations were used in the NOAA dataset. Now only 35 are used, with only one 

above the Arctic Circle. Yet, Environment Canada reports that the government maintains 

1400 stations with over 100 above the Arctic Circle. 

Response (1-65):

According to Environment Canada, there are 1480 stations with climate normals in 

Canada. Of these stations, only a subset (about 140) are marked as reporting data 

through the CLIMAT system (WMO, 2010). As noted in the Section 1.4.2 of this 

document, Peterson and Vose (1997) finished their data collection effort in the mid 

1990s. As part of this collection effort, they integrated historical data from hundreds of 

Canadian stations. The main source of updated data since this collection effort has been 

the automated CLIMAT reports. Therefore, the weather stations that do not produce 

CLIMAT reports would not be expected to be included in GHCN records for the past 

decade—this includes the majority of the Canadian stations. The NOAA GHCN dataset 

does contain data from 49 stations in Canada. Because many of the Canadian stations 

that report CLIMAT data only started doing so recently, they do not have the minimum 

quantity of data during the baseline period (1961 to 1990) to be included in the 

GHCN dataset. Given that Jones (1994) found that only 100 well-placed stations 

105
around the world would be sufficient to determine hemispheric average trends, 49 

stations within Canada should be more than sufficient for determining large-scale 

trends. 

1.4.3.2 Issues Raised With Respect to Adjustments for the UHI Effect 

Comment (1-66): 

Petitioners assert that the UHI adjustments performed by NASA are insufficient or 

improperly applied, both globally and in the USHCN. The State of Texas claims, “But 

according to the TSD, the CRU’s temperature data ‘applies an urbanization adjustment,’” 

and therefore “the CRU temperatures cited by both the IPCC and EPA do not reflect 

temperatures that were actually captured by weather station thermometers, but rather 

temperatures that have been recalculated by the CRU for one purported scientific reason 

or another.” The Southeastern Legal Foundation objects that Version 2 of the USHCN 

record does not correct for UHI, that “The notion that there is zero urban heat island 

effect in Manhattan is not valid,” and that NASA UHI adjustments have the wrong sign 

based on an analysis by D’Aleo and Watts (2010) of the Puerto Maldon station in Peru. 

The Southeastern Legal Foundation points to an analysis of UHI adjustments by the 

Science & Public Policy Institute (Long, 2010). The petitioner quotes from the study,

“Thus, the adjustments to the data have increased the rural rate of increase by a factor of 

5 and slightly decreased the urban rate, from that of the raw data,” and states that 

therefore, “The consequence, intended or not, is to report a false rate of temperature 

increase for the Contiguous U.S.” Additionally, the Southeastern Legal Foundation 

claims that a project—surfacestation.org—has shown that 90% of stations in the United 

States “were sited in ways that result in errors exceeding 1°C.” 

Response (1-66): 

The Long (2010) study cited by petitioners averaged together 48 rural stations (one per 

state) in the continental United States and compared them with 48 urban stations (one per 

state). Based on this method, Long found that the net effect of NOAA adjustments to the 

raw data had little effect on temperature trends for urban stations but led to more 

warming in rural stations. However, neither the petitioners nor Long analyze the reasons 

for the adjustments to rural stations or present any reason or argument indicating that the 

adjustments were inappropriate. Their sole argument is that the result of the adjustment 

must mean the adjustment was wrong. However it is the reason behind the adjustment 

that determines its validity, not the result of the adjustment. In the United States, the time 

of day at which temperature observations were made was changed at some stations. This 

change of observation time is known to introduce a nonclimatic trend into the raw data 

that would create apparent cooling if uncorrected (Vose et al. 2003). These time of 

observation changes were mostly limited to rural stations in the United States. Therefore, 

the warming adjustments found in rural stations by Long are likely the result of the 

correction of this “time of observation bias.”48 

 

48 Time of observation bias refers to the fact that if temperatures were recorded at noon for one year, but at 

8 a.m. for another year, there needs to be an adjustment to make them consistent. 

106
With regard to the objection that some temperature records do not correct for the UHI 

effect, we responded to a very similar comment when finalizing the Endangerment 

Findings. Response 2-28, notes, “The different surface temperature datasets shown or 

cited in the TSD all account for urbanization, either directly and/or indirectly.” The 

claim that NASA makes corrections of the wrong sign, using Puerto Maldon as an 

example, does not take into account the homogenization routine that NASA employs that 

uses neighboring stations to correct station data. Under that routine, stations identified as 

urban are automatically shifted to come into agreement with the neighboring stations. 

These automated homogenization routines use the fact that temperature changes over 

time (i.e., anomalies) are correlated over distances to correct for things like weather 

station moves and other changes of the immediate environment of a weather station. 

These changes, as explained in NASA’s documentation, can be either positive or 

negative. 

The argument by the State of Texas that these temperature records “do not reflect 

temperatures that were actually captured by weather station thermometers” is without 

scientific merit as the adjustments are appropriate and necessary either because of station 

moves, changes in time of observation, urbanization, or other reasons. If changes such as 

switching from afternoon measurements to morning measurements were not corrected, 

then the temperature record would not accurately reflect the surface temperature reality. 

We also note that overall, these adjustments have had little effect on the global 

temperature trends. This can be seen in the two GHCN figures included below, one 

based on adjusted data and one based on the unadjusted, raw data. Adjustments are more 

important on a local basis. Also, within the United States itself, adjustments have more 

importance because of the need to correct for systematic changes in the time of 

observations and measurement instruments that were more widespread in the United 

States than elsewhere. 

107
GHCN Figure showing temperature record using adjusted data. 

 GHCN Figure showing temperature record using raw data. 

With regard to the surfacestation.org analysis, this was addressed in depth in response 2-

27 of the RTC document for the Endangerment Findings. EPA found that “NOAA has 

provided extensive information to the public in response to the concerns raised by the 

commenters, available at http://www.ncdc.noaa.gov/oa/about/response-v2.pdf (NOAA 

Climate Services, 2009).” NOAA stated in this document, “A peer-reviewed study 

specifically quantified the potential bias in trends caused by poor station exposure 

(Peterson, 2006). The analysis examined only a small subset of stations – all that had 

their exposure checked at that time – and found no bias in long-term trends.” Since the 

publication of the RTC document, another analysis by Menne et al. (2010) has also 

concluded that well-sited stations give a trend similar to the full set of stations, therefore 

108
providing further evidence that poorly sited stations have not undermined the final 

temperature record. The surfacestation.org analysis estimated station errors by visual 

inspection, not by measuring actual temperatures. In addition, the station error visual 

rating method results in estimated errors for absolute temperatures, not for changes in 

temperature. Therefore, methodologies using changes in temperature that average across 

a large number of stations could be expected to have much smaller errors than the error in 

absolute temperature at any individual station. This projection of small errors for largescale trends was confirmed by the analyses by Peterson (2006) and Menne et al. (2010). 

Comment (1-67):

The Southeastern Legal 

Foundation, in their Third 

Amendment to Petition, objects 

to the changes in the USHCN 

temperature record between 

Version 1 and Version 2. To 

support this argument, they 

present several graphs. The 

first is a temperature graph 

from D’Aleo and Watts (2010) 

attributed to James Hansen in 

2010. 

The petitioner states that the 

20th-century record was 

“misrepresented” in order to “exaggerate a 20th century warming trend and claim it was 

caused by AGW [anthropogenic global warming].” They object to the replacement of the 

UHI adjustment used in Version 1 of the USHCN with the “change point algorithm” used 

in Version 2 because the petitioners claim that while this algorithm can detect abrupt 

changes it “cannot account for long term changes to the temperature record, such as UHI, 

making such signals indistinguishable from the climate change signal that is sought.” 

The petitioner provides another chart 

from D’Aleo and Watts (2010) showing 

the difference between USHCN Version 

1 and Version 2 (Figure USHCN V2-

V1). 

The petitioner objects: “The warming of 

the 1930’s has been minimized by 

negative adjustments, and the recent 

warming has been exaggerated by 

positive adjustments (or by failure to 

properly adjust for urban heat islands), 

thereby imparting to the 20th century a 

warming trend that the raw data and 

109
rural stations do not show.” 

A third chart that the petitioner provides related to this issue is one showing the 

adjustments to the temperature record in Central Park in New York City, stating: “The 

notion that there is zero heat island effect in Manhattan is not valid.” 

 

The petitioners note that GISS uses a different procedure: 

The GISS temperature dataset maintained by NASA retains an urban heat island 

adjustment for the US, and for this reason diverges from USHCN. Between 1950-2008, 

the trend difference between GISS and USHCN is approximately 0.7 F°/century. See id. 

at 42-43. The asserted warming trend over the 20th century is 0.74 ± 0.18°C (TSD p. 27). 

However, for the rest of the world, the GISS UHI adjustments have the wrong sign. Id. At 

47-50. As summarized by D’Aleo & Watts, there is compelling evidence that the 20th

century surface temperature record has been improperly adjusted downward during the 

warming of the 1930’s, and improperly adjusted upward (or not adjusted for UHI) in the 

late 20th century warming. These improper adjustments and failures to adjust impart a 

spurious warming signal to the 20th century temperature record and render it scientifically 

invalid and unreliable for use in the EPA’s Endangerment Finding. 

Response (1-67): 

The changes between USHCN Version 1 and Version 2 are well documented. This 

documentation shows that the changes between the two versions in the past 50 years are 

not related to any changes in how the USHCN versions address the UHI effect (although 

the UHI adjustment change is important pre-1960). In their analysis, the petitioners do 

not account for the valid corrections to the data for dates after 1995 due to a lack of 

correction for known instrumentation changes. Furthermore, the petitioners make 

assertions about NASA adjustments that are not supported by the underlying document 

they cite, and that show a misunderstanding of the purpose of the NASA algorithms. 

110
Figure 11 in Menne et al. (2009) shows an analysis of the differences between the various 

USHCN versions. 

The changes between the two versions after 1995 are a result of the fact that USHCN 

Version 1 had not updated its data to correct for changes in measurement instrumentation 

at some weather stations after that date. 

An analysis of gradual trends (like those expected from the UHI effect) by Menne et al. 

(2009) found that in some cases the fully adjusted HCN Version 2 did remove trends at 

the station when compared with its neighboring stations (including a specific example of 

Reno, Nevada). Additionally, when comparing the HCN network with the larger 

Cooperative Observer Program (COOP) Network, the analysis found that trends in the 

HCN network were more likely to be cooler than warmer than the trends in the COOP 

network. Finally, Menne et al. calculated a trend from the 30% of stations that were 

identified as being most urbanized and found that the trend from these urbanized stations 

was actually slightly smaller than the trend from the remaining stations. These analyses 

suggest that the USHCN Version 2 methodology is appropriately accounting for UHI 

trends. 

With regards to the assertion that outside of the United States the NASA UHI 

adjustments “have the wrong sign,” the petitioners ignore the clearly documented 

methodology regarding the NASA adjustments, and they make unsupported 

extrapolations of the non-peer-reviewed literature that they are quoting. 

A discussion of the data sources and routines used by NASA to produce the GISS 

temperature record can be accessed on the NASA website (NASA 2010b). As stated on 

this site, the urban homogenization adjustments are designed to address a changing 

urban environment—whether “warming or cooling”: 

111
The goal of the homogenization effort is to avoid any impact (warming or cooling) of the 

changing environment that some stations experienced by changing the long term trend of 

any non-rural station to match the long term trend of their rural neighbors, while retaining 

the short term monthly and annual variations. If no such neighbors exist or the overlap of 

the rural combination and the non-rural record is less than 20 years, the station is 

completely dropped; if the rural records are shorter, part of the non-rural record is 

dropped. 

What this documentation states is that NASA’s methodology replaces the long-term trend 

of any “urban” station (as identified by nightlights) with the trend of the neighboring 

rural stations, regardless of whether these rural stations are warming faster or slower than 

the urban station. If there are no neighboring rural stations, the urban station’s trend is 

not used at all. Therefore, the existence of some stations that are adjusted to have a larger 

warming trend is consistent with the documentation. 

The implication by the petitioners that all of the NASA adjustments outside the United 

States lead to greater warming than the unadjusted data would show is without support: 

the literature on which petitioners rely shows only one example of a station that was 

adjusted to show greater warming in order to agree with neighboring rural stations, along 

with a hypothetical example where the methodology could potentially result in a warming 

adjustment to an urban station that would be problematic if the rural stations all had 

artificial warming. 

Several analyses have been replicated for different subsets of the data: stations ranked 

highly by surfacestations.org compared with stations ranked poorly (Menne et al., 2010), 

stations that drop out early compared with stations that are still reporting (Clear Climate 

Code, 2010), rural stations compared with urban stations (Menne et al., 2010), and so 

forth. Every one of these analyses that we are aware of that uses appropriate 

methodologies (e.g., anomaly and spatial interpolation techniques and, in the United 

States, corrections for time of observation bias changes) has resulted in similar trends 

over the century for the United States and for the globe with only small differences from 

analysis to analysis. 

With regards to the differences between the United States temperature record in the 

NOAA and NASA analyses, the petitioners’ comments are not new: see Response 2-28 in 

the RTC. Note that the discrepancy between NASA and NOAA discussed in Response 

2-28 is much smaller now that NASA has updated to using USHCN Version 2. NASA 

previously used Version 1 without the UHI adjustment, and now uses Version 2 as an 

input. As noted above, Version 2 includes important corrections for stations that changed 

measurement instruments after 1995. The updated trends for U.S. data in the two 

datasets are 1.28°F/century for NOAA and 1.12°F/century for NASA from 1901 to 2008. 

For 1950 to 2008, the trends are 1.50 and 1.39 °F/century for the two temperature records 

respectively. The smaller trend in the NASA temperature record is due to the nightlight 

based urban correction routines. 

We find that while NASA uses a nightlights map and an adjustment methodology for the 

United States that produces a smaller trend, it is not clear that this is to be preferred over 

112
the NOAA approach. It might produce more realistic temperature estimates for some 

stations, but might over-correct for urban effects for other stations. Also, the NOAA 

algorithm has the advantage of using the larger COOP database for its closest neighbor 

calculations. In the case of Central Park specifically, NASA’s nightlight adjustment 

routine does result in a smaller trend than NOAA uses in its USHCN temperature record. 

Recall, however, that it is not the heat island effect in Manhattan that is in question, but 

rather the change in the heat island effect over time that is important. NASA uses more 

distant HCN stations to determine such trends and the appropriate correction, whereas 

NOAA uses a larger number of nearby COOP stations to determine appropriate 

“changepoint” corrections. (The HadCRUT temperature record does not include the 

Central Park station, as it does not use the USHCN dataset.) 

In sum, the petitioners have not shown inappropriately manipulated data in terms of 

either the U.S. or global temperature records. The findings of a warming temperature 

trend in the United States and the globe over both the past 50 years and the past century 

remains robust, as shown by different methodologies used by different groups, as well as 

analyses that use only subsets of the data (such as only those stations that are not near 

brightly lit areas as defined by nighttime satellite measurements). 

Comment (1-68): 

The Southeastern Legal Foundation, in their Third Amendment to Petition, discusses the 

surfacestations.org project and the related critiques of the USHCN network and the U.S. 

temperature record: 

Anthony Watts’ project, surfacestations.org, has surveyed 1067 of 1221 (87.4%) surface 

stations in the USHCN network. Stations are evaluated for the quality of their location 

according to criteria developed by the Climate Reference Network (“CRN”) Site 

Information Handbook, which specifies the requirements for establishing and maintaining a 

weather instrument site. Id. at 32.8 Deviations from the siting standards introduce a range 

of error in the measurements according to a scale set forth in the handbook. The error 

scale runs from less than 1° C for stations classified as CRN class 1 or 2, up to greater 

than 5° C for stations rated CRN class 5. Id. 28-33. For the stations surveyed the 

SurfaceStations.org volunteers determined that 90% were sited in ways that result in 

errors exceeding 1° C according to the handbook’s error scale. In the following chart, 

these stations are categorized by where they fall in the CRN handbook’s error scale: 

113
 

Since the asserted warming trend over the 20th century is 0.74 ± 0.18°C (TSD p. 27), the 

petitioner claims that the error swamps the signal. On this basis, the petitioner asserts that 

the data are invalid and unreliable and cannot be relied on for the Endangerment Finding. 

Response (1-68): 

The petitioner cites a study that has determined that a large number of stations do not 

match the best criteria as developed for the Climate Reference Network. However, the 

petitioner does not show that the identified siting issues contribute to a systematic bias. 

The error scale used covers both positive and negative error. Errors that vary randomly 

from one station to another would not be expected to bias large-scale temperature 

records. In addition, these errors refer to errors in absolute temperatures, not in changes 

in temperature. In contrast, researchers at NOAA have performed analyses that show the 

difference between trends calculated from stations that have been identified as “wellsited” compared to trends calculated from stations that have been identified as “poorly 

sited.” A key figure from Menne et al. (2010) (Figure 7, provided below) compares 

various U.S. temperature records derived by using all the stations, only stations using 

“good” siting, only stations using “poor” siting, and only stations using the new US 

Climate Reference Network (USCRN). USCRN was developed over the past few years 

with the goal of having stations designed for the purpose of long-term climate 

monitoring, in contrast to the current network of stations primarily designed for weather 

monitoring. These USCRN stations are all designed for the purpose of long-term climate 

monitoring. Note that all four sets of stations give almost identical trends (for USCRN, 

only over the recent years that it has been operational). 

114
The assumption by the petitioner than an error of 1 degree or more at individual stations 

“swamps the signal” is also incorrect based on basic statistics. Because there are a large 

number of measurements at a large number of stations, the statistical error is much 

smaller than the error for a single measurement at a single station. 

See also Response 1-67 in this document regarding the surfacestations.org project. 

Therefore, the conclusion of the Watts surfacestation.org project that, using one method 

of rating stations, only a small subset of the U.S. temperature stations are well sited does 

not demonstrate that the overall temperature record is biased or unreliable. In fact, 

analysis using only the subset of stations determined as “good” by Watts, as well as 

analysis using the new Climate Reference Network stations, found very similar trends to 

the analysis using all the stations, demonstrating that the conclusions about U.S. 

temperature trends are robust. 

Comment (1-69): 

The Southeastern Legal Foundation in their Fifth Amendment to Petition and in their 

Petition to Stay refer to a study by Edward Long (2010) stating: 

115
On February 25, 2010, Edward R. Long, Ph.D.10 published a paper through the Science 

and Public Policy Institute analyzing the effect of adjustments to the temperature record 

for the continental United States that are made in the NCDC temperature record for rural 

and urban stations.11 For the rural stations in the study, the raw data showed a linear 

trend of 0.13o C per century, while for urban stations the raw data showed a trend of 0.79o 

C per century. Id. at p. 8-9. The long term trends were very similar until about 1965, 

when the trend in the urban raw data increases faster than in the rural data. Id. at 9-10. 

NCDC’s adjusted data for rural stations show a trend of 0.64 o C per century, compared 

to 0.13 o C per century for the raw data. In other words, the NCDC adjustment increased 

the rural trend by nearly five times. Id. at 11. The adjusted data for urban stations show a 

trend of 0.77o C per century, compared to a raw urban trend of 0.79o C per century. Id. 

“Thus, the adjustments to the data have increased the rural rate of increase by a factor of 

5 and slightly decreased the urban rate, from that of the raw data.” Id. This has the effect 

of hiding urban heating, and permitting the warming present in the adjusted data to be 

attributed not to urban warming, but to climactic warming. As Long concludes, “The 

consequence, intended or not, is to report a false rate of temperature increase for the 

Contiguous U.S.” Id. at 13. The EPA should not base economically devastating 

regulations, or any regulations, on false reports, and should reconsider the Endangerment 

Finding to make sure that it has not done so here. 

Response (1-69): 

The Long study does not demonstrate inappropriate adjustment for rural temperature 

stations, because this study did not take into account the appropriate “time of observation 

bias” adjustments or adjustments for changes in measurement instruments. Because of 

these flaws in the Long analysis, the conclusions by Long are without scientific merit. 

As demonstrated in previous responses, U.S. trends calculated using only “good” stations 

or only Climate Reference Network stations show very similar trends to the trends 

calculated using the full set of data. See also Response 1-66 on the Long study and other 

UHI issues in this section. 

1.4.3.3 Issues Raised in Additional Literature Provided by Petitioners 

Comment (1-70): 

The Coalition for Responsible Regulation cited two papers that they state show that 

replication of temperature records is difficult, and that therefore, EPA’s Endangerment 

Finding does not meet the requirements of the Data Quality Act. Regarding these two 

papers, the coalition states, “One study, noting that the raw temperature records in the 

USHCN are adjusted substantially to account for a variety of potential contaminants, 

concluded the effects of such adjustments ‘produce a significantly more positive, and 

likely spurious trend in the USHCN data’” (Balling and Idso, 2002). The other study 

concluded “that the inability to replicate the [Northern Hemisphere surface thermometer 

temperature] trend was likely a result of ‘data padding’ used to smooth and filter data” 

(Soon et al., 2004). 

Response (1-70): 

EPA has reviewed the petitioners’ submission of Balling and Idso (2002) and Soon et al. 

(2004) and finds that it was not impracticable to raise the objection during the public 

116
comment period and that the reasons for the objection did not arise between June 24, 

2009, and February 16, 2010. Petitioners could have submitted these studies during the 

comment period on the proposed Endangerment Finding. Although, in most cases, the 

petitioners provide excerpts from the CRU e-mails in support of their assertions, EPA’s 

review has determined that this evidence does not support their allegations, and that the 

information submitted by petitioners on these topics was available before the comment 

period for the Endangerment Finding. Petitioners have not shown why it would have 

been impractical for them to have submitted these studies then. Indeed, similar points 

were already raised, and responded to, in the RTC. Despite the fact that these objections 

fail to meet the statutory timeframe for evidence supporting a petition for reconsideration, 

we briefly explain why, contrary to petitioners’ allegation, they fail to call into question 

the Finding. 

Balling and Idso (2002) draws conclusions based on an analysis that is no longer valid, as 

it relies on the University of Alabama–Huntsville (UAH) satellite temperature dataset 

before corrections identified by Karl et al. (2006) in CCSP Product 1.1 were applied to 

the satellite record. These corrections have been accepted by all the researchers involved, 

including those at UAH, and increased the temperature trend in the satellite dataset, 

eliminating many of the discrepancies with the surface temperature dataset. Additionally, 

even before these corrections were identified, Vose et al. (2003) found with respect to 

Balling and Idso (2002) that “the time of observation bias adjustments in HCN appear to 

be robust,” contrary to the assertions of Balling and Idso that these adjustments were 

biased. 

As background, Soon et al. critiqued the application of the smoothing algorithm used by 

Mann and Jones (2003) at the very end of the time period that was analyzed. The 

algorithm is a 20-year average, and a decision must be made about what temperature to 

use for the last 10 years. For example, one could choose to reflect the end of the 

temperature record (making the years after the end of the record a mirror image of the 

years before the end of the record), or assume that all years after the last year of the 

record are equal in temperature to the last year, or assume that the subsequent years 

continue the trend of the previous years in the record. Soon et al. felt that application of 

this “data padding” (though they were not able to exactly duplicate Mann and Jones) led 

to unjustifiably high temperatures at the end of the smoothed temperature record. 

A subsequent peer-reviewed rebuttal of Soon et al.’s critique was published by Mann 

(2004). Mann (2004) states that “Comparisons that are uninformed (e.g., Soon et al., 

2004) by objective evaluation criteria (e.g., MSE [Mean Square Error]), are unlikely to 

provide useful insights into the relative merits of alternative boundary constraints.” 

Mann’s contention is that there needs to be an objective way to evaluate which smoothing 

routine to use. While he does not claim that MSE is necessarily the best function, he 

notes that Soon et al. do not use any objective criteria at all. His analysis also suggests 

that his approach will choose methods that reflect the underlying trends in the data, 

whereas smoothing that does not use the MSE criteria can generate spurious trends. 

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1.4.3.4 Petitioners’ Allegations Regarding Data Adjustments at Specific Stations 

Comment (1-71): 

Petitioners identify several instances of allegedly flawed data adjustments at specific 

weather stations, citing the records of some individual stations that they claim show 

inappropriate manipulation. The Coalition for Responsible Regulation references a nonpeer-reviewed analysis by Eschenbach (2009) as a basis for claiming: “For example, 

adjustments made by the Global Historical Climatology Network (GHCN) in Darwin, 

Australia, transformed a temperature trend falling at 0.7°C per century to one that was 

warming 1.2°C per century.” 

The Southeastern Legal Foundation, the State of Texas, and the Coalition for Responsible 

Regulation makes similar claims regarding stations in New Zealand, stating, “Similar 

‘adjustments’ are also evident in one striking comparison of raw temperature data with 

homogenized temperature data ‘adjusted’ by the New Zealand national weather service, 

the National Institute of Water & Atmospheric Research (NIWA),” claiming that the 

“New Zealand Climate Science Coalition concluded that all of the ‘adjustments’ made by 

Salinger and the NIWA served to show inaccurate increases in warming” (referencing a 

non-peer-reviewed analysis by Treadgold, 2009). 

Response (1-71): 

The specific assertions made about the Darwin and New Zealand stations rely upon two 

non-peer-reviewed analyses that found that temperature adjustments at various stations 

caused temperatures to be higher than they otherwise would have been. In the case of 

New Zealand, the petitioners do not show that the adjustments performed by these 

organizations were inappropriate, just that the adjustments resulted in a larger warming 

trend. As we have explained previously, there are several legitimate reasons to adjust 

temperature records, from time of observation changes to moving the location of the 

thermometer. 

NIWA has published details of its temperature analysis online (New Zealand NIWA, 

2010). Their site includes links both to a set of 11 stations with no required adjustments 

since 1930 and the set of seven stations analyzed by Treadgold. Both sets of stations 

show warming over the period between 1930 and present. In the latter set, NIWA links 

to a complete description of the station history of Hokitika, the station with the largest 

change in trend due to adjustments. NIWA shows that the composite, adjusted Hokitika 

record is similar to that of two nearby stations from the unadjusted set during those 

periods when the stations were all recording data. We also note that the raw data (for all 

18 New Zealand stations linked to by NIWA) provided to NOAA for the GHCN dataset 

does not include the homogeneity adjustments from the NIWA researchers. The adjusted 

NOAA temperature record does show a warming trend for these stations, however. 

While the NOAA GHCN adjustments differed in some ways from the NIWA 

adjustments, the largest adjustment made to the Hokitika station by both NOAA and 

NIWA occurred before 1912, consistent with this statement from NIWA: “It is noted in 

the Hokitika station history file (see Appendix 2) that the maximum temperatures were 

believed to be about 3°F too high through the period 1894 to August 1912.” Given that 

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NOAA uses automated procedures to correct for station moves based on data from 

neighboring stations, this is strong independent confirmation that the manual adjustments 

made by NIWA were appropriate (and vice versa). 

Of the other 2 major temperature records, HadCRUT uses most of the same manual 

adjustments as NIWA. The automated algorithm used by NASA, on the other hand, is 

designed to correct for changes in trends at urban stations rather than sharp 

discontinuities, and therefore does not capture the errors that are corrected by both the 

NOAA algorithm and the HadCRUT/NIWA manual adjustments. 

While NIWA has only addressed in depth one of the seven stations analyzed by 

Treadgold, based on comparisons to nearby stations, New Zealand researchers have 

shown that the adjustments to the other stations were appropriate (New Zealand NIWA, 

2010). Additionally, Folland and Salinger (1995) found that the nearby sea surface 

temperatures also showed similar warming since the beginning of the century, adding 

further independent confirmation that the adjusted trend used by NIWA, NOAA, and 

HadCRUT is a good reflection of reality. Therefore the evidence indicates that NOAA 

and NIWA both made similar, independent, and appropriate adjustments. Note that this 

example is also further confirmation of the independence of the adjustment 

methodologies of the NOAA, NASA, and HadCRUT temperature records addressed in 

1.4.3.5. 

 

Regarding the Darwin station, these adjustments only appear in one of the three 

temperature records—the adjusted GHCN record from NOAA (HadCRUT uses raw 

GHCN data, and NASA uses raw data starting in the 1960s). There is a clear 

discontinuity at Darwin in 1941 at the time of a major station move when the temperature 

record apparently dropped by more than half a degree, and it would be expected that 

adjustments would be required under such circumstances to ensure that the station trend 

best represents the real temperature trend at that location. However, according to a letter 

by Tom Peterson of NOAA (reproduced in full in Response 1-73 below), the Darwin 

station might be an example of a “random walk” where a rare combination of 

circumstances means the automated algorithm can introduce an erroneous trend. 

However, a possible error at one station (which only occurs in one out of three datasets) 

will not materially affect large scale trends. Statistical analysis has showed that: 

[t]he difference in trends between homogeneity-adjusted and unadjusted data can be 

enormous at an individual station and very significant in regional analyses. However, 

Easterling and Peterson (1995a,b) found that on very large spatial scales (half a continent 

to global), positive and negative homogeneity adjustments in an individual station’s 

maximum and minimum temperature time series largely balance out, so when averaged 

into a single time series, the adjusted and unadjusted trends were similar (Peterson et al. 

1998). 

Thus, it is not surprising that data from one station or region would show a large 

difference between adjusted and unadjusted data. The important point is that when the 

stations and regions are combined for a global analysis, these kinds of effects are 

balanced out and do not introduce bias in the overall result. 

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Therefore, we find that the petitioners have not shown evidence that the adjustments in 

New Zealand were inappropriate, or shown that the adjustments at Darwin biased larger 

scale temperature reconstructions. We also note that the three temperature records used 

different methods to determine the appropriate adjustments: in the case of New Zealand, 

NOAA and HadCRUT used independent methods (one manual and one automatic) and 

found similar adjustments needed to be made, whereas in the case of Darwin NASA and 

HadCRUT both used the raw data with no adjustments (though different time periods of 

useable data). 

Comment (1-72): 

The Coalition for Responsible Regulation provides a number of references (Exhibits K 

through V) to support their statement that “There are numerous and recently-released 

studies documenting significant warming biases in the temperature databases that, in light 

of the Disclosures [i.e. the CRU emails], reveal the fruit of this manipulated process.” 

Exhibits K through V are Balling and Idso, 2002; Christy et al., 2006; Christy and Norris, 

2009; D’Aleo, 2009; D’Aleo, 2010; Davey and Pielke, 2005; Davey et al., 2006; Hale et 

al., 2006; Pielke et al., 2007a; Pielke et al., 2007b; Soon et al., 2004; and Watts, 2009. 

Response (1-72): 

EPA has reviewed the petitioners’ submission of these 12 studies and finds that for many 

of these submissions it was not impracticable to raise the objection during the public 

comment period or that the reasons for the objection did not arise between June 24, 2009, 

and February 16, 2010. Petitioners could have submitted most of these studies during the 

comment period on the proposed Endangerment Finding. Although, in most cases, the 

petitioners provide excerpts from the CRU e-mails in support of their assertions, EPA’s 

review has determined that this evidence does not support their allegations, and that the 

information submitted by petitioners on these topics was available before the comment 

period for the Endangerment Finding. Petitioners have not shown why it would have 

been impractical for them to have submitted these studies then. Indeed, similar points 

were already raised, and responded to, in the RTC. Despite the fact that these objections 

fail to meet the statutory timeframe for evidence supporting a petition for reconsideration, 

we briefly explain why, contrary to petitioners’ allegation, they fail to call into question 

the Finding. 

Most of the 12 references provided to support the statement by the petitioners that 

“document significant warming biases” are not new. Three references (Christy et al., 

2006, 2009; Pielke Sr. et al., 2007a) were explicitly addressed in the Volume 2 of the 

RTC document (Responses 2-28 and 2-29), which found that these effects would be 

negligible on hemispheric and continental scale averages. Below is EPA’s response from 

RTC Volume 2: 

EPA has reviewed additional literature submitted by commenters on this issue (e.g., 

Christy et al., 2006, 2009; Lin et al., 2007; Pielke Sr. et al., 2007, Ren et al., 2007; Walters 

et al., 2007), which documents effects that may result in biases at individual stations. 

CCSP (2006) also addresses this issue, and finds: “To the effect that these effects could be 

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large enough to have a measurable influence on global temperature, these changes will be 

detected by the land-based surface network [which corrects for these effects].” The large 

number of stations in land-based surface networks greatly facilitates temporal 

homogenization, since a given station may have several “near-neighbors” for “buddy 

checks” where adjustments and/or change point algorithms can be employed per the 

previous response 2-28 (CCSP, 2006). In a comprehensive reassessment of errors in the 

HadCRUT temperature record, Brohan et al. (2006) conclude: “Since the mid-20th century 

the uncertainties in global and hemispheric mean temperatures are small and the 

temperature increase greatly exceeds its uncertainty.” 

Through our review of the data sets and the literature, EPA concurs with IPCC (Trenberth 

et al., 2007) and CCSP’s overall assessment that the effects of urbanization and land use 

changes on the land-based temperature record are negligible as far as hemispheric- and 

continental-scale averages are concerned because the very real but local effects are 

avoided or accounted for in the datasets used. 

Three more references (Davey and Pielke, 2005; Hale et al., 2006; and Pielke et al., 

2007b) were not raised during public comment, but we find that they are variations on the 

same issues of effects at individual stations that may result in bias at the individual 

stations and responded to with respect to the Christy and Pielke studies discussed in the 

RTC document (as quoted above). Thus, these references do not lead to any changes in 

EPA’s conclusions on the robustness of global and continental-scale averages. 

Davey et al. (2006) is a study of the use of a different metric (equivalent temperature) 

that takes into account how the heat capacity of air depends on humidity and explores the 

implications of weighting temperature measurements by this heat capacity. However, 

while this is an interesting academic exercise, the current standard metric is the average 

surface temperature, and this study does not demonstrate any biases in the measurement 

of this standard metric. The equivalent temperature trends found in Davey et al. (2006) 

are actually larger (averaged over the year) than the comparable, standard surface 

temperature trends for the region examined. 

Two more references (Soon, 2004; Balling, 2002) have been superseded in the literature 

or depend on obsolete data, as discussed in Response 1-70. 

The only new material (D’Aleo, 2009, 2010; Watts 2009) addressed the U.S. surface 

temperature record and are very similar to D’Aleo and Watts (2010) and share the same, 

fundamental flaws that were discussed in many responses in Section 1.4 (such as 

Response 1-62). 

Therefore none of the 12 exhibits submitted by the petitioner support the contention that 

there are “significant warming biases” in the U.S. or global surface temperature records, 

and most of them do not meet the statutory timeframe for evidence supporting a petition 

for reconsideration. 

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Comment (1-73): 

The Southeastern Legal Foundation cites Eschenbach (2009), stating:

A similar instance of chicanery arose with the manipulation of the Australian climate 

data. The HARRY_READ_ME.txt file makes numerous references to manipulating the 

Australian data, but one must examine the data itself to fully understand what the 

Climategate crew was doing. While it concerns a single location, the adjustments to data 

from Darwin, Australia, admit no legitimate explanation. 

The petitioner quotes Willis Eschenbach: 

Those, dear friends, are the clumsy fingerprints of someone messing with the data 

Egyptian style ... they are indisputable evidence that the “homogenized” data has been 

changed to fit someone’s preconceptions about whether the earth is warming. One thing 

is clear from this. People who say that “Climategate was only about scientists behaving 

badly, but the data [are] OK” are wrong. At least one part of the data is bad, too. The 

Smoking Gun for that statement is at Darwin Zero.20 [Footnote 20: Id.] 

The Coalition for Responsible Regulation also cites the same Web page (Eschenbach, 

2009) as further support for their statement that “There are numerous and recentlyreleased studies documenting significant warming biases in the temperature databases 

that, in light of the Disclosures, reveal the fruit of this manipulated process.” 

Response (1-73): 

EPA responds to the allegations regarding data adjustments in Response 1-71. There is a 

clear rationale for at least one adjustment to the Darwin station because of a major station 

move in 1941. Because the adjustments by NOAA use an automated procedure based on 

nearest neighbor and other calculations, there is no opportunity for human “chicanery” or 

“messing with the data.” Note that we are unclear as to what is meant by messing with 

the data “Egyptian-style.” 

Additionally, as shown in Response 1-66, the sum total effect of all land-based 

adjustments by NOAA on trends in the global GHCN temperature record are very small 

(as discussed in Subsection 1.3.2, ocean data adjustments result in a smaller warming 

trend). For the continental United States, the time of observation bias correction (to 

correct for the shift in temperature measurement from the afternoon to the morning) and 

the corrections due to changes in measurement technology do result in a warmer trend 

than the raw data would suggest, but these corrections are essential for proper analysis, 

not “chicanery.” 

Tom Peterson from the NCDC at NOAA responded to a request for information from the 

author of the “smoking-gun-at-darwin-zero” post, posted in the comments at Watts 

(2010) and reproduced here: 

Dear Willis Eschenbach, 

I received your questions today. They are quite detailed and would take some digging 

through files from the mid to late 1990s for me to answer all of them. This would take time 

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I don’t have right now (I actually should be on annual leave right now, but had a few things 

I wanted to get done before I take off for the rest of the year in a few hours). So let me 

respond in general terms first and provide you with some articles to make sure we’re both 

starting from the same page. 

One of the problems we were trying to address in some of the procedures we developed 

back in the mid-1990s was how to take advantage of the best climate information we had at 

each location at each point in time. We had spent a great deal of time and energy digitizing 

European colonial era data (article sent) which went a great deal towards making global 

data prior to 1950 more global (see http://www.ncdc.noaa.gov/img/col.gif for a movie loop 

of the stations we digitized or acquired for GHCN by this project). This means that in 

some parts of the world, we might have more stations available to build a reference series 

from prior to the country’s independence than afterwards. To utilize data that did not span 

the whole period of record, we used what we called the first difference method (article 

sent). Using this approach we built a reference series (article sent) one year at a time. 

There were two concerns about this approach. The first was how to make sure we didn’t 

incorporate a change in station location (etc.) artifact into the reference series. That aspect 

was done by using the 5 highest correlated stations for the reference series and removing 

the value from the highest and lowest of the 5 highest correlated first difference values for 

that year based on the assumption that the mean of the three center most values provided a 

robust measure of the climate signal and if a station moved up or down a hill, its value 

would likely be the highest or lowest due to the impact of the station move that year. (This 

last part was a later addition and is explained in the homogeneity review paper (paper 

sent).) 

The homogeneity review paper explains the reasons behind adopting this complex 

reference series creation process. It did indeed maximize the utilization of neighboring 

station information. The downside was that there was a potential for a random walk to 

creep into the reference series. F or example, if the nearest neighbor, the one with the 

highest correlation, had a fairly warm year in 1930, its first difference value for 1930 would 

likely be fairly high. The first difference value for 1931 would therefore likely be low as it 

probably was colder than that experienced in that very warm year preceding it. So the 

reference series would go up and then down again. The random walk comes in if the data 

for 1931 were missing. Then one gets the warming effect but not the cooling of the 

following year. The likelihood of a warm random walk and a cold random walk are equally 

possible. Based on the hundreds of reference series plots I looked at during my mid-1990s 

evaluation of this process, random walks seemed do be either non-existent or very minor. 

However, they remained a possibility and a concern. 

Partly in response to this concern, over the course of many years, a team here at NCDC 

developed a new approach to make homogeneity adjustments that had several advantages 

over the old approaches. Rather than building reference series it does a complex series of 

pairwise comparisons. Rather than using an adjustment technique (paper sent) that saw 

every change as a step function (which as the homogeneity review paper indicates was 

pretty standard back in the mid-1990s) the new approach can also look at slight trend 

differences (e.g., those that might be expected to be caused by the growth of a tree to the 

west of a station increasingly shading the station site in the late afternoon and thereby 

cooling maximum temperature data). That work was done by Matt Menne, Claude 

Williams and Russ Vose with papers published this year in the Journal of Climate 

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(homogeneity adjustments) and the Bulletin of the AMS (USHCN version 2 which uses this 

technique). 

Everyone here at NCDC is very pleased with their work and the rigor they applied to 

developing and evaluating it. They are currently in the process of applying their adjustment 

procedure to GHCN. Preliminary evaluation appears very, very promising (though of 

course some very remote stations like St Helena Island (which has a large discontinuity in 

the middle of its long record due to moving downhill) will not be able to be adjusted using 

this approach). GHCN is also undergoing a major update with the addition of newly 

available data. We currently expect to release the new version of GHCN in February or 

March along with all the processing software and intermediate files which will dramatically 

increase the transparency of our process and make the job of people like you who evaluate 

and try to duplicate surface temperature data processing much easier. 

I hope this email and the series of articles I am sending will answer some of your questions 

at least (e.g., in the homogeneity review paper it clearly states that the first difference 

correlation threshold of 0.8 is between the candidate station and the final reference series, 

not the individual stations that make up the reference series). They are likely to also 

stimulate some additional questions. So if it is all right with you, I won’t follow up on your 

questions when I return in January but rather will wait until you send in a new set of 

questions or just send these old ones back to me. 

We’re doing a lot of evaluation of our new approach to adjusting global temperature data to 

remove artificial biases but additional eyes are always welcome. So I would encourage you 

to consider doing additional GHCN evaluations when we release what we are now calling 

GHCN version 2.5 in, hopefully, February or March of 2010. 

Happy Holidays, 

Tom Peterson 

This letter demonstrates the care and rigor used by the researchers at NOAA when 

considering possible problems involved in the methodologies being used to construct 

global surface temperature records. Even though the researchers had determined that 

problems such as “random walks” were “non-existent or very minor,” they were working 

to develop a new methodology that would be superior and would not include the 

possibility of these errors. Importantly, such “random walks” would be, as the name 

suggests, random—as likely to be a random walk warmer as cooler—and therefore very 

unlikely to be a source of large scale bias, even if a spurious trend on a local scale might 

be introduced. Darwin might actually be an example of such a “random walk” where 

missing data, a lack of nearby neighbors, and the fact that Darwin included a lot of data 

from the colonial era and therefore had more data in the past than in more modern times, 

could have led to a rare case of the automated procedure introducing a spurious warming. 

However, on the global scale Darwin is a very small contributor, and there is no evidence 

that the algorithm performed similarly elsewhere. Neither NASA nor CRU use the same 

algorithm as NOAA, and therefore this potential spurious warming is not included in 

either of those records. Yet the large-scale trends of the NASA and HadCRUT 

temperature records are consistent with the large-scale trends of the NOAA temperature 

record, demonstrating the robustness of large-scale trends to errors in individual stations. 

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Additionally, note that the “Darwin” adjustments highlighted by the petitioner are from 

NOAA, not CRU, and have nothing to do with the HARRY_READ_ME file which was 

about the CRU TS (time series) dataset and not the HadCRUT temperature record. 

Comment (1-74): 

The Southeastern Legal Foundation cites a document by Richard Treadgold of the New 

Zealand Climate Science Coalition (Treadgold, 2009) to support their contention that 

there is data manipulation to show warming: 

Other instances of such data manipulation are also beginning to surface. For example, new 

information published November 25, 2009 also shows an eerily similar pattern of 

“adjustments” was made to raw temperature data in New Zealand – downward adjustments 

in the early 20th century and upward adjustments from the middle of the 20th century 

onward.23 While the information on the New Zealand temperature adjustments was not 

part of Climategate, it is new, and it adds to the pattern of similar manipulations - 

downward adjustments in the first part of the 20th century and upward adjustments in the 

latter half - yielding a warming trend over the last century that is almost entirely fictitious. 

EPA should evaluate this controversy to determine whether these recently revealed 

“adjustments,” like those of Climategate, indicate more of the same collusion, 

manipulations, and chicanery.24 

The Southeastern Legal Foundation also states (in a footnote to the above paragraph): 

“Without belaboring the point, yet another curious manipulation occurs in the context of 

the USHCN dataset. See ‘Difference Between Raw and Final USHCN Data Sets,’ found 

at: http://www.ncdc.noaa.gov/img/climate/research/ushcn/ts.ushcn_anom25_diffs_urbraw_pg.gif (last visited December 23, 2009). Absent Climategate, one might assume the 

adjustments were legitimate. In light of the extensive (and ever expanding) evidence of 

improper manipulations, however, one must wonder.” 

The Southeastern Legal Foundation raises similar questions about New Zealand in their 

Third Amendment to Petition, citing D’Aleo and Watts (2010). The State of Texas 

claims that “the CRU created an exaggerated appearance of 20th century warming in New 

Zealand” and cites the USHCN graphic discussed by the Southeastern Legal Foundation 

to support the statement “The CRU manipulated the raw data to show lower temperatures 

for New Zealand in the early century.” The Coalition for Responsible Regulation also 

cites Treadgold about the New Zealand Temperature record. 

Response (1-74): 

As discussed previously (see Response 1-71), EPA has evaluated claims concerning 

adjustments to data in New Zealand, and concluded that the adjustments by NIWA are in 

line with the station records and nearby station trends. Note that in almost all the stations 

the majority of the adjustments come before 1950. Therefore, the adjustments do not 

influence any warming trends after 1950. In addition, the State of Texas and the 

Southeastern Legal Foundation cite the graph “Difference Between Raw and Final 

USHCN Data Sets” in support of their contentions about the New Zealand data. This 

graph documents the NOAA adjustments that correct for variations in the time of 

observation and changes in temperature measurement instruments for the U.S. 

temperature record. Petitioners do not explain or present argument to show why the 

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adjustments are inappropriate. Also, this graph is not pertinent to the claims of 

inappropriate manipulations by CRU to the New Zealand data. 

Comment (1-75): 

The Southeastern Legal Foundation, in their Third Amendment to Petition, references a 

blog discussion of Nordic temperature reconstructions: 

Their fifth case study is by Willis Eschenbach10 recounting the attempts by Professor 

Wibjorn Karlen to replicate the IPCC’s temperature analysis for the Nordic region. See 

Id. at 79; available at http://wattsupwiththat.com/2009/11/29/when-results-go-bad/ (last 

visited Feb. 10, 2010). Eschenbach was drawn to the subject by the inclusion in the 

Climategate e-mails of correspondence between Professor Karlen and Phil Jones, former 

Director of the CRU, which follows the now familiar pattern of Jones willfully obstructing 

legitimate scientific inquiry. The IPCC shows substantial increases in temperature in the 

late 20th century, to 0.5 C above the levels of the 1930s in the Nordic region. Karlen 

could not replicate the assertion by the IPCC that the recent warming exceeded that of the 

1930s, either in the Nordic regions or in many other regions of the world, and sought 

clarification from Jones and Trenberth. They did little more than refer him back to the 

IPCC reports from which the question arose in the first place. Karlen’s analysis, 

replicated by Eschenbach, shows the same pattern of suppressing the warming of the 

1930’s and inflating the warming of the late 20th century that is seen in surface 

temperature record discussed above. Eschenbach’s analysis of the Climategate e-mails 

concludes that Karlen made legitimate inquiries and “got incomplete, incorrect and very 

misleading answers.” Id.

Response (1-75): 

The analysis by the IPCC was of the “NEU” region (Northern Europe), which included 

48N to 75N, and 10W to 40E. Therefore, in addition to the Nordic region analyzed by 

Karlen, the IPCC region included Ireland, the United Kingdom, half of France, Germany, 

Belarus, and several other nations. Thus the Karlen and Eschenbach analysis covers a 

different geographic region, which they failed to account for. In addition, they appear to 

have used a flawed methodology as there is no evidence that either Karlen or Eschenbach 

performed any kind of spatial interpolation. Instead it appears that they used the flawed 

approach of taking a straight average of station anomalies (which is not the appropriate 

method to use unless the stations are perfectly evenly distributed geographically, which 

they are not). Additionally, Eschenbach used a 17-year Gaussian average to compare 

against an IPCC figure that is clearly labeled as using decadal averages. Therefore, the 

Eschenbach analysis was of a different region, using a different (and inferior) 

methodology for combining weather station data, and using different temporal averaging. 

These reasons explain why the results of Eschenbach differ from those of the IPCC, and 

do not support petitioners claim that the trend was manipulated, thus “inflating” the late 

20th-century warming. 

The assertion by Eschenbach that Karlen received “incomplete, incorrect and very 

misleading answers” is not supported by the record, which showed two researchers 

(Trenberth and Jones) taking the time to answer repeated questions from an emeritus 

126
professor from Sweden. The final e-mail cited by Eschenbach was from Phil Jones to 

Karlen, demonstrating the completeness and helpfulness of these researchers in contrast 

to the assertions by the petitioners: 

[Jones] Fennoscandia is just a small part of the NH. When I’m back next week, I’ll be 

able to calculate the boxes that encompass Fennoscandia, so you can compare with this 

region. As you’re aware Anders did lots of the update work in 2001-2002 and he 

included all the NORDKLIM data. I can send you a list of the Fennoscandian data if you 

want – either the sites used or their data as well.49

Therefore, it is clear that the analysis by Eschenbach was a flawed and inappropriate 

comparison, and that Trenberth and Jones, in contrast to the assertions of the petitioners, 

were attempting to be helpful in their answers. 

1.4.3.5 Allegations Regarding the Independence of NOAA, NASA, and HadCRUT 

Temperature Records 

Comment (1-76): 

Some petitioners claim that the NOAA and NASA temperature records are not 

independent from the HadCRUT temperature record because they share the same raw 

data. The Commonwealth of Virginia states, “If NASA and NOAA used the same raw 

data as CRU, and if they have reached conclusions similar to those of CRU, then a 

finding of data unreliability with regard to the CRU Data may indicate systemic problems 

with all three of the data sets upon which EPA relied in promulgating its Endangerment 

Finding.” The Competitive Enterprise Institute cites D’Aleo and Watts (2010) as stating, 

“Since all three use the same data, all three have experienced the same degradation in 

data quality in recent years” (referring to the station dropout issue). Pacific Legal 

Foundation refers to the EPA RTC document, stating, “Curiously, EPA admits that the 

NOAA and NASA datasets show similar trends and were developed at least in part 

through similar methodologies to those employed by CRU. By making this admission, 

EPA unintentionally leads us to the inexorable conclusion that, if the CRU Data are 

methodologically problematic, the NOAA and NASA data may share such 

methodological problems. See EPA’s Response to Public Comments, Vol. 2, 2-28” and 

that therefore “any finding that the CRU Data and its conclusions are unreliable should 

lead to a review of the NOAA and NASA data sets as well.” 

Response (1-76): 

We agree that these three major temperature records rely on a large amount of raw data 

obtained from GHCN, although the HadCRUT temperature record, in particular, 

integrates additional data obtained from other, independent sources. However, the 

petitioners have not demonstrated any major flaws in the raw data. The allegations that 

station dropout was inappropriate or would bias the data are unfounded as described in 

Response 1-62 of this document. A number of analyses using different subsets of data 

have produced similar global temperature trends to the whole set of data. See the 

 

49 E-mail file 1221683947.txt, (September 17, 2008), page 1554, lines 25-29 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

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description of the Jones paper (Jones, 1994) in the previous section, which found that 100 

well-placed stations were sufficient to determine a global temperature trend, the Menne et 

al. (2010) paper that showed that subsets of the U.S. data that had been rated more highly 

by surfacestations.org also led to the same trend as the whole set of data, and the Clear 

Climate Code project (Clear Climate Code, 2010) which demonstrated that the dropped 

stations and remaining stations have similar trends in overlapping periods. 

The processing of the GHCN and other data by the three groups is independent. 

HadCRUT used significant manual processing of the data; NOAA uses an automated 

adjustment procedure that corrects for discontinuities; and NASA uses an automated 

adjustment procedure that changes trends in urban stations to match nearby rural stations. 

The three groups use different procedures to extrapolate temperatures to data sparse 

regions, and different sources of ocean sea surface temperature data. Therefore, the 

similarities of the final temperature trends resulting from the processing of the raw data 

between the three groups provide additional confidence in those processing routines. 

Additionally, the GHCN data are available online, so it is possible for independent parties 

to test their own algorithms for producing global temperature records from the raw data. 

Petitioners and others have not done so, and instead rely on arguments and claims, 

discussed above, that do not support the broad conclusions they draw. Finally, the 

temperature trends derived from these datasets are consistent with modeling, satellite 

data, and various observational indicators, further supporting their reliability. 

Comment (1-77): 

Peabody Energy, the Southeastern Legal Foundation (in their Third Amendment to 

Petition), and the Competitive Enterprise Institute all argue that the “similar trends” 

between the three major surface temperature records are not sufficient if the three 

datasets are not independent and are, in the words of the Competitive Enterprise Institute, 

“extensively compromised.” Peabody Energy states: 

EPA says that the NOAA and NASA surface temperature records show “similar trends” 

as the HadCRUT3 data set and hence the IPCC’s and EPA’s reliance on the HadCRUT3 

records is not unreasonable.246 This contention does not hold up. The HadCRUT3 data 

was relied on extensively by the IPCC and in numerous studies cited by both the EPA 

and all of the “assessment literature” that EPA cites. It is not enough for EPA to say that 

the HadCRUT3 data reveals “similar trends” as other data. The specific amount of 

warming that occurred during the last several decades of the 20th century, and how that 

warming compares to other periods in the temperature record, was obviously critically 

important in all of these studies. Many of these studies involved complex statistical 

analyses of the underlying data. Those studies may have yielded different results had 

they used the NASA or NOAA data instead of the HadCRUT3 data. 

Moreover, there are now significant questions about whether the NASA and NOAA 

temperature records are truly independent of the HadCRUT3 data set. In this regard, the 

investigation of the Science and Technology Committee of the United Kingdom Parliament 

that was recently initiated to investigate CRU’s conduct includes investigation into the 

question of “How independent are the other two international data sets?”247 This is a 

critically important question given EPA’s view, based on the IPCC, that the rate and 

extent of warming in the last several decades of the 20th century is the key “fingerprint” 

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of an anthropogenic GHG cause. If that warming has been overstated in all three data 

sets, then the “fingerprint” disappears, or grows more faint even if all three data sets 

show “similar” warming. 

Response (1-77): 

As EPA shows throughout these responses, the petitioners have not demonstrated that 

there are flaws in the global temperature datasets that would call into question the clear 

warming trends. In addition, these issues were raised during notice and comment on the 

Endangerment Findings, and EPA responded in Volume 2 of the RTC document. The 

full statement from RTC 2-29 was: 

EPA has concluded that the three primary global surface temperature records (NOAA, 

NASA, and HadCRUT) are reliable and credible. We note that these datasets have been 

widely reviewed and assessed within the climate change research community, and that 

while they are distinct and use different approaches, there is good agreement in the 

overall trend (as described in response 2-28). 

EPA did not state that the similar trend was the only basis for concluding that the 

HadCRUT temperature record was reliable. EPA also recognizes that each temperature 

record includes possible errors as discussed both in the RTC and in this RTP Document. 

However, potential errors are reflected in the uncertainty assessments developed for these 

datasets, such as the Brohan et al. (2006) figure reproduced in Subsection 1.3.2, and are 

small compared with the overall trend. The petitioner provides no evidence that any 

study would have yielded substantially different conclusions had it used the NOAA or 

NASA temperature records instead of HadCRUT. Indeed, many studies do use these 

other datasets. 

Additionally, the British House of Commons Science and Technology Committee report 

(2010), referred to by the petitioner, has been released. With respect to the independence 

of these datasets, it states: 

48. In its memorandum UEA explained the differences between the methodologies used by 

three basic datasets for land areas of the world, NOAA, NASA and CRU/UEA: 

All these datasets rely on primary observations recorded by NMSs [National 

Meteorological Services] across the globe. 

GISS and NCDC each use at least 7,200 stations. CRUTEM3 uses fewer. In 

CRUTEM3, each monthly temperature value is expressed as a departure from the 

average for the base period 1961–90. This “anomaly method” of expressing 

temperature records demands an adequate amount of data for the base period; this 

limitation reduces the number of stations used by CRUTEM3 to 4,348 (from the 

dataset total of 5,121). The latest NCDC analysis [...] has now moved to the 

“anomaly method” though with different refinements from those of CRU. 

NCDC and GISS use different approaches to the problem of “absolute temperature” 

from those of CRUTEM3. The homogeneity procedures undertaken by GISS and 

NCDC are completely different from those adopted for CRUTEM3. NCDC has an 

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automated adjustment procedure [...], whilst GISS additionally makes allowances for 

urbanization effects at some stations. 

49. In our call for evidence we asked for submissions on the question of how independent 

the other international data sets are. We have established to the extent that a limited 

inquiry of this nature can, that the NCDC/NOAA and GISS/NASA data sets measuring 

temperature changes on land and at sea have arrived at similar conclusions using similar 

data to that used by CRU, but using independently devised methodologies. We have 

further identified that there are two other data sets (University of Alabama and Remote 

Sensing Systems), using satellite observations that use entirely different data than that 

used by CRU. These also confirm the findings of the CRU work. We therefore conclude 

that there is independent verification, through the use of other methodologies and other 

sources of data, of the results and conclusions of the Climate Research Unit at the 

University of East Anglia. 

50. The fact that all the datasets show broadly the same sort of course of instrumental 

temperature change since the nineteenth century compared to today was why Professor 

John Beddington, the Government Chief Scientific Adviser, had the confidence to say 

that human induced global warming was, in terms of the evidence to support that 

hypothesis, “unchallengeable”: 

I think in terms of datasets, of the way in which data is analysed, there will always be 

some degree of uncertainty but when you get a series of fundamentally different 

analyses on the basic data and they come up with similar conclusions, you get a [...] 

great deal of certainty coming out of it. 

51. Even if the data that CRU used were not publicly available—which they mostly are—or 

the methods not published—which they have been—its published results would still be 

credible: the results from CRU agree with those drawn from other international data sets; in 

other words, the analyses have been repeated and the conclusions have been verified. 

Therefore, EPA finds that the three major global surface temperature records use 

independent methodologies, though they do share a large quantity of the same raw data. 

Because the results are robust to different choices of and adjustments to the raw data, and 

because there are additional data (from satellites, oceans, ice sheets, ecosystem shifts, and 

so forth) that are consistent with these surface temperature records, there is great 

confidence in the major conclusions based on these records of historical temperature 

change (within the acknowledged uncertainty limits). Petitioners inappropriately look at 

the overlap of underlying raw data in isolation, and draw conclusions about the resulting 

temperature records based on this. EPA’s confidence in the results shown by the various 

global surface temperature records is based on considering all of the evidence, including 

the differences and similarities in the analyses performed by NOAA, NASA, and CRU, 

and the consistency with other records of warming, as discussed above. 

Comment (1-78): 

The State of Texas quotes EPA as stating that "The NOAA global surface temperature 

dataset (Smith et al., 2008) employs the same methodology for addressing urbanization as 

is used in the HadCRUT." and draws the conclusion that “two of the three temperature 

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sets that EPA relied on to reach its Endangerment Finding were homogenized based on 

CRU mathematical models.” 

Response (1-78): 

EPA has already addressed these issues in Responses 1-76 and 1-77 above, as well as 

other UHI issues in Subsection 1.3.4. While NOAA does use urbanization uncertainty 

estimates based on the methodology developed by CRU, that urbanization estimate is 

only a small part of the full analysis, and not used for the U.S. portion of the temperature 

record. Therefore, it is not correct to state that two of the three temperature sets that EPA 

relied on were homogenized based on CRU mathematical models. 

1.4.3.6 Additional Issues Regarding Allegations of Manipulation of Data 

Comment (1-79): 

The Coalition for Responsible Regulation claims that there was another type of 

“manipulation of data to produce the outcome IPCC authors wanted” related to the 

temperature data. In support of their assertion that “Emails contained in the Disclosures 

confirm certain scientists’ efforts to ‘artificially adjust’ data through active 

collaboration,” the Coalition for Responsible Regulation provides the following evidence: 

Sept. 27, 2009 (Tom Wigley, of the University Corporation for Atmospheric Research, 

(UCAR) strategizing “to partly explain the 1940s warming blip,” and noting that “if we 

could reduce the ocean blip by, say, 0.15 degC, then this would be significant for the 

global mean - but we’d still have to explain the land blip . . . It would be good to remove 

at least part of the 1940s blip, but we are still left with `why the blip’.”) 

Response (1-79): 

We first note that this quote is clearly not related to the IPCC AR4. In the e-mail, Wigley 

explicitly states that he was working on a report that he was “writing for EPRI” (the 

Electric Power Research Institute).50 There is no evidence that the analysis was 

performed or that it was used in IPCC reports, or how it was a “manipulation of data to 

produce the outcome IPCC authors wanted.” 

In addition, there is a known issue with the sea surface data in the 1940s that was recently 

highlighted by Thompson et al. (2008). This is based on the shift from recording sea 

surface temperature mainly by U.S. vessels (already using modern engine intake 

measurements) to a higher percentage of UK vessels (still using the older bucket 

measurements) after the end of World War II. The e-mail from Wigley does not make 

clear whether this is or is not the attempt of a modeler to assess potential implications of 

correcting for known biases in the instrumental ocean record in the 1940s. The language 

from Wigley suggests that he is interested in an explanation for the existence of a “land 

blip” in addition to the ocean blip. This makes sense in the context of the Thompson et 

al. paper. This paper explains the ocean blip as being the result of an artificial bias of 

 

50 E-mail file 1254108338.txt, (September 27, 2009), page 1743, line 15 of PDF version entitled: CRU 

Emails 1996-2009.pdf 

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shifting to U.S. ships during World War II, but this explanation of bias would not explain 

a blip in land temperatures. Therefore, a full explanation of the historical temperature 

record would require some other rationale for the “land blip,” whether an actual 

temperature event due to natural variability, or another artificial bias due to some other 

issue involved with temperature records during World War II. It is normal science to 

work to understand the minor variations or wiggles in the temperature record. In 

addition, Wigley’s language does not appear to be the language of someone trying to 

“artificially adjust data” for a deceitful purpose. Note that Wigley specifically is not 

suggesting any adjustments to the land record of that time period. Therefore, the 

petitioners’ evidence is too vague and uninformative to support a claim of improper data 

manipulation particularly in the context of IPCC assessments. 

Comment (1-80): 

The Coalition for Responsible Regulation quotes a number of e-mails in support of their 

contention that scientists “artificially adjust” data: 

The pressure to conform to a perceived “global warming” consensus also led to 

manipulation of data to produce the outcome IPCC authors wanted. Emails and computer 

code contained in the Disclosures reveal that scientists at CRU manipulated their 

temperature databases and their findings with undisclosed, unverified and arbitrary 

adjustments. See supra, Section III(A) and (B). Emails contained in the Disclosures 

confirm certain scientists’ efforts to “artificially adjust” data through active collaboration 

to “reduce the positive slope,” “reduce the ocean blip,” and “contain the medieval warm 

period.” See, e.g., Exhibit A, 843161829.txt, Sept. 19, 1996 (Gary Funkhouser, of the 

University of Arizona, writing to Briffa, "I really wish I could be more positive about the 

Kyrgyzstan material, but I swear I pulled every trick out of my sleeve trying to milk 

something out of that");51 Exhibit A, 1163715685.txt, Nov. 16, 2006 (Briffa noting that 

“the PC1 time series in the Mann et al. analysis was adjusted to reduce the positive slope 

in the last 150 years,” and that “this adjustment was arbitrary and the link between 

Bristlecone pine growth and CO2 is, at the very least, arguable.”); 52Exhibit A, 

1254108338.txt, Sept. 27, 2009 (Tom Wigley, of the University Corporation for 

Atmospheric Research, (UCAR) strategizing "to partly explain the 1940s warming blip,” 

and noting that “if we could reduce the ocean blip by, say, 0.15 degC, then this would be 

significant for the global mean - but we’d still have to explain the land blip . . . It would 

be good to remove at least part of the 1940s blip, but we are still left with ‘why the 

blip’.”); 53Exhibit A, 1059664704.txt, July, 31, 2003 (Mann sending calibration residuals 

to Tim Osborn, at CRU, and acknowledging that some are “pretty red,” and asking 

Osborn not to “pass this along to others without checking w/ me first. This is the sort of 

‘dirty laundry’ one doesn’t want to fall into the hands of those who might potentially try 

to distort things...”);54 Exhibit A, 0939154709.txt, Oct. 15, 1999 (Osborn discussing how 

 

51 E-mail file 0843161829.txt, (September 19, 1996), page 11, lines 12-14 and 15-16 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

52 E-mail file 1163715685.txt, (November 16, 2006), page 1239, lines 9-10 and 15-16 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

53 E-mail file 1254108338.txt, (September 27, 2009), page 1742-1743, line 45-46 and 6-7 of PDF version 

entitled: CRU Emails 1996-2009.pdf 

54 E-mail file 1059664704.txt, (July 31, 2003), page 558, line 23-25 of PDF version entitled: CRU Emails 

1996-2009.pdf 

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data are truncated to stop an apparent cooling trend that appears in the results);55 Exhibit 

A, 1054736277.txt, June 4, 2003 (Mann noting “it would be nice to try to ‘contain’ the 

putative ‘MWP’ [Medieval Warm Period]”).56

Response (1-80): 

EPA responds to these allegations of data manipulation in Subsection 1.1.4 of this 

Response to Petitions document. These e-mails are in general quoted out of context and 

in many cases are examples of scientists following appropriate procedures of not using 

data that doesn’t meet proper standards (e.g., Funkhouser) or testing the impacts of 

hypotheses (e.g., Wigley). Only two quotes were not addressed in those previous 

sections, and these two quotes are addressed here. 

First, with regards to the calibration residuals mentioned in the e-mail from Mann to 

Osborn, Mann also states in the same e-mail, “In any case, the incremental changes are 

modest after 1600--its pretty clear that key predictors drop out before AD 1600, hence the 

redness of the residuals, and the notably larger uncertainties farther back...”. This quote 

indicates that the redness of the residuals (a term related to the type of noise in the signal: 

white noise is perfectly random, red noise indicates a “random walk” where the signal 

can drift over time) are already reflected in the fact that the uncertainties presented in the 

paper are “notably larger” before 1600. This is also consistent with the general 

conclusions of the NRC (2006) and the IPCC (2007c) assessments. In fact, the paper 

discussed in the e-mail (MBH1999) (Mann et al., 1999) explicitly discusses red noise in 

the context of reconstructions, though it does not present the specific data that Mann is 

sharing with Osborn. In other words, the e-mail quote is consistent with the published 

literature. 

The Osborn e-mail discussing data truncation “to stop an apparent cooling trend” is a 

reference to the divergence issue discussed in Section 1.1 on Paleoclimate 

Reconstructions and the “Divergence” Issue, and as discussed in that section the 

divergence issue was well known in the literature, and therefore this e-mail is not 

evidence of inappropriate data manipulation. 

1.4.4 Summary 

The observed warming of the climate is an important factor in the Endangerment Finding. 

The Finding states, “The global surface temperature record relies on three major global 

temperature datasets developed by NOAA, NASA, and the United Kingdom’s Hadley 

Center. All three show an unambiguous warming trend over the last 100 years, with the 

greatest warming occurring over the past 30 years.” The Finding notes that this observed 

warming is observed in surface and ocean temperatures, melting of snow and ice, rising 

sea levels, and other evidence as well. Petitioners do not attempt to review the body of 

scientific evidence and show that the conclusion on warming is inaccurate or more 

 

55 E-mail file 0939154709.txt, (October 15, 1999), page 229, line 32 of PDF version entitled: CRU Emails 

1996-2009.pdf 

56 E-mail file 1054736277.txt, (June 4, 2003), page 520, lines 7-8 of PDF version entitled: CRU Emails 

1996-2009.pdf 

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uncertain than indicated. Instead they contest certain individual aspects or details of the 

surface temperature evidence, and in general raise objections that fail to take into account 

the context and reason behind various aspects of the surface temperature record. 

Many of the issues raised by the petitioners are not new, and have been addressed within 

the TSD and RTC documents. Some objections fail to distinguish assessments that 

evaluate absolute temperature rather than changes in temperature. The petitioners, and 

the researchers on which the petitioners rely, repeatedly use incorrect methodology to 

make their claims. They average temperatures between stations without using anomalybased methods that properly take into account the change in temperature rather than the 

absolute temperature, and they average together stations without methods that account for 

the geographic distribution of these stations. These basic and fundamental flaws underlie 

many of the petitioner’s arguments. 

Other objections misconstrue the underlying studies. In several cases petitioners object 

that various adjustments to the raw data have an effect of changing the data, but they fail 

to consider that adjustments to the data are appropriately performed for the purpose of 

having an effect: to account for circumstances that otherwise would interfere with 

accurately isolating and determining a trend in surface temperature. For example, 

adjustments are made to account for the effect of a change in the measurement devices, 

so that such changes do not interfere with accurately assessing any change in the actual 

surface temperature. Petitioners fail to address the reasons behind the adjustments and 

fail to explain or show that the types of adjustments are not appropriate. Petitioners also 

fail to account for the various analyses which generally show that the same temperature 

trends result on a global scale using the adjusted or unadjusted temperature data, 

Likewise petitioners fail to account for the valid data-driven reasons that have led to a 

reduction over time in the number of weather stations used for the surface temperature 

analysis, fail to explain or show that the reductions have biased the temperature record, 

and overstate the magnitude of the reduction in some cases. Petitioners fail to account for 

the analyses that show even a limited number of stations can provide a robust global 

temperature trend, and the same trends are indicated using only those stations that were 

not reporting data after 1992 or the stations that were reporting data the entire time. 

Petitioners fail to explain why consistency between all three separate surface temperature 

records, as well as consistency between the three surface temperature records and other 

evidence of warming, such as satellite data, ocean temperature data, physical evidence of 

the effects of warming, should not be seen as confirmation of the evidence of warming. 

Petitioners instead appear to assume that all of this evidence must be wrong because they 

allege some of it is, and implicitly suggest EPA do the same. 

Overall, petitioners’ arguments about the portions of the evidence they focus on fail to 

withstand scrutiny. They also fail to evaluate and take into account the entire body of 

evidence before EPA. The arguments made by petitioners do not change EPA’s views on 

the validity and reliability of the three major surface temperature records, or the overall 

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body of evidence supporting the basic conclusion that there is an unambiguous warming 

trend over the last 100 years, with the greatest warming occurring over the past 30 years. 

1.5 Implications of New Studies and Data Submitted by the Petitioners

1.5.1 Overview 

Several petitioners identify new scientific studies and data published since the 

Endangerment Finding was finalized, which they claim require EPA to reconsider our 

Finding. Some petitioners also argue that EPA ignored or misinterpreted scientific data 

that were significant and available when the Finding was made. 

EPA has reviewed the new literature provided by petitioners. In many cases, we note that 

the issues raised by the petitioners are not new, but were in fact raised and addressed 

during notice and comment on the Endangerment Findings. In other cases, petitioners 

have misinterpreted or misrepresented the meaning and significance of the scientific 

literature, findings, and data they cite. Finally, there are instances where the petitioners 

have failed to take into account relevant other new studies in making their arguments. 

The following issues are addressed in this section: 

 Implications of a new study on stratospheric water vapor. 

 Implications of material concerning whether CO2 is well mixed in the atmosphere 

and whether the airborne fraction of CO2 has changed. 

 Implications of new tropical cyclone studies. 

 Implications of new data on observational snow cover trends. 

 A claim that EPA ignored a satellite dataset. 

After reviewing all of these issues, EPA concludes that the studies, data, and arguments 

presented by petitioners do not change the solid scientific basis for the Administrator’s 

Finding. 

1.5.2 Implications of a New Study on Stratospheric Water Vapor 

Comment (1-81): 

Several petitioners (the Competitive Enterprise Institute, Coalition for Responsible 

Regulation, Peabody Energy) argue that a new study published by Solomon et al. (2010), 

“Contributions of Stratospheric Water Vapor to Decadal Changes in the Rate of Global 

Warming,” demonstrates that scientific understanding of the causes of climate change is 

incomplete. This study finds that stratospheric water vapor concentrations decreased by 

about 10% after 2000, and that this decrease slowed the rate of increase in global surface 

temperature over the period 2000– by about 25% compared with that which would have 

occurred due only to CO2 and other GHGs. According to the Coalition for Responsible 

Regulation, the study’s findings “indicate that human emissions may have a considerably 

smaller role in climate change than previously thought.” Peabody Energy concludes that 

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the study “provides another example of how unsettled global warming science actually 

is.” 

Response (1-81): 

This study improves our understanding of how changes in the composition of the 

stratosphere can act to enhance or dampen GHG-induced climate change. Contrary to the 

petitioners’ claims, it does not demonstrate that anthropogenic GHG emissions play a 

smaller role in climate change. Just as reductions in stratospheric water vapor might have 

acted to decrease warming from 2000 to 2009, the study finds that increases in 

stratospheric water might have acted to steepen the observed warming trend in the 1990s. 

The study’s authors make no claim that global warming science is “unsettled.” In fact, 

they introduce the study with the following statement: “Over the past century, global 

average surface temperatures have warmed by about 0.75°C. Much of the warming 

occurred in the past half-century, over which the average decadal rate of change was 

about 0.13°C, largely due to anthropogenic increases in well-mixed greenhouse gases.” 

The study improves scientific understanding of effects of changes in atmospheric 

composition on climatic observations, and it should lead to further improvements in the 

representation of stratospheric processes in models, allowing more refined projections of 

short-term climate behavior. As the study concludes (Solomon et al., 2010): “This work 

highlights the importance of using observations to evaluate the effect of stratospheric

water vapor on decadal rates of warming, and it also illuminatesthe need for further 

observations and a closer examination ofthe representation of stratospheric water vapor 

changes in climate models aimed at interpreting decadal changes and for future

projections.” 

This study does not have meaningful implications for the Endangerment Finding, as it 

does not cast doubt on the fundamental role that GHGs have in climate change. As 

Solomon told the New York Times (Bhanoo, 2010): 

This [study] doesn’t alter the fundamental conclusion that the world has warmed and that 

most of that warming has to do with greenhouse gas emissions caused by man. 

As in almost all areas of scientific endeavor, further research often leads to greater 

understanding, but contrary to the petitioners’ claim, an advance in knowledge does not 

per se mean the prior knowledge base was any more or less certain or settled. The 

advance in knowledge needs to be put in context to understand its meaning, and 

petitioners fail to do that. In this case, the study increases our knowledge of other factors 

that can amplify or reduce the warming effect of GHGs, but it does not change in any 

way the warming trend that is expected from the GHGs themselves. 

1.5.3 Implications of Material Indicating That CO2 Is Not Well Mixed in the 

Atmosphere and That the Airborne Fraction of CO2 Has Not Changed 

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Comment (1-82): 

One petitioner (the Southeastern Legal Foundation) refers to literature that it claims alters 

our understanding of the distribution of CO2 in the atmosphere. The Southeastern Legal 

Foundation challenges the long-held conclusion that CO2 is well mixed in atmosphere 

(i.e., that its concentration is about the same everywhere across the globe). It cites a 

NASA press release (NASA, 2009c, dated December 15, 2009), which describes findings 

drawn from data taken from its Atmospheric Infrared Sounder (AIRS) instrument on the 

Aqua spacecraft. In this press release, NASA reports: 

...data have shown that, contrary to prior assumptions, carbon dioxide is not well mixed 

in the troposphere, but is rather “lumpy.” Until now, models of carbon dioxide transport 

have assumed its distribution was uniform. 

The Southeastern Legal Foundation states that the “AIRS satellite has collected data 

refuting the well-mixed assumption” and that the “well-mixed assumption is 

indispensible to AGW model of the CO2 cycle.” 

 

Response (1-82):

We agree with NASA that on shorter time scales, there is some variability in the 

distribution of CO2 and that it is not uniformly mixed. This has long been known. For 

example, Seinfeld and Pandis (1998) discuss hemispheric and seasonal differences in 

CO2 distribution. In fact, we acknowledge this behavior in the RTC (2-8), noting that 

there is a period of time or a lag before long-lived gases become well mixed in the 

atmosphere: “all long-lived gases become well-mixed at large distances from their 

sources or sinks over a period of one to two years.” It is, therefore, not surprising that 

there may be some variability in CO2 concentrations averaged over a month as shown in 

this NASA image (referenced by the Southeastern Legal Foundation, NASA, 2009b): 

137
 

But even this variability is small in magnitude, only on the order of 1.5 to 2% at most 

across this highly sensitive concentration gradient. 

CO2’s variability is especially small compared with GHGs that are traditionally described 

as non-well-mixed, such as tropospheric ozone, the concentration of which typically 

varies by a factor of 10 as shown in the July 2009 graphic from NASA below (NASA, 

2009d), and water vapor, as also shown below from May 2009 in a graphic from NASA 

(NASA, 2009a): 

138
The relatively low spatial variability in CO2 shown in the AIRS imagery would even be 

smaller averaged over a longer time scale. While NASA’s press release does not 

distinguish between short and long time scales, there is no ambiguity that CO2 is well 

mixed on time scales relevant to the study of climate change—decades—as documented 

in the assessment literature and discussed by EPA. In referring to the group of wellmixed GHGs, including CO2 (methane and nitrous oxide), the IPCC (Solomon et al., 

2007) states: 

Because these gases are long lived, they become well mixed throughout the atmosphere 

much faster than they are removed and their global concentrations can be accurately 

estimated from data at a few locations. 

When NASA states that researchers had not previously assumed CO2 is “lumpy” as the 

AIRS data visualizations demonstrate, it is to highlight the improvements in resolution of 

small-scale CO2 variability made possible by the AIRS data. The data allow scientists to 

see the very limited variability in CO2 in much finer detail than before. The fact that this 

finer detail has not yet been incorporated into CO2 transport models is not relevant for the 

projections of climate change on which EPA’s Endangerment Finding relied. For further 

discussion about the relevance of this NASA finding for computer models, see Response 

1-84. 

Comment (1-83): 

Background: The Southeastern Legal Foundation raises an issue concerning our 

understanding of how CO2 in the atmosphere cycles through the Earth system. As 

background, some of the CO2 that is emitted to the atmosphere remains in the 

atmosphere, and some of it is absorbed by other parts of the Earth system, for example, 

139
the oceans and terrestrial biosphere (vegetation and trees) sometimes referred to as CO2

“sinks.” The portion of CO2 that remains in the air is known as the “airborne fraction.” 

If the airborne fraction of CO2 increases, the rate of global warming would likely 

increase. EPA states in Section 6(a) of the TSD (U.S. EPA, 2009): 

....for future projections, Meehl et al. (2007) found “unanimous agreement among the 

coupled climate carbon cycle models driven by emission scenarios run so far that future 

climate change would reduce the efficiency of the Earth system (land and ocean) to 

absorb anthropogenic CO2. As a result, an increasingly large fraction of anthropogenic 

CO2 would stay airborne in the atmosphere under a warmer climate.” 

Comment: The Southeastern Legal Foundation disputes the IPCC’s projection cited by 

EPA that the airborne fraction of CO2 will increase and disputes whether CO2 is wellmixed. Southeastern Legal Foundation claims the airborne fraction will not increase 

because the airborne fraction metric has been relatively constant since 1850 according to 

a study the Southeastern Legal Foundation cites by Knorr (2009). Specifically, Knorr 

(2009) finds: 

It is shown that with those uncertainties, the trend in the airborne fraction since 1850 has 

been ... close to and not significantly different from zero. 

The Southeastern Legal Foundation concludes that the Knorr study: 

... gravely undermines the assumption that CO2 is long-lived and well-mixed and by the 

same token dovetails with NASA’s observations that CO2 is in fact not well-mixed, and 

with many experimental proofs that CO2 has a short residence time. 

Response (1-83):

The Southeastern Legal Foundation presents no new evidence to challenge the IPCC’s 

projections, as summarized by EPA. The Knorr (2009) finding is not new. Section 6(a) 

of the TSD, referring to the assessment literature (IPCC), describes exactly the same 

conclusion as found in Knorr: 

Historically, the airborne fraction of CO2 ... has shown no long term trend ... (Denman et 

al., 2007). 

However, there are several scientific problems with the Southeastern Legal Foundation’s 

conclusion that the Knorr study “gravely undermines the assumption that CO2 is longlived and well-mixed.” First, by itself a trend in the airborne fraction of a gas provides 

no information about its atmospheric lifetime and whether it is well mixed, and the 

Southeastern Legal Foundation offers no explanation to the contrary. Second, as 

discussed in Response 1-82 above, NASA’s observations do not change the finding that 

the CO2 is well mixed on time scales relevant to the study of climate change. Third, the 

Southeastern Legal Foundation’s reference to “proofs” that CO2 has a short residence 

time, citing work by Segalstad (e.g., Segalstad, 1997), were responded to in Volume 2 of 

EPA’s RTCs in the endangerment record. After reviewing this public comment, EPA 

determined (in RTC 2-3) that Segalstad’s work “does not address the lifetime of a change 

in atmospheric concentration of CO2, but rather the lifetime in the atmosphere of an 

140
individual molecule of CO2” and that these “are two different concepts.” This confusion 

of residence time and the adjustment time in the atmosphere is discussed at length in 

O’Neill (1997). 

In addition, the latest scientific research suggests that the airborne CO2 fraction is likely 

increasing—consistent with future projections. A recent (December 2009) study (Le 

Quéré et al., 2009) published in Nature Geoscience updates trends in the sources and 

sinks of CO2 and finds: “In the past 50 years, the fraction of CO2 emissions that remains 

in the atmosphere each year has likely increased, from about 40% to 45%, and models 

suggest that this trend was caused by a decrease in the uptake of CO2 by the carbon sinks 

in response to climate change and variability.” 

The Southeastern Legal Foundation does not acknowledge or take into account this new 

study. 

Comment (1-84): 

Southeastern Legal Foundation suggests that the current computer models on which EPA 

relies are based on assumptions that are challenged by the NASA finding regarding CO2

not being well mixed and the Knorr study discussed above (in Response 1-82 and 1-83). 

It concludes: “These results contradict the IPCC’s version of the carbon cycle, on which 

the climate models and claims of catastrophic AGW are based” and that EPA should, 

therefore, reconsider its Endangerment Finding. 

Response (1-84): 

As described above (in Response 1-82), the NASA finding does not refute the wellestablished conclusion that CO2 is well mixed on time scales relevant to the study of 

climate change. Moreover, the primary finding of the Knorr (2009) study cited by the 

Southeastern Legal Foundation pertaining to trends in the CO2 airborne fraction is not 

new and was already reflected in EPA’s TSD. The information presented by the 

Southeastern Legal Foundation does not change or undermine either the view that GHGs 

are long lived and well mixed, in the time scales relevant to climate change projections, 

or the basis for scientific projections suggesting the airborne fraction of CO2 will increase 

as the climate warms. And, in fact, another peer-reviewed study (Le Quéré et al., 2009) 

presents contrasting results finding an increase in the airborne fraction in the past 50 

years. 

Significantly, the same NASA press release that the Southeastern Legal Foundation cites 

concerning the short term “lumpy” distribution of CO2 provides validation for the climate 

models results cited by EPA in the TSD which project substantial CO2-induced warming 

(NASA, 2009c): 

“AIRS temperature and water vapor observations have corroborated climate model 

predictions that the warming of our climate produced as carbon dioxide levels rise will be 

greatly exacerbated -- in fact, more than doubled -- by water vapor,” said Andrew 

Dessler, a climate scientist at Texas A&M University, College Station, Texas. 

141
Dessler explained that most of the warming caused by carbon dioxide does not come 

directly from carbon dioxide, but from effects known as feedbacks. Water vapor is a 

particularly important feedback. As the climate warms, the atmosphere becomes more 

humid. Since water is a greenhouse gas, it serves as a powerful positive feedback to the 

climate system, amplifying the initial warming [caused by CO2]. AIRS measurements of 

water vapor reveal that water greatly amplifies warming caused by increased levels of 

carbon dioxide. Comparisons of AIRS data with models and re-analyses are in excellent 

agreement. 

In summary, the Southeastern Legal Foundation’s evidence and arguments do not change 

the validity of EPA’s characterization of CO2 and/or the carbon cycle, or their 

representation in climate models whose results were cited in support of the Endangerment 

Finding. 

1.5.4 Implications of New Tropical Cyclone Studies 

Comment (1-85): 

Two petitioners (the Competitive Enterprise Institute and the Southeastern Legal 

Foundation) present new studies that provide new and/or updated information on 

1) historical trends in tropical cyclone activity, including frequency and intensity, and 

2) whether these trends can be attributed to anthropogenic GHGs. The petitioners claim 

that the conclusions of these studies cast doubt on EPA’s characterization of these issues 

in the Endangerment Finding and therefore require a reconsideration of the Finding. 

The Competitive Enterprise Institute provides a study by Hatton (2010) titled, “Has the 

Intensity and Frequency of Hurricanes Increased?” This non-peer-reviewed study 

analyzes trends in hurricane data from 1999 to 2009 tested against the period from 1946 

to 2009. It finds “that hurricane intensity and frequency is significantly higher in this 

period [1999–2009] in the North Atlantic. However in the Eastern Pacific, Western 

Pacific, and Northern and Southern Indian oceans, there is no evidence of significant 

change.” The Competitive Enterprise Institute states that this finding “undermines EPA’s 

own claims regarding the supposedly increased risk of storms and hurricanes.” 

Southeastern Legal Foundation presents a peer-reviewed study from Knutson et al. 

(2010). This study, developed under the auspices of the WMO, evaluates the current 

state of knowledge of tropical cyclones and climate change. The Southeastern Legal 

Foundation highlights two key findings from the study: 

1) “In terms of global tropical cyclone frequency, it was concluded that there was no 

significant change in global tropical storm or hurricane numbers [i.e. frequency] from 

1970 to 2004, nor any significant change in hurricane numbers [i.e. frequency] for any 

individual basin over that period, except for the Atlantic...” 

2) “....we cannot at this time conclusively identify anthropogenic signals in past tropical 

cyclone data.” 

142
On the basis of these findings, the Southeastern Legal Foundation argues, “EPA should 

reconsider its conclusions that GHGs endanger human health and welfare.” 

Response (1-85): 

We have reviewed both of the studies and considered their implications for EPA’s 

characterization of trends in tropical cyclone activity, including frequency and intensity, 

and our ability to attribute the trends to anthropogenic GHGs. 

With respect to observed trends in frequency and intensity of tropical cyclones, the 

findings in these two studies are, in fact, consistent with EPA’s TSD and the 

Endangerment Finding. The TSD states in Section 4(k), “Kunkel et al. (2008) refer to a 

study that was not able to corroborate the presence of upward intensity trends over the 

last two decades in ocean basins other than the North Atlantic” and “there is no clear 

trend in the annual numbers [i.e. frequency] of tropical cyclones [globally]...”. Specific 

to trends in the North Atlantic, the TSD states in Section 4(l): “IPCC (2007b) and Karl et 

al. (2009) report observational evidence of an increase in intense tropical cyclone activity 

in the North Atlantic (where cyclones develop that affect the U.S. East and Gulf Coasts) 

since about 1970, correlated with increases of tropical sea surface temperatures of nearly 

2oF (1oC) in the main Atlantic hurricane development region (Karl et al., 2009). The 

strongest hurricanes (Category 4 and 5) have, in particular, increased in intensity (Karl et 

al., 2009).” 

EPA’s characterization of whether any trends in tropical cyclone activity (either 

frequency or intensity) could be attributed to anthropogenic GHGs, drawn from the 

IPCC, does differ slightly from the Knutson et al. study (the Hatton study does not 

address attribution). Knutson found no conclusive evidence of an anthropogenic signal in 

observed hurricane activity to date, and like Knutson, the TSD did not claim any such 

conclusive evidence. Instead, the TSD states in Section 5(a) that it is “more likely than 

not that anthropogenic influence has contributed to increase in the frequency in the most 

intense storms.” After that statement, EPA provided the following caveat, reflecting the 

uncertainty in science regarding attribution, stating: 

... the IPCC (Hegerl et al., 2007) cautions that detection and attribution of observed 

changes in hurricane intensity or frequency due to external influences remains difficult 

because of deficiencies in theoretical understanding of tropical cyclones, their modeling, 

and their long-term monitoring. 

Importantly, given this uncertainty, EPA did not refer to any anthropogenic signal in 

historical tropical cyclone trends in the Findings themselves (nor in the Executive 

Summary of the TSD) and instead focused only on the limited evidence of a directional 

trend in the Atlantic, and more importantly on increasing future risks (Section I.A. of the 

Findings): 

The conclusion in the assessment literature that there is the potential for hurricanes to 

become more intense (and even some evidence that Atlantic hurricanes have already 

become more intense) reinforces the judgment that coastal communities are now 

143
endangered by human-induced climate change, and may face substantially greater risk in 

the future. 

The risk of stronger hurricanes in the future is echoed by the Knutson et al. (2010) study, 

which finds: 

...future projections based on theory and high-resolution dynamical models consistently 

indicate that greenhouse warming will cause the globally averaged intensity of tropical 

cyclones to shift towards stronger storms... 

In summary, the new studies presented by petitioners are consistent with EPA’s 

characterization of observed tropical cyclone trends. The Knutson et al. (2010) study 

reaches a slightly revised conclusion on an anthropogenic GHG signal to date, but the 

revision is not meaningful considering EPA’s qualified discussion of the issue and the 

similarities in EPA’s and Knutson et al.’s characterization of future projections. 

1.5.5 Implications of New Studies on the Statistical Significance of Increases 

in Antarctic Sea Ice 

Comment (1-86): 

The Southeastern Legal Foundation discusses two studies (Comiso and Nishio, 2008; 

Turner et al., 2009), which it alleges find that the observed increase in Antarctic sea ice is 

statistically significant. The petitioner argues that this finding is contrary to information 

in the record for EPA’s Endangerment Finding, as well as information contained in the 

IPCC AR4. It states: “If the increase [in Antarctic sea ice] is statistically significant, then 

it is yet another empirical refutation of the IPCC models, which predict a loss of sea ice 

in the Antarctic.” It ultimately concludes: 

EPA has contradicted the literature and mischaracterized the statistical significance of the 

trend in Antarctic sea ice extent increase. It appears that this mischaracterization permits 

EPA to claim that the model projections have not been refuted and remain “robust” even 

though any fair analysis shows they have been at best undermined and at worst falsified. 

Response (1-86): 

EPA has reviewed the petitioner’s submission of Comiso and Nishio (2008) and Turner 

et al. (2009) and finds that it was not impracticable to raise the objection during the 

public comment period and that the reasons for the objection did not arise between June 

24, 2009, and February 16, 2010. Nonetheless, we have reviewed these arguments and 

responded. 

The first study by Comiso and Nishio (2008) computes a positive trend in Antarctic sea 

extent of 0.9 ± 0.2% per decade since the late 1970s, but contrary to the assertion of the 

Southeastern Legal Foundation, the study does not assess statistical significance. The 

second study, Turner et al. (2009), states, “the annual mean extent of Antarctic sea ice 

has increased at a statistically significant rate of 0.97% per decade since the late 1970s.” 

In other words, both studies compute a similar trend, and one assesses statistical 

significance while the other does not. 

144
In Section 4(i) of the TSD, EPA cites U.S. National Snow and Ice Data Center (NSIDC) 

data indicating that for the period 1979–2008, Antarctic sea ice had undergone a not 

statistically significant increase of 0.9% per decade (U.S. EPA, 2009). Although the 

conclusion about statistical significance differs from Turner et al. (2009), the magnitude 

of the trend reported by EPA is very similar, and the NSIDC trend reported by EPA is 

identical to the trend found in Comiso and Nishio (2008). 

Therefore, EPA’s TSD and the studies referenced by the Southeastern Legal Foundation 

all portray Antarctic sea ice as increasing at about the same rate. The only difference 

between the TSD and one of the studies referenced by the Southeastern Legal Foundation 

is in the characterization of statistical significance in Turner et al. (2009). This narrow 

and limited basis does not support the Petitioner’s sweeping and unsupportable 

conclusion. 

The fact that studies reach different conclusions regarding statistical significance in 

observed trends does not imply that model projections have been “refuted,” 

“undermined,” or “at worst falsified,” especially when the trends do not materially differ 

in either direction or magnitude. Furthermore, the statistical significance of observed 

trends is not a criterion required for validation of models. Of particular importance is that 

EPA’s reporting of Antarctic sea trends is substantively consistent with the literature. 

Although EPA did not rely on the IPCC (2007a) for this discussion in the TSD, the 

Southeastern Legal Foundation makes much of the fact that the newer literature also 

differs from the IPCC’s coverage of this issue. It claims that the IPCC’s finding that 

Antarctic sea ice trends are not statistically significant is “an outlier that is inconsistent 

with the peer reviewed literature”—specifically referring to literature published after 

publication of the IPCC AR4. But given that the one study (Turner et al., 2009) 

referenced by the Southeastern Legal Foundation (finding statistical significance) was not 

available to the IPCC when it did its assessment, its claim that the IPCC’s treatment of 

the issue is inconsistent with more recent literature has little relevance. EPA relied on the 

latest available data and analysis from NSIDC rather than the IPCC. 

Separate from its discussion of the new literature, the Southeastern Legal Foundation—in 

a footnote—refers to a blog post (Knappenberger, 2010) that alleges that the IPCC’s 

treatment of the issue was incomplete based on literature that was available at the time of 

its assessment. But again, this is not relevant to EPA’s treatment of the issue because 

EPA relied on the more current analysis by NSIDC, which is consistent with the latest 

literature on the issue, aside from statistical significance as discussed above. 

Finally, it is important to put this issue into context. Antarctic sea ice is one climate 

indicator referenced in the TSD but not explicitly referred to in the Findings themselves. 

Given the multiple lines of evidence presented in the TSD, a small, and in this context 

trivial change in the statistical characterization of one of numerous physical indicators of 

warming does not materially impact the Endangerment Finding. The TSD appropriately 

states that Antarctic sea ice is increasing. The fact that as more studies are published it 

145
may now be possible to ascribe “statistical significance” to this increase is not of material 

impact for the Endangerment Finding. 

1.5.6 Implications of Recent Data on Observational Snow Cover Trends 

Comment (1-87): 

One petitioner (the Southeastern Legal Foundation) argues that recent trends in winter 

snow cover over the Northern Hemisphere and North America are at odds with future 

model projections. It notes that since 1989, there has been virtually no trend in snow 

cover in the Northern Hemisphere and that winter snow extent in North America has been 

increasing over this period. 

To support its arguments, the Southeastern Legal Foundation relies primarily on two 

snow cover data time series (Goddard 2010a, 2010b) published on the blog 

WattsUpWithThat.com. These time series exhibit data from the Rutgers University 

Global Snow Laboratory (GSL). The first time series the petitioner displays shows an 

increasing trend in North American winter snow cover extent (e.g., for the months of 

December to February) from 1989 to 2010 (source of image: Goddard, 2010a) (SLF 

Graph #1). 

SLF Graph #1 

The second time series the petitioner displays shows the annual Northern Hemisphere 

snow cover since 1989, which shows “virtually no trend” according to the Southeastern 

Legal Foundation (source of image: Goddard, 2010b) (SLF Graph #2). 

146
SLF Graph #2 

On the basis of these graphs, the petitioner concludes that “the IPCC and the EPA 

predicted reduced snow fall and reduced snow cover due to AGW [anthropogenic global 

warming]” and that this is “yet another instance of the failure of model predictions.” 

Response (1-87): 

The Rutgers GSL is a credible and legitimate source of data on snow cover, and 

numerous peer-reviewed studies have used Rutger’s GSL data, including some that were 

cited by the IPCC. However, the Southeastern Legal Foundation reaches inappropriate 

and flawed conclusions based on these graphs, as the conclusions are biased by the 

selective time periods analyzed. 

Southeastern Legal Foundation’s North American Winter Snow Cover Extent Graph 

(SLF Graph #1) 

The North American winter snow cover graphic presented by the Southeastern Legal 

Foundation and shown above only samples the period 1989–2010, yet Rutgers GSL data 

date back to 1967. Using GSL data for the entire period of record (1967–2010, source: 

Rutgers, 2010a), EPA produced the following graph (EPA Graph #157): 

 

57 For underlying data, see file North American Winter Snow Cover Extent.PDF in Docket ID No. EPAHQ-OAR-2009-0171 

147
EPA Graph #1 

North America Winter (Dec-Feb) Snow Cover Extent 1967-2010

15000000

15500000

16000000

16500000

17000000

17500000

18000000

18500000

1967 1972 1977 1982 1987 1992 1997 2002 2007

Year

Square Kilometers

An examination of this graph of the entire dataset (EPA Graph #1) makes it clear that 

Southeastern Legal Foundation relies upon a graph (SLF Graph #1) that presents an 

exaggerated upward snow cover extent trend during the winter months by using 

unrepresentative start and end dates. The SLF Graph #1 start and end dates coincide with 

relatively small (1989) and large (2010) snow cover extents. The full time series we 

produce above shows a much smaller upward trend. The small long-term increase we 

show is broadly consistent with our statement in the TSD on this issue. In Section 4(j) of 

the TSD, citing the IPCC, we state that over North America “from 1915 to 2004, snowcovered area increased in November, December, and January due to increases in 

precipitation” (U.S. EPA, 2009). 

It is also important to recognize that snow cover trends in one season over one continent 

are not representative of snow cover trends in other seasons, on an annual basis, or in 

other parts of the world. In fact, one impact of climate change is expected to be an 

increase in snow cover in many areas due to increases in precipitation, which have been 

observed as noted above. As the TSD notes in Section 5(a): “...heavy precipitation 

events averaged over North America have increased over the past 50 years ... consistent 

with the observed increases in atmospheric water vapor, which have been associated with 

human-induced increases in GHGs.” In contrast, in the warmer seasons of spring and 

summer, when cold air is more limited, warming has tended to deplete snow cover, and 

there has been little trend (slightly positive) during fall. The graph below, which EPA 

produced (EPA Graph #258, data source: Rutgers, 2010a), shows long-term North 

America snow cover extent by season and on an average annual basis. 

 

58 For underlying data, see file North American Snow Cover Extent.PDF in Docket ID No. EPA-HQ-OAR2009-0171 

148
EPA Graph #2 

North American Snow Cover Extent 1972*-2010

2000000

4000000

6000000

8000000

10000000

12000000

14000000

16000000

18000000

20000000

1972 1976 1980 1984 1988 1992 1996 2000 2004 2008

Year

Square Kilometers

Annual

Winter

Spring

Summer

Fall

*Whereas winter snow cover data are available from GSL beginning in 1967, annual 

snow cover data begin in 1972. 

This graph (EPA Graph #2) clearly shows that average annual snow cover (blue 

diamonds) has declined over the long term over North America, with pronounced 

declines in spring (yellow triangles) and summer (light blue Xs) and small increases in 

fall (purple asterisks) and winter (pink squares). By focusing on just one season and 

149
arbitrarily using only part of the available dataset, the Southeastern Legal Foundation 

(SLF Graph #1) provides an incomplete analysis, which does not change or undermine 

projections for future declines in snow cover over North America. 

Southeastern Legal Foundation’s Annual Northern Hemisphere Snow Cover Extent 

Graph (SLF Graph #2) 

As with its first graph (SLF Graph #1), the petitioner’s second graph (SLF Graph #2) for 

the Northern Hemisphere also presents only a portion of the available data. Importantly, 

its choice of start date (1989) is biased because it conceals the long-term decline in snow 

cover extent evident when analyzing the entire data series. We graphed the entire 

Northern Hemisphere Snow Cover extent time series, plotting annual averages to produce 

the time series below (EPA Graph #359, data source: Rutgers, 2010b). 

EPA Graph #3 

Annual Average Northern Hemisphere Snow Cover Extent 1972-

2009

22000000

23000000

24000000

25000000

26000000

27000000

28000000

1972 1977 1982 1987 1992 1997 2002 2007

Year

Square Kilometers

This time series (EPA Graph #3) clearly shows a long-term decline in annual average 

Northern Hemisphere snow cover extent, which is consistent with model projections for 

the future. 

 

59 For underlying data, see file Annual Average Northern Hemisphere Snow Cover Extent.PDF in Docket 

ID No. EPA-HQ-OAR-2009-0171 

150
The clear conclusion is that the petitioner bases its claim that the models are wrong on the 

use of time series that are biased both with respect to the time of year analyzed and 

choice of start and end date. Their assertion that future projections are flawed is based on 

this inappropriately limited analysis. The petitioner’s evidence and arguments do not 

show that models projecting future decreases in snow cover are flawed. In fact, observed 

long-term snow cover trends over both North America and the Northern Hemisphere are 

directionally consistent with future projections. Therefore, the information presented by 

the petitioner is inaccurate and does not support their claims. 

1.5.7 Petitioners Claim That EPA Ignored a Satellite Dataset 

Comment (1-88): 

One petitioner, the Competitive Enterprise Institute, contends that EPA’s Endangerment 

Finding ignores satellite datasets, which, unlike surface datasets, provide comprehensive 

coverage of the globe. The Competitive Enterprise Institute specifically refers to the 

satellite dataset produced by UAH. It states: 

This dataset meets the critical principle of science of repeated, independent verification. 

These data show modest thirty year warming trends in the middle to upper latitudes of the 

Northern Hemisphere, little warming of the tropics and the Southern Hemisphere, and 

distinct cooling of the Antarctic region - hardly the endangering global warming 

proclaimed by EPA. 

Response (1-88): 

EPA clearly did not ignore satellite datasets, including the UAH dataset. The satellite 

datasets are discussed in detail in the record for the Endangerment Finding. EPA 

summarized trends from satellite datasets in both the TSD and RTC document. The TSD 

contains an entire section (4b) in which upper air temperatures are summarized, and that 

incorporates the trends from both Remote Sensing System and UAH satellite temperature 

records. In Section 4(b), the TSD summarizes the IPCC’s discussion of tropospheric 

satellite temperature records, which incorporate the UAH dataset: 

The satellite tropospheric temperature record is broadly consistent with surface 

temperature trends. The range (due to different data sets) of global surface warming 

since 1979 is 0.29°F (0.16°C) to 0.32°F (0.18°C) per decade compared to 0.22°F 

(0.12°C) to 0.34°F (0.19°C) per decade for estimates of tropospheric temperatures 

measured by satellite. 

Furthermore, also in Section 4(b), we update the IPCC’s summary of the satellite 

temperature record with a summary of the latest satellite temperature data trends in 

NOAA publications (NOAA, 2009 and Peterson and Baringer, 2009) through 2009, 

which also incorporate the UAH data: 

For example, in NOAA (2009b) the satellite mid-tropospheric temperature trend 

computed for 1979–2008 ranges from +0.20 to 0.27°F (+0.11°C to + 0.15°C) per decade 

compared to the estimate of +0.22 to +0.34°F (+ 0.12°C to + 0.19°C) per decade given in 

IPCC (2007a). Combining the radiosonde and satellite records of the troposphere, the 

[NOAA] State of the Climate in 2008 report estimates the trend is +0.261 ± 0.04°F 

151
(+0.145 ± 0.02°C) per decade for the period 1958–2008 with the range of the trends 

calculated from the various datasets (Peterson and Baringer, 2009). 

In addition, Volume 2 of the RTC document specifically refers to UAH data in four 

separate comment responses (2-47, 2-48, 2-49, and 2-51). 

The commenter’s assertion about specific regional trends in temperatures derived from 

satellite records (including UAH’s) were also already addressed in the RTC: 

 Temperature trends in the tropics were discussed in RTC 3-7. 

 Temperature trends in the Southern Hemisphere relative to the Northern 

Hemisphere were discussed in RTC 3-5. 

 Antarctic temperature trends were discussed in RTC 2-56. 

To conclude, the warming observed in the satellite record, including the UAH data, was 

considered by EPA and supports EPA’s conclusion that the warming of the climate 

system is “unequivocal” (see the Findings, Section IV.2.a.). 

1.5.8 Summary 

None of the issues raised by petitioners pertaining to new science or data that EPA 

allegedly did not address changes or undermines the scientific basis for EPA’s Findings. 

In many cases, the issues raised by the petitioners are not new, but were fact raised and 

addressed during the rulemaking. Petitioners have misinterpreted or misrepresented the 

meaning and significance of the scientific literature, findings, and data they cite, made 

claims that are not supported by the evidence they rely on, provided incomplete and 

biased analyses to support their claims, failed to acknowledge or account for important 

results, and, at times, ignored EPA’s endangerment record. 

Climate science continues to advance and our understanding will continue to improve as 

new data and studies that are published will continue to add to our understanding of 

important climate science issues. But rather than challenging the scientific basis for the 

Endangerment Finding, the new science cited by petitioners does not undermine the key 

findings and conclusions that were reached in the assessment literature, and the very solid 

scientific foundation for EPA’s Findings. 

152
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EPA’s Response to the Petitions 

to Reconsider the Endangerment 

and Cause or Contribute 

Findings for Greenhouse Gases 

under Section 202(a) of the Clean 

Air Act 

Volume 2: Issues Raised by 

Petitioners on EPA’s Use of IPCC

U.S. Environmental Protection Agency 

Office of Atmospheric Programs 

Climate Change Division 

Washington, D.C.

1 

TABLE OF CONTENTS 

Page

2.0 Issues Raised by Petitioners on EPA’s Use of IPCC.................................................................6 

2.1 Claims That IPCC Errors Undermine IPCC Findings and Technical Support for 

Endangerment ........................................................................................................................6 

2.1.1 Overview....................................................................................................................6 

2.1.2 Accuracy of Statement on Percent of the Netherlands Below Sea Level..................8 

2.1.3 Validity of Himalayan Glacier Projection .................................................................9 

2.1.4 Characterization of Climate Change and Disaster Losses .......................................12 

2.1.5 Validity of Alps, Andes, and African Mountain Snow Impacts..............................20 

2.1.6 Validity of Amazon Rainforest Dieback Projection ................................................21 

2.1.7 Validity of African Rain-Fed Agriculture Projection ..............................................23 

2.1.8 Summary..................................................................................................................33 

2.2 Claims That the IPCC Has a Policy Agenda and Is Not Objective and Impartial...............34 

2.2.1 Overview..................................................................................................................34 

2.2.2 Background..............................................................................................................34 

2.2.3 Responses to Arguably New Objections Raised by the Petitioners.........................39 

2.2.3.1 Allegations of Inappropriate Authorship and Reviewer Roles Among 

IPCC Personnel ...............................................................................................39 

2.2.3.2 Allegations That Citing One’s Own Papers Compromises Objectivity...........46 

2.2.3.3 Allegations That IPCC Is Biased .....................................................................48 

2.2.3.4 Allegations That IPCC Lead Authors Forced Consensus and Suppressed 

Dissenting Views..............................................................................................57 

2.2.4 Responses to Allegations Based on Information That Is Not New .........................65 

2.2.4.1 Allegations of Inappropriate Collaborations Among IPCC Authors ..............65 

2.2.4.2 Allegations Regarding Insufficient Peer Review Processes for the IPCC.......67 

2.2.4.3 Allegations That IPCC Authors Manipulated Deadlines for New 

Literature .........................................................................................................68 

2.2.4.4 Allegations Regarding the IPCC’s Use of Gray Literature.............................71 

2.2.5 Summary..................................................................................................................73 

References..............................................................................................................................................75 

3 
ACRONYMS 

°C degrees Celsius 

°F degrees Fahrenheit 

AIRS Atmospheric Infrared Sounder 

AMS American Meteorological Society 

AOGCM Atmosphere-Ocean General Circulation Models 

AR4 IPCC Fourth Assessment Report 

BOM Australian Bureau of Meteorology 

CH4 methane 

cm centimeter 

CCSP U.S. Climate Change Science Program 

CDIAC Carbon Dioxide Information Analysis Center 

CMIP Coupled Model Intercomparison Project 

CO2 carbon dioxide 

CRU Climatic Research Unit 

EPA U.S. Environmental Protection Agency 

FOIA Freedom of Information Act 

GHCN Global Historical Climatology Network 

GHG greenhouse gases 

GISS Goddard Institute for Space Studies (NASA) 

GSL Global Snow Laboratory (Rutgers University) 

IAC InterAcademy Council 

IEA Institute of Economic Analysis 

IISD International Institute for Sustainable Development 

IJC International Journal of Climatology 

IPCC Intergovernmental Panel on Climate Change 

IQA Information Quality Act 

LIA Little Ice Age 

MET United Kingdom Meteorological Office 

MWP Medieval Warm Period 

NASA National Aeronautics and Space Administration 

NCAR National Center for Atmospheric Research 

NCDC National Climatic Data Center 

NIWA National Institute of Water & Atmospheric Research 

NMS National Meteorological Station 

NOAA National Oceanic and Atmospheric Administration 

NRC National Research Council 

NSIDC U.S. National and Snow and Ice Data Center 

ORNL Oak Ridge National Laboratory 

PBL Netherlands Environmental Assessment Agency 

RMS Risk Management Solutions 

RTC Response to Comments 

RTP Response to Petitions 

SAB Scientific Advisory Board 

SALR saturated adiabatic lapse rate 

TSD Technical Support Document 

4 
UAH University of Alabama–Huntsville 

UCAR University Corporation for Atmospheric Research 

UHI urban heat island 

UK United Kingdom 

USGCRP U.S. Global Change Research Program 

USHCN United States Historical Climatology Network 

W/m2 watts per meter squared 

WMO World Meteorological Organization 

WWR World Weather Reports 

5 
2.0 Issues Raised by Petitioners on EPA’s Use of IPCC 

2.1 Claims That IPCC Errors Undermine IPCC Findings and Technical Support for 

Endangerment 

2.1.1 Overview 

Several petitioners (Peabody Energy, the State of Texas, the Coalition for Responsible 

Regulation, the Competitive Enterprise Institute, the Ohio Coal Association, and the 

Southeastern Legal Foundation) contend that alleged errors and/or unsupported findings in IPCC 

reports demonstrate that the science on which the Administrator relied for the Endangerment 

Finding is uncertain and/or not credible. We have examined each specific instance of error, 

alleged error, and/or alleged unsupported statement in the voluminous IPCC report and we find 

that the evidence cited by petitioners does not support this conclusion. 

In reviewing the information provided by petitioners, EPA has determined that most—if not 

all—of the alleged errors and/or unsupported statements highlighted by petitioners are not 

relevant, not truly erroneous or unsupported, and/or inconsequential to the Administrator’s 

Finding. In many cases, the petitioners’ interpretation of both the alleged error (or alleged 

unsupported statement) and its implications is not supported by the evidence provided. Clearly, 

the charge that there are or might be errors or unsupported statements in the IPCC’s Fourth 

Assessment Report (AR4) is serious, and we agree with petitioners that such claims merit 

thorough review. EPA has done such a review; we find that the documented errors in the AR4 

are not significant, and do not call into question the fundamental and broad evidence on which 

the Endangerment Finding rests. Moreover, the occurrence of the few documented errors in a 

study the size of the IPCC report is not unexpected and does not call into question the credibility 

of the entire report and all of its findings. 

The Netherlands Environmental Assessment Agency (PBL) conducted its own independent 

assessment of the regional chapters (9 through 16) in Working Group II’s contribution to the 

AR4, where many of the errors, alleged errors, and/or alleged unsupported statements have been 

identified. The report Assessing an IPCC Assessment (PBL, 2010a) finds “no significant errors” 

in summary conclusions, though it notes that “provenance of summary statements needs to 

become more transparent in future reports.” 

PBL (2010a) also states that “examples of negative impacts dominate at summary level,” 

indicating that the IPCC selected a “risk-oriented” approach in communicating to policymakers. 

The report states: 

The PBL subscribes to the importance of an approach that highlights what may go wrong 

under unmitigated climate change, but Working Group II Report lacked a clear 

explanation of the choice of approach and its consequences. Alternatively, it could be 

argued that policymakers should be presented with a complete picture in the Summary 

for Policymakers, not just with negative examples (without suggesting that potential 

positive effects cancel out potential effects). 

6 
While we cited the IPCC Working Group II Summary for Policymakers in the Endangerment 

Technical Support Document (TSD), we relied most heavily on information from the full 

chapters in the Working Group II report, specifically Chapter 14 on North America, as well as 

other assessment literature such as the U.S. Global Change Research Program (USGCRP) 

assessment Global Climate Change Impacts in the United States (Karl et al., 2009). The 

Administrator considered both the positive and negative effects of climate change, as the 

Endangerment Finding states (Section I.A.): 

The Administrator is using her judgment, based on existing science, to weigh the threat 

for each of the identifiable risks, to weigh the potential benefits where relevant, and 

ultimately to assess whether these risks and effects, when viewed in total, endanger 

public health or welfare. 

In addition, the Administrator found endangerment based on impacts in the United States alone, 

with international impacts providing some supporting information, as the Endangerment Finding 

states (Section III.D): 

EPA is not considering international effects to determine whether the health and welfare 

of the public in a foreign country is endangered. Instead, EPA’s consideration of 

international effects for purposes of determining endangerment is limited to how those 

international effects impact the health and welfare of the U.S. population. 

The Administrator looked first at impacts in the United States itself, and determined that 

these impacts are reasonably anticipated to endanger the public health and the welfare of 

the U.S. population. That remains the Administrator’s position, and by itself supports her 

determination of endangerment. 

Despite its few criticisms of the IPCC, PBL (2010a) concludes: 

Our findings do not contradict the main conclusions of the IPCC on impacts, adaptation 

and vulnerability related to climate change. There is ample observation evidence of 

natural systems being influenced by climate change on regional levels. The negative 

impacts under unmitigated climate change pose substantial risks to most parts of the 

world, with risks increasing at higher global average temperatures. 

This conclusion is very consistent with the conclusion the Administrator reached in the 

Endangerment Finding, after weighing the balance of evidence. 

This section responds to the major arguments of the petitioners on the significance of alleged 

errors and/or unsupported statements in the IPCC reports, and assesses the implications of these 

errors and/or unsupported statements for the credibility and reliability of the major findings and 

conclusions of the IPCC and other assessment literature. 

7 
2.1.2 Accuracy of Statement on Percent of the Netherlands Below Sea Level 

Comment (2-1): 

Peabody Energy and the State of Texas contend that the IPCC erroneously stated (in Working 

Group II’s contribution to the AR4) that 55% of the Netherlands is below sea level, whereas the 

actual number is much lower according to Dutch materials (26%). 

Response (2-1): 

The statistic quoted in the IPCC AR4 is inaccurate. When this error was identified, PBL (2010b) 

published a correction: 

In the 2007 IPCC report by the Working Group 2 (Climate change 2007: Impacts, 

Adaptation and Vulnerability) a mistake has entered the text that was supplied by the 

Netherlands Environmental Assessment Agency, regarding the risks of flooding for the 

Netherlands. In the chapter on Europe, on page 547, it says that 55 per cent of the 

Netherlands is below sea level (‘The Netherlands is an example of a country highly 

susceptible to both sea level rise and river flooding because 55% of its territory is below 

sea level’). This should have read that 55 per cent of the Netherlands is at risk of 

flooding; 26 per cent of the country is below sea level, and 29 per cent is susceptible to 

river flooding. Examples of the latter are the near floodings, in the mid-1990s, of areas 

along the rivers Meuse and Waal – areas that are well above sea level. 

The IPCC agrees that this statistic is incorrect in the AR4, and also notes that the same mistake 

was made by other reputable groups (Reuters, 2010). For example, the IPCC—in a written 

statement provided to Reuters—indicated that a report from the Dutch Ministry of Transport had 

stated “‘about 60%’ of the country is below sea level,” and referred to a European Commission 

study saying “about half” (Reuters, 2010). As noted by the IPCC statement, the error was not 

made by authors of the AR4, but originated with PBL, which supplied the text. To correct the 

mistake, the IPCC published an official erratum (IPCC, 2010d): 

2) Page 547. Section 12.2.3. Line 20: Delete “below sea level” and replace with “at risk 

flooding”. 

The IPCC was further quoted as saying (Reuters, 2010): “The sea level statistic was used for 

background information only, and the updated information remains consistent with the overall 

conclusions.” 

In its independent report Assessing an IPCC Assessment (PBL, 2010a), PBL, which was 

responsible for the error, states: 

We acknowledge that this error was not the fault of the IPCC (Coordinating) Lead 

Authors or Co-Chairs. The error was made by a Contributing Author from the PBL, and 

the (Coordinating) Lead Authors [of the IPCC] are not to blame for relying on Dutch 

information provided by a Dutch agency. 

8 
EPA concludes that this error is minor and inconsequential to the Administrator’s Endangerment 

Finding. EPA does not refer to or rely on this statistic in the Endangerment Finding or 

supporting documents, and this information does not pertain to endangerment of public health 

and welfare in the United States in any meaningful way. It does not call into question the 

integrity of the IPCC, and it has no impact on the scientific support for EPA’s Endangerment 

Finding. Furthermore, as the error pertains to a statistic outside the United States, it is not 

relevant to the Endangerment Finding. As noted in Subsection 2.1.1, the Endangerment Finding 

states (Section III.D): “The Administrator looked first at impacts in the United States itself, and 

determined that these impacts are reasonably anticipated to endanger the public health and the 

welfare of the U.S. population. That remains the Administrator’s position, and by itself supports 

her determination of endangerment.” 

2.1.3 Validity of Himalayan Glacier Projection 

Comment (2-2): 

Several petitioners (the Coalition for Responsible Regulation, the Competitive Enterprise 

Institute, the Ohio Coal Association, Peabody Energy, the Southeastern Legal Foundation, and 

the State of Texas) state that the IPCC erred in including a projection that glaciers in the 

Himalayas would disappear by 2035, and they claim EPA relied on this projection in the 

Endangerment Finding. Petitioners argue that this error undermines the credibility of the IPCC 

reports. The Ohio Coal Association writes: “The Agency no longer has a basis for unquestioned 

confidence that the IPCC reports present a fair, unbiased, and accurate assessment of climate 

science.” Peabody states the error: “...undercuts EPA’s conclusion that the IPCC review process 

was ‘rigorous’ and shows how reliance on the IPCC led to errors in EPA’s Endangerment 

Finding.” 

Response (2-2): 

The IPCC has issued a correction pertaining to this projection for the melting of Himalayan 

glaciers (IPCC, 2010f): 

The Synthesis Report, the concluding document of the Fourth Assessment Report of the 

Intergovernmental Panel on Climate Change (page 49) stated: “Climate change is 

expected to exacerbate current stresses on water resources from population growth and 

economic and land-use change, including urbanization. On a regional scale, mountain 

snow pack, glaciers and small ice caps play a crucial role in freshwater availability. 

Widespread mass losses from glaciers and reductions in snow cover over recent decades 

are projected to accelerate throughout the 21st century, reducing water availability, 

hydropower potential, and changing seasonality of flows in regions supplied by 

meltwater from major mountain ranges (e.g. Hindu-Kush, Himalaya, Andes), where more 

than one-sixth of the world population currently lives.” 

This conclusion is robust, appropriate, and entirely consistent with the underlying science 

and the broader IPCC assessment. It has, however, recently come to our attention that a 

paragraph in the 938-page Working Group II contribution to the underlying assessment 

refers to poorly substantiated estimates of rate of recession and date for the disappearance 

of Himalayan glaciers. In drafting the paragraph in question, the clear and well9 
established standards of evidence, required by the IPCC procedures, were not applied 

properly. 

The Chair, Vice-Chairs, and Co-chairs of the IPCC regret the poor application of wellestablished IPCC procedures in this instance. This episode demonstrates that the quality 

of the assessment depends on absolute adherence to the IPCC standards, including 

thorough review of “the quality and validity of each source before incorporating results 

from the source into an IPCC Report”. We reaffirm our strong commitment to ensuring 

this level of performance. 

First, as described in Response 2-3 below, this error concerns a single study, out of many that 

support the IPCC’s conclusions regarding glacier recession. Second, EPA does not refer to this 

projection in the Endangerment Finding or supporting material. We acknowledge that the TSD 

mentions Himalayan glaciers; Table 16.1 of Section 16(b) (“Overview of International 

Impacts”), highlighting “examples” of international impacts, states (U.S. EPA, 2009): 

Glacier melt in the Himalayas is projected to increase flooding and rock avalanches from 

destabilized slopes and to affect water resources within the next two to three decades. 

This will be followed by decreased river flows as the glaciers recede. 

This statement is entirely consistent with the IPCC’s statement in its Synthesis Report (on page 

49) (IPCC, 2007b), cited above, which the IPCC notes is “robust, appropriate, and entirely 

consistent with the underlying science and the broader IPCC assessment.” EPA did not refer to a 

rate of recession or a timeframe in which the Himalayan glaciers would be gone. 

This error represents one lapse in the deliberate preparation and review of a multi-volume 

assessment containing thousands of pages of findings and conclusions. Despite petitioners’ 

claims to the contrary, the timing of glacier recession in the Himalayas has no impact on the 

scientific support for EPA’s Endangerment Finding. As noted in Section 2.1.1, the 

Endangerment Finding states (Section III.D): 

The Administrator looked first at impacts in the United States itself, and determined that 

these impacts are reasonably anticipated to endanger the public health and the welfare of 

the U.S. population. That remains the Administrator’s position, and by itself supports her 

determination of endangerment. 

After careful review, the facts do not substantiate the petitioners’ assertion that this error 

undercuts EPA’s conclusion that the IPCC review process was ‘rigorous’ or that reliance on the 

IPCC, among other assessments, led to errors in EPA’s Endangerment Finding.

Comment (2-3): 

The Southeastern Legal Foundation questions the IPCC claim that the conclusions regarding 

Himalayan glaciers presented in the AR4 Synthesis Report are “robust, appropriate, and entirely 

consistent with the underlying science and the broader IPCC assessment” despite the erroneous 

projection. The Southeastern Legal Foundation states: “The IPCC has now grudgingly retracted 

10 
the claim of imminent Himalayan glacier melt, though it claims the overall conclusions regarding 

glacial melt are robust. How their conclusions can be fake but accurate is not evident.” 

Response (2-3): 

Southeastern Legal Foundation is referring to the following conclusions in the IPCC’s 2007 

Synthesis Report (IPCC, 2007b, page 49): 

Climate change is expected to exacerbate current stresses on water resources from 

population growth and economic and land-use change, including urbanization. On a 

regional scale, mountain snow pack, glaciers and small ice caps play a crucial role in 

freshwater availability. Widespread mass losses from glaciers and reductions in snow 

cover over recent decades are projected to accelerate throughout the 21st century, 

reducing water availability, hydropower potential, and changing seasonality of flows in 

regions supplied by meltwater from major mountain ranges (e.g. Hindu-Kush, Himalaya, 

Andes), where more than one-sixth of the world population currently lives. 

EPA has reviewed the complete discussion of this issue in the AR4, in the Synthesis Report, and 

in the contributions of Working Groups I (IPCC, 2007e) and II (IPCC, 2007g). The IPCC cites 

numerous studies that document Himalaya and other Asian glacier trends, projections, and 

impacts. For example, it references the following findings from a range of studies supporting its 

conclusion: 

 Glaciers in the Asian high mountains have generally shrunk at varying rates (from Su and 

Shi, 2002; Ren et al., 2004; Solomina et al., 2004; Dyurgerov and Meier, 2005)—in IPCC 

Working Group I Chapter 4 (Lemke et al., 2007). 

 The entire Hindu-Kush-Himalaya ice mass has decreased in the last two decades. Water 

supply in areas fed by glacial meltwater from the Hindu Kush and Himalayas, on which 

hundreds of millions of people in China and India depend, will be negatively affected 

(Barnett et al., 2005)—in IPCC Working Group II Chapter 3 (Kundzewicz et al., 2007). 

 The Himalayan glacier Gangotri receded at an average rate of 7.3 meters every year from 

1842 to 1935; from 1985 to 2001, it receded at a rate of 23 meters per year (Hasnain, 

2002)—in IPCC Working Group II Chapter 10 (Cruz et al., 2007). 

 Reductions in the mass of a sample of Northern Hemisphere glaciers (including several in 

Asia) of up to 60% are projected by 2050 (Schneeburger et al., 2003)—in IPCC Working 

Group II Chapter 3 (Kundzewicz et al., 2007). 

 Rapid melting of glaciers can lead to flooding of rivers and the formation of glacial meltwater lakes, which may pose a serious risk of outburst floods (Coudrain et al., 2005)—in 

IPCC Working Group II Chapter 3 (Kundzewicz et al., 2007). 

Thus, EPA finds that the single faulty projection highlighted by petitioners does not compromise 

the IPCC’s overall assessment of observed glacier loss, projected glacier loss, and the impacts of 

glacier loss on water resources in the Himalayas. Numerous studies document a general decline 

in Himalayan glacier mass, project substantial future declines, and discuss the impacts of these 

11 
changes on water resources and society, which is consistent with the conclusions drawn by the 

IPCC. The petitioner’s claim implies that the IPCC conclusion in the Synthesis Report depends 

upon a single study, without which we are uncertain as to the fate and timing of Himalayan 

glacier melt. The full discussion of this issue by the IPCC clearly demonstrates that the 

petitioners’ argument is flawed and that the IPCC’s conclusions are well-supported by the 

scientific literature. 

2.1.4 Characterization of Climate Change and Disaster Losses 

Comment (2-4): 

Some petitioners raise concerns with certain aspects of the IPCC’s treatment of climate change 

and natural disasters. The Southeastern Legal Foundation asserts that the IPCC mischaracterized 

the findings of a non-peer-reviewed study (Muir-Wood et al., 2006) on climate change and 

disaster losses. It states that the IPCC reported that global warming was causing an increase in 

losses from weather disasters of 2% per year, even after controlling for economic growth, citing 

the Muir-Wood study even though that study had actually found no trend. Along with the 

Southeastern Legal Foundation, the Competitive Enterprise Institute refers to an article in the 

Sunday Times (Leake, 2010b) indicating that the IPCC wrongly linked climate change to natural 

disasters. Southeastern Legal Foundation finds: 

The EPA Endangerment Finding relies heavily on the assertion that AGW [anthropogenic 

global warming] will cause extreme weather events to become more frequent and more 

severe and thus constitute a danger to human health and welfare—an essential element of 

the Finding. To support this assertion the Finding in turn relies heavily on the IPCC’s 

reports on weather disasters. 

Response (2-4): 

To support the Endangerment Finding, EPA cited the potential impacts of climate change on the 

number and/or severity of certain extreme weather events, for which the Southeastern Legal 

Foundation levels no specific criticism. The TSD did not discuss the link between climate 

change and the historical trends in the economic magnitude of disaster losses. In responding to 

public comments on the issue (e.g., see Responses 7-5 and 7-38 in the Response to Comments 

[RTC] document), EPA acknowledged that many factors influence the economic losses caused 

by disasters which make it difficult to use historical data on trends in economic disaster loss to 

determine the impact of climate change on the losses from weather events in the past. Further, 

the Endangerment Finding is clear that the Administrator’s decision was based on the physical 

and environmental impacts associated with climate change, and how they can affect the 

characteristics of weather events, not the link between climate change and disaster losses. As the 

Endangerment Finding states (Section I.A): 

The evidence concerning how human induced climate change may alter extreme weather 

events also clearly supports a finding of endangerment, given the serious adverse impacts 

that can result from such events and the increase in risk, even if small, of the occurrence 

and intensity of events such as hurricanes and floods. 

12 
With respect to the Muir-Wood study, we neither cited nor relied upon it in our discussion of 

extreme events. In fact, our only specific reference to this study in the record for the 

Endangerment Finding is in Response 1-15 in the RTC documents, which addressed criticism of 

the IPCC’s use of gray literature. The technical aspects of this study were not discussed because 

EPA did not focus on the relationship between climate change and the economic magnitude of 

disaster losses as underlying support for the Endangerment Finding. We note that the TSD did 

include a figure (TSD Figure 14.1) showing information on several factors, including one portion 

(panel e) on observed U.S. hurricane economic damages compared to a measure of Atlantic 

hurricane intensity. This figure was taken from the chapter on North America from Working 

Group II’s contribution to the AR4 (Field et al., 2007, Figure 14.1); the TSD provides no 

commentary on the hurricane economic damages portion (panel e). 

The controversy surrounding the relationship between climate change and economic losses from 

disasters did arise in public comments (e.g., see comments 7-5 and 7-38 in the RTC document), 

to which EPA provided measured, balanced responses consistent with the assessment literature. 

In comment 7-38, for example, the commenter argued that increasing raw damage totals 

associated with tropical storm (or hurricane) damage in coastal communities are not the result of 

climate change, but rather are caused by changes in coastal population, the wealth of the 

population, inflation, and poor sediment management practices. EPA responded: 

EPA agrees that the interaction of a series of drivers adversely impacts coastal areas and 

can contribute to tropical storm damage totals. These drivers include changes in coastal 

population, wealth of the population, inflation, and sediment management practices. 

EPA’s response then focused on the physical impacts of climate change that suggest increased 

risk to the public from severe weather events, pointing to the following findings from the 

assessment literature: 

 Superimposed on accelerated sea level rise, the present storm and wave 

climatology and storm surge frequency distributions suggest more severe coastal 

flooding and erosion hazards (Nicholls et al., 2007). 

 Higher sea level provides an elevated base for storm surges to build upon and 

diminishes the rate at which low-lying areas drain, thereby increasing the risk of 

flooding from rainstorms (CCSP, 2009a). 

 Apart from nonclimatic events such as tsunamis, extreme sea levels occur mainly 

in the form of storm surges generated by tropical or extra-tropical cyclones. 

There is evidence for an increase in extreme high sea level since 1975 based upon 

an analysis of 99th percentiles of hourly sea level at 141 stations over the globe 

(Bindoff et al., 2007). 

We also noted: “USGCRP concludes that future increases in losses will be attributable to 

climate change with high confidence as climate change increases the frequency and intensity of 

many types of extreme weather (Karl et al., 2009).” EPA agrees with this conclusion regarding 

losses in the future—if climate change causes an increase in the frequency or intensity of certain 

severe weather events, then it follows that climate change could lead to increased losses 

compared with what would occur without the increase in those severe weather events. However, 

13 
EPA did not focus on historical trends in the magnitude of economic disaster losses to evaluate 

the likelihood that climate change would lead to an increase in the number or frequency of such 

weather events. For that reason, the charge that the IPCC mischaracterized reports on the 

implications of such historical trends does not materially affect the basis for EPA’s 

Endangerment Finding. 

For its part, the IPCC responded to the allegation that it mischaracterized the Muir-Wood study 

on climate change and disaster losses with an official statement (IPCC, 2010e). The IPCC 

stated, among other things, that the Sunday Times article cited by Southeastern Legal Foundation 

and the Competitive Enterprise Institute: 

Incorrectly assumes that a brief section on trends in economic losses from climate-related 

disasters is everything the IPCC Fourth Assessment Report (2007) has to say about 

changes in extremes and disasters. In fact, the Fourth Assessment Report reaches many 

important conclusions, at many locations in the report, about the role of climate change in 

extreme events. The assessment addresses both observations of past changes and 

projections of future changes in sectors ranging from heat waves and precipitation to 

wildfires. Each of these is a careful assessment of the available evidence, with a 

thorough consideration of the confidence with which each conclusion can be drawn. 

To summarize, petitioners do not properly characterize the information on which EPA relied in 

making the Endangerment Finding. Petitioners also mischaracterize the statements of the IPCC. 

The IPCC reasonably characterized the links between climate change and the projected increase 

in frequency and severity of severe weather events. The IPCC discussed the various types of 

evidence supporting this view, which include but are clearly not limited to consideration of the 

evidence for and against the ability to identify a climate change impact from the trend in 

economic magnitude of disaster losses, and the IPCC caveated its discussion of this issue. To 

support the Endangerment Finding, EPA cited the physical and environmental factors indicating 

that climate change would lead to an increase in frequency and severity of certain severe weather 

events. Only in response to public comments did EPA discuss what can be determined from 

analyses of past trends in disaster losses. Accordingly, EPA did not rely on a linkage between 

climate change and the economic magnitude of disaster losses to support the Endangerment 

Finding, and petitioners’ arguments do not undermine the reasoning supporting EPA’s 

Endangerment Finding. 

Our response to a petitioner’s specific claims regarding the Muir-Wood study is provided in 

Response 2-5, below. 

Comment (2-5): 

Southeastern Legal Foundation writes: 

The IPCC reported that global warming was causing an increase in losses from weather 

disasters of 2% per year, even after controlling for economic growth, citing a non-peer 

reviewed study by Robert Muir-Wood. Yet the IPCC mischaracterized the study, which 

actually found no trend and expressly eschewed the proposition for which it was cited. 

14 
Muir-Wood et al. expressly caveated that the exceptionally strong hurricane seasons in 

2004 and 2005 accounted for almost all of the 2% increase from 1970-2005. 

Response (2-5): 

First, while the version of the Muir-Wood et al. (2006) paper cited in the IPCC was not yet peerreviewed, a subsequent version of this work was peer-reviewed and accepted for publication just 

weeks after the cutoff for inclusion in the IPCC, according to a statement by Risk Management 

Solutions (RMS), where Robert Muir-Wood is employed as a chief research officer. In a 

frequently asked questions document posted on its website (RMS, 2010), RMS states: 

The research was conducted during the first half of 2006 and the full paper summarizing 

the results was peer reviewed and accepted for publication in November 2006. This was 

a few weeks outside of the cut-off date for the IPCC 4th Assessment Report in October, 

which is why an earlier summary version of the paper—written for a scientific workshop 

held in May 2006 and published in the conference proceedings in October 2006—was 

referenced (the IPCC can only cite published material). Despite not being able to 

reference it, the IPCC was aware of the full report and that it had been accepted for 

publication before the 4th Assessment Report was finalized. 

While the paper was completed and accepted for publication in November 2006, delays 

in publication meant that it did not officially appear as a book chapter until 2008. 

Second, the same frequently asked questions document (RMS, 2010) indicates that the IPCC did 

not mischaracterize the results of the paper: 

RMS believes the IPCC fairly referenced its paper, with suitable caveats around the 

results, highlighting the factors influencing the relationship that had been discovered 

between time and increased catastrophe costs. We believe it was appropriate to include 

the RMS paper in the report because, at that time, it was the only paper addressing global 

multi-peril catastrophe losses over time that had been normalized for changes in the 

values and exposure at risk. 

Thus, we find the study to be valid. As discussed in Response 1-15 of the RTC document, the 

use of non-peer-reviewed literature is allowed under IPCC procedures. In this case, the paper 

was clearly a reasonable reference and was ultimately peer-reviewed. We further find the 

petitioner’s discussion of the caveats in the Muir-Wood paper to be potentially misleading. The 

petitioner claims that “the IPCC mischaracterized the study” and states in the next sentence that 

“Muir-Wood et al. expressly caveated that the exceptionally strong hurricane seasons in 2004 

and 2005 accounted for almost all of the 2% increase from 1970-2005.” This could give the 

impression that the IPCC does not provide such caveats. An examination of the discussion in 

Working Group II’s contribution to the IPCC AR4, however, reveals that it also caveats the 2% 

increase, stating (Rosenzweig et al., 2007): “The significance of the upward trend is influenced 

by the losses in the USA and the Caribbean in 2004 and 2005 and is arguably biased by the 

relative wealth of the USA, particularly relative to India.” 

15 
Comment (2-6): 

Background: Southeastern Legal Foundation cites the following IPCC expert reviewer comment 

(IPCC, 2006c), which was submitted while the Working Group II report was in preparation and 

pertains to the IPCC’s characterization of climate change and disaster losses and the Muir-Wood 

et al. (2006) study: 

I think this is inappropriate. It leads the reader into interpreting recent events in a 

particular way without providing supporting information. This suggestion, that the losses 

in 2004 and 2005 draw Pielke’s results into question, needs to be supported with a 

reference or a solid in-chapter assessment. What does Pielke think about this? (Francis 

Zwiers, Canadian Centre for Climate Modelling and Analysis) 

According to Roger Pielke Jr. (Pielke, 2010a), a professor of environmental studies at the 

University of Colorado, the expert reviewer, Zwiers, is referring to this passage in the AR4 

(Rosenzweig et al., 2007): 

 

A previous normalisation of losses, undertaken for U.S. hurricanes by Pielke and Landsea 

(1998) and U.S. floods (Pielke et al., 2002) included normalising the economic losses for 

changes in wealth and population so as to express losses in constant dollars. These 

previous national U.S. assessments, as well as those for normalised Cuban hurricane 

losses (Pielke et al., 2003), did not show any significant upward trend in losses over time, 

but this was before the remarkable hurricane losses of 2004 and 2005. 

The IPCC writing team responded to the Zwiers comment with the following: “I believe Pielke 

agrees that adding 2004 and 2005 has the potential to change his earlier conclusions – at least 

about the absence of a trend in US Cat losses” (IPCC, 2006c). 

Comment: The Southeastern Legal Foundation claims that “The IPCC knew from the comments 

of reviewers that their use of the [Muir-Wood] study was wrong before the report was 

published.” Citing a blog post from Roger Pielke Jr., Southeastern Legal Foundation suggests 

the IPCC fabricated its response to the expert reviewer, Zwiers: 

The IPCC reviewer had asked “What does Pielke think about this?” The answer given 

was a fabrication, according to Pielke, Jr. As he commented on his blog, “[N]ot only did 

the IPCC AR4 WGII egregiously misrepresent the science of disasters and climate change, 

but when questions were raised about that section by at least one expert reviewer, it 

simply made up a misleading and false response about my views.” 

Response (2-6): 

It is unfortunate that Dr. Pielke found that his views were misrepresented by the IPCC. EPA 

cannot speculate how or why this happened. Dr. Pielke had the opportunity to comment on the 

IPCC’s draft treatment of these issues as a reviewer, but did not. (He is officially listed as an 

IPCC Working Group II expert reviewer for the United States in Appendix III of the IPCC AR4 

Working Group II report (IPCC, 2007f). 

16 
The representative for the IPCC’s author team wrote “I believe Pielke agrees,” which suggests a 

possible honest misunderstanding of Dr. Pielke’s views. This incident certainly does not support 

the petitioner’s contention that the IPCC “knew” that its use of the Muir-Wood study was wrong. 

In fact, as discussed in the previous response (2-5), it is not at all clear that the study was wrong 

or was used inappropriately by the IPCC in any way. 

At the time the Muir-Wood et al. study was completed in 2006, it was the only global analysis 

we are aware of that included 2004 and 2005 data. While it is true that Pielke Jr.’s remarks from 

the Seventh Annual Roger Revelle Commemorative Lecture contained an analysis of normalized 

Atlantic hurricane damages through 2005 and were published in Oceanography (Pielke, 2006), 

those remarks were not assessed by the IPCC, likely because they were presented as a lecture 

rather than a scientific study. Much of the scientific content of Dr. Pielke’s talk was 

subsequently peer-reviewed and published in 2008 (Pielke et al., 2008), but this was well after 

the IPCC deadline for inclusion in the AR4. Furthermore, whereas Dr. Pielke’s 2006 analysis in 

Oceanography limited its focus to Atlantic hurricanes, the Muir-Wood analysis was multi-hazard 

and global. 

Thus, while the IPCC may have made mistaken assumptions about Dr. Pielke’s views, its 

reliance on the Muir-Wood et al. (2006) study was reasonable, as that study contained the latest 

and most relevant published global analysis. 

Comment (2-7): 

The Southeastern Legal Foundation states that EPA’s Response 1-15 (in Volume 1 of the RTC 

document, concerning the use of non-peer-reviewed literature) did not respond to the substance 

of the comment concerning the IPCC’s and Climate Change Science Program’s (CCSP’s) 

misrepresentation of the literature and the central underlying point that there was no legitimate 

evidence that manmade climate change was causing an increase in weather disasters. 

The Southeastern Legal Foundation notes: “This comment showed that both the IPCC and 

especially the CCSP had fraudulently asserted that AGW was causing increased frequency and 

severity of extreme weather events.” It provides the following excerpt from the comment 

(3303): 

In 2007 the IPCC released its Fourth Assessment Report and it relied on the single nonpeer reviewed Muir-Wood (2006) [9] study cherrypicked from the Hohenkammer 

workshop as the single study to highlight in its review of this topic. [12] The same 

critique of the Stern report’s reliance on this Muir-Wood study above applies to the 

IPCC’s reliance on it as well. Further, the IPCC included a graph [13] attempting to 

show how closely temperature anomalies match up with disaster losses, using a scaling of 

the axes to suggest a relationship where none has been shown in the peer-reviewed 

literature. Again it relies on Muir-Wood (2005). Coincidentally, Robert Muir-Wood, of 

Risk Management Solutions, Inc., was an author of the chapter of the IPCC report that 

selectively highlighted his own non-peer reviewed work. 

The US Climate Change Science Program systematically and repeatedly misrepresented 

the science of disasters and climate change. First, the CCSP US extremes report [14] 

miscited several of Roger Peilke’s papers in support of claims that they did not make and 

17 
relied on Mills 2005 as the definitive source on this topic. [16] The disasters and climate 

change section of this CCSP report is also a fact checker’s nightmare. Second the CCSP 

draft Synthesis report and final Synthesis report [15] relied on non-peer reviewed work 

by Evan Mills and ignored relevant peer reviewed research showing different results (in 

fact all peer reviewed research points in the same direction on this subject). 

Coincidentally, Evan Mills was an author of the CCSP Synthesis Report that highlights 

his own non-peer reviewed work. Mills also apparently consults for companies with an 

interest in climate policies, and yet this was not disclosed by the CCSP. 

It then cites EPA’s response (RTC 1-15): 

The commenter describes two pieces of literature that were referenced by IPCC but not 

published in peer reviewed journals: 1) a natural catastrophes report by Munich Re 

(2000) that was cited in IPCC Third Assessment Report (IPCC, 2001), and 2) a paper on 

trends in weather-related catastrophes by Muir-Wood et al. (2006). The identification of 

only two examples out of the thousands of references cited in the IPCC (2000) and 

(2007) reports provides more support for the rigor of the IPCC process. Further, these 

specific studies were neither the central nor sole evidence used in forming the broader 

conclusions of the IPCC; such broader conclusions are based on multiple lines of 

evidence and peer-reviewed literature. 

On the basis of EPA’s response, the Southeastern Legal Foundation concludes: 

It is a very peculiar logic that treats proof of what appears to be scientific fraud as 

demonstrating “the rigor of the IPCC’s process.” No response whatsoever is made to the 

substance of the comment concerning the CCSP’s misrepresentation of the literature and 

the central underlying point that there was no legitimate evidence that manmade climate 

change was causing an increase in weather disasters. The question naturally arises as to 

why the EPA avoided these points. One of the lead authors of the CCSP report so 

vigorously attacked in Comment 3303 is Thomas Wilbanks, of the DOE Oak Ridge 

National Laboratory. The same Thomas Wilbanks was a Federal expert reviewer for the 

TSD. TSD p. 2. Thus, the EPA ignored and avoided the substance of a comment that 

pointed out that a report of which one of its expert reviewers was a lead author had 

“systematically and repeatedly misrepresented the science of disasters and climate 

change.” 

Response (2-7): 

First, EPA’s RTC document, Volume 1, covers EPA’s “General Approach to the Science and 

Other Technical Issues,” not the substantive issues pertaining to climate change and disaster 

losses. Those issues are discussed in RTC Volume 7, “Water Resources, Coastal Areas, and 

Ecosystems and Wildlife.” Specifically, RTC 7-38 address substantive issues pertaining to 

climate change and disaster losses raised by commenters (as does RTC 7-5) as discussed in 

Response 2-4 above. Accordingly, EPA’s commentary on the Muir-Wood literature in Volume 

1 focuses on process issues, and the scientific issues are addressed in Volume 7. 

18 
Furthermore, as we indicate in Response 2-5 above, a subsequent version of Muir-Wood et al. 

(2006) was, in fact, peer-reviewed and accepted for publication just weeks after the IPCC cutoff 

according to RMS. Irrespective of the peer review issue, we reiterate our conclusion from RTC 

1-15: “...these specific studies were neither the central nor sole evidence used in forming the 

broader conclusions of the IPCC; such broader conclusions are based on multiple lines of 

evidence and peer-reviewed literature.” The magnitude of observed disaster losses from extreme 

events in general, and the Muir-Wood study in particular, were not central to EPA’s 

Endangerment Finding. 

We discuss allegations that the IPCC misrepresented the literature on observed climate change 

and disaster losses in Response 2-5. With respect to the “graph [13, IPCC Supplementary 

Material Figure SM1.1, Working Group II AR4, 2007] attempting to show how closely 

temperature anomalies match up with disaster losses” referred to in the cited comment (3303) 

above, we note that said graph was not cited or relied upon in the Endangerment Finding and, 

furthermore, that it did not appear in the main IPCC Working Group II report but in 

supplementary material. We acknowledge this graph is controversial. RMS, for example, stated 

the following in its frequently asked questions document pertaining to climate change and 

disaster losses (RMS, 2010): 

A graph showing averaged global temperature and averaged catastrophe loss since 1970 

was included in supplementary material rather than the IPCC report itself and was not 

itself published. RMS believes that the graph could be misinterpreted and should not 

have been included in these materials. 

Despite this statement, the inclusion of one controversial graph in supplementary material does 

not compromise the IPCC’s credibility or legitimacy. 

The charges that CCSP (and hence USGCRP) miscited and misrepresented Roger Pielke Jr.’s 

work, over-relied on the work of Evan Mills, and ignored some other studies on the issue of 

climate change and disaster loss are difficult to assess as they were made in blog posts (of Roger 

Pielke Jr. (Pielke, 2010b)), represent the perspective of one individual (Roger Pielke Jr.), and 

have not been published in any official capacity (e.g., in the peer-reviewed literature). However, 

they do not materially affect the basis for EPA’s Endangerment Finding. Dr. Pielke himself 

stated: “...I am of the view that the Obama Administration is perfectly justified in advancing the 

[Endangerment] finding” (Pielke, 2010b). As we state in Response 2-4, EPA did not focus on 

historical trends in the magnitude of economic disaster losses to evaluate the likelihood that 

climate change would lead to an increase in the number or frequency of extreme weather events. 

Furthermore, in RTC 7-5 we cite the CCSP (2008) statement acknowledging that the relative 

contribution of climate change and socioeconomic vulnerability (to weather and climate 

extremes) to observed increases in disaster costs are “subject to debate.” 

Finally, the fact that Robert Muir-Wood and Evan Mills were selected as authors for chapters in 

the IPCC and CCSP, respectively, and may have cited their own work does not delegitimize 

these assessments or their findings. Rather, it is only appropriate that leading experts on these 

topics—familiar with the range of literature—would be asked to assist in these assessments. 

Petitioners provide no evidence to support the allegation that Evan Mills’ work was 

19 
compromised or biased; speculating that he “apparently” does consulting for companies “with an 

interest in climate policies” is innuendo, not proof. 

Lastly, the fact that Thomas Wilbanks was an expert reviewer for EPA’s TSD (U.S. EPA, 2009) 

and was lead author of a report that the petitioner alleges “systematically and repeatedly 

misrepresented the science of disasters and climate change” is irrelevant. As we state in 

Response 2-4, EPA did not discuss observed climate change and disaster losses in the TSD. 

Thus, though we discuss some of CCSP’s conclusions in RTC 7-5 and 7-38 that focus on the 

challenges in linking observed climate change and disaster losses, CCSP’s treatment of this issue 

was not and is not materially relevant to the Endangerment Finding. Furthermore, the petitioner 

does not present evidence Wilbanks played any role in the presentation of material on this issue. 

Thus, the charge that EPA “ignored and avoided” the substance of the comment on disasters and 

climate change because of Wilbanks is unsupported and false. EPA relied on a team of federal 

experts to ensure that EPA was correctly synthesizing the existing assessment literature in the 

TSD. As RTC 1-10 states: 

....the purpose of the federal expert review was to ensure that the TSD accurately 

summarized the conclusions and associated uncertainties from the assessment reports. 

The federal experts were ideal candidates because they have contributed significantly to 

the body of climate change literature and played active roles in IPCC and CCSP—

therefore making them experts on various aspects of climate science and very familiar 

with the underlying literature and state of the science. Furthermore, the federal climate 

change experts represent a range of technical specialties that span the range of topics 

covered in the TSD and covered by the range of topics that the Administrator needed to 

consider. In addition, the federal experts were not involved with developing the TSD or 

Findings in any way other than their review roles. 

 

Petitioners are making a very serious accusation—that “what appears to be scientific fraud” 

occurred—without providing supporting scientific evidence. Instead, they mischaracterize 

EPA’s actions in claiming that disaster losses are central to the Endangerment Finding when they 

clearly are not. They mischaracterize EPA’s treatment of comments on the proposed 

Endangerment Finding by implying that we did not address the issues surrounding disaster 

losses, when the issue is clearly addressed in the appropriate volume of the RTC. And they 

impugn the integrity of several scientists, on the basis of speculation not evidence, seemingly for 

no other reason than that they disagree with the conclusions of the assessment literature. 

2.1.5 Validity of Alps, Andes, and African Mountain Snow Impacts 

Comment (2-8): 

Several petitioners (the Competitive Enterprise Institute, the Ohio Coal Association, Peabody 

Energy, the State of Texas, and the Southeastern Legal Foundation) argue that claims of glacier 

melt in the Andes, the Alps, and parts of Africa arise from anecdotal comments in a magazine 

article and a master thesis. They challenge the IPCC’s use of this non-peer-reviewed literature, 

suggesting the findings may be suspect. The Southeastern Legal Foundation states: “The EPA 

should reconsider its reliance on the IPCC’s reporting now that the IPCC’s conclusion has been 

shown to be so poorly supported.” 

20 
Response (2-8): 

The citations referred to by petitioners regarding the reduction of mountain ice in the Andes, 

Alps, and Africa are actually references to “loss of ice climbs,” not assessments of mountain 

glacier retreat. Loss of ice climbs is an example of the observed effects of warming on the icecovered areas of the Earth. In this context, these citations are appropriate and within the IPCC’s 

guidelines on the use of so-called gray literature. They provide additional evidence consistent 

with the well-supported peer-review conclusions that snowpack is declining in many places and 

that glaciers are melting worldwide. Note that we respond to petitioners’ broader claims 

regarding the IPCC’s use of gray literature in Subsection 2.2.4.4. 

Furthermore, as the finding in question pertains to indicators outside the United States, the 

petitioners’ claims are not relevant to the Endangerment Finding. As noted in Subsection 2.1.1, 

the Endangerment Finding states (Section III.D): “The Administrator looked first at impacts in 

the United States itself, and determined that these impacts are reasonably anticipated to endanger 

the public health and the welfare of the U.S. population. That remains the Administrator’s 

position, and by itself supports her determination of endangerment.” 

EPA did not rely on these specific references or refer to “loss of ice climbs” as an indicator of 

climate change. Our primary focus was on the implications of climate change for the United 

States, and we relied on peer-reviewed literature to assess these impacts. We did not refer to this 

specific issue in either the TSD or the Endangerment Finding, and we did not include any 

discussion on “loss of ice climbs.” The TSD does include discussion of mountain glacier retreat, 

based on peer-reviewed literature, which the petitioners do not critique. 

2.1.6 Validity of Amazon Rainforest Dieback Projection 

Comment (2-9): 

Several petitioners (the Competitive Enterprise Institute, the Ohio Coal Association, Peabody 

Energy, the State of Texas, the Southeastern Legal Foundation) challenge the IPCC’s statement 

that “[U]p to 40% of the Amazonian forests could react drastically to even a slight reduction in 

precipitation,” alleging that it arises from gray literature and cannot be substantiated. The 

Southeastern Legal Foundation states that the source for the IPCC’s statement, Nepstad et al. 

(1999) from the journal Nature, “does not support the IPCC’s assertion”. Peabody states that 

“the Nature article does not contain the 40% figure” and “the provenance of the IPCC’s striking 

‘40%’ figure is uncertain.” The Competitive Enterprise Institute finds that “the IPCC claim that 

the findings in AR4 are based on peer reviewed science is false.” 

Response (2-9): 

First, we note that this issue is not discussed anywhere in the TSD or Endangerment Finding, and 

is thus of little relevance to the Finding. Second, while we agree that the IPCC cited gray 

literature in this case—i.e., Rowell and Moore (2000), a report of the World Wildlife 

Federation—we note that the underlying studies supporting the Rowell and Moore report are, in 

fact, peer-reviewed. 

21 
In response to the publicity surrounding this purportedly unsubstantiated finding in the IPCC 

AR4, Daniel Nepstad—a senior scientist at Woods Hole Research Center and author of the study 

(Nepstad et al., 1999) that contained the finding referred to by Rowell and Moore—issued a 

statement on this matter. In the statement, he noted that the citations listed in the Rowell and 

Moore report were incomplete but that the AR4’s statement on Amazon forest susceptibility to 

rainfall reduction was correct. Here is the relevant excerpt from his statement (Nepstad, 2010): 

The IPCC statement on the Amazon is correct, but the citations listed in the Rowell and 

Moore report were incomplete. (The authors of this report interviewed several 

researchers, including the author of this note, and had originally cited the IPAM website 

where the statement was made that 30 to 40% of the forests of the Amazon were 

susceptible to small changes in rainfall). Our 1999 article (Nepstad et al. 1999) estimated 

that 630,000 km2 of forests were severely drought stressed in 1998, as Rowell and Moore 

correctly state, but this forest area is only 15% of the total area of forest in the Brazilian 

Amazon. In another article published in Nature, in 1994, we used less conservative 

assumptions to estimate that approximately half of the forests of the Amazon depleted 

large portions of their available soil moisture during seasonal or episodic drought 

(Nepstad et al. 1994). After the Rowell and Moore report was released in 2000, and prior 

to the publication of the IPCC AR4, new evidence of the full extent of severe drought in 

the Amazon was available. In 2004, we estimated that half of the forest area of the 

Amazon Basin had either fallen below, or was very close to, the critical level of soil 

moisture below which trees begin to die in 1998. This estimate incorporated new rainfall 

data and results from an experimental reduction of rainfall in an Amazon forest that we 

had conducted with funding from the US National Science Foundation (Nepstad et al. 

2004). Field evidence of the soil moisture critical threshold is presented in Nepstad et al. 

2007. 

Specifically, we note that the Nepstad et al. (2004) study states: “Increases in ET [evapotranspiration] of only 15% or similar reductions in rainfall can lead to severe soil moisture 

deficits over roughly half of the Amazon.” This statement certainly is consistent with the 

statement “Up to 40% of the Amazonian forests could react drastically to even a slight reduction 

in precipitation” in the IPCC AR4. 

Nepstad’s 2010 statement in response to this controversy reached the following conclusion 

(Nepstad, 2010): 

In sum, the IPCC statement on the Amazon was correct. The report that is cited in 

support of the IPCC statement (Rowell and Moore 2000) omitted some citations in 

support of the 40% value statement. 

Similarly, in its report Assessing an IPCC Assessment, PBL (2010a) identified a problem with 

the IPCC’s referencing of this finding, but not the finding itself. It states: 

More adequate peer-reviewed, scientific journal literature would have been available to 

support this statement, such as Cox et al. (2000; 2004) (C6). This minor comment has no 

consequences for the IPCC conclusions in the various Summaries for Policymakers. 

22 
Finally, the United Kingdom’s Sunday Times newspaper, which reported the alleged problem 

with the IPCC’s representation of this issue on January 31, 2010 (Sunday Times, 2010), has 

subsequently reversed itself, arriving at the same conclusion as Nepstad. Consequently, it 

removed the article from its website and printed a correction on June 20, 2010 (Sunday Times, 

2010), which stated in part: 

The article “UN climate panel shamed by bogus rainforest claim” (News, Jan 31) stated 

that the 2007 Intergovernmental Panel on Climate Change (IPCC) report had included an 

“unsubstantiated claim” that up to 40% of the Amazon rainforest could be sensitive to 

future changes in rainfall. The IPCC had referenced the claim to a report prepared for the 

World Wildlife Fund (WWF) by Andrew Rowell and Peter Moore, whom the article 

described as “green campaigners” with “little scientific expertise.” The article also stated 

that the authors’ research had been based on a scientific paper that dealt with the impact 

of human activity rather than climate change. 

In fact, the IPCC’s Amazon statement is supported by peer-reviewed scientific evidence. 

In the case of the WWF report, the figure had, in error, not been referenced, but was 

based on research by the respected Amazon Environmental Research Institute (IPAM) 

which did relate to the impact of climate change. We also understand and accept that Mr 

Rowell is an experienced environmental journalist and that Dr Moore is an expert in 

forest management, and apologise for any suggestion to the contrary. 

To summarize, contrary to the assertions of the petitioners, though the IPCC may have not 

adequately referenced the Amazon finding, the basis for its statement originated from and is 

supported by peer-reviewed literature. Furthermore, as this finding is specific to the Amazon 

region, petitioners’ claims are not relevant to the Endangerment Finding. As noted in Subsection 

2.1.1, the Endangerment Finding states (Section III.D): “The Administrator looked first at 

impacts in the United States itself, and determined that these impacts are reasonably anticipated 

to endanger the public health and the welfare of the U.S. population. That remains the 

Administrator’s position, and by itself supports her determination of endangerment.” 

For further discussion on petitioners’ broader claims regarding the IPCC’s use of gray literature, 

please refer to Subsection 2.2.4.4. 

2.1.7 Validity of African Rain-Fed Agriculture Projection 

The comments and responses in this section refer to the following statement pertaining to crop 

yields in Africa from Chapter 9 of Working Group II’s contribution to the IPCC AR4 (Boko et 

al., 2007): 

In other countries [of Africa] additional risks that could be exacerbated by climate change 

include greater erosion, deficiencies in yields from rain-fed agriculture of up to 50% 

during the 2000-2020 period, and reductions in the crop growth period (Agoumi, 2003). 

A version of this statement appeared in the IPCC’s AR4 Synthesis Report (IPCC, 2007b): 

23 
By 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 

50%. Agricultural production, including access to food, in many African countries is 

projected to be severely compromised. This would further adversely affect food security 

and exacerbate malnutrition. 

A similar statement also appeared in the IPCC’s AR4 Working Group II Summary for 

Policymakers (IPCC, 2007c): 

Agricultural production, including access to food, in many African countries and regions 

is projected to be severely compromised by climate variability and change. The area 

suitable for agriculture, the length of growing seasons and yield potential, particularly 

along the margins of semi-arid and arid areas, are expected to decrease. This would 

further adversely affect food security and exacerbate malnutrition in the continent. In 

some countries, yields from rain-fed agriculture could be reduced by up to 50% by 2020. 

The same statement (from IPCC, 2007c) was incorporated into EPA’s TSD (U.S. EPA, 2009) 

within Table 16.1: “Examples of Key Regional Impacts as Identified by IPCC.” 

Comment (2-10): 

The Competitive Enterprise Institute, the Ohio Coal Association, Peabody Energy, and the 

Southeastern Legal Foundation take issue with a statement in Section 16(b) of the TSD that: “In 

some countries, yields from rain-fed agriculture could be reduced by up to 50% by 2020.” They 

claim the statement originated from gray literature in the IPCC AR4 and is therefore illegitimate. 

Southeastern Legal Foundation concludes: “The African Crop Yields claim stands as another 

example of the IPCC making a claim of imminent disaster that inappropriately relied on nonpeer-reviewed literature...” 

Response (2-10): 

The IPCC statement cites a report by Dr. Ali Agoumi, a climate expert from Morocco (Agoumi, 

2003) that was published by the International Institute for Sustainable Development (IISD) and 

funded by the government of Canada, the U.S. Agency for International Development, and other 

public and private institutions. Based on EPA’s review of the report, it appears that the 50% 

number was not obtained from the peer-reviewed literature but rather from “vulnerability studies 

on three North African countries (Algeria, Morocco and Tunisia) with respect to climatic 

changes.” These vulnerability studies were prepared under the U.N. Environment Programme 

Global Environment Fund and included in the National Communications of these three countries 

to the U.N. Framework Convention on Climate Change (Ministry of Territory Development and 

Environment, 2001, Kingdom of Morocco, 2001 and Republic of Tunisia, 2001). 

In response to publicity regarding this purportedly unsubstantiated statement in the IPCC report, 

Dr. Coleen Vogel, a contributing lead author of the IPCC chapter on Africa impacts, described 

the context in which Dr. Agoumi’s research was used. She explained that Agoumi’s report 

received rigorous scrutiny by her fellow authors and was thoroughly discussed during 

development of the chapter (Kretzmann, 2010). She explained that the decision to include this 

(gray literature) study was based on the paucity of peer-reviewed material relating to some parts 

24 
of the world, particularly Africa, and the desire of the authors of the report to provide balanced 

information. The process described by Dr. Vogel is consistent with the IPCC’s guidance on the 

use of gray literature, as previously described in Volume 1 of the RTC document and further 

discussed in Subsection 2.2.4.4 of this Response to Petitions (RTP) document. 

Finally, we note that this statement relates to impacts outside the United States, and it did not 

materially impact the determination of endangerment of public health and welfare in the United 

States. As noted in Subsection 2.1.1, the Endangerment Finding states (Section III.D): “The 

Administrator looked first at impacts in the United States itself, and determined that these 

impacts are reasonably anticipated to endanger the public health and the welfare of the U.S. 

population. That remains the Administrator’s position, and by itself supports her determination 

of endangerment.” 

Comment (2-11): 

Referring to an analysis published by Ben Pile, co-editor of the blog climateresistance.org (on 

the blog of Roger Pielke, Jr.) (Pile, 2010), the Southeastern Legal Foundation states that the 

primary reference supporting the IPCC’s statement on African crop yields “Vulnerability of 

North African Countries to Climatic Changes” (Agoumi, 2003) was from IISD, an advocacy 

group. 

Regarding the IISD reference, Peabody Energy states: 

Thus, the EPA based its findings on the IPCC WGII report, which based its findings on a 

report [the IISD report] published by an organization with a declared political interest in 

climate change that based its findings from an assessment of other non-peer reviewed 

national studies. This is not the way EPA science should be carried out. 

Response (2-11): 

The implication that the credibility of IPCC’s statement on African crop yields is diminished 

because the IPCC’s source (Agoumi, 2003) for the statement was published by an advocacy 

organization or an organization with a “declared political interest in climate change” is 

unsupported. The organization in question is IISD, which describes itself as follows: 

The International Institute for Sustainable Development contributes to sustainable 

development by advancing policy recommendations on international trade and 

investment, economic policy, climate change, measurement and indicators, and natural 

resource management. By using Internet communications, we report on international 

negotiations and broker knowledge gained through collaborative projects with global 

partners, resulting in more rigorous research, capacity building in developing countries 

and better dialogue between North and South. 

IISD’s vision is better living for all—sustainably; its mission is to champion innovation, 

enabling societies to live sustainably. IISD receives operating grant support from the 

Government of Canada, provided through the Canadian International Development 

Agency (CIDA) and Environment Canada, and from the Province of Manitoba. The 

institute receives project funding from the Government of Canada, the Province of 

25 
Manitoba, other national governments, United Nations agencies, foundations and the 

private sector. IISD is registered as a charitable organization in Canada and has 

501(c)(3) status in the United States. 

We find no reason to question the credibility and legitimacy of information produced by this 

organization on the basis of either its mission or funding sources. Moreover, neither the 

Southeastern Legal Foundation nor Peabody Energy provide any support for the implication that 

work by an organization such as IISD is automatically suspect or flawed. 

Finally, Peabody Energy’s statement that EPA’s findings are based on this material is incorrect. 

As noted in Subsection 2.1.1, the Endangerment Finding states (Section III.D): “The 

Administrator looked first at impacts in the United States itself, and determined that these 

impacts are reasonably anticipated to endanger the public health and the welfare of the U.S. 

population. That remains the Administrator’s position, and by itself supports her determination 

of endangerment.” 

We discuss the legitimacy of the science and underlying references for the African crop yields 

statement in Response 2-12. 

Comment (2-12): 

The Southeastern Legal Foundation alleges that EPA uncritically adopted the IPCC’s “faulty 

conclusion” with respect to crop yields. It refers to a blog by writer/commentator Richard North 

(North, 2010) to conclude the Agoumi (2003) reference cited by the IPCC on the issue of rainfed agricultural yields in Africa relies on studies that “do not support the proposition for which 

they are cited.” 

Relying on Richard North’s blog, the Southeastern Legal Foundation summarizes the 

vulnerability studies cited by Agoumi (2003) from the National Communications of Morocco, 

Tunisia, and Algeria. The Southeastern Legal Foundation notes that the Morocco National 

Communication “lends some support [to the Agoumi reference], saying that by 2020 during 

drought conditions cereal yields would decline up to 50%” but that “the data apply to cereal 

yields only, not crops in general as is implied by the IPCC.” The Southeastern Legal Foundation 

further states that “Algeria’s report said their yields would double, and be trimmed only slightly 

by ‘climate change’” and “Tunisia’s submission concluded the picture was mixed, but they could 

have an increase in rain and agricultural production.” 

Response (2-12): 

The IPCC’s statement on rain-fed agriculture in Northern Africa is not “faulty” and the 

Southeastern Legal Foundation presents no evidence that it was included uncritically in EPA’s 

TSD. Furthermore, the Southeastern Legal Foundation’s portrayal of findings on climate and 

crop yields from the National Communications of Morocco, Tunisia, and Algeria derived from 

Richard North’s blog is not complete. When all of the information in these National 

Communications is considered, we find there is broad support for Agoumi’s (2003) statements 

on North African rain-fed agriculture, which are: 

26 
 “Some of the key statistics regarding water, soil, urban areas and coastal zones are 

outlined below. . . . Decreasing rain-based agricultural yields with grain yields reduced 

by up to 50 percent in periods of drought.” 

 “Studies on the future of vital agriculture in the region have shown the following risks, 

which are linked to climate change: . . . deficient yields from rain-based agriculture of up 

to 50 percent during the 2000–2020 period.” 

PBL, in its report Assessing an IPCC Assessment (PBL, 2010a), makes the following important 

point with respect to IPCC’s statement on rain-fed agriculture in Africa: 

This statement is not directly a statement on climate change, but on climate variability: in 

individual years, droughts can cause up to 50% in yield reductions. The implicit message 

here is that when droughts would become more frequent due to climate change, more 

years with up to 50% in yield reductions would occur. The statement could easily 

mislead readers into thinking that average annual yields could be reduced by up to 50% 

due to climate change. In the Summary for Policymakers of the Working Group II 

Report, the paragraph that contains this statement starts with a sentence introducing the 

notion of climate variability, which puts the statement more into context. 

It is possible that petitioners misinterpreted the IPCC’s statement as suggesting that the IPCC’s 

projection was on the basis of climate change alone, given the Southeastern Legal Foundation’s 

assertion, for example, that IPCC was projecting “imminent disaster.” While we agree with PBL 

that the IPCC’s statement could easily mislead readers without the proper context, we note that, 

before quoting the IPCC’s projection on rain-fed agriculture, EPA’s TSD includes the statement 

“Agricultural production, including access to food, in many African countries and regions is 

projected to be severely compromised by climate variability [emphasis added] and change.” 

Therefore, EPA provided the proper context for the IPCC’s conclusion. 

With respect to the basis for the conclusion itself, the following excerpts from the three 

countries’ National Communication reports on the issues of climate variability and change, 

precipitation, and crop yields provide broad support for the Agoumi (2003) statements along 

with accompanying discussion: 

 The National Communication of Morocco states (Kingdom of Morocco, 2001): 

The development of climate scenarios for Morocco according to IPCC 

methodology reveals the following results: . . . 

 A trend towards a decrease in average annual rainfall volume by about 4% 

in 2020 compared to 2000 levels. . . . 

 An increase in the frequency and intensity of droughts in the south and the 

east of the country. 

27 
The first quantitative estimate of possible CC [climate change] impacts on water 

resources in 2020 points to the fact that there would be an average and general 

decrease in water resources (in the order of 10 to 15 %...). 

The study of CC [climate change] impacts on agriculture (dominated by cereal 

cultivation) in 2020 unfolds the following results: A decrease in cereal yields by 

50% in dry years and 10% in normal years. 

As the Southeastern Legal Foundation admits, the numbers from Morocco’s National 

Communication lend support to the statement in Agoumi (2003) that “studies on the 

future of vital agriculture in the region have shown the following risks, which are linked 

to climate change: . . . deficient yields from rain-based agriculture of up to 50 per cent 

during the 2000–2020 period.” 

Richard North’s contention (North, 2010, as referred to by the Southeastern Legal 

Foundation) that “the data apply to cereal yields only, not crops in general as is implied 

by the IPCC” is arguable considering that Morocco’s National Communication 

indicates that agriculture is “dominated by cereal cultivation.” Thus, it is not 

unreasonable to use cereal cultivation as a proxy for all of agriculture in this cerealcrop-dominated region. 

 The National Communication of Algeria (Ministry of Territory Development and 

Environment, 2001) states:1

Because of global warming, we must brace ourselves for chronic climate 

instability and greater frequency of droughts and floods. Droughts damage soils 

and floods destroy ground cover and contribute to the erosion of soils. With 

longer spans of time between dry and wet spells comes an even greater impact 

due to erosion. The southern regions of the country will be most directly 

impacted by increased temperatures and will be subject to the numerous 

consequences of accelerated desertification. The increased risk of drought 

presents the greatest challenge as a result of climate change. The 

Intergovernmental Panel on Climate Change (IPCC) expect that the desert regions 

will extend northward in the Maghreb. 

The above text provides a clear qualitative description of the risks climate change pose to 

agriculture in Algeria. In addition, this information from the National Communication of 

Algeria provides quantitative output from a model known as CROPWAT, which 

estimates changes in crop yields using climate change projections obtained from two 

general circulation models. The National Communication of Algeria reports: 

... one can consider an average reduction in the output cereal of about 5.5 to 

6.8%, corresponding mainly to instances of climate change [in 2020]( Ministry of 

Territory Development and Environment, 2001) 

 

1

 The excerpt that follows was professionally translated from French. 

28 
When considering these quantitative cereal yield changes, it is very important to note that 

these percentages refer to changes in cereal yields resulting primarily from climate 

change alone and not climate variability and change combined. The climate and hence 

precipitation variability in northern Africa can be quite large. For example, in the report 

Assessing an IPCC Assessment (PBL, 2010a), PBL states “...the [IPCC] authors made 

plausible that, due to current climate variability, the yields in Algeria, Morocco and 

Tunisia have been varying annually, including yield reductions of nearly 70% in 

individual years, in the period between 2000 and 2006.” 

In other words, if these yield reductions resulting from greenhouse gas–induced climate 

change were superimposed on the yield reductions that might occur during a particularly 

dry period arising from the region’s characteristic precipitation variability, they would be 

higher and comparable with the results from the Morocco National Communication. 

Finally, the Southeastern Legal Foundation’s reference to the Algeria National 

Communication’s projections for net increases in cereal projections in 2020 (relative to 

prior decades) is irrelevant and misleading. These increases are related not to climate 

variability and change but to changing agricultural practices and technology. Algeria’s 

National Communication makes clear that the effect of climate change on cereal yields is 

projected to be negative. 

 

 The National Communication of Tunisia states (Republic of Tunisia, 2001): 

...Tunisia is in a hydrous stress situation close to a shortage, sharpened by a high 

anthropic pressure. So minor they be, the Climate Changes can so, result in 

harmful consequences on water resources, on ecosystems depending of water, and 

on the different economic activities that need large quantities of water such as 

agriculture and tourism. 

By modifying the evaporation and precipitation rate, the global warming will 

probably affect the hydrous climate balance and therefore the Tunisian water 

resources. In this way, if the intensification of the evaporation can lead to a 

possible important increase of the rain falls, it might not be sufficient to offset the 

decrease of the sweet water resources. Moreover, due to the global warming, the 

rain situation can be characterized by a bigger frequency of rains resulting from 

torrential storms and downpours, disappearing generally in streaming waters 

rather than be absorbed by the soils. 

This information in the Tunesian National Communication does not provide any 

quantitative estimates of climate variability and/or change on rain-fed agriculture, but the 

clear qualitative implication is that climate changes—both drought and heavy 

precipitation events—will stress agriculture in Tunisia. We, therefore, find that the 

Southeastern Legal Foundation’s statement that “Tunisia’s submission concluded the 

picture was mixed, but they could have an increase in rain and agricultural production” is 

an overly optimistic interpretation of clearly expressed negative impacts. 

29 
Overall, these three National Communications (Morocco, Algeria, and Tunisia) provide 

qualitative support for the fact the climate change will likely stress rain-fed agriculture in 

northern Africa, consistent with the portrayal of Agoumi (2003) and the IPCC. The National 

Communication of Morocco presents quantitative information consistent with what is reported 

by Agoumi (2003) and the IPCC (and hence the TSD), while the National Communication of 

Algeria provides quantitative information that is consistent with these sources when factoring in 

precipitation variability in addition to climate change. The National Communication of Tunisia 

does not provide quantitative information. 

Our view of the literature behind Agoumi (2003) provides considerable evidence that the 

scientific basis for the IPCC’s conclusion is legitimate. The PBL assessment of the IPCC notes 

that “...additional explanations could have provided further foundations for the statement, had 

they been included in [IPCC’s Working Group II] Chapter 9.” We concur, but the Southeastern 

Legal Foundation conclusion that “...there is no support for the IPCC’s dramatic pronouncement 

on African crop yields” is significantly overstated. 

Comment (2-13): 

The Southeastern Legal Foundation provides the following reaction to the African rain-fed 

agriculture projection, which appeared in the Sunday Times (Leake, 2010a) and comes from 

former IPCC chair Robert Watson: “Any such projection [pertaining to African crop yields] should 

be based on peer-reviewed literature from computer modeling of how agricultural yields would 

respond to climate change. I can see no such data supporting the IPCC report.” 

Response (2-13): 

Watson may not have appreciated that peer-reviewed modeling studies of climate change impacts on 

agriculture in parts of Africa are limited. As the IPCC’s AR4 WGI report states (Christensen et al., 

2007): “Several climate change projections based on RCM (regional climate model) simulations are 

available for southern Africa, but are much scarcer for other regions.” Accordingly, as we discuss in 

Subsection 2.2.4.4 of this RTP document, the IPCC references gray literature in these circumstances. 

We also note in Response 2-10 that these studies are not central to the TSD or the Endangerment 

Finding. Finally, though we discuss some additional modeling studies pertinent to Africa in RTP 2-

15, those modeling studies (Parry et al., 2005 and Hulme et al., 2001) were conducted at the global 

and continental scales and contain limited results pertinent to northern Africa specifically. 

Comment (2-14): 

The Southeastern Legal Foundation states that EPA ignored contrary peer-reviewed literature 

and submits literature that the Sahel is greening (from National Geographic and several studies) 

in contrast to “IPCC horror stories” (projecting reductions in rain-fed agriculture). 

Response (2-14): 

EPA is aware of the literature cited by the petitioner that suggests greening in parts of the Sahara 

and Sahel (e.g., Seaquisti, et al., 2009; Anyamba, and Tucker, 2005; Hutchinson et al., 2005; Olsson 

et al., 2005). The issue raised by petitioners is not new and was raised and responded to through 

the public comment process (see Response 2-73 in Volume 2 of the RTC document). Thus, 

these objections do not meet the test in Clean Air Act (CAA) Section 307(d)(7)(B) that it be 

impracticable to raise the objection during the public comment period or the reasons for the 

30 
objection arose between June 24, 2009, and February 16, 2010. Nonetheless, we have reviewed 

these arguments and respond once again. 

The fact that precipitation has increased recently in this region, as we note in our TSD in Section 

4(d), does not mean that a combination of climate variability and change could not substantially 

reduce rain-fed agriculture in the future. The climate in this region is highly variable and while it 

has been relatively wet over the past decade or so, severe drought impacted the region for several 

decades from the 1960s to the 1990s and dry patterns could return to the region. As one of the 

studies (Nicholson, 2005) cited by the petitioner states: “The fluctuations between ‘wet’ and 

‘dry’ in the Sahel/Soudan zones are extreme even on decadal and multi-decadal time scales.” 

Therefore, if the current wet period reverses to a dry period, the impacts of rain-fed agriculture 

on the region could be profound, especially when considering the potential enhancement of the 

drying from human-induced warming (i.e., climate change). 

Finally, we note that the literature presented relates to impacts outside the United States, and it 

did not materially impact the determination of endangerment of public health and welfare in the 

United States. As noted in Subsection 2.1.1, the Endangerment Finding states (Section III.D): 

“The Administrator looked first at impacts in the United States itself, and determined that these 

impacts are reasonably anticipated to endanger the public health and the welfare of the U.S. 

population. That remains the Administrator’s position, and by itself supports her determination 

of endangerment.” 

Comment (2-15): 

The Southeastern Legal Foundation suggests that the IPCC ignored literature that drew different 

conclusions on the issue of rain-fed agriculture projections in Africa, specifically referring to two 

studies: Parry et al., 2005 and Hulme et al., 2001. The Southeastern Legal Foundation states: 

“Both Parry’s own paper and Hulme’s paper were known to and available to Professor Parry [cochair of IPCC Working Group II] in composing the WGII Report and the Synthesis Report. Yet, 

Parry’s WGII report ignored his own paper and that of Hulme, which did not predict disaster, and 

instead relied on one that did, the Agoumi paper, even though it did so incorrectly and 

improperly and was not peer-reviewed.” The Southeastern Legal Foundation further notes that 

Hulme et al. (2001) were careful to note uncertainties in understanding African climate change, 

and implies that the IPCC was not as careful. 

Response (2-15): 

We have reviewed these papers (Parry et al., 2005, and Hulme et al., 2001) and find that, while not 

directly comparable with Agoumi (2003), they do not contradict that source. We also find, 

contrary to the Southeastern Legal Foundation’s assertion, that both of these studies were in fact 

cited by the IPCC, although not always in the same section or context as Agoumi (2003). 

The Parry et al. (2005) study reports the results of a series of research projects that aimed to 

evaluate the implications of climate change for food production and risk of hunger. The analysis 

in this study is performed at global and continental scales rather than the regional scale. This is 

likely why it is not discussed in Chapter 5 of Working Group II’s contribution to the AR4 

(Easterling et al., 2007), where Agoumi (2003) is cited in a section focusing on regional impacts 

in Africa (specifically on Morocco, Algeria, and Tunisia). The Parry et al. (2005) study is cited 

31 
multiple times in Chapter 5 of Working Group II’s contribution (“Food, Fiber, and Forest 

Products,” Easterling et al., 2007), which provides a global perspective. Therefore, Parry did not 

“ignore his own paper” as stated by the Southeastern Legal Foundation. 

One of the primary conclusions of Parry et al. is that “the region of greatest risk [of losses in 

food production, and hunger due to climate change] is Africa.” Parry et al. (2005) provide 

specific cereal yield projections for the 2020s and 2080s resulting from different GHG emission 

scenarios. They state for the globe: “By the 2020s, small changes in cereal yield are evident in 

all scenarios, but these fluctuations are within historical variations.” For the 2080s, Parry et al. 

(2005) provide projections specific to Africa – but not northern Africa specifically, stating that 

climate change could reduce cereal yields by up to 30%. Importantly, the changes in cereal yield 

projected for the 2020s and 2080s are driven by GHG-induced climate change and likely do not 

fully capture interannual precipitation variability which can result in large yield reductions 

during dry periods, as the IPCC (Christensen et al., 2007) states: “...there is less confidence in 

the ability of the AOGCMs (atmosphere-ocean general circulation models) to generate 

interannual variability in the SSTs (sea surface temperatures) of the type known to affect African 

rainfall, as evidenced by the fact that very few AOGCMs produce droughts comparable in 

magnitude to the Sahel droughts of the 1970s and 1980s.” Given the different scopes of the two 

analyses, it is misleading to state that the Parry et al. projections are inconsistent with the 

Agoumi (2003) yield projections. 

The Hulme et al. (2001) study, which reviews observed (1900–2000) and possible future (2000–

2100) continent-wide changes in temperature and rainfall over Africa, is also not ignored by the 

IPCC, contrary to the assertion of the petitioner. In fact, it is cited twice in IPCC’s Working 

Group II Chapter 9 on Africa (Boko et al., 2007): 

 Hulme et al. (2001) is cited in a statement about the complexity of African climatology: 

“Other factors that complicate African climatology include dust aerosol concentrations 

and sea-surface temperature anomalies, which are particularly important in the Sahel 

region (Hulme et al., 2001; Prospero and Lamb, 2003) and southern Africa (Reason, 

2002), deforestation in the equatorial region (Semazzi and Song, 2001; Bounoua et al., 

2002)...” 

 Hulme et al. (2001) is also cited in a statement pertaining to uncertainties in precipitation 

projections in the western Sahel (Boko et al., 2007): “For the western Sahel (10 to 18°N, 

17.5°W to 20°E), there are still discrepancies between the models: some projecting a 

significant drying (e.g., Hulme et al., 2001; Jenkins et al., 2005) and others simulating a 

progressive wetting with an expansion of vegetation into the Sahara (Brovkin, 2002; 

Maynard et al., 2002; Claussen et al., 2003; Wang et al., 2004; Haarsma et al., 2005; 

Kamga et al., 2005; Hoerling et al., 2006).” 

These examples demonstrate that the IPCC both cited Hulme et al. (2001) and transparently 

discussed the complexity of Africa’s climate and the uncertainty in African climate projections. 

This treatment is appropriate and reasonable, contrary to the petitioner’s implication. 

32 
Even in light of the complexities and uncertainties, Hulme et al. (2001) state that a “warming 

climate will nevertheless place additional stresses on water resources [in Africa], whether or not 

future rainfall is significantly altered” and they project reduced precipitation over Tunisia. 

Hulme et al. (2001) do not, however, provide projections for changes in cereal yields (from 

changes in rain-fed agriculture), so their results cannot be compared directly with Agoumi (2003) 

or its supporting documents (discussed in Response 2-12). 

Overall, the IPCC does not ignore either the Parry et al. (2005) or Hulme et al. (2001) studies. 

The findings of these studies, while not directly comparable with Agoumi (2003), are broadly 

consistent. Hulme et al. (2001) project increased drying over northern Africa while Parry et al. 

(2005) project an increased risk of reduced cereal yields over all of Africa. The petitioner’s claim 

that IPCC was not careful or acted inappropriately in this regard is not confirmed by careful 

review of the material. 

2.1.8 Summary 

The small number of real or alleged errors in the IPCC report is not materially relevant for 

EPA’s Endangerment Finding. Neither of the two errors that are verifiable (the percentage of the 

Netherlands below sea level and the projections for Himalayan glaciers) is relevant to the United 

States and neither is contained within EPA’s endangerment record. Although it is unfortunate 

when any error occurs, two errors in a nearly 3,000-page study are not evidence of a complete 

breakdown of the IPCC’s review process, contrary to petitioners’ suggestions. 

The remaining alleged errors or unsupported statements have not been shown to be erroneous 

and can be traced to findings in the gray literature from which they were derived. As discussed 

further in Subsection 2.2.4.4 in this volume and previously in Volume 1 of the RTC, the IPCC 

provides guidance on how and when to use gray literature, and petitioners do not demonstrate 

that the guidance was not followed. There is no de facto assumption that all gray literature is 

incorrect or suspect, and an examination of the instances raised by petitioners demonstrates that 

the specific allegations of petitioners are unfounded. Furthermore, the statements at issue drawn 

from the gray literature have no material relevance to conclusions supporting EPA’s Findings, as 

explained in RTP Subsection 2.1.1. 

In conclusion, the evidence cited by petitioners does not undermine the overall credibility and 

reliability of the scientific conclusions relied upon and underlying EPA’s Endangerment Finding. 

33 
2.2 Claims That the IPCC Has a Policy Agenda and Is Not Objective and Impartial 

2.2.1 Overview 

Several petitioners argue that the e-mails from the University of East Anglia’s Climatic Research 

Unit (CRU), and other information that has arisen since publication of the Endangerment 

Finding, show that a select group of influential authors who wrote, contributed to, or reviewed 

parts of IPCC assessment reports (or the studies on which the assessment reports were based) 

were not objective and impartial while developing the reports. Several petitioners also argue that 

the CRU e-mails confirm that the IPCC and some of its authors and reviewers have a policy 

agenda and are tailoring the science to suit that agenda. The petitioners allege that the e-mails 

show that the peer-review and report development processes employed by the IPCC are 

“fundamentally corrupt,” lack scientific integrity, are policy prescriptive, and do not yield “true” 

consensus conclusions regarding the state of the science. The petitioners request that EPA 

reconsider its reliance on the IPCC assessment reports that were used as the basis for the 

Endangerment Finding. 

As discussed in detail below, after reviewing the petitioners’ arguments, EPA finds that the 

evidence and arguments provided by petitioners do not support their conclusion that the peerreview and assessment report processes employed by the IPCC were “fundamentally corrupt” 

and policy prescriptive. Further, the petitioners’ arguments, which for the most part rely on 

selective use of the CRU e-mails, misinterpretations of the e-mails, and quotations from press 

articles, do not show that either the IPCC peer-review and report development processes were 

inadequately designed or that they were not implemented properly. We note that several of the 

petitioners’ arguments are not new; many of these comments were submitted and responded to in 

the process of developing the Findings. 

2.2.2 Background 

Several petitioners criticize the IPCC’s report development and peer-review procedures. We 

respond specifically to each allegation in the sections that follow. EPA received similar 

comments during notice and comment on the Endangerment Findings. In Volume 1 of the RTC 

document, we responded in detail to these comments, describing the IPCC’s report development 

and peer-review procedures. However, to provide context for evaluating the merit of these more 

recent allegations, in this background section we revisit the structure and procedures employed 

by the IPCC in developing their reports. 

In response to the allegations raised against it, the IPCC released the following statement in 

December 2009 describing their report development process from beginning to end (IPCC, 

2010a). 

The assessment process begins with a Scoping Meeting attended by scientific experts 

whose task it is to outline the report. The IPCC Bureau selects the experts attending the 

Scoping Meeting after an open call for nominations to Governments and IPCC observer 

organizations. The Bureau consists of experts elected by an IPCC Plenary composed of 

all WMO and UNEP member nations. The outline is then approved by Working Group 

34 
Sessions and endorsed by the Plenary. A call for nominations of authors for the report is 

sent out to Governments and observer organizations. The individual Working Group 

Bureaus select the authors for respective contributions to the Assessment Report, 

ensuring that the composition of the author teams reflects a range of views, scientific 

expertise and geographical diversity. Over the ensuing 3-4 years, writing teams 

collaborate on drafting chapters – including four Lead Author meetings, plus chapter 

meetings as necessary. The author teams prepare two externally reviewed drafts and then 

a final version of their respective chapters. All chapters undergo a rigorous writing and 

open review process to ensure consideration of all relevant scientific information from 

established journals with robust peer review processes or from other sources which have 

undergone robust and independent peer review. Additional procedures are provided for 

information found in sources that have not been published or peer-reviewed. In these 

cases, authors and chapter teams should critically assess and review the quality and 

validity of each source before incorporating results. 

 

The First Order Draft is subject to a formal Expert Review, where any expert is 

encouraged to comment on all aspects of the draft, including, but not limited to, issues of 

interpretation, missed literature, and presentation. Author teams must make a written 

response, explaining how they responded to each comment in developing the next draft. 

A Second Order Draft is compiled based on the comments received during the Expert 

Review. This draft undergoes a second combined formal Expert and Government 

Review. Author teams have to react to the second round of review comments as well and 

prepare the final draft, taking into account all the comments received. The entire review 

process is overseen by a team of 2-3 independent Review Editors for each chapter, whose 

role is limited to overseeing the reviews, ensuring the thoroughness of the responses. All 

the AR4 review comments and responses by the author teams are available online (IPCC, 

2006a). 

 

In parallel, the Summary for Policymakers and the Technical Summary are prepared by 

authors selected from chapter writing teams. The Summary for Policymakers and the 

Technical Summary undergo a formal Expert and Government Review and are revised 

based on the review comments. Again, 2-3 Review Editors oversee the review process 

for the Technical Summary. The Summary for Policymakers is then distributed to the 

Governments for final comment. The Summary for Policymakers undergoes a line-byline approval process by Governments during a multi-day meeting. The Governments 

must reach consensus before text is approved. After the Working Group Session 

approves the Summary for Policymakers, the IPCC Plenary then accepts the entire 

underlying Report (including the individual chapters and Technical Summary). 

To ensure objectivity, transparency, and information quality, the IPCC’s report development 

procedures (IPCC, 1999) clearly describe the roles and responsibilities of coordinating lead 

authors, lead authors, contributing authors, expert reviewers, and review editors in report 

development. It states: 

35 
1. LEAD AUTHORS 

Function: 

To be responsible for the production of designated sections addressing items of the work 

program on the basis of the best scientific, technical and socio-economic information 

available. 

Comment: 

Lead Authors will typically work as small groups which have responsibility for ensuring 

that the various components of their sections are brought together on time, are of 

uniformly high quality and conform to any overall standards of style set for the document 

as a whole. 

The task of Lead Authors is a demanding one and in recognition of this the names of 

Lead Authors will appear prominently in the final Report. During the final stages of 

Report preparation, when the workload is often particularly heavy and when Lead 

Authors are heavily dependent upon each other to read and edit material, and to agree to 

changes promptly, it is essential that the work should be accorded the highest priority. 

The essence of the Lead Authors’ task is synthesis of material drawn from available 

literature as defined in Section 4.2.3. Lead Authors, in conjunction with Review Editors, 

are also required to take account of expert and government review comments when 

revising text. Lead Authors may not necessarily write original text themselves, but they 

must have the proven ability to develop text that is scientifically, technically and socioeconomically sound and that faithfully represents, to the extent that this is possible, 

contributions by a wide variety of experts. The ability to work to deadlines is also a 

necessary practical requirement. Lead Authors are required to record in the Report views 

which cannot be reconciled with a consensus view but which are nonetheless 

scientifically or technically valid. 

Lead Authors may convene meetings with Contributing Authors, as appropriate, in the 

preparations of their sections or to discuss expert or government review comments and to 

suggest any workshops or expert meetings in their relevant areas to the Working 

Group/Task Force Bureau Co-Chairs. The names of all Lead Authors will be 

acknowledged in the Reports. 

2. COORDINATING LEAD AUTHORS 

Function: 

To take overall responsibility for coordinating major sections of a Report 

Comment: 

Coordinating Lead Authors will be Lead Authors with the added responsibility of 

ensuring that major sections of the Report are completed to a high standard, are collated 

and delivered to the Working Group/Task Force Bureau Co-Chairs in a timely manner 

and conform to any overall standards of style set for the document. 

Coordinating Lead Authors will play a leading role in ensuring that any crosscutting 

scientific or technical issues which may involve several sections of a Report are 

addressed in a complete and coherent manner and reflect the latest information available. 

36 
The skills and resources required of Coordinating Lead Authors are those required of 

Lead Authors with the additional organizational skills needed to coordinate a section of a 

Report. The names of all Coordinating Lead Authors will be acknowledged in the 

Reports. 

3. CONTRIBUTING AUTHORS 

Function: 

To prepare technical information in the form of text, graphs or data for assimilation by 

the Lead Authors into the draft section. 

Comment: 

Input from a wide range of contributors is a key element in the success of IPCC 

assessments, and the names of all contributors will be acknowledged in the Reports. 

Contributions are sometimes solicited by Lead Authors but unprompted contributions are 

encouraged. 

Contributions should be supported as far as possible with references from the peer 

reviewed and internationally available literature, and with copies of any unpublished 

material cited; clear indications of how to access the latter should be included in the 

contributions. For material available in electronic format only, the location where such 

material may be accessed should be cited. Contributed material may be edited, merged 

and if necessary, amended, in the course of developing the overall draft text. 

4. EXPERT REVIEWERS 

Function: 

To comment on the accuracy and completeness of the scientific/technical/socio-economic 

content and the overall scientific/technical/socio-economic balance of the drafts. 

Comment: 

Expert reviewers will comment on the text according to their own knowledge and 

experience. They may be nominated by Governments, national and international 

organizations, Working Group/Task Force Bureau, Lead Authors and Contributing 

Authors. 

5. REVIEW EDITORS 

Function: 

Review Editors will assist the Working Group/Task Force Bureau in identifying 

reviewers for the expert review process, ensure that all substantive expert and 

government review comments are afforded appropriate consideration, advise lead authors 

on how to handle contentious/controversial issues and ensure genuine controversies are 

reflected adequately in the text of the Report. 

Comment: 

There will be one or two Review Editors per chapter (including their executive 

summaries) and per technical summary. In order to carry out these tasks, Review Editors 

will need to have a broad understanding of the wider scientific and technical issues being 

addressed. The workload will be particularly heavy during the final stages of the Report 

preparation. This includes attending those meetings where writing teams are considering 

37 
the results of the two review rounds. Review Editors are not actively engaged in drafting 

Reports and cannot serve as reviewers of those chapters of which they are Authors. 

Review Editors can be members of a Working Group/Task Force Bureau or outside 

experts agreed by the Working Group/Task Force Bureau. Although responsibility for 

the final text remains with the Lead Authors, Review Editors will need to ensure that 

where significant differences of opinion on scientific issues remain, such differences are 

described in an annex to the Report. Review Editors must submit a written report to the 

Working Group Sessions or the Panel and where appropriate, will be requested to attend 

Sessions of the Working Group and of the IPCC to communicate their findings from the 

review process and to assist in finalizing the Summary for Policymakers, Overview 

Chapters of Methodology Reports and Synthesis Reports. The names of all Review 

Editors will be acknowledged in the Reports. 

In implementing these procedures across the three working groups of the IPCC’s AR4, 1,250 

scientists (450 lead authors and more than 800 contributing authors) from 130 countries served 

as authors and more than 2,500 experts provided over 90,000 review comments. Many 

petitioners specifically critique the practices employed by IPCC Working Group I, for which 

there were 152 lead authors and 26 review editors from 32 countries, in which 6,000 peerreviewed publications were cited, for which 625 experts from 42 countries provided over 30,000 

review comments, and for which the Summary for Policymakers was approved line by line by 

113 countries. Furthermore, the petitioners specifically critique the practices employed by 

Chapter 6 (Jansen et al., 2007) authors and reviewers of Working Group I, which had two 

coordinating authors and 14 lead authors from 12 countries, 33 contributing authors from nine 

countries, and two review editors who oversaw the handling of more than 2,900 comments from 

the rounds of expert and governmental review. The petitioners also critique the practices 

employed by Chapter 9 (Hegerl et al., 2007) authors and reviewers of Working Group I, which 

had two coordinating authors and seven lead authors from nine countries, 44 contributing authors 

from 12 countries, and three review editors who oversaw the handling of about 2,600 comments 

from the rounds of expert and governmental review. 

The IPCC processes have been developed for the express purpose of ensuring integrity and 

avoiding any possibility of bias in the conclusions drawn from the scientific literature. The level 

of detail and clarity of the requirements—especially concerning report review, the specific 

responsibilities of review editors to assess the quality of author responses to comment, and the 

transparency of the record of comments and responses—provide the foundation for ensuring that 

the reports are credible and sound. 

The IPCC’s peer-review and report development processes are very important components of the 

overall integrity, quality, transparency, and objectivity of its reports. As stated in the TSD (U.S. 

EPA, 2009) for the Endangerment Finding, EPA relied on the assessment literature because: 

they 1) are very recent and represent the current state of knowledge on GHG emissions, 

climate change science, vulnerabilities, and potential impacts; 2) have assessed numerous 

individual, peer-reviewed studies in order to draw general conclusions about the state of 

science; 3) have been reviewed and formally accepted, commissioned, or in some cases 

38 
authored by U.S. government agencies and individual government scientists; and 4) they 

reflect and convey the consensus conclusions of expert authors. 

Finally, we note the following recent IPCC statement regarding their report development 

process: 

The IPCC procedures, which are regularly reviewed and amended by the IPCC members, 

have served the international community effectively for over 20 years. The conclusions 

of the IPCC assessment reports, and especially the Fourth Assessment Report, are as 

solid as careful science can make them. They reflect the current state of knowledge about 

one of the most complex and important of all topics -- climate change science (IPCC, 

2010b). 

2.2.3 Responses to Arguably New Objections Raised by the Petitioners 

The petitioners submit four arguably “new” objections along with excerpts from the CRU emails related to: 1) authorship and reviewer roles among IPCC personnel; 2) an e-mail allegedly 

showing that IPCC authors were aware that citing their own papers could be seen as using the 

IPCC process to advance their own views rather than to present a neutral overview of the 

science; 3) allegations that the IPCC is a biased organization, including claims that IPCC lead 

authors encouraged other authors to focus on policy-prescriptive science; and 4) allegations that 

IPCC authors forced consensus and altered the contents of the assessment reports to eliminate 

any suggestion of non-consensus. We respond to each of these allegations in the subsections 

below. 

2.2.3.1 Allegations of Inappropriate Authorship and Reviewer Roles Among IPCC 

Personnel 

Comment (2-16): 

Peabody Energy argues that the CRU e-mails show inappropriate authorship roles in the 

development of Chapter 6 (“Paleoclimate”) of Working Group I’s contribution to AR4 (Jansen et 

al., 2007). The petitioner alleges that Michael Mann (Penn State) and Thomas Crowley 

(University of Edinburgh) contributed significantly to the development of the chapter, but were 

not listed as contributing authors. In addition, the petitioner alleges that Mann and Crowley were 

inappropriately given the opportunity to comment on drafts of the chapter outside the formal 

review process, thereby compromising their objectivity as reviewers and introducing bias to the 

chapter development process. 

Response (2-16):

EPA has reviewed the petitioners’ submissions and finds that the evidence and arguments they 

provide do not support the conclusions they draw. The content of the e-mails does not show that 

Michael Mann or Thomas Crowley contributed substantially to the writing or key development 

decisions of Chapter 6 (Jansen et al., 2007), or that they introduced any bias. Chapter 6 assesses 

paleoclimatic data and knowledge of how the climate system changes over inter-annual to 

millennial time scales and how well these variations can be simulated with climate models. 

39 
 On December 23, 2004, Michael Mann wrote to Keith Briffa (Chapter 6 lead author) and 

stated, “Thanks again for your phone call, and the (informal) opportunity to help out 

where I can. I’m perfectly happy in that role (as an informal contributor and a formal 

reviewer, for example), if you and Peck, for example, are both comfortable with that.” 2

 

He also sent some website links regarding arguments that some have made against his 

work. In a follow-up e-mail that same day3

, Mann again writes to Briffa, stating “I went 

ahead and tried to make some constructive comments on what you sent...Let me say I 

think it’s shaping up very nicely--looks like it should be a significant improvement on the 

‘01 report. You’ve handled the various controversies and points of dispute delicately and 

adeptly...I made a dozen or so minor comments--please make use of them as you see 

fit...Thanks again for including me in and giving me an opportunity to comment.” 4 

These e-mails show that Mann served as an informal contributor on a preliminary draft of 

Chapter 6 (Jansen et. al, 2007), and the IPCC’s response to comments document for 

Chapter 6 confirm that Mann was also a formal reviewer (IPCC, 2006a). The petitioners 

allege that Mann could not have objectively reviewed the chapter if he also provided 

information for its development, but these e-mails do not show that Mann “significantly 

contributed” to the development of this chapter. In fact, the evidence provided by the 

petitioner indicates that Mann participated at most in a limited way as an informal 

contributor, providing a small amount of information, such as Web links, to the authors. 

This level of involvement would not warrant being listed as a contributing author, as 

Mann was involved neither with assessing the underlying literature nor with writing text 

for the chapter. The IPCC does not require informal contributors of this nature to be 

acknowledged as authors in the final report. There is no basis to conclude that listing him 

as an author would have changed the content or conclusions of the chapter in any way. 

There is also no basis to conclude that his comments were biased or lacked objectivity, or 

that the resulting chapter was biased or lacked objectivity. The fact that Mann provided 

the Chapter 6 authors with a limited amount of information does not mean that his 

objectivity was compromised during the formal review process. Petitioners appear to 

conclude otherwise, but nothing they provide supports drawing such a broad conclusion. 

Finally, we note that the petitioner does not provide any examples of Mann’s review 

comments on this chapter that they claim demonstrate bias or lack of objectivity. 

 Several e-mails from June and July of 2005 (e-mail files 1122300990.txt5

, 

1121869083.txt6

, and 111886641.txt)7 show that Thomas Crowley was consulted by 

Keith Briffa and Jonathan Overpeck (Chapter 6 coordinating lead author) regarding a 

medieval warming figure that Crowley had been developing, which Briffa and Overpeck 

 

3

 E-mail file 1102956436.txt, (December 13, 2004), page 763, line 13 of PDF version entitled: CRU Emails 1996-

2009.pdf 

3

 E-mail file 1103828684.txt, (December 23, 2004), page 771, line 37 of PDF version entitled: CRU Emails 1996-

2009.pdf 

4

 E-mail file 1103828684.txt, (December 23, 2004), page 771, line 37 of PDF version entitled: CRU Emails 1996-

2009.pdf 

5

 E-mail file 1122300990.txt, (July 25,2005), page 952, line 33 of PDF version entitled: CRU Emails 1996-2009.pdf 6

 E-mail file 1121869083.txt, (July 20,2005), page 916, line 42 of PDF version entitled: CRU Emails 1996-2009.pdf 7

 E-mail file 1118866419.txt, (June 15,2005), page 889, line 32 of PDF version entitled: CRU Emails 1996-2009.pdf 

40 
were possibly interested in using for Chapter 6. There is no evidence in the e-mails that 

Crowley helped write or develop the chapter in any other capacity. In fact, the e-mails 

simply document an interaction between the lead authors and Crowley, in which the 

authors are seeking clarification regarding a particular figure. Such inquiries are 

completely appropriate and in no way compromise the objectivity and credibility of that 

chapter’s development. It appears that Crowley provided useful background and advice 

on the use of his figure, and the e-mails provide no support that he contributed significant 

text or had any editorial power over the chapter. 

Given the technical nature of this field of climate science, it is reasonable and expected 

that IPCC authors might require detail or clarification regarding some of the underlying 

studies. Therefore they might need to consult the authors of specific studies to better 

understand how the results were achieved or to ask questions regarding how the data 

were applied, as was the case in this situation. Petitioners have not explained how the 

mere fact that this type of correspondence occurred between Crowley and 

Briffa/Overpeck lead to the conclusion that bias was introduced to the chapter 

development process. The evidence provided by the petitioner does not support this 

argument. 

 In the same set of e-mails, Crowley also states, “I am not sure whether it is wise to add 

me to the CA [contributing author] list, just because the reviewer is supposed to be 

impartial and a CA loses that appearance of impartiality if he has now been included as a 

CA - may want to check with Susan S. on this one to be sure - still happy to provide 

advice.” The petitioner alleges that Crowley’s e-mail signifies that he knew of the risk of 

compromising objectivity and did so anyway by both contributing significantly to the 

chapter’s development and being an expert reviewer. The evidence provided by the 

petitioner does not show that Crowley participated in any manner beyond having a 

limited role in answering questions concerning a figure he had developed, or that his 

doing so compromised his objectivity as a reviewer. The petitioners do not, for example, 

provide any examples of his review comments on this chapter that they claim 

demonstrate bias or lack of objectivity. As stated above, IPCC does not require informal 

contributors to be acknowledged in the final report. The petitioners’ evidence does not 

show that Crowley’s informal contribution and correspondence with the Chapter 6 

authors led to improper and erroneous changes or conclusions in the report. Furthermore, 

after the exchange of these e-mails, Overpeck wrote: “Thanks for moving this forward 

and making sure we do it right (i.e., without any bias, or perception of bias)”.8

 This 

demonstrates that the coordinating lead author understood IPCC’s guidelines, ensured 

that they were properly implemented, and therefore avoided any lack of or lapse in 

objectivity. 

The petitioner draws broad conclusions from these e-mails about the intentions of the authors 

and the content of the IPCC chapters, in an attempt to discredit overall the chapter development 

and review processes of the IPCC, and implicitly the IPCC reports themselves. However, the emails cited show that Mann and Crowley had very limited, informal roles in the chapter and the 

 

8

 E-mail file 1121869083.txt, (July 20, 2005), page 918, line 8 of PDF version entitled: CRU Emails 1996-2009.pdf 

41 
e-mails provide no evidence to support assertions of bias or a lack of objectivity. The 

interactions that occurred are allowable under IPCC procedures, and petitioners have not 

demonstrated that the events in question changed the content or conclusions of the chapter in any 

way. 

The Muir Russell investigative panel summarized information Briffa gave them on this issue, 

describing Briffa as having said (Russell, 2010): 

There is no proscription in the IPCC rules to prevent the author team seeking expert 

advice when and where needed. The Technical Support Unit (TSU) and the CLAs of 

Chapter 6 agree that the author team was allowed to seek such advice. Copies of 

communications from both CLAs (Jansen and Overpeck) and the IPCC WG1 TSU are 

provided by Briffa (and published on the website) to provide support to Briffa’s claim 

that his actions did not contravene IPCC procedures. 

Even if the petitioner’s allegations that Mann and Crowley “significantly contributed” to the 

development of Chapter 6 were true—which we do not believe to be the case—and even if this 

contribution were atypical, this does not lead to the conclusion that the scientific integrity of the 

conclusions from the chapter was compromised. The evidence provided by petitioners does not 

indicate errors or significant changes that resulted from involvement of these persons, and does 

not demonstrate that the final product was either inaccurate or lacked impartiality, nor does the 

petitioner to any such result. We find that Chapter 6 was developed in an objective manner, is 

accurate, and represents the best available scientific information. 

Comment (2-17): 

Peabody Energy argues that the CRU e-mails show that IPCC lead authors “viewed their work as 

advocacy, rather than scientific analysis, which could be marshaled against opponents.” In 

support of this argument, the petitioner provides a February 2005 e-mail from Michael Mann to 

Phil Jones, which states “I saw the paleo draft (actually I saw an early version, and sent Keith 

some minor comments). It looks very good at present--will be interesting to see how they deal 

w/ the contrarian criticisms--there will be many. I’m hoping they’ll stand firm (I believe they 

will--I think the chapter has the right sort of personalities for that).” 

Response (2-17):

The petitioner’s interpretation of the e-mail statement is unfounded. The e-mail from Michael 

Mann9

 describes his reaction to a preliminary draft of a Medieval Warm Period (MWP) section 

of Chapter 6 (“Palaeoclimate”) of Working Group I’s contribution to the AR4 (Jansen et al., 

2007). First, it is important to note that Michael Mann and Phil Jones were neither lead nor 

contributing authors for Chapter 6, as the petitioner implies. Therefore, any allegations that 

Mann and Jones used their authorship authority to advocate against critics of Chapter 6’s 

findings are unfounded. For our response to allegations that Michael Mann had a significant role 

in the development of Chapter 6, please see Response 2-16 in this section. Moreover, the e-mail 

does not support the petitioner’s allegation that Mann and Jones were viewing their work as 

“advocacy” to use “against opponents.” Rather, Mann is simply stating his opinion regarding 

 

9

 E-mail file 1107454306.txt, (Feb. 3, 2005), page 821, line 44 of PDF version entitled: CRU Emails 1996-2009.pdf 

42 
how the paleoclimate chapter should be written and that he looked forward to seeing how the 

Chapter 6 authors dealt with criticisms. At no point does Mann suggest that the scientific 

findings be manipulated to support a pre-determined view. It is clear that he is merely 

expressing his hope for how the authors will respond to comments they (not Mann) are tasked 

with addressing. 

Comment (2-18): 

The State of Texas argues that the IPCC scientists who wrote the CRU e-mails “wielded 

tremendous authority over the IPCC.” In support of their argument, the petitioners state, “For 

example, AR4 cites Dr. Jones’s work 38 times in 21 chapters of two Working Groups, Mann is 

cited 27 times in 7 chapters of two Working Groups, Briffa is cited 23 times in 9 chapters of two 

Working Groups, Wigley is cited 66 times in 18 chapters of all three Working Groups, Overpeck 

is cited 15 times in 5 chapters of two Working Groups, Osborn is cited 30 times in 10 chapters of 

two Working Groups, Trenberth is cited 58 times in 18 chapters of two Working Groups, and 

Santer is cited 26 times in 8 chapters of two Working Groups, just to name a few.” The 

petitioner goes on to argue that “Thus, to the extent their objectivity, impartiality, truthfulness, 

and scientific integrity are compromised or in doubt, so too is the objectivity, impartiality, 

truthfulness, and scientific integrity of the IPCC report, the CRU temperature data, the NOAA 

[National Oceanic and Atmospheric Administration] temperature data, and other scientific 

research that is shown to have relied on their compromised research.” 

Response (2-18):

Many of the scientists who wrote the CRU e-mails were and still are important figures in the 

field of climate change science. It is important to note that the statistics provided by the 

petitioner regarding how frequently the studies of these scientists (e.g., Phil Jones and Michael 

Mann) were cited in AR4 are neither surprising nor unreasonable. The IPCC AR4 (IPCC, 

2007a) cited over 18,000 peer-reviewed studies. Therefore these statistics (e.g., “Wigley is cited 

66 times in 18 chapters of all three Working Groups, Overpeck is cited 15 times in 5 chapters of 

two Working Groups”) do not support the petitioner’s allegation that these studies were cited too 

frequently and that these scientists therefore “wielded tremendous authority over the IPCC.” 

These scientists are some of the most well-published climate scientists in the world, and their 

work was synthesized across the three Working Group reports of the AR4. We conclude that 

these facts by themselves demonstrate nothing other than the fact that the IPCC, as intended, is 

assessing available, peer-reviewed literature. The simple fact that these individuals are wellpublished and that their studies are cited in AR4 does not imply “tremendous authority.” The 

petitioner provided no additional evidence to support their allegation. 

As explained in Section 2.2.2 (Background) of this Volume, over 1,250 scientists from 130 

countries served as authors for the AR4. It was these hundreds of authors who had the authority 

to assess the available literature, summarize the state of the science, and reference the studies in 

the AR4. The IPCC has robust procedures to ensure that the assessment reports are objective, 

unbiased, and represent the state of the science regarding climate change. These procedures 

include processes to ensure that no one individual or group of individuals exerts disproportionate 

influence in developing any piece of the assessment reports. Further, as addressed in the specific 

responses in Section 2.2.3.1 of this Volume, the evidence provided by the petitioners does not 

show that these procedures were flawed or improperly implemented. For more information on 

43 
these procedures, please see Volume 1, Section 1, of the RTC document and this section (2.2) of 

the RTP document. 

The mere fact that someone is frequently cited is also not evidence for the petitioners’ argument. 

The petitioner must also demonstrate that the referenced literature is biased or flawed, which 

they have not done, as compared to the straightforward view that the studies produced by these 

scientists are very robust and of high quality. The petitioner is making allegations without giving 

due regard for the content of the actual science, which we thoroughly reviewed in the 

Endangerment Finding’s RTC documents and again in the response to both the new and 

previously submitted comments of the petitioners. 

Please see the Denial and Volume 1 of the RTP document for our response to specific allegations 

regarding what the CRU e-mails mean for the objectivity and integrity of the IPCC assessments, 

the CRU temperature data, the NOAA temperature data, and other research that is based on this 

information. 

Comment (2-19): 

Peabody Energy argues that “An IPCC chapter author should not peer review journal articles that 

he intends to include in his chapter because of the clear conflict of interest. The chapter author is 

supposed to be providing a neutral summary of the science, not advancing his own view of the 

science. If the chapter author reviews papers that are then included in his chapter, he could be 

seen as advancing his own agenda both in his review of the paper and its selection for inclusion 

in the IPCC report.” To support their argument, the petitioner provides a July 2005 e-mail from 

Phil Jones to John Christy that states, “I am reviewing a couple of papers on extremes, so that I 

can refer to them in the chapter for AR4. Somewhat circular, but I kept to my usual 

standards”10. The petitioner goes on to state that “Jones reviewed papers so that he could get 

them published and therefore could refer to them in AR4 Chapter 3. The petitioner concludes 

that “this is indeed ‘circular’ and violates his supposed neutrality both as an AR4 author and as

reviewer of the paper.” As additional support, Peabody Energy references another e-mail dated 

May 20, 2005, from Phil Jones to Michael Mann regarding Jones’ review of a temperature 

reconstruction paper for Climatic Change.

 a 

 papers that he favored.” 

11 The petitioner states: “One wonders just how 

unbiased Jones’ review of this paper really was, particularly in light of Jones’ admission that he 

applied less than stringent review standards to

Response (2-19): 

First, we find it unconvincing and unclear why, according to the petitioner, an author of an IPCC 

chapter should not serve as a peer reviewer of a journal paper that in turn may be incorporated 

into that IPCC chapter. Thus, we disagree with the petitioner’s allegations that Phil Jones 

introduced bias and reviewed these papers unobjectively in an effort to advance his own views of 

the science. Jones did not appoint himself to review the papers for the journals, but was selected 

 

10 E-mail file 1120593115.txt, (July 5, 2005), page 906, lines 21-22 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

11 E-mail file 1116611126.txt, (May 20, 2005), page 882, line 45 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

44 
by an independent editor to be a reviewer based on his experience and expertise related to 

climate science. Since Jones is well-published and a prominent paleoclimate scientist, it is 

reasonable and logical to conclude that the editor who chose him was aware of his work on the 

AR4 and judged that it was not an inherent conflict of interest. In addition, Jones would not have 

been the only reviewer for those studies. Typically, between two and four independent experts 

are selected to review manuscripts. Therefore, Jones would not have had the authority or power 

to coerce or bias the process to “advance his own agenda.” The petitioner is inferring that Jones 

was trying to do this, but provides no evidence that Jones’ actions resulted in papers being 

unjustly published when they should not have been, or papers being unjustly cited in the AR4 

when they should not have been. 

The petitioner’s claim that an e-mail between Jones and Mann represents an “admission that he 

[Jones] applied less than stringent review standards to papers that he favored” is also 

unsupported by evidence. Rather, the petitioner misinterprets and misrepresents Jones’ e-mail to 

Michael Mann regarding Jones’ review of a temperature reconstruction paper for Climatic 

Change. This e-mail sent on May 20, 2005, reads: 

Mike, 

Just reviewed Caspar’s [Amman, of the National Center for Atmospheric Research] paper 

with Wahl [Eugene Wahl of the National Climatic Data Center] for Climatic Change. 

Looks pretty good. Almost reproduced your series and shows where MM [Steve 

McIntyre, formerly of Northwest Exploration Co., and Ross McKitrick of the University 

of Guelph] have gone wrong. Should keep them quiet for a while. Also they release all 

the data and the R software. Presume you know all about this. Should make Keith’s life 

in Ch 6 easy! Also, confidentially for a few weeks, Christy and Spencer [John Christy 

and Roy Spencer of the University of Alabama in Huntsville] have admitted at the 

Chicago CCSP meeting that their 2LT record is wrong!! They used the wrong sign for 

the diurnal correction! Series now warms - not quite as much as the surface but within 

error bands. Between you and me, we’ll be going with RSS in Ch 3 and there will be no 

discrepancy with the surface and the models. Should make Ch 3 a doddle now! Keep 

quiet about this until Bern at least. Can tell you more then. RSS (Carl Mears and Frank 

Wentz) found the mistake! The skeptic pillars are tumbling! 

Cheers Phil12

Despite the allegations by the petitioner, this e-mail shows no indication that Jones’ review of the 

Ammann and Wahl paper for Climatic Change was biased or that he did not employ rigorous 

standards of objectivity and neutrality in evaluating the merits of the studies. The e-mail simply 

indicates that Jones approved of the findings by the authors and that he found the results to have 

important implications regarding the validity of temperature reconstructions. The petitioner is 

significantly skewing the meaning of these e-mails and misrepresenting what Jones said to infer 

improper conduct in his review of the paper. 

 

12 E-mail file 1116611126.txt, (May 20, 2005), page 882, lines 6-15 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

45 
Finally, the evidence provided by Peabody Energy does not support their allegation that Jones 

was biased or failed to objectively assess the available literature for the AR4 as a result of having 

reviewed these papers. From our review of the evidence, we conclude only that Jones reviewed 

the studies and that he was also an author for Chapter 3 (“Observations: Surface and 

Atmospheric Climate Change”) of Working Group I’s contribution to the AR4 (Trenberth et al., 

2007). For that chapter, over 65 authors from 16 countries were tasked with reviewing and 

assessing the best available science regarding observed climate change and distilling this 

information into key messages that capture the state of knowledge. Once again, Jones would not 

have had the authority or power to coerce or bias the process to “advance his own agenda” by 

developing conclusions that do not represent the state of the science. Chapter 3, like all of the 

AR4, went through multiple rounds of expert and government review, in which more than 3,400 

comments were received and addressed, to ensure that the conclusions accurately represent and 

summarize the best available science. The large number of authors, the multiple rounds of 

expert and government reviews, and the detailed approval process are all deliberate procedures 

developed by the IPCC to ensure that the reports maximize objectivity, credibility, and quality. 

See Section III.A of the Findings, Volume 1 of the RTC document and Section 2.2.2 

(Background) of the RTP document for more information on the IPCC’s report development 

procedures. 

2.2.3.2 Allegations That Citing One’s Own Papers Compromises Objectivity 

Comment (2-20):

Peabody Energy states that IPCC authors cited their own papers extensively in the AR4, which 

invalidates the purpose of these assessment reports, which are designed to objectively look 

across the literature and convey the state of the science. The petitioner cites an e-mail by 

Jonathan Overpeck from June 200513 as evidence that allegedly “reveals that the IPCC authors 

were aware that citing their own papers could be seen as using the IPCC process to advance their 

own views rather than to present a neutral overview of the science.” The petitioner further 

provides a statistic regarding the frequency at which the authors of Chapter 9 of Working Group 

I of AR4 cited their own papers: “About 40% of the papers cited in Chapter 9 were written by 

Chapter 9 authors.” 

Response (2-20):

It should come as no surprise that many papers by Chapter 9 authors were cited in the chapter. 

IPCC authors are chosen in part based on their expertise on a particular subject and the degree to 

which they have published recent, high-quality papers in the field. Moreover, in some areas 

(e.g., medieval warming period analysis, ocean acidification), there can be limited studies 

outside the research published by particular scientists, including IPCC authors, on which to base 

summaries of the science. Contrary to the petitioner’s allegations, this does not mean that IPCC 

authors were not providing neutral and objective summaries of the science. In fact, the petitioner 

provides no evidence that the practice of citing one’s own papers led to biased conclusions in the 

AR4. Given the rigor of the IPCC review process, described in Section 2.2.2 (Background) of 

this Volume, it is indeed highly unlikely that an author’s improper citation of his or her own 

work would escape notice. 

 

13 E-mail file 1120014836.txt, (June 28, 2005), page 900, line 32 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

46 
Moreover, the e-mail from Jonathan Overpeck (coordinating lead author of Chapter 6 of 

Working Group I’s contribution to the AR4), does not support the petitioner’s assumption of 

misconduct, and instead shows that Overpeck was encouraging the authors of that chapter to 

minimize citing their own papers to the extent possible, and to only do so when “absolutely 

necessary.” Overpeck’s awareness that the authors “citing their own papers could be seen as 

using the IPCC process to advance their own views rather than to present a neutral overview of 

the science” does not mean that such citation actually was for the alleged improper purpose—

especially when the e-mail demonstrates that Overpeck intentionally took steps to avoid 

impropriety, or even the appearance of impropriety. The evidence provided by petitioners does 

not show that the authors cited their own studies in order to advance their own policy views; in 

fact, it shows they were cautioned to avoid citing their own studies except where absolutely 

necessary and appropriate. The full text of Overpeck’s e-mail is provided here: 

Hi all - thanks Fortunat and Stefan for more debate on the 1470. Sounds like the final 

decision is up to Eystein, but I can guess the way he’s thinking. With regard to refs - 

remember that our goal is to cut the number of references significantly. Since this is an 

assessment and not a review, we can delete all but the most recent and comprehensive 

references. I don’t like cutting out the original refs any more than you, but we just don’t 

have room, and its more important to have text than exhaustive references. Our 

colleagues will hopefully understand, and if they don’t then they need to do an ego check. 

It’s more important that we make an impact with policy makers rather than with citation 

indices. Does this make sense? In any case, please help make sure we trim the total 

references DOWN in number by a significant number. This is not happening [to] the 

degree it should. Also, please not[e] that in the US, the US Congress is questioning 

whether it is ethical for IPCC authors to be using the IPCC to champion their own 

work/opinions. Obviously, this is wrong and scary, but if our goal is to get policy makers 

(liberal and conservative alike) to take our chapter seriously, it will only hurt our effort if 

we cite too many of our own papers (perception is often reality). PLEASE do not cite 

anything that is not absolutely needed, and please do not cite your papers unless they are 

absolutely needed. Common sense, but it isn’t happening. Please be more critical with 

your citations so we save needed space, and also so we don’t get perceived as self serving 

or worse. Again, we can debate this if anyone thinks I’ve gone off the deep end. 

Thanks, peck 

PS - this is not to say anything critical of the refs Fortunat is suggesting - we must cite the 

most relevant papers, and we must be as up to date as possible.14 

Regarding the statistics submitted, the petitioner has not provided any evidence that the Chapter 

9 authors cited their own studies more frequently than would be appropriate given the number of 

peer-reviewed and published studies on this particular climate science topic (understanding and 

attributing climate change in the case of Chapter 9), and the statistics alone, without context, 

prove nothing. More than 50 authors from 15 different countries contributed to the development 

of Chapter 9. Given the large number of perspectives and the wide-ranging expertise of this 

group, it is not surprising that 40% of the papers were written by the chapter’s authors. Contrary 

 

14 E-mail file 1120014836.txt, (June 28, 2005), page 901, line 13 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

47 
to the petitioner’s allegations, and consistent with the IPCC’s report development guidelines as 

described in Volume 1 of the RTC document, the statistics provided by the petitioner show that 

the most qualified and experienced personnel contributed to the development of this chapter. 

When read in full, Overpeck’s email clearly shows that he was taking deliberate actions to ensure 

that the science was presented in an objective and unbiased manner. 

We note that the petitioners do not provide or reference any studies that they say should have 

been included instead. Importantly, petitioners again fail to show how the allegedly irregular 

practice that they challenge resulted in conclusions that are inaccurate or contrary to the 

consensus science. 

2.2.3.3 Allegations That IPCC Is Biased 

Comment (2-21): 

The Competitive Enterprise Institute, the Southeastern Legal Foundation, the State of Texas, and 

the Ohio Coal Association argue that Jonathan Overpeck, the coordinating lead author for 

Chapter 6 (“Palaeoclimate”) of Working Group I’s contribution to the AR4, encouraged 

contributing authors to focus on findings that are most policy relevant (thereby, according to the 

petitioners, “supporting preconceived” assessments of the science), and that he did not encourage 

open and neutral presentations of the science. The petitioners draw this conclusion from an email written by Overpeck and Eystein Jansen (the other coordinating lead author) to the lead and 

contributing authors for Chapter 6, which states, “With respect to text, try hard to get it down to 

size, and to ensure that it is FOCUSED on only that science which is policy relevant. ALL 

TEXT should support an Exec Summary Bullet”15. 

 

15 E-mail file 1121392136.txt, (July 14, 2005), Page 912, Line 35 of PDF version entitled: CRU Emails 1996-

2009.pdf. 

48 
Response (2-21):

The Overpeck/Jansen e-mail to Chapter 6 authors indicates that he encouraged them to focus on 

the findings that are most policy relevant. However, “policy relevant and compelling” does not 

mean or imply “policy prescriptive,” as alleged by the petitioners. “Policy relevant” means the 

neutral and objective presentation of scientific, technical, and socio-economic factors that are 

relevant to the issues or policies that policymakers care about. This is to be contrasted with other 

issues that are less relevant to policymakers and thus less appropriate for these types of 

assessment reports, which aim to objectively and thoroughly synthesize scientific information to 

support development of informed policies. “Policy relevant” is completely different from 

“policy prescriptive,” which refers to the presentation of scientific information with the aim of 

advancing a particular public policy agenda. 

The e-mail from Overpeck and Jansen does not support petitioners’ conclusion that they were 

being policy prescriptive. There is no indication that authors were encouraged to limit their 

contributions only to findings that supported a particular policy agenda. Rather, it shows the 

opposite: they were encouraged to avoid this and to provide policy relevant information that 

would be of use to policymakers as they consider the various possible policies. We further note 

that the petitioners do not identify information in Chapter 9 that is “policy prescriptive,” or 

provide any information on what policies Overpeck and Jansen were purportedly advancing. 

As the IPCC clearly states on its website regarding its mission statement, the organization 

reviews and assesses the most recent scientific information to produce assessment reports that 

are “policy relevant and policy neutral, never policy prescriptive” (IPCC, 2010c). The 

petitioners’ evidence does not show that the IPCC failed to execute this very important principle. 

The petitioners’ allegations and implications do not call into question the integrity of these IPCC 

authors. Finally, we note (as described in Volume 1 of the RTC document) that the official 

expert and government reviews of the summary for policymakers for each working group (IPCC, 

2007c, 2007d, 2007h) further ensure that the reports are not policy prescriptive. 

Comment (2-22): 

Peabody Energy argues that the contents of several CRU e-mails from August 200516 between 

Jonathan Overpeck, Tim Osborn, and Keith Briffa show that the authors for Chapter 6 of 

Working Group I’s contribution to the AR4 (Jansen et al., 2007) were focusing not on the 

presentation of “neutral science” but rather on “presenting a strong case.” 

Response (2-22): 

The full content of the e-mails at issue is important for understanding what the authors were 

actually saying. 

 

16 E-mail file 1123268256.txt, (August 5, 2005), page 963, line 29 of PDF version entitled: CRU Emails 1996-

2009.pdf; e-mail file 1123513957.txt, (August 8, 2005), page 964, line 25 of PDF version entitled: CRU Emails 

1996-2009.pdf 

49 
E-mail from Overpeck to Osborn and Briffa on Monday, August 5, 2005

Hi Tim and Keith - Hope you’re not going to kill me, but I was talking with Susan 

Solomon today, and she impressed me with the need to make several points if we can. 

One issue (other to come in a subsequent email) is whether we can extend the MWP box 

figure to include the 15th century. I don’t read the blogs that regularly, but I guess the 

skeptics are making hay of their being a global warm event around 1450AD. I agree w/ 

Susan that it is our obligation to weigh in on issues like this, so.... can we extend the fig 

to extend up to 1500AD? Sorry about this, Tim. Of course we need it yesterday. Thanks 

x10**6 best, peck17

E-mail from Osborn and Briffa to Overpeck on Monday, August 8, 2005

Hi Peck, there is a period around 1400 AD when the proxy records we’ve used in this 

MWP figure do indicate a warm period - and all records show positive anomalies at the 

same time. Thus it couldn’t/shouldn’t be dismissed in the same way as the MWP, as a 

period of disparate regional behaviour, albeit with more records showing warming than 

cooling. For 1400, all indicate warming but with smaller magnitude than the 20th 

century. If the figure were extended to cover the 15th century, then it would also seem 

necessary to extend it to the present so that the 1400 period could be compared with the 

20th century. I’ve attached 3 versions of the figure. 850-1350 as originally sent. 850-

1500 showing warm anomaly in 1400, but cannot tell how warm relative to present-day. 

850-2000 showing 1400 was not as anomalous as present-day. Take your pick, Peck! 

Cheers Tim and Keith18

E-mail from Overpeck to Osborn and Briffa on Monday, August 8, 2005

Hi Tim - Decisions, decisions... thanks so much for taking the initiative. I think - for the 

reason you state, we should go for the one that includes the 20th century. We make clear 

that these are not reconstructed temp, but normalized anomalies - this keeps us out of 

some trouble. But, I think the main message is that we’re looking at this issue from every 

angle. And, we’re letting others see the issue from every angle. It adds punch. this 

means that the MWP box needs to talk about the period around 1400 - can you make sure 

that’s on Keith’s radar screen. I believe that historians talk about the Medieval Period 

going to at least 1450, so what the heck... I you can adjust the caption to work, and then 

send both it and the final fig to Øyvind, me and Eystein that would be good - make sure 

Keith is ok with it all first, too. Thanks Tim! Best, Peck19

These e-mails describe a conversation between the three scientists in which they are deciding the 

most appropriate timeframe for a particular set of graphics depicting normalized temperature 

anomalies. From our review, the context for the e-mails in question is that Susan Solomon (of 

NOAA, and serving as the co-chair of IPCC Working Group I) wanted to ensure that the views 

 

17 E-mail file 1123268256.txt, (August 5, 2005), page 963, line 29 of PDF version entitled: CRU Emails 1996-

2009.pdf. 

18 E-mail file 1123513957.txt, (August 8, 2005), page 964, line 25 of PDF version entitled: CRU Emails 1996-

2009.pdf. 

19 E-mail file 1123513957.txt, (August 8, 2005), page 964, line 43 of PDF version entitled: CRU Emails 1996-

2009.pdf. 

50 
of various climate change scientists were addressed in AR4. She was clearly trying to 

acknowledge and respond to their concerns, even to the point of reading blogs to better 

understand their arguments when there was no peer-reviewed literature articulating their points. 

In response, Jonathan Overpeck, Tim Osborn, and Keith Briffa discussed a number of options for 

presenting their data on normalized temperature anomalies: first extending the timeline to 1500 

A.D. to address the concerns with data around 1450 A.D., then extending the timeline to the 

present day to provide even more context for these early data. They discussed and ultimately 

decided to modify the graphic to depict the relationship of the MWP to the 20th century because 

that approach would provide important context for understanding current temperature trends, it 

would be “looking at this issue from every angle. And, we’re letting others see the issue from 

every angle.” There is no evidence of bias in this decision. Their presentation of various options 

for the graphic demonstrates their commitment to considering alternative viewpoints and 

thoroughness in assessing the science. The e-mails speak for themselves and show no 

inappropriate behavior among these individuals. We disagree with the petitioner that these emails indicate that the scientists were trying to present science that is not neutral or were 

motivated by a desire to present a “strong case” rather than to present the best science. We 

further note that this graphic went through expert and governmental review and was deemed 

appropriate for inclusion in the IPCC chapter. The petitioner provided no additional evidence 

beyond the text of the e-mails to further justify this allegation. 

Thus, these e-mails do nothing more than indicate that three scientists were trying to present a 

figure that was comprehensive and offered key contextual information on temperature trends 

over the past several centuries. There is nothing inappropriate or biased about that, and the 

petitioner has not provided evidence suggesting that there was. When examined in their full 

context, the e-mails do not indicate any wrongdoing by the three scientists or support the 

petitioner’s claims. 

Comment (2-23): 

In support of their argument that the IPCC is a politicized and biased organization, the 

Competitive Enterprise Institute provided a quote from the Environment Minister of India in 

which he responds to the incorrect IPCC conclusion of disappearing glaciers by announcing that 

India is forming its own independent climate change review panel that will not depend on IPCC 

reports. The Minister stated that “There is a fine line between climate science and climate 

evangelism. I am all for climate science but not for climate evangelism. I think people misused 

the IPCC report” (Indo-Asian News Service, 2010). 

Response (2-23):

See Subsection 2.1.3 in this Volume of the RTP document for EPA’s responses regarding the 

validity of the IPCC’s Himalayan glacier projection and our conclusion that this error does not 

undermine the IPCC’s broader findings and the technical support for endangerment. 

With respect to the implications of the statements from the Indian Environment Minister, Jairam 

Ramesh, they clearly show that he disagreed with the specific IPCC Himalayan glacier 

projection that has been identified as being an error. His statement indicates that he thought that 

the projection was inappropriately developed based on inconclusive science. As described in 

Subsection 2.1.3, the IPCC’s overall assessment of observed glacier loss, projected glacier loss, 

51 
and the impacts of glacier loss on water resources in the Himalayas was not compromised by this 

single faulty projection. Numerous studies cited by the IPCC document a general decline in 

Himalayan glacier mass, project substantial future declines, and discuss the impacts of these 

changes on water resources and society, which is consistent with the conclusions drawn by the 

IPCC. 

The evidence provided by the petitioner appears to mischaracterize the Minister’s position. The 

Minister did not make any statements that support the petitioner’s allegation that the IPCC is 

biased or politicized. Rather, the Minister expressed his disapproval of the incorrect glacier 

projections and stated that India needed to perform its own research related to this issue and 

other climate change impacts in the country. Specifically, the Minister stated (Indo-Asian News 

Service, 2010): 

I respect the IPCC. At the same time India is a large country... we can’t depend only on 

IPCC. So we have launched the Indian Network on Comprehensive Climate Change 

Assessment... It’s got 125 research institutions from across the country. We will have 

international collaborations. It’s a kind of an Indian IPCC and not a rival to the IPCC. 

We will do our own assessment. 

It is not uncommon for countries to undertake their own climate change assessments, and it is 

misleading for the petitioner to imply that the Minister’s statements represent a lack of faith in 

the IPCC. Finally, even if the statements by the Minister were to be stretched and interpreted as 

a comment about the IPCC as a politicized organization, it would be the view of one 

representative of one country and would not represent the official position of the 194 countries 

that participate in the IPCC. The fact that another country chooses to complement the IPCC with 

another assessment process has no implications for the Endangerment Finding. For example, the 

United States has its own climate change science assessment process that is administered by the 

USGCRP, and this body has provided excellent and robust information. 

Comment (2-24): 

The Competitive Enterprise Institute and Ohio Coal Association argue that the IPCC is “not a 

scientific organization,” that people in the organization realize it is not, and that the IPCC is a 

political “organization that reviews and reports science that support its goals.” In support of their 

argument, the petitioner provided a quote from The Guardian (a UK newspaper) which in turn 

quoted Anton Imeson, a former IPCC Working Group II author: 

The Nobel prize was for peace not science ... government employees will use it to 

negotiate changes and a redistribution of resources. It is not a scientific analysis of 

climate change... For the media, the IPCC assessments have become an icon for 

something they are not. To make sure that it does not happen again, the IPCC should 

change its name and become part of something else. The IPCC should have never 

allowed itself to be branded as a scientific organization. 

Response (2-24):

The quote provided by the petitioner comes from a newspaper article in The Guardian (Adam 

and Goldenberg, 2010), not a scientific journal or a comprehensive review of the IPCC. Imeson 

52 
was one of 10 lead authors for Chapter 1 (“Assessment of Observed Changes and Responses in 

Natural and Managed Systems”) of Working Group II’s contribution to the AR4 (Rosenzweig et 

al., 2007). He is presenting an opinion, not a scientific evaluation, and is one of more than 1,250 

authors from 130 countries that wrote the AR4 with him. It appears that Imeson is concerned 

about potential policy implications of the IPCC reports, namely that governments may use the 

IPCC reports to “redistribute resources.” He does not provide a specific scientific critique, but 

rather a critique of how governments and the media characterize the IPCC reports and 

government policy direction. 

The evidence provided by the petitioner does not show that Imeson’s views are shared by other 

IPCC authors. To evaluate the merits and credibility of Imeson’s statements, one must look at 

the principles governing the IPCC’s work, and the organization’s established procedures for the 

preparation, review, acceptance, adoption, approval, and publication of the assessment reports. 

In addition, it is also important to assess how these principles and procedures were implemented 

in developing the AR4. EPA has conducted such assessments; they are described in detail in 

Section III.A of the Findings; Volume 1, Sections 1 and 5, of the RTC document; Appendix A of 

Volume 1 of the RTC document; and this section of the RTP document. Ultimately, one author’s 

sentiments about how the IPCC’s key findings may be used do not provide us with evidence 

indicating wrong-doing. 

Comment (2-25): 

The Southeastern Legal Foundation and the State of Texas argue that since the comment period 

closed, it has been revealed in the press that the chairman of the IPCC, Rajendra K. Pachauri, has 

multiple potential conflicts of interest. As support for their argument, the petitioners reference a 

Daily Telegraph (UK newspaper) article published on December 20, 2009, titled “Questions over 

business deals of UN climate change guru Dr. Rajendra Pachauri” (Booker and North, 2009). 

The article, along with several other newspaper blogs and articles referenced by the petitioners, 

allege that Pachauri’s connections with various corporations, along with consulting services 

provided to some of these companies, have generated conflicts of interest and resulted in biased 

and compromised IPCC reports. The Southeastern Legal Foundation further states: 

It is remarkable how only very recently has the staggering scale of Dr Pachauri’s links to 

so many of these concerns come to light, inevitably raising questions as to how the 

world’s leading “climate official” can also be personally involved in so many 

organizations which stand to benefit from the IPCC’s recommendations. 

Similarly, the State of Texas argues: 

Pachauri’s conflicts of interest weaken the Endangerment Finding. Dr. Pachauri’s 

conflicts of interest indicate that the IPCC is being led toward a conclusion that climate 

change is a dire threat to the planet that must be reversed; a conclusion that would enrich 

Dr. Pachauri and the entities that employ him. Consequently, EPA has relied on an 

assessment that ensures bias and imbalance, a result that EPA claims to want to avoid. 

53 
Response (2-25):

Rajendra Pachauri is the elected, unpaid chairman of the IPCC. The IPCC chairmanship requires 

expertise and experience in climate change science and policy. The chairperson is elected based 

on this level of expertise and experience. As a result, it is difficult to imagine that a qualified 

candidate would not have connections and interactions with various academic, science, political, 

and business communities. Having such connections is not, in and of itself, evidence of conflict 

of interest in the development of the assessment reports. The petitioners insinuate that 

Pachauri’s professional connections with various companies constitute conflicts of interest, yet 

they did not provide any evidence that Pachauri’s outside activities generated conflicts of interest 

or violated any ethics rules of the World Meteorological Organization or the U.N. Environment 

Programme. In fact, in the interest of transparency, Dr. Pachauri has made available his tax 

returns and details regarding the honorariums and payments from his consulting activities. 

Further, it appears that the auditing firm KPMG examined his personal finances and found that 

all such payments were made to The Energy and Resources Institute, an Indian nongovernmental organization chaired by Dr. Pachauri (Harvey, 2010). 

Most importantly, the petitioners’ argument that these consulting activities led to biased, 

imbalanced, and compromised IPCC assessments is completely unsupported by evidence. The 

petitioners do not provide a single example of a scientific conclusion that was somehow 

influenced by Dr. Pachauri’s alleged conflicts of interest. The Endangerment Finding must and 

does rest on strong science, not innuendo and speculation of the sort provided by the petitioners. 

See Sections 2.2.2 and 2.2.3 in this volume of the RTP document, which address our view that 

the IPCC’s procedures are sufficient to ensure that no one individual—including the IPCC 

chairman—or group of individuals can exert disproportionate influence in developing any piece 

of the assessment reports. The IPCC has robust procedures to ensure that the assessment reports 

are objective, are unbiased, and represent the state of the science regarding climate change. 

Thus, EPA has no reason to conclude, and there is no evidence to suggest, that Pachauri’s 

professional connections influenced the IPCC reports in any way. 

 

Comment (2-26): 

The State of Texas argues that EPA’s RTC document insufficiently addressed comments on the 

Administrator’s consideration of studies that disagreed with the assessment literature. 

Specifically, the petitioner stated: 

In response to public comments suggesting that the Administrator should have included 

studies that disagreed with the Endangerment Finding, EPA notes that “IPCC, 

USGCRP/CCSP [the U.S. Global Change Research Program/Climate Change Science 

Program], and NRC [National Research Council] make considerable effort to ensure that 

their assessment reports reflect a balance of perspectives regarding the state of the 

science.” To support that response, EPA quotes a National Academies report noting that 

the NRC screens all “provisional committee members . . . in writing and in a confidential 

group discussion about possible conflicts of interest.... [N]o individual can be appointed 

to serve (or continue to serve) on a committee of the institution used in the development 

of reports if the individual has a conflict of interest that is relevant to the functions to be 

performed.” Thus, EPA identifies the National Academies’ prohibition on conflicts of 

interest as a means of ensuring that the Endangerment Finding is balanced and unbiased. 

54 
Response (2-26):

We responded to this issue in Response 1-2 of Volume 1 of the RTC document, and we find that 

our response to public comments on this issue was sufficient, detailed, and responsive. The 

petitioner misrepresents EPA’s actual response, which we provide again here to put the 

petitioner’s allegation in perspective. 

Comment (1-2):

A number of commenters (3324.1, 3394.1, 3429.1, 3440.1, 3481.1, 3533.1, 3579.1, 

3596.1, 3707.1, 3747.1, 3764.1, 3915, 4509, 5716, 8624, 10197, 10948, and 11335) argue 

that the Administrator did not reference any documents in her decision-making process 

that offered alternative views on the scientific basis for causes of climate change. 

Commenters recommend that EPA provide a more complete discussion of global 

warming science by using information outside the assessment literature, including studies 

that do not support its conclusions and studies submitted to the docket through the public 

comment period for the Proposed Findings. 

Response (1-2):

We disagree that the Administrator did not consider alternative views on climate change 

science and impacts. Such a contention incorrectly implies that all individual studies 

reviewed and incorporated into the assessments of U.S. Global Change Research 

Program (USGCRP), U.S. Climate Change Science Program (CCSP), Intergovernmental 

Panel on Climate Change (IPCC), and National Research Council (NRC) support uniform 

conclusions on the different elements of greenhouse gas (GHG) and climate change 

science, and that the many thousands of studies reviewed and reflected in these major 

assessment works represent a narrow view of GHG and climate change science. In fact, 

these assessment reports look at the range of the scientific literature without “cherrypicking” and it is EPA’s conclusion that by placing primary reliance on the major 

assessment reports, we have ensured that the determinations are based on reports that 

have considered and weighed all views. EPA relied on the major peer-reviewed 

assessment reports in developing the TSD (U.S. EPA, 2009) precisely to avoid an overreliance on and narrow consideration of individual studies and to ensure that the 

Administrator’s decision would be based on a comprehensive assessment of the scientific 

literature. EPA has determined that the approach taken provided the high level of 

transparency and consistency outlined by EPA’s Guidelines for Ensuring and Maximizing 

the Quality, Objectivity, Utility and Integrity of Information Disseminated by the 

Environmental Protection Agency. 

Regarding the recommendation that EPA provide a more comprehensive discussion and 

consideration of global warming science and literature that is representative of 

“alternative views,” we have done this through our review of comments and literature 

submitted, the associated revision of the TSD, and the development of the eleven 

volumes of the Response to Comments document. See Section III.A. of the Findings, 

“The Science on Which the Decisions Are Based,” for our response to comments on the 

use of the assessment literature and previous responses in this section regarding our 

treatment of new and additional scientific literature provided through the public comment 

55 
process. For EPA’s responses to comments and literature provided on specific climate 

science issues in the TSD, please refer to the appropriate Response to Comment volumes. 

Finally, we note that IPCC, USGCRP/CCSP, and NRC make considerable effort to 

ensure that their assessment reports reflect a balance of perspectives regarding the state of 

the science. We note that the CCSP report Guidelines for Producing CCSP Synthesis and 

Assessment Products state that the reports should “identify disparate views that have 

significant scientific or technical support” (CCSP, 2004). We refer commenters to 

Appendix B of this volume for the full listing of these Guidelines. Further, NRC 

(National Academies, 2006) report development procedures state that: 

[C]areful steps are taken to convene [report development] committees that meet 

the following criteria: 

An appropriate range of expertise for the task. The committee must include 

experts with the specific expertise and experience needed to address the study’s 

statement of task. One of the strengths of the National Academies is the tradition 

of bringing together recognized experts from diverse disciplines and backgrounds 

who might not otherwise collaborate. These diverse groups are encouraged to 

conceive new ways of thinking about a problem. 

A balance of perspectives. Having the right expertise is not sufficient for success. 

It is also essential to evaluate the overall composition of the committee in terms of 

different experiences and perspectives. The goal is to ensure that the relevant 

points of view are, in the National Academies’ judgment, reasonably balanced so 

that the committee can carry out its charge objectively and credibly. 

Screened for conflicts of interest. All provisional committee members are 

screened in writing and in a confidential group discussion about possible conflicts 

of interest. For this purpose, a “conflict of interest” means any financial or other 

interest which conflicts with the service of the individual because it could 

significantly impair the individual’s objectivity or could create an unfair 

competitive advantage for any person or organization. The term “conflict of 

interest” means something more than individual bias. There must be an interest, 

ordinarily financial, that could be directly affected by the work of the committee. 

Except for those rare situations in which the National Academies determine that a 

conflict of interest is unavoidable and promptly and publicly disclose the conflict 

of interest, no individual can be appointed to serve (or continue to serve) on a 

committee of the institution used in the development of reports if the individual 

has a conflict of interest that is relevant to the functions to be performed.” 

We refer commenters to Appendix C of this volume for more information on NRC report 

development process. In addition, please see response to comments below regarding the 

IPCC report development process and procedures for ensuring a balance of perspectives. 

Petitioners reference only a small part of our response in their allegations. Our full response and 

the record for the Endangerment Finding demonstrate that the Administrator thoroughly 

56 
considered a range of studies, including those that disagree with the conclusions of the 

assessment literature. 

2.2.3.4 Allegations That IPCC Lead Authors Forced Consensus and Suppressed 

Dissenting Views 

Comment (2-27): 

The Southeastern Legal Foundation, the State of Texas, Peabody Energy, the Competitive 

Enterprise Institute, and the Ohio Coal Association argue that the CRU e-mails (in particular an 

e-mail from Phil Jones to Michael Mann expressing their disapproval of two new studies 

authored by Stephen McIntyre and Ross McKitrick) reveal that the contents of the IPCC reports, 

in this case Chapter 3 of the AR4 Working Group I report (Trenberth et al., 2007), were altered 

to eliminate any suggestion of non-consensus on key issues. Petitioners claim that this occurred 

so as to support a specific policy agenda, and that dissenting views were not given appropriate 

attention and consideration. The petitioners also argue that a group of authors have actively tried 

to suppress external challenges to consensus. 

Response (2-27): 

Although the petitioners draw broad conclusions of unethical and biased conduct from the e-mail 

between Phil Jones and Michael Mann, this e-mail does not show that the two IPCC authors 

acted unethically, or that they took any actions to suppress dissenting views, as alleged by the 

petitioners. The e-mail at issue was sent on July 8, 2008, and states: 

Mike, 

Only have it in the pdf form. FYI ONLY - don't pass on. Relevant paras are the last 2 in 

section 4 on p13. As I said it is worded carefully due to Adrian knowing Eugenia for 

years. He knows the're wrong, but he succumbed to her almost pleading with him to tone 

it down as it might affect her proposals in the future ! I didn't say any of this, so be 

careful how you use it - if at all. Keep quiet also that you have the pdf. The attachment 

is a very good paper - I've been pushing Adrian over the last weeks to get it submitted to 

JGR or J. Climate. The main results are great for CRU and also for ERA-40. The basic 

message is clear - you have to put enough surface and sonde obs into a model to produce 

Reanalyses. The jumps when the data input change stand out so clearly. NCEP does 

many odd things also around sea ice and over snow and ice. The other paper by MM is 

just garbage - as you knew. De Freitas again. Pielke is also losing all credibility as well 

by replying to the mad Finn as well - frequently as I see it. I can't see either of these 

papers being in the next IPCC report. Kevin and I will keep them out somehow - even if 

we have to redefine what the peer-review literature is! 

Cheers Phil20

The e-mail shows that Phil Jones strongly disapproved of the quality of the two studies21 and that 

he did not deem them to be of sufficient quality and credibility for inclusion in an IPCC 

 

20 E-mail file 1089318616.txt, (July 8, 2008), Page 720, Line 46 of PDF version entitled: CRU Emails 1996-

2009.pdf 

21 The paper Jones refers to by “MM” was McKitrick and Michaels (2004). It is not clear what the second paper is, 

however it was possibly De Laat and Maurellis (2006). 

57 
assessment report. In addition, both of the papers were in fact included in the IPCC assessment 

report. The “MM” study (McKitrick and Michaels, 2004) is referenced in the IPCC chapter, and 

assuming that the second study Jones referred to is De Laat and Maurellis (2006), that was 

included as well. This disproves the allegations of the petitioners that this e-mail is evidence that 

dissenting views were suppressed or that the IPCC assessment report was biased by such efforts. 

For example, these two studies are discussed in Chapter 3 (Trenberth et al., 2007): 

McKitrick and Michaels (2004) and De Laat and Maurellis (2006) attempted to 

demonstrate that geographical patterns of warming trends over land are strongly 

correlated with geographical patterns of industrial and socioeconomic development, 

implying that urbanization and related land surface changes have caused much of the 

observed warming. 

Thus, the events surrounding the citation of the McKitrick and Michaels (2004) and De Laat and 

Maurellis (2006) studies provide stronger support for the proposition that the IPCC assessed and 

cited critical literature than for the petitioners’ view that these events demonstrate that the IPCC 

is biased. 

The e-mail between Jones and Mann, which is the only evidence offered by petitioners to support 

this allegation, simply does not show that either 1) the contents of this chapter, let alone all of the 

IPCC assessment reports, were altered to eliminate a suggestion of nonconsensus, or 2) IPCC 

authors actively tried to suppress external challenges to consensus. It is not uncommon for 

scientists to disagree with the work of others, and this e-mail does not provide evidence that Phil 

Jones or any other IPCC author acted unethically or took actions to suppress dissenting views, 

notwithstanding the loose talk in the e-mail. 

Our conclusion regarding this e-mail is consistent with the findings of the Independent Climate 

Change E-mails Review investigation, which concluded “that it is not uncommon for strongly 

opposed and robustly expressed positions to be taken up in heavily contested areas of science. 

We take the view that such behaviour does not in general threaten the integrity of peer review or 

publication.” The final report of the investigation also stated that the panel has “not found any 

direct evidence to support the allegation that members of CRU [in this case Phil Jones] misused 

their position on IPCC to seek to prevent the publication of opposing ideas”(Russell, 2010). On 

this issue, Brian Hoskins, one of three review editors for Chapter 3, provided statements to the 

Independent Climate Change E-mails Review that were summarized in the panel’s report as 

stating (Russell, 2010): 

Hoskins confirmed that Las [lead authors], working individually and as small groups, 

were responsible for the collation and primary assessment of material relevant to the 

topics for which they were responsible. The CLAs [convening lead authors] led the 

plenary meetings of the writing team prior to production of each of the drafts, led the 

process of overall collation of the Chapter material and the production of the initial drafts 

of the First and Second Draft Reports and the Final Draft Report of the Chapter. These 

drafts were discussed and agreed during plenary meetings of the whole writing team. 

58 
There were a very large number of comments from reviewers, of which a majority were 

from a relatively small group. The Review Editors made sure that they were all given 

proper consideration, and that they were either responded to by a change in the text or by 

an adequate reason for omission that was recorded in the author responses to expert and 

governmental review comments. Hoskins, as a Review Editor, took part in the Chapter 3 

plenary discussions and ensured that conflicting views were addressed. 

Led by the two CLAs, Jones and Trenberth, the writing team for Chapter 3 was assiduous 

in dealing with comments. Hoskins was very impressed by Jones’ attention to detail, and 

the rigor of the Chapter 3 process. 

The levels of confidence and uncertainty reflected in the drafts were based on the 

consensus of a group of CLAs and LAs who were chosen for their expertise and 

experience in relevant fields. Irrespective of whether a paper is published in a peer 

reviewed journal, it is the responsibility of the whole team to assess whether a 

paper‘s conclusions are robust and to justify whether its arguments should carry weight in 

the assessment. These decisions for each draft were taken in plenary sessions of the 

whole team. Hoskins said that it is inconceivable that a paper making significant claims 

relevant to the work of IPCC and the Chapter 3 team would not be considered by the 

team as a whole. The basis for rejecting one of the papers that is a focus of the allegation 

is included in IPCC records. Decisions about the inclusion of the MM2004 [McKitrick 

and Michaels] paper would have been taken by the whole team. Jones’ voice would have 

been one amongst many. 

The petitioners do not present scientific evidence or argument showing that the IPCC assessment 

is inaccurate or that it does not appropriately reflect the degree of scientific consensus on the 

issues discussed. The petitioner’s broad conclusion that this is the case is unsupported by 

evidence or arguments on the science and assessment literature itself. Finally, we note that the 

science regarding this issue was raised in the comment period for the Endangerment Finding and 

responded to in Response 2-29 of the RTC document. Response 2-29 states: 

"In the case of de Laat and Maurellis (2006) and an earlier paper by McKitrick and 

Michaels (2004), IPCC (Trenberth et al., 2007) assessed these papers and noted that the 

locations of greatest socioeconomic development coincided with those most warmed by 

atmospheric circulation changes, which are not limited to urban areas but rather have 

large-scale coherence. When this is taken into account, IPCC concludes that the 

correlation of warming with industrial and socioeconomic development ceases to be 

statistically significant." 

59 
Comment (2-28):

The Southeastern Legal Foundation argues: 

The so-called “science” of global warming has been conducted in an ideologically 

charged environment, such that any possibility of giving due regard to dissenting views 

was foreclosed at the outset. Thus, the conclusions of organizing bodies, especially 

IPCC, cannot be said to reflect scientific “consensus” in any meaningful sense of that 

word. Instead, they reflect a political movement that has commandeered science to the 

service of its agenda. This is “post-normal science”: the long-dreaded arrival of 

deconstructionism to the natural sciences, according to which scientific quality is 

determined not by its fidelity to truth, but by its fidelity to the political agenda. A leading 

climate scientist and contributor to the IPCC, Mike Hulme, has called the IPCC “a classic 

example” of “post normal science.” 

The petitioner further asserts: 

Post-normal science was defined by Eva Kunseler, in her paper “Towards a new 

paradigm of Science” as follows: A new concept of science was introduced by Funtowicz 

and Ravetz during the 1990s...The concept of post-normal science goes beyond the 

traditional assumptions that science is both certain and value-free...The exercise of 

scholarly activities is defined by the dominance of goal orientation where scientific goals 

are controlled by political or societal actors...Scientists’ integrity lies not in 

disinterestedness but in their behaviour as stakeholders.”(Kunseler, 2007) 

Response (2-28):

We first note that this allegation that the IPCC’s work does not represent objective scientific 

assessment but is motivated by a political agenda is not new. The petitioner is rehashing an 

argument previously submitted during public comment on the proposed endangerment finding. 

We responded to numerous comments received regarding the scientific integrity and objectivity 

of the IPCC’s processes in developing its assessment reports in Volume 1, Section 1, of the RTC 

document. 

We note that the evidence submitted by the petitioner—consisting of a newspaper op-ed by Mike 

Hulme in The Guardian (Hulme, 2007) and the definition of “post-normal science” from a nonpeer-reviewed essay by Eva Kunseler (Kunseler, 2007)—are not new; they were both developed 

in 2007. Therefore, it was not impracticable to raise the objection during the public comment 

period and the reasons for the objection did not arise between June 24, 2009, and February 16, 

2010. The petitioner could have raised this comment during the comment period on the 

proposed Endangerment Finding. The petitioner has not shown why it would have been 

impractical to do so. 

In addition, the evidence does not support the petitioner’s allegation that the science behind 

climate change has been developed in a biased and “ideologically charged environment.” The 

petitioner mischaracterizes Hulme’s discussion of post-normal science and defines what he 

meant by “post-normal science” with the use of an unrelated paper by Eva Kunseler that has 

60 
nothing to do with climate change. This is an excerpt of the relevant part of Hulme’s op-ed in 

The Guardian newspaper: 

That science is an unfolding process of discovery is fairly self-evident. The more we 

seem to know, the more questions we seem to need answering. Some avenues of 

scientific inquiry may close off, but many new ones open up. We know a lot more about 

climate change now than 17 years ago when the first IPCC scientific assessment was 

published. And no doubt in another 17 years our knowledge of how the climate system 

works and the impact that humans have made on it will be significantly different to today. 

Yet it is important that on big questions such as climate change scientists make an 

assessment of what they know at key moments when policy or other collective decisions 

need to be made. Today is such a time. But our portrayal of the risks of climate change 

will always be provisional, subject to change as our understanding advances. Having 

challenges to this unfolding process of discovery is essential for science to thrive, as long 

as those challenges play by the methodological rule book that science has painstakingly 

written over many generations of experience. 

The other important characteristic of scientific knowledge - its openness to change as it 

rubs up against society - is rather harder to handle. Philosophers and practitioners of 

science have identified this particular mode of scientific activity as one that occurs where 

the stakes are high, uncertainties large and decisions urgent, and where values are 

embedded in the way science is done and spoken. It has been labelled “post-normal” 

science. Climate change seems to fall in this category. Disputes in post-normal science 

focus as often on the process of science - who gets funded, who evaluates quality, who 

has the ear of policy - as on the facts of science. 

Hulme’s discussion of post-normal science presents his opinion about how societal values and 

policy decisions intersect with the practice of science. His statement does not say or imply that 

post-normal science means that “a political movement [has] commandeered science to the 

service of its agenda,” nor does he state that climate change is a “classic example of post-normal 

science.” In contrast, Hulme stresses that science is a “process of discovery” that thrives on 

challenges that “play by the methodological rule book that science has painstakingly written over 

many generations of experience.” This is clearly not a statement about science being controlled 

by politics, nor a statement that politics have prevented climate change scientists from giving 

“due regard to dissenting views,” as the petitioner asserts. 

Even if Hulme did claim an overly “ideologically charged environment,” this would only 

represent the opinion of one person among numerous scientific fields comprising an immense 

number of scientists, institutions, assessment bodies, and governmental organizations. This 

evidence, presented as a conclusion with no supporting evidence and with no scientific 

explanation of the errors that resulted, would not come close to undermining the credibility and 

quality of the findings of the assessment literature. As described in this volume, and Volume 1 

of the RTC document for the Endangerment Finding, the assessment literature upon which EPA 

based the Endangerment Finding has robust processes and procedures to ensure that the best 

available scientific information is reviewed and assessed, with checks and balances included to 

61 
produce high-quality, unbiased reports. We respond to specific objections raised by petitioners 

regarding the implementation of the IPCC procedures throughout Section 2.2 of this volume. 

We also note that we considered and responded to multiple perspectives and views of climate 

science in the RTC document for the Endangerment Finding, and considered and responded 

again to the various perspectives of the petitioners here in the RTP document and in the Denial. 

As discussed extensively in our responses, the IPCC and the USGCRP also considered 

alternative views in their assessment processes. See Volume 1 of the RTC document and Section 

2.2.2 (Background) of this Volume of the RTP document for a discussion of these report 

development processes. 

We have reviewed the petitioner’s arguments and materials and do not find that they support the 

allegations that the IPCC was co-opted by politics and biased against dissenting views. The 

balance of the scientific literature represented in the assessment reports on climate change, of 

which the IPCC is one, clearly supports the Administrator’s findings. 

Comment (2-29): 

The Ohio Coal Association and the Coalition for Responsible Regulation argue that the CRU emails “demonstrate that climate scientists felt pressured to present a unified front - and an 

agreed-upon narrative of global warming - even when there was not one.” Both petitioners 

reference an e-mail from Keith Briffa to Michael Mann which states: “I tried hard to balance the 

needs of the science and the IPCC, which were not always the same.” Also, as evidence to 

support their argument, the Coalition for Responsible Regulation provides a letter to the IPCC 

from Christopher Landsea, a former IPCC author, in which he states that he could not “in good 

faith continue to contribute to a process that I view as both being motivated by preconceived 

agendas and being scientifically unsound” (Landsea, 2005). 

Response (2-29): 

Seeing the entire content of the e-mails cited by the petitioner is important to place the first issue 

raised by petitioners in context: 

E-mail from Mann to Briffa on Sunday, April 29, 2007

Keith, just a quick note to let you know I’ve had a chance to read over the key bits on last 

millennium in the final version of the chapter, and I think you did a great job. obviously, 

this was one of the most (if not the most) contentious areas in the entire report, and you 

found a way to (in my view) convey the the[sic] science accurately, but in a way that I 

believe I will be immune to criticisms of bias or neglect--you dealt w/ all of the 

controversies, but in a very even-handed and fair way. bravo! I hope you have an 

opportunity to relax a bit now. Looking forward to buying you a beer next time we have 

an opportunity :) mike22

E-mail from Briffa to Mann on Sunday, April 29, 2007

Mike your words are a real boost to me at the moment. I found myself questioning the 

whole process and being often frustrated at the formulaic way things had to be done - 

 

22 E-mail file 1177890796.txt, (April 29, 2007) page 1310, line 44 of PDF version entitled: CRU Emails 1996-

2009.pdf 

62 
often wasting time and going down dead ends. I really thank you for taking the time to 

say these kind words. I tried hard to balance the needs of the science and the IPCC, 

which were not always the same. I worried that you might think I gave the impression of 

not supporting you well enough while trying to report on the issues and uncertainties. 

Much had to be removed and I was particularly unhappy that I could not get the statement 

into the SPM [Statement for Policymakers] regarding the AR4 reinforcement of the 

results and conclusions of the TAR [Third Assessment Report]. I tried my best but we 

were basically railroaded by Susan. I am happy to pass the mantle on to someone else 

next time. I feel I have basically produced nothing original or substantive of my own 

since this whole process started. I am at this moment, having to work on the ENV 

submission to the forthcoming UK Research Assessment exercise, again instead of 

actually doing some useful research! Anyway thanks again Mike.... really appreciated 

when it comes from you 

very best wishes 

Keith23

These two e-mails were written after the release of the Working Group I report of AR4 (IPCC, 

2007e). Michael Mann writes an e-mail showing his approval of the final version of Chapter 6 

(“Paleoclimate”) of Working Group I report (Jansen et al., 2007) and to congratulate Briffa on 

the accomplishment. Keith Briffa responds to show his appreciation for Mann’s e-mail; he 

explains some of the challenges and difficulties he encountered while finalizing the chapter and 

getting it through the ultimate stages of review. As stated in Section 2.2.2 (Background) and 

Response 2-16 above, Chapter 6 had two convening authors and 14 lead authors from 12 

countries, 33 contributing authors from nine countries, and two review editors who oversaw the 

handling of more than 2,900 comments from the rounds of expert and governmental review. It is 

perfectly understandable and reasonable that Briffa, who was one of the 14 lead authors, would 

have been frustrated by some of the challenges in examining all of the available scientific 

literature on topics related to paleoclimate (whether or not it agrees with the dominant paradigms 

and whether or not it has yet stood the test of time compared to other studies that have 

considered the topic), putting that literature in context through a process of assessment, distilling 

the information into key messages that capture the state of knowledge at the time of the 

assessment, addressing all of the expert and government reviews, and developing key points for 

the summary for policymakers. Briffa’s e-mail does not support the petitioner’s allegation that 

he “felt pressured to present a unified front - and an agreed-upon narrative of global warming - 

even when there was not one.” The petitioner is taking Briffa’s statement that he “tried hard to 

balance the needs of the science and the IPCC, which were not always the same” completely out 

of context and making unsupported allegations. Although he describes some frustrations with 

the challenges of the IPCC’s rigorous and robust report development procedures, Briffa’s e-mail 

does not indicate that he was not satisfied with the final version, that he did not agree with the 

conclusions, nor that he felt pressured in any way to “present a unified front.” 

 

The e-mails in question also reveal that the process of scientific assessment is personally and 

professionally challenging because scientists who volunteer their time are taken away from their 

 

23 E-mail file 1177890796.txt, (April 29, 2007) page 1310, line 24 of PDF version entitled: CRU Emails 1996-

2009.pdf 

63 
own research and must sideline their own personal views of what should and should not be 

included in the reports. In fact, Michael Mann compliments Keith Briffa’s objectivity and evenhandedness in handling the challenges. Briffa also clearly expresses frustration with the time 

spent away from doing new science, which is not the primary job of an IPCC chapter author or 

of the IPCC in general. The primary role of the IPCC is to assess existing science already 

published in the literature, i.e., in Briffa’s words, “the needs of the science and the IPCC” are not 

always the same. In context, it is clear that the needs of the IPCC in this case are the “formulaic 

way things had to be done” and the need to do assessments of existing literature rather than 

producing “original and substantive” work or “useful research.” It appears original research 

would be what Briffa is referring to as the needs of the science. When the e-mails are read in 

their full context, it is clear that the authors of these e-mails sought to convey the science 

accurately and address all the controversies in a fair and even-handed way. Again, petitioners 

appear to have selectively picked excerpts from emails. 

We note that the Landsea letter provided by the Coalition for Responsible Regulation is not new. 

As stated in the link of the letter provided by the petitioner (Taylor, 2005), Landsea wrote this 

letter in January 2005. Therefore, it was not impracticable to raise the objection during the 

public comment period and the reasons for the objection did not arise between June 24, 2009, 

and February 16, 2010. The petitioner could have raised this comment during the comment 

period on the proposed Endangerment Finding. The Coalition for Responsible Regulation has 

not shown why it would have been impracticable to do so, especially given the fact that the 

public has been aware that EPA might rely on the IPCC assessments since the July 2008 

Advance Notice of Proposed Rulemaking. 

Despite this, we will respond briefly to the petitioner’s allegations. Christopher Landsea served 

as a contributing author for the IPCC Second and Third Assessment Reports (IPCC 1995, IPCC 

2001), but chose not to participate in AR4. In the initial planning stages of the AR4, Landsea 

wrote this letter to the IPCC expressing his disapproval with IPCC procedures. Specifically, 

Landsea disapproved of the fact that Kevin Trenberth, an IPCC lead author for the TAR, 

purportedly used his position to “promulgate to the media and general public his own opinion 

that the busy 2004 hurricane season was caused by global warming, which is in direct opposition 

to research written in the field and is counter to conclusions in the TAR [Third Assessment 

Report].” Landsea went on to state that “As the IPCC leadership has seen no wrong in Dr. 

Trenberth’s actions and have retained him as a Lead Author for the AR4, I have decided to no 

longer participate in the IPCC AR4.” This letter shows that Landsea disagreed with Trenberth 

regarding a particular aspect of the attribution of hurricanes to climate change and that Landsea 

did not approve of Trenberth representing the IPCC when discussing his views about the issue. 

This impact of climate change on hurricane activity is a very dynamic issue. There are still 

significant uncertainties in the underlying climate science, so it not surprising that two scientists 

would disagree regarding the attribution of the 2004 hurricane season to climate change effects. 

However, the contents of the letter do not “demonstrate that climate scientists felt pressured to 

present a unified front - and an agreed-upon narrative of global warming - even when there was 

not one,” as alleged by the petitioner. Landsea was not taking issue with the content of the IPCC 

reports, but with how Trenberth discussed certain issues during the period between the Third and 

Fourth Assessment Reports. The fact that Landsea disapproved of how Trenberth represented 

64 
the IPCC in discussing a specific scientific issue at a press conference preceding development of 

the AR4 provides absolutely no support for petitioners’ claim that the conclusions reached in 

AR4 are incorrect or biased, or that they were developed in a way that pressured scientists into 

presenting “a united front.” The petitioners did not provide any evidence to support that 

conclusion. 

We also note that the discussion in AR4 of uncertainties associated with the impact of climate 

change on hurricane activity reflected the ongoing debate and alternative views on the issues. 

EPA also clearly described the uncertainties related to hurricane activity and climate change in 

the TSD and again in Volumes 2 and 4 of the RTC document for the Endangerment Finding. 

Finally, our response to allegations involving the IPCC’s characterization of climate change and 

disaster losses can be found in Subsection 2.1.4 of this volume of the RTP document. 

2.2.4 Responses to Allegations Based on Information That Is Not New 

The petitioners submitted four objections concerning: 1) the collaborations among IPCC authors, 

2) the general IPCC peer review process, 3) the alleged manipulation of dates and deadlines for 

accepting literature, and 4) the IPCC’s use of gray literature. EPA has reviewed the petitioners’ 

submissions and finds that it was not impracticable to raise the objection during the public 

comment period and that the reasons for the objection did not arise between June 24, 2009, and 

February 16, 2010. The IPCC AR4 has been public since early 2007, and petitioners could have 

raised these comments during the comment period on the proposed Endangerment Finding. 

Although, in most cases, the petitioners provide excerpts from the CRU e-mails in support of 

their assertions, EPA’s review has determined that this evidence does not support their 

allegations, and that the vast majority of the information submitted by petitioners on these topics 

was available well before the comment period for the Endangerment Finding. Petitioners have 

not shown why it would have been impracticable for them to raise these issues then, especially 

given the fact that the public has been aware that EPA relied, in part, on the IPCC assessments 

since the July 2008 ANPR. Indeed, some of these same points were already raised, and 

responded to, in the RTC. 

Despite the fact that these objections fail to meet the criteria for a petition for reconsideration, we 

briefly explain why, contrary to petitioners’ allegation, they fail to call into question the overall 

integrity or validity of the IPCC AR4. As noted above, very similar comments questioning the 

appropriateness of IPCC author and reviewer roles were submitted and responded to during the 

development of the Findings (see Volume 1 of the RTC document). 

2.2.4.1 Allegations of Inappropriate Collaborations Among IPCC Authors 

Comment (2-30): 

The State of Texas, Peabody Energy, and the Coalition for Responsible Regulation contend that 

the CRU e-mails show that IPCC authors and reviewers are close associates who frequently 

collaborate on projects and studies, and claim that such collaborations create conflicts of interest 

(for example, when one person authors an IPCC chapter and another serves as an official 

reviewer). Peabody Energy argues that the Wegman Report, Social Network Analysis of 

Authorship in Temperature Reconstruction, confirms that IPCC scientists are closely networked 

65 
with each other and dominate their field. The petitioner references testimony given by Edward J. 

Wegman (George Mason University) to Congress (Wegman, 2006) in arguing that “the 

paleoclimate field is dominated by interlinked scientists who no longer produce research that has 

the desired degree of independence.” 

Based on this report, Peabody Energy provides a detailed example of the small paleoclimate 

research community and how these scientists frequently co-author papers together, review each 

other’s papers, and collaborate in other ways that generate conflicts of interest. Specifically, the 

petitioner, in referring to Chapter 9 (“Understanding and Attributing Climate Change”) of 

Working Group I’s contribution to the AR4 (Hegerl et al., 2007), provides a series of statistics 

that were also provided to EPA during the public comment period (these statistics are provided 

below) and argues that EPA did not respond to these specific issues in the RTC document: 

 Forty of the 53 authors of this chapter co-authored papers with each other. 

 More than half of the contributing authors co-authored papers with lead authors or 

coordinating lead authors. 

 The review editor of the chapter contributed to 13 papers cited in the chapter and had coauthored these papers with 10 other authors of Chapter 9. 

 Of the published papers in Chapter 9: 

o 94 were authored by two or more of that chapter’s authors. 

o One cited paper had six chapter authors. 

o Five cited papers had five chapter authors. 

o 26 papers had three chapter authors, including six papers written entirely by 

chapter authors. 

o 50 of the cited papers listed two chapter authors each, and 10 of these papers were 

written entirely by chapter authors. 

Response (2-30):

Neither the facts nor the evidence provided support the petitioners’ claim that the collaborations 

among climate researchers led to conflicts of interest and bias, or that these collaborations 

interfered with their ability to be objective and impartial. Some climate science fields (e.g., 

paleoclimatology) are highly specialized and are the focus of only a limited number of 

researchers. In such fields, scientists who have at one point in the past collaborated on work can 

be called on to review each other’s work. This practice is common in a variety of scientific areas 

with a relatively limited number of researchers, not just these specific climate science fields. It is 

actually the most robust practice of ensuring scientific credibility, because the reviewing 

scientists are the true experts who know the material and are most capable of fulfilling the review 

role. Petitioners’ conclusions of impropriety or bias are not supported by the mere fact that 

authors know each other and have collaborated. 

We respond to Peabody Energy’s statistics regarding Chapter 9 in Subsection 2.2.3.2 of this 

volume of the RTP document. Given the limited number of researchers in this particular area, 

the statistics regarding author and reviewer roles in Chapter 9 of Working Group I’s contribution 

66 
to the AR4 (Hegerl et al., 2007) are not surprising and do not indicate, as alleged by the 

petitioner, that there were “built-in conflicts of interest that had the potential for undermining the 

reliability of the reports.” Rather, these statistics show that the most qualified and experienced 

authors and reviewers were involved in developing that particular chapter. EPA carefully 

reviewed and responded to these statistics regarding collaborations among IPCC authors in 

Volume 1 of the RTC document. 

Furthermore, all scientific papers have to abide by strict ethical, conflict of interest, and scientific 

integrity/quality rules. The evidence provided by the petitioners does not show that these rules 

have been broken, that the peer-review system has been compromised, or that the assessment 

literature did not consider a range of perspectives in summarizing the state of the science. 

Essentially, the petitioners’ argument can be boiled down to the view that if scientists work 

together and know each other, something improper is probably happening. This is an 

unwarranted and unjustified view of professional relationships, based on pure speculation. 

Finally, we note that Peabody Energy does not provide any evidence to support its allegation that 

the past collaborations of these authors and reviewers actually led to “less than fully independent 

and rigorous” assessments of the science. The petitioner provided limited and unsubstantiated 

critiques of the science presented in Chapter 9, which we address in Volume 1 of this RTP 

document. Peabody Energy also provides no scientific argument or analysis indicating that the 

research produced by theses scientists or the IPCC chapter at issue was in any way biased or less 

than scientifically rigorous. 

2.2.4.2 Allegations Regarding Insufficient Peer Review Processes for the IPCC 

Comment (2-31):

Peabody Energy claims that the IPCC’s peer review process is less robust and credible than the 

processes employed by scientific journals because IPCC lead and contributing authors are the 

ones who decide whether to accept or reject critical reviews. The petitioner argues that the 

IPCC’s process is flawed because there is no neutral scientist, who was not involved in the 

writing, to ensure that the reviews are judged objectively. 

Response (2-31): 

First, we note that the petitioner provides no new information to substantiate their allegation, and 

that Peabody Energy’s argument regarding the rigor of the IPCC’s peer review does not 

accurately describe the actual review process used by the IPCC. As described above in 

Subsection 2.2.2 (Background) of this volume, lead and contributing authors are indeed tasked 

with initially responding to comments; however, independent and objective review editors (i.e., 

editors not involved in the writing of the chapter) are assigned to each chapter to ensure that each 

comment is addressed properly and accurately. Furthermore, the contributing authors are not 

allowed to simply reject critical reviews without documenting their rationale. The IPCC 

carefully documented all comments received on the first and second order drafts of each chapter 

of each working group. These comments and responses are, and have always been, publically 

available (IPCC, 2006a for Working Group I and IPCC, 2005 for Working Group II). 

67 
In addition, it would be illogical and inappropriate for the IPCC, as suggested by the petitioner, 

to allow only unrelated parties to respond to comments on chapters that they did not write. What 

the petitioner seems to believe would be appropriate—allowing unrelated people to respond to 

comments on the draft documents, as opposed to having the authors respond and revise their 

drafts—makes absolutely no sense and is not common in any scientific discipline because the 

unrelated parties would not possess the experience and context necessary to properly understand 

and respond to the comments. We therefore disagree with the petitioner’s argument that the 

IPCC’s peer review procedures are less rigorous than the processes employed by scientific 

journals. Petitioners provide no evidence that the IPCC authors inappropriately influenced the 

response to comments process or that review editors failed to perform their role in ensuring that 

all comments were properly addressed. The mere allegations and conclusory claims made by the 

petitioner are insufficient to support the broad conclusion they draw. Finally, we note that the 

petitioner did not provide examples of other peer review processes that they deemed to be more 

robust and credible than those procedures employed by the IPCC. 

2.2.4.3 Allegations That IPCC Authors Manipulated Deadlines for New Literature 

Comment (2-32): 

Peabody Energy argues that the IPCC manipulated dates and deadlines for receipt of new 

literature to provide additional evidence in substantiating its conclusions regarding 20th-century 

warming. Specifically, the petitioner provides an example of two papers (both by Caspar 

Ammann and Eugene Wahl) on long-term temperature reconstructions, one of which was 

allegedly allowed to be referenced by IPCC authors in the AR4 only because, the petitioners 

claim, the IPCC manipulated the deadline for receipt of literature. 

Response (2-32): 

The evidence provided by Peabody Energy does not demonstrate that the IPCC, specifically the 

lead author of Chapter 6 of Working Group I’s contribution to the AR4 (Jansen et al., 2007), 

manipulated the deadline for receipt of new literature for the purpose of including the two papers 

by Ammann and Wahl (Ammann and Wahl, 2007; Wahl and Ammann, 2007). We note that the 

IPCC AR4 has been public since early 2007, and petitioners could have raised these objections 

during the comment period on the proposed Endangerment Finding. Petitioners have not shown 

why it would have been impractical for them to do so. The only part of their argument that is 

“new” (i.e., has arisen since the close of the comment period on June 23, 2009) is an e-mail 

between Wahl and Ammann, which is a very minor part of their overall interaction. The e-mail 

only shows that Wahl and Ammann were making final proofing edits in September 2007. The email stated: 

Hi Phil: 

There were inevitably a few things that needed to be changed in the final version of the 

WA paper, such as the reference to the GRL paper that was not published (replaced by 

the AW paper here), two or three additional pointers to the AW paper, changed 

references of a Mann/Rutherford/Wahl/Ammann paper from 2005 to 2007, and a some 

other very minor grammatical/structural things. I tried to keep all of this to the barest 

minimum possible, while still providing a good reference structure. I imagine that MM 

[Ross McKitrick and Pat Michaels] will make the biggest issue about the very existence 

68 
of the AW paper, and then the referencing of it in WA; but that was simply something we 

could not do without, and indeed AW does a good job of contextualizing the whole 

matter. Steve Schneider seemed well satisfied with the entire matter, including its 

intellectual defensibility (sp?) and I think his confidence is warranted. That said, any 

other thoughts/musings you have are quite welcome. 

Peace, Gene24 

As stated by the petitioner, the deadline for receipt of new literature was changed during the 

development of the Working Group I report. The deadline was originally December 2005 and 

was changed to July 24, 2006. When the coordinating lead authors for Working Group I 

extended the deadline for receipt of new literature, they provided the following justification 

(IPCC, 2006b): 

To ensure clarity and transparency in determining how such material might be included 

in the final Working Group I report, the following guidelines will be used by Lead 

Authors in considering such suggestions. In preparing the final draft of the IPCC 

Working Group I report, Lead Authors may include scientific papers published in 2006 

where, in their judgment, doing so would advance the goal of achieving a balance of 

scientific views in addressing reviewer comments. 

The authors of Chapter 6 followed this guidance and included the Wahl and Ammann (2007) 

study. We note that the Wahl and Ammann paper was accepted into Climatic Change on March 

1, 2006, which means that at that point, the paper had passed peer review and the editor had 

agreed with the reviewers regarding its merit for publication. Thus, although the citation for the 

paper is in 2007, the acceptance date met the IPCC’s revised deadline of July 24, 2006, for 

receipt of new literature that was established by AR4 lead authors. It appears that the same 

authors’ other paper, Ammann and Wahl (2007), was not accepted for publication in time to 

meet the extended deadline for receipt of new literature, and we note that it is therefore not 

referenced in Chapter 6 of the AR4. 

The petitioner alleges impropriety because the IPCC referenced Wahl and Ammann (2007), even 

though some of the underlying statistical analysis for that study, which was eventually published 

in Amman and Wahl (2007), had not been accepted for publication by the extended deadline. 

There are two flaws with petitioner’s arguments. First, in the event that any of the expert 

reviewers for Chapter 6 expressed concern regarding the Wahl and Ammann (2007) paper, they 

would have had the opportunity to request any supplemental information necessary for reviewing 

the credibility of the Wahl and Ammann results. Second, the Ammann and Wahl paper went 

through peer review and was eventually published in Climatic Change in 2007, in the same issue 

as Wahl and Ammann (2007). The petitioners do not claim or demonstrate that the methods or 

results described in the Ammann and Wahl paper were incorrect or flawed. They simply allege 

that a decision to change deadlines slightly is “manipulation,” even if no scientific flaw or 

challenge is raised against the literature affected by the date change. 

 

24 E-mail file 1189722851.txt, (September 12, 2007), page 1357, line 6 of PDF version entitled: CRU Emails 1996-

2009.pdf 

69 
Moreover, contrary to the petitioner’s argument, the evidence provided by the petitioner does not 

indicate that the deadline was inappropriately extended to accommodate the inclusion of these 

papers in AR4. On this issue, the Independent Climate Change E-mails Review found that: 

Taking into account the evidence of the Review Editor [for Chapter 6, i.e. John Mitchell], 

IPCC papers [documentation of IPCC responses to comments], the statement from the 

CLA [Jonathan Overpeck], and the importance of the issues raised by M&M2003 

[McIntyre and McKitrick], we consider it to be reasonable that work that might throw 

further light on these issues and to ensure that assessments were as up to date as possible 

should be included. We do not consider therefore that these were exceptional 

unwarranted efforts to defend a particular position, but reasonable attempts to use up to 

date information that might resolve an issue. They appear to be consistent with IPCC 

principles and to reflect a concern for objectivity (Russell, 2010). 

There was a general decision to allow extension of the deadline for the entire Working Group, 

and the chapter authors applied this guidance and extended the deadline for scientific studies 

relevant to that chapter. The fact that it was extended does not show it was extended because of 

these specific papers. In addition, petitioners have not shown that the extension altered the 

results of the report or the appropriateness of EPA’s relying on it. First, inclusion of the peerreviewed study represents one very small part in the deliberate preparation and review of a multivolume assessment containing several thousands of pages of findings and conclusions. Second, 

Chapter 6 relied upon a number of long-term temperature reconstructions for its conclusions, 

including the findings of NRC’s 2006 report (NRC, 2006) on surface temperature 

reconstructions. The NRC findings were fully consistent with the conclusions of the Ammann 

and Wahl papers. The papers in question provided additional, but not the only, evidence 

concerning the validity of using long-term proxy temperature reconstructions to compare 

historical and current climates. Indeed, and perhaps most importantly, the petitioner has 

provided no evidence showing that the conclusions of the Ammann and Wahl paper were 

mistaken or incorrect, or that the conclusions by themselves changed the findings of Chapter 6. 

Third, we note the statements that John Mitchell, one of two Chapter 6 review editors for 

Chapter 6, provided to the Independent Climate Change E-mails Review regarding how in-press 

material was handled and how decisions about the text of successive drafts were made. He 

commented as follows: 

I was not aware of the debate about whether the Wahl and Ammann paper had or had not 

met the deadline for the 2nd order draft for chapter 6, until after the event. The 

concentration on specific deadlines however misses the larger point. It must be 

recognized that if only published sources were used, the report would be two years old by 

the time of publication. In a fast-moving area such as climate change research, 

assessments could be significantly behind the times if important, but as yet unpublished, 

new results could not be used. The assessments for policymakers could also therefore be 

behind the times... 

In earlier assessments, there had been a relatively liberal regime in using unpublished 

material provided that there was a sound basis for regarding it as rigorous or reliable, 

although priority was always given to finding published sources. In AR4 however, the 

70 
regime was tightened significantly, so that such material was only to be used under 

exceptional circumstances, but the use of unpublished material was not prohibited. 

Hockey-stick issues were regarded at the time as sufficiently important to justify using 

new data. The dilemma between using only published material and being out of date, or 

using more recent unpublished material was increased in AR4 as the latest publication 

date was about 12 months earlier than in the process than in the previous assessment 

(Russell, 2010). 

2.2.4.4 Allegations Regarding the IPCC’s Use of Gray Literature 

Comment (2-33):

The Coalition for Responsible Regulation, Peabody Energy, the Southeastern Legal Foundation, 

and the State of Texas argue that the IPCC’s use of non-peer-reviewed literature (e.g., reports 

they claim are developed by environmental advocacy groups) in the AR4 calls into question the 

quality and objectivity of these pieces of literature and contradicts EPA’s assertion that the IPCC 

is based on peer-reviewed science. The petitioners provide examples of gray literature sources 

that were used by the IPCC in AR4. 

Response (2-33):

First, we note that the petitioners provided no new information in support of their allegations. As 

stated above, the petitioners are simply rehashing a comment that was submitted and responded 

to in the development of the Findings. Therefore, we find that their allegations were not 

impracticable to raise the objection during the public comment period and the reasons for the 

objection did not arise between June 24, 2009, and February 16, 2010. The IPCC AR4 has been 

public since early 2007, and petitioners could have raised these comments during the comment 

period on the proposed Endangerment Finding. Petitioners have not shown why it would have 

been impracticable for them to raise these issues then, especially given the fact that the public 

has been aware that EPA relied, in part, on the IPCC assessments since the July 2008 ANPR. 

The IPCC relied on and referenced a very limited number of non-peer-reviewed sources in 

developing AR4. The IPCC’s report development procedures recognized and allowed for the 

limited use of non-peer-reviewed literature where this was necessary and appropriate. Indeed, 

neither the IPCC nor EPA ever stated that the assessment reports relied exclusively on peerreviewed material. For EPA’s responses showing how the limited use of gray literature 

documents did not undermine the IPCC’s scientific findings and the technical support for 

endangerment, please see Section 2.1 of this volume, including Responses 2-8, 2-9, and 2-10. 

Looking across the thousands of scientific studies reviewed, assessed, and referenced by the 

IPCC in the AR4, it is clear that the number of non-peer-reviewed documents was dwarfed by 

the number of peer-reviewed references (estimated by the IPCC to be approximately 18,000). 

The IPCC, as clearly described in Volume 1 of the RTC document, has specific procedures to 

ensure that any non-peer-reviewed materials are sufficiently robust and credible in the context in 

which they were cited. While there are a very few instances in which erroneous conclusions 

were developed from the gray literature sources (see Section 2.1 of this RTP document for more 

detail on our responses to these issues), the overall process is exceedingly robust. Furthermore, 

71 
the few errors in this regard are trivial when viewed against the backdrop of the IPCC’s multivolume assessment containing several thousand pages of findings and conclusions. The few 

errors do not affect the climate change science findings or have any material or meaningful 

implication for the determination of endangerment to public health and welfare in the United 

States. The examples of gray literature provided by the petitioners were not cited by EPA in 

describing the key IPCC conclusions that EPA relied on in developing the TSD (U.S. EPA, 

2009). The examples provided by the petitioners are cited in chapters of the Working Group II 

and III AR4 reports when describing climate change impacts in other world regions, which was 

not a focus of the TSD. 

Comment (2-34): 

Peabody Energy claims that the IPCC Working Group II “frequently used a citation method that 

did not candidly reveal an underlying affiliation with an environmental advocacy group.” For 

example, the petitioner claims that in many instances the IPCC report “referred only to the name 

of the author when the work was actually sponsored by an interest group” such as the World 

Wildlife Fund. Peabody concludes that “It is unclear whether these sponsored works provide 

independent, objective, and peer-reviewed science that should be the basis for AR4, or whether 

they advance the environmental agenda of their sponsor. It is also unclear whether these sources 

were independently verified by IPCC authors and contributors.” 

Response (2-34):

First, we note that the IPCC’s citation method for the AR4 is not new and that this information 

has been known since the assessment report was released in 2007 (IPCC, 2007a). Therefore, the 

petitioner’s arguments were not impracticable to raise during the public comment period and the 

reasons for the objection did not arise between June 24, 2009, and February 16, 2010. The 

petitioner could have raised this comment during the comment period on the proposed 

Endangerment Finding. Peabody Energy has not shown why it would have been impractical to 

do so. Despite this, we respond below to the merits of their argument. 

The petitioner alleges that the IPCC employed a parenthetical citation method in the text of the 

chapters that hid information showing that references were developed by environmental nongovernment organizations. In fact, the IPCC employed a common citation method for the 

thousands of studies that are referenced among the more than 3,000 pages in AR4. This format 

consists of listing the author’s names first for each entry in the references section, and 

mentioning the publisher and/or organization (e.g., World Wildlife Fund) toward the end of the 

reference. Parenthetical citations, for each reference in the text of a chapter, list the author(s)’ 

name(s) and the year of publication. This citation methodology is consistent with many 

established citation guidelines, including those developed by the Modern Language Association, 

the American Psychological Association, and the University of Chicago. 

The evidence provided by the petitioner does not show that the IPCC hid the fact that some of 

the reports it cited were developed by non-government organizations like the World Wildlife 

Fund. The petitioner seems to suggest that the IPCC should have included the names of the nongovernment organizations in the parenthetical citations for these literature sources. However, 

this practice is contrary to the well-established conventions and styles that are commonly used in 

all disciplines of science and literature. Special treatment for these literature sources would be 

72 
inappropriate and unreasonable, and the petitioner’s only justification for such an approach is the 

speculation that this literature might have been created to “advance the environmental agenda of 

their sponsor.” Again, the IPCC included the names of the organizations in the full reference for 

each report in the references section at the end of each chapter. The IPCC did not hide the 

publisher or sponsoring organization’s name. 

For our response to the petitioner’s argument that “It is unclear whether these sponsored works 

provide independent, objective, and peer-reviewed science that should be the basis for AR4, or 

whether they advance the environmental agenda of their sponsor,” please see Section 2.1 of this 

volume, including Responses 2-8, 2-9, and 2-10. 

Finally, the procedures employed by the IPCC in evaluating sources of gray literature are 

described in Section 1 and Appendix A of Volume 1 of the RTC document. The petitioner has 

provided no evidence suggesting that the reports developed by environmental non-government 

organizations were not evaluated by AR4 authors according to the IPCC’s procedures. 

2.2.5 Summary 

The evidence provided by the petitioners does not support their allegations that the IPCC’s peer 

review and report development processes are designed inappropriately, or that they were 

inappropriately implemented in the development of the AR4. Specifically, the evidence 

provided by the petitioners and all of the information in the record for the Endangerment Finding 

shows that, contrary to the claims of the petitioners: 

 It was proper to not list certain scientists as contributing authors as they did not 

contribute significantly to the writing and editorial decisions in developing any AR4 

chapter, including Chapter 6 of Working Group I’s contribution (Jansen et al., 2007), and 

therefore did not compromise their objectivity during the peer-review process. 

 IPCC authors did not cite their own studies more frequently than what was acceptable 

and reasonable. 

 IPCC authors were not directed to focus on policy-prescriptive conclusions, but rather 

implemented IPCC guidelines by presenting policy-relevant and neutral findings. 

 IPCC authors did not alter the content of reports to eliminate suggestions of 

nonconsensus. 

 Collaborations among IPCC authors and reviewers prior to the development of AR4 did 

not compromise objectivity or generate conflicts of interest. 

 The IPCC’s peer-review processes are appropriate and adequate, and were properly 

implemented. 

 IPCC authors did not manipulate deadlines for receipt of new literature. 

73 
 The IPCC’s very limited use of gray literature does not call into question the quality and 

objectivity of the assessment reports. 

Petitioners do not present scientific evidence or argument showing that the Chapters of 

assessment report at issue are inaccurate or that they do not appropriately reflect the range of 

scientific evidence and the degree of scientific consensus on the scientific issues discussed. The 

evidence they present does not support the broad assertion that this is the case. They do not 

present credible scientific evidence or arguments on the science itself to support their claims. 

Therefore, petitioners’ evidence and arguments do not support changing our position, as stated in 

the Endangerment Finding, that the assessment literature, including the IPCC AR4, represents 

the “best reference materials for determining the general state of knowledge on the scientific and 

technical issues before the agency in making an endangerment decision.” 

74 
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. Accessed July 23, 2010. 
EPA’s Response to the Petitions to 

Reconsider the Endangerment and 

Cause or Contribute Findings for 

Greenhouse Gases under Section 

202(a) of the Clean Air Act 

Volume 3: Process Issues Raised 

by Petitioners 

U.S. Environmental Protection Agency 

Office of Atmospheric Programs 

Climate Change Division 

Washington, D.C.

1
TABLE OF CONTENTS 

Page

3.0 Process Issues Raised by Petitioners............................................................................................5 

3.1 Approaches and Processes Used to Develop the Scientific Support for the 

Findings............................................................................................................................5 

3.1.1 Overview..............................................................................................................5 

3.1.2 Issues Regarding Consideration of the CRU E-mails..........................................6 

3.1.3 Assessment of Issues Raised in Public Comments and Re-Raised in 

Petitions for Reconsideration...............................................................................7 

3.1.4 Summary............................................................................................................19 

3.2 Response to Claims That the Assessments by the USGCRP and NRC Are Not 

Separate and Independent Assessments.........................................................................20 

3.2.1 Overview............................................................................................................20 

3.2.2 EPA’s Response to Petitioners’ Arguments ......................................................21 

3.2.3 Summary............................................................................................................27 

3.3 Issues Concerning the Integrity of Peer-Reviewed Literature.......................................27 

3.3.1 Overview............................................................................................................27 

3.3.2 Allegations Regarding Reviews of Manuscripts................................................28 

3.3.3 Allegations Regarding Journal Publication Practices........................................35 

3.3.4 Allegations Regarding Efforts to Remove Editors and Boycott Journals..........48 

3.3.5 Allegations Regarding Objectivity of the Peer-Reviewed Literature................55 

3.3.6 Allegations of Intimidating Scientists and Those With Dissenting Views........66 

3.3.7 Summary............................................................................................................75 

3.4 Issues Concerning Freedom of Information Act Requests ............................................76 

3.4.1 Overview............................................................................................................76 

3.4.2 Allegations of Withholding Key Data and Information ....................................77 

3.4.3 Allegations of Improper Conduct With Regard to UK FOI and U.S. FOIA 

Laws...................................................................................................................93 

3.4.3.1 General Allegations...............................................................................93 

3.4.3.2 Specific FOI Request Regarding the IPCC’s Fourth Assessment 

Report...................................................................................................102 

3.4.3.3 Allegations of Improperly Influencing University FOIA Officials ......109 

3.4.4 Summary..........................................................................................................110 

References............................................................................................................................................112 

2
ACRONYMS 

AGU American Geophysical Union 

AIC Akaike information criterion 

ANPR Advance Notice of Proposed Rulemaking 

AOCGCM atmosphere-ocean coupled general circulation model 

APA Administrative Procedure Act 

AR autoregressive 

AR4 IPCC Fourth Assessment Report 

BIC Bayesian information criterion 

CAA Clean Air Act 

CCSP Climate Change Science Program 

CO2 carbon dioxide 

CR Climate Research 

CRCES Center for Research on the Changing Earth System 

CRU Climatic Research Unit 

DCPS07 Douglass, Christy, Pearson, and Singer, 2007 

E.O. Executive Order 

FCC Federal Communications Commission 

FOI Freedom of Information 

FOIA Freedom of Information Act 

GHG greenhouse gas 

GRL Geophysical Research Letters 

HadCRUT Climatic Research Unit temperature record 

ICO Information Commissioner’s Office 

IJC International Journal of Climatology 

IPCC Intergovernmental Panel on Climate Change 

IQA Information Quality Act 

NRC National Research Council 

LIA Little Ice Age 

MBH Mann, Bradley, and Hughes 

MIT Massachusetts Institute of Technology 

MM McIntyre and McKitrick 

NASA National Aeronautics and Space Administration 

NH Northern Hemisphere 

QSR Quaternary Science Reviews 

RCS regional curve standardized 

RMS Royal Meteorological Society 

RSC Royal Society of Chemistry 

RSS Royal Statistical Society 

RTC Response to Comments 

RTP Response to Petitions 

SAB Science Advisory Board 

TSD Technical Support Document 

UEA University of East Anglia 

UHI urban heat island 

3
USGCRP U.S. Global Change Research Program 

WMO World Meteorological Organization 

4
3.0 Process Issues Raised by Petitioners 

3.1 Approaches and Processes Used to Develop the Scientific Support for the 

Findings 

3.1.1 Overview 

Several petitioners (the Coalition for Responsible Regulation, the Commonwealth of Virginia, 

the Ohio Coal Association, Peabody Energy, the State of Texas, the Southeastern Legal 

Foundation, and Arthur Randol) take issue with the process and approach EPA used in 

developing the scientific support for the Endangerment Finding. Many of these arguments are a 

repetition of arguments submitted during the public comment period for the Proposed Findings. 

These include claims that EPA did not independently judge the underlying science, violated the 

Information Quality Act (IQA, also referred to as the Data Quality Act), violated the law by 

failing to post the underlying data and scientific studies in the docket, and did not convene a truly 

independent external peer review. 

The sole arguably new argument made by some petitioners (the Ohio Coal Association, the 

Pacific Legal Foundation, and Peabody Energy) is the claim that EPA ignored public concerns 

about the implications of the e-mails involving scientists at the Climatic Research Unit (CRU) at 

the University of East Anglia in the United Kingdom. The petitioners claim that statements 

made in the CRU e-mails cast doubt on the validity of underlying data relied on by EPA’s 

Endangerment Finding, and argue that EPA’s response to this issue is inadequate in the record 

for the Endangerment Finding. 

Based on our review, petitioners’ claims regarding the implications of the CRU e-mails are 

wrong. In late 2009, EPA carefully reviewed many of the e-mails and responded to the issues 

that were presented to us shortly before the Endangerment Finding was completed. Since that 

time, we have reviewed all of the e-mails in light of additional issues raised by petitioners. 

Based on this review, we reaffirm that petitioners’ claims and the information they submit do 

not change or undermine our understanding of how anthropogenic emissions of greenhouse gases 

cause climate change and how human-induced climate change generates risks and impacts to 

public health and welfare. The information provided by petitioners does not change any of the 

scientific conclusions that underlie the Administrator’s Findings, nor do the petitions lower the 

degrees of confidence associated with each of these major scientific conclusions. The science 

issues raised by petitioners, which we respond to in Volume 1 of this document, do not 

undermine the core understanding of climate change, which is based on multiple lines of 

evidence from independent sources. For example, petitioners allege that the surface temperature 

record produced by CRU is flawed, but our review indicates that the surface data is sound and 

that the surface temperature record trends are corroborated by satellite temperature records and 

the impacts we see on the ground, such as glacier retreat and lengthening of the growing season. 

With respect to the arguments already raised during the rulemaking leading to the Endangerment 

Finding, the petitioners do not provide any new information to bolster arguments previously 

submitted. For reasons elaborated below, we conclude that the responses provided in the 

Findings and the Response to Comments (RTC) document are still robust. 

5
In this section, we summarize and respond to the new argument being raised by the petitioners 

regarding EPA’s initial response to comments about the implications of the CRU e-mails. We 

then review the petitioners’ resubmitted arguments (originally addressed in Volume 1 of the 

RTC document) in light of any new evidence provided in the petitions for reconsideration. 

3.1.2 Issues Regarding Consideration of the CRU E-mails 

Comment (3-1):

A few petitioners (the Coalition for Responsible Regulation, the Ohio Coal Association, the 

Pacific Legal Foundation, and Peabody Energy) allege that EPA did not properly consider the 

implications of the CRU e-mails on the validity of the underlying data on which the Findings rest 

and that EPA did not provide an adequate response to the late comments that were raised 

concerning the e-mails. The Ohio Coal Association states that although allegations about 

problems with the CRU data had come to light prior to the Administrator signing the Findings, 

EPA did not consider the implications and instead “plowed ahead with compromised data, 

undermining its core conclusions in the process.” The Pacific Legal Foundation and Peabody 

Energy state that EPA could not have thoroughly examined the thousands of e-mails and 

documents released from CRU in the five-day period between the Competitive Enterprise 

Institute’s petition supplement and the signing of the Endangerment Finding. Peabody Energy 

concludes that EPA’s brief discussion of the CRU material in its RTC document “cannot 

substitute for the searching re-analysis of the Endangerment Finding that the CRU material 

demands.” The Pacific Legal Foundation states that “EPA has dismissed public concerns over 

the CRU e-mails and documents by its single, abbreviated response to a comment made by the 

Competitive Enterprise Institute.” The Pacific Legal Foundation argues that because the CRU emails and documentation were not available to be included in the record during the public 

comment period, neither the general public nor the EPA Science Advisory Board (SAB) have 

had the opportunity to comment on the new information therein. 

Response (3-1):

The petitioners identify several issues in the e-mails that they consider to be “smoking guns,” 

evidence of scientific misconduct, and fatal blows to the “theory of anthropogenic global 

warming.” Although petitioners claim that the e-mails introduce new information, they concern 

many of the same scientific issues on which the public commented during notice and comment 

for the proposed findings. Prior to finalizing the Endangerment Finding, EPA carefully reviewed 

many of the e-mails, and through this review, we determined that many of the issues raised 

therein had also been raised through the public comments and were responded to at the time (see, 

for example, Volume 2 of the RTC document). Based on that initial review, we concluded that 

the scientific conclusions of the assessment literature remained sound as to the state of the 

science on GHGs and climate change. We did not inappropriately “plow ahead,” as one 

petitioner claims. Rather, we assessed the issues raised by commenters and the CRU e-mails in 

light of our comprehensive review of climate science, and in light of all of the objections to the 

science that were raised by commenters, and concluded that our review of the science and the 

conclusions based on it were sound. As explained in more detail in the other volumes of this 

Response to Petitions (RTP) document, the petitioners make unfounded leaps regarding 

implication of the CRU e-mails to the overall state of climate change science. 

6
Following issuance of the Endangerment Finding, petitioners raised more specific concerns with 

respect to the CRU e-mails. EPA has reviewed all of the e-mails in light of the petitioners’ 

assertions, and our substantive responses on the science are provided in the Decision and the 

three volumes of the RTP document. On the basis of our analysis of the scientific issues raised, 

and our thorough review of the contents of the e-mails, we disagree with the petitioners’ 

contention that additional “searching reanalysis” of the Endangerment Finding is required. Our 

examination of the CRU e-mails in light of the current science shows that the petitioners 

routinely misunderstand or mischaracterize the scientific issues they are raising, and draw faulty 

conclusions on the state of the science. We show throughout this RTP document multiple 

examples where petitioners have resorted to hyperbole, broadly impugned the ethics and 

scientific integrity of climate scientists in general, and characterized actions as “falsification” 

and “manipulation” with no basis or support. As we reviewed the many footnotes in their 

documents, we found an inordinate reliance on blogs, news stories, and literature that is neither 

peer-reviewed nor accurately summarized in their petitions. 

Nothing has been presented that challenges the current understanding of climate change science 

and the causal linkage between human-caused GHG emissions and warming of the climate 

system. Indeed, EPA finds that petitioners most often rely on “cherry-picked” language from 

select e-mails that creates the suggestion or appearance of impropriety, without looking deeper 

into the issues or providing corroborating evidence that improper action actually occurred. 

Throughout the three volumes of this document, we have provided detailed and specific 

responses to petitioners’ assertions based on the CRU e-mails.

3.1.3 Assessment of Issues Raised in Public Comments and Re-Raised in Petitions for 

Reconsideration 

The Administrator Exercised Her Judgment in Reviewing the Science and Making the Findings 

Comment (3-2):

Several petitioners (the Coalition for Responsible Regulation, the Commonwealth of Virginia, 

the Ohio Coal Association, Peabody Energy, the State of Texas, the Southeastern Legal 

Foundation, and Arthur Randol) argue that the Administrator did not independently judge the 

primary scientific literature and data. Instead, they claim that she improperly relied on summary 

scientific reports produced by third parties or “foreign entities.” They argue this is a violation of 

Clean Air Act (CAA) Section 202(a)’s requirement that the Administrator exercise her own 

expert judgment. EPA responded to similar arguments during notice and comment on the 

Findings. More recently, petitioners re-raise this argument in light of new information that they 

claim calls into greater question EPA’s reliance on the assessment literature. For example, the 

Southeastern Legal Foundation argues that “the Administrator cannot possibly exercise the form 

of ‘judgment’ required by the Clean Air Act based on data or procedures from other agencies that 

are potentially faulty, manipulated, contrived, or otherwise subject to the kinds of irregularities 

that have been alleged with respect to current climate information.” The Coalition for 

Responsible Regulation and the Commonwealth of Virginia argue that in relying on the 

assessment reports of the IPCC, EPA ceded or sub-delegated its responsibility for independent 

judgment to the IPCC, which the petitioners characterize as “an international body not subject to 

7
U.S. data quality and transparency standards and whose reports were prepared in total disregard 

to those standards,” and whose processes are politically motivated and advance “policy 

objectives masquerading as science.” 

Several petitioners (the Coalition for Responsible Regulation, the State of Texas, Arthur Randol, 

the Pacific Legal Foundation, and Peabody Energy) make the related argument that EPA violated 

the IQA and Administrative Procedure Act (APA) because it “did not independently investigate 

and confirm the quality and transparency of the information cited in the ‘assessment literature,’ 

relying instead on its review of the written procedures of the organizations preparing that 

literature to conclude that those organizations had ensured quality and transparency.” Finally, 

the Coalition for Responsible Regulation and Peabody Energy argue that EPA cannot rely on the 

IPCC because the CRU e-mails demonstrate that influential IPCC scientists failed to meet EPA’s 

data quality and transparency obligations under the IQA. 

Response (3-2):

As noted previously, we find that these issues raised by petitioners are not new, and were, in fact, 

raised and responded to through the notice and comment process. Thus, objections based on 

EPA’s general reliance on assessment reports, rather than EPA’s undertaking a separate 

assessment itself, were not impracticable to raise during the public comment period and the 

reasons for the objection did not arise between June 24, 2009, and February 16, 2010. 

To the extent petitioners argue that new information in the CRU e-mails calls into question the 

reasoning behind EPA’s position on the use of assessment reports in the final Findings, the 

petitioners do not demonstrate that additional information has become available that merits 

reconsideration of the Findings, or EPA’s use of the assessment literature. Nonetheless, we have 

carefully reviewed the new concerns raised regarding the implications of the CRU e-mails. 

Here, we focus specifically on the issue of whether information in the CRU e-mails requires us 

to undertake additional procedural steps with respect to the Endangerment Finding. Our 

response to each of the issues raised by petitioners follows. Note that we respond to petitioners’ 

allegations on substantive science issues elsewhere in this RTP document. 

 

With respect to the petitioners’ claims that EPA should have conducted its own independent 

assessment of the primary scientific literature and not relied on scientific reports produced by 

third parties or “foreign entities,” we note that the Administrator provided a detailed discussion 

of her position in Section III.A of the Findings (see “The Science on Which the Decisions Are 

Based”). In other sections of this RTP document, we have already explained why the CRU 

e-mails and the nature and number of reported errors in the IPCC report, as well as arguments or 

objections over the scientific conclusions EPA reached in the Findings, do not lead EPA to 

change its scientific conclusions and do not necessitate the reconsideration of the Findings. We 

find that the issues raised by petitioners do not lead us to change our decision regarding our 

approach and do not demonstrate that an additional or separate review is either required or 

appropriate. 

For the same reasons, these claims do not warrant revisiting EPA’s approach to analyzing that 

science. We note that the IPCC reports are a primary but not the only source of scientific 

information underlying the Findings. As is clearly stated in the Findings, the Administrator 

8
relied on numerous other assessment reports prepared by the U.S. Global Change Research 

Program (USGCRP), the National Research Council (NRC), and others. In addition, the 

Administrator tested her approach and proposed conclusions by subjecting them to notice and 

comment, and in reaching final conclusions drew on the wealth of information submitted through 

public comments to inform her decision. Many commenters provided additional scientific 

literature, which we carefully reviewed, considered, and responded to. A cursory examination of 

the detailed discussions in the multi-volume RTC document demonstrates the care and rigor with 

which EPA approached the underlying science. Therefore, we reject Peabody Energy’s 

allegation that EPA “used a rulemaking process that effectively permits no replies and no 

rebuttals” to the science that formed the technical basis for the Findings. In addition, in May 

2010 the NRC issued another major climate change assessment report that further solidifies the 

science supporting the Administrator’s decision and supports that decision. This recent NRC 

report is discussed further in the Denial and Volume 1 of the RTP document. 

In responding to petitioners’ objections that the Administrator failed to exercise her own 

judgment in reaching the Endangerment Finding, we note that this issue is not new and 

petitioners have not raised new arguments calling into question the process for the Endangerment 

Finding. Nonetheless, it is useful to describe the process EPA followed in compiling and 

analyzing the science to support the Administrator’s Endangerment Finding. Contrary to 

petitioners’ assertions, EPA did not passively accept a scientific judgment or conclusion supplied 

to it by outsiders. Instead, EPA evaluated all of the scientific information before it, and 

determined from this information the current state of the science on climate change and the 

degree of scientific consensus on this science. The Administrator then considered this 

information in light of the legal criteria for determining endangerment. This process included 

EPA presenting its scientific views and judgments for public comment and then evaluating and 

considering all such comments received. The Administrator properly and carefully exercised her 

judgment in all matters related to the Endangerment Finding. 

The following is an outline of the actions taken that evidence EPA’s comprehensive and in-depth 

exercise of judgment: 

1. EPA has a strong scientific background and understanding in global climate change 

science. EPA scientists have worked for years in this area, and many EPA scientists have 

been part of the development of the Intergovernmental Panel on Climate Change (IPCC) 

and USGCRP assessment reports. EPA has strong in-house science expertise in this area, 

while recognizing that no one organization will have experts or expertise in all of the 

variety of areas involved. However, EPA has a solid grounding in the core areas of 

science involved in climate change. Many EPA scientists were part of the development 

of the various assessment reports. 

2. EPA’s goal was to evaluate the current state of the science for all of the relevant areas at 

issue for the Endangerment Finding, and to evaluate the degree of scientific consensus in 

these areas. EPA performed a detailed review of all elements of the various assessment 

reports as part of evaluating this. 

3. EPA evaluated the assessment reports and their conclusions in several ways: 

9
o EPA reviewed the process employed to develop the reports, relying in part on its own 

experience and involvement in various parts of the process for the IPCC and 

USGCRP reports. EPA concluded that the lengthy, comprehensive process was very 

robust, with checks and steps included to produce high-quality, unbiased reports. 

o EPA reviewed the content of the reports in light of its in-house science expertise. 

EPA found the reports’ contents to be comprehensive, balanced, carefully caveated 

with respect to certainty, clearly identifying supporting as well as non-supporting 

evidence, with conclusions drawn based on the entire body of the evidence, not just 

one part of it. 

o EPA took into consideration the depth of scientific consensus the reports represented. 

They reflect a very strong consensus of the scientific community across the world. 

EPA has never claimed that there is unanimity on all aspects of the science, but there 

is a very broad scientific consensus on the multiple lines of evidence on which the 

Findings are based (as described in Section III.B of the Denial). This consensus 

includes concurrence and clearance within the U.S. government science community, 

on many of the major assessment reports. 

o EPA took into consideration the trends in the science. Over the last 30-plus years, as 

we study more, learn more, and advance our understanding, the general trend is 

toward more certainty that warming is occurring, that it is caused by anthropogenic 

emissions, and that we are currently on a path to future increases in warming. 

4. After conducting this review of the state of the science, EPA reached an initial conclusion 

that the assessment reports provide a reliable and credible assessment of the current state 

of the science, reflecting the many areas of consensus across the science community, and 

also documenting those areas that are less settled and where uncertainty remains. 

5. EPA then provided an opportunity for public comment on EPA’s initial conclusions and 

judgments on the science and the question of endangerment, with a detailed explanation 

of the basis for these conclusions and judgments. The public and all of the petitioners 

had the opportunity to present their views, agreeing or disagreeing, and why. EPA did 

this twice—on the Advance Notice of Proposed Rulemaking (ANPR) and on the 

Proposed Findings. 

This public process was designed to provide a full opportunity to test EPA’s initial 

conclusions and judgments and allow anyone to present scientific evidence or argument 

showing that EPA’s judgments on the science were inaccurate. 

6. EPA carefully reviewed all of the comments submitted on the science and its judgments. 

o In general, people who opposed EPA’s initial conclusion presented evidence and 

argument on one side or one part of an issue, discussing a limited number of old or 

10
o EPA reviewed the studies, arguments, and evidence presented by commenters, 

assessed them in light of the entire body of evidence, and responded to the comments. 

These responses can be found in the Findings and the 11 volumes of the RTC 

document. 

o Commenters who opposed EPA’s initial conclusion on the science did not provide a 

comprehensive peer-reviewed alternative assessment of the science showing how the 

body of evidence as a whole supports their conclusion and does not support EPA’s 

initial conclusion. We note that some commenters (who are also petitioners) 

submitted a non-peer reviewed assessment report by the Nongovernmental 

International Panel on Climate Change during notice and comment and recommended 

it as an alternative to the assessment reports prepared by the IPCC, USGCRP, and 

NRC. Response 1-12 in Volume 1 of the RTC document explains that we reviewed 

the process for preparing this report, as well as its content, and found that it lacked the 

depth, breadth, and rigor of the assessment reports on which the Findings rely. 

7. After reviewing and considering all of the comments and arguments, EPA reached final 

conclusions on the state of the science. EPA generally confirmed its initial view, while 

making a variety of changes and modifications in various places of the TSD where it was 

warranted. 

8. The Administrator carefully evaluated the scope of her legal discretion under section 

202(a) in making a decision on endangerment, after providing notice of her initial legal 

views and receiving comments on that initial view. 

9. In making the decision on endangerment, the Administrator exercised her own judgment 

by applying the science to the legal framework provided in section 202(a). 

The core of petitioners’ objection is that they do not agree with important parts of the scientific 

information on which the Endangerment Finding is based. They frame this as a failure of EPA 

or the Administrator to exercise independent judgment, or as EPA ceding to an outside body its 

responsibility to exercise independent judgment. The above makes it clear that neither EPA nor 

the Administrator did such a thing. EPA exercised its own judgment when reviewing the 

assessment reports, and did not cede or sub-delegate its authority or judgment to anyone. The 

petitioners disagree with the information EPA relied on and the conclusions EPA drew, and EPA 

addresses those objections throughout this document and the record for the Endangerment 

Finding. However, a disagreement over whether a source of information is useful or credible is 

not evidence of a lack of exercise of discretion or judgment. 

There has been considerable criticism of EPA’s use of the IPCC as a source for the TSD (U.S. 

EPA, 2009a), with some petitioners going so far as to refer to it as “an overt scientific 

organization with a covert political agenda of making the science conform to the desired result.” 

A high level of vitriol has been directed at the IPCC, and gross misstatements have been made 

11
regarding the quality and integrity of their processes and reports. We strongly disagree with 

these mischaracterizations. The Findings, Volume 1 of the RTC document, and Volume 2 of the 

RTP document rebut petitioners’ allegations that the IPCC is a political, not scientific, 

organization and that it does not adhere to U.S. standards of transparency and data quality. 

We respond to petitioners’ argument regarding the existence of errors in the IPCC Fourth 

Assessment Report (AR4) in Volume 2, Section 2.1, of this document and find that the errors are 

minimal, mischaracterized and inconsequential to the Findings. We respond to petitioners’ 

arguments that the IPCC is a biased organization that advances a policy agenda in Volume 2, 

Section 2.2 of this RTP document, and we find that petitioners provide no evidence to support 

their claims that IPCC authors supported or promoted a unified policy agenda. Throughout 

Volume 1 of this RTP document, we also respond to petitioners’ scientific arguments that the 

IPCC and other assessment reports presented the body of science in a biased or incomplete 

manner or reached inappropriate scientific conclusions. On issue after issue, we review the 

scientific evidence provided by petitioners and find that they misunderstand or mischaracterize 

the issues and the evidence. 

The petitioners’ arguments that the Agency violated the IQA and APA are also not new, and 

EPA provided a detailed response in Volume 1 of the RTC document. Several commenters 

previously raised specific scientific concerns, which they claimed demonstrated that EPA 

violated the IQA and APA. These were addressed in both Volume 1 and the accompanying 

scientific volumes of the RTC. The petitioners now make essentially the same general argument 

that EPA’s use of third-party assessment reports violates the IQA and APA. As noted in Volume 

1 of the RTC, the IQA requires that an agency issue guidelines regarding data quality and ensure 

their implementation. EPA complied with the IQA by issuing its Guidelines for Ensuring and 

Maximizing the Quality, Objectivity, Utility and Integrity of Information Disseminated by the 

Environmental Protection Agency (U.S. EPA, 2002) and has acted consistently with these 

guidelines in developing the Findings. As stated in Volume 1 of the RTC, EPA’s use of the 

assessment literature as a basis for the Endangerment Finding “is consistent with these guidelines 

because we thoroughly reviewed and evaluated the author selection, report preparation, expert 

review, public review, information quality, and approval procedures of IPCC, USGCRP/CCSP, 

and NRC to ensure the information adhered to a basic standard of quality, including objectivity, 

utility, and integrity.” The CRU e-mails do not undermine this view. Our detailed responses on 

the science issues raised by petitioners concerning these e-mails are provided in several other 

sections of this RTP document, and show that petitioners’ science claims do not support the view 

that the IPCC or other assessment reports were biased, inaccurate, or scientifically incorrect. 

Likewise, the few scientific or technical errors identified by petitioners in the IPCC report, such 

as the amount of land in the Netherlands that is below sea level, are all minor errors that are 

irrelevant in the context of EPA’s Endangerment Finding. See Volume 2 of this RTP document 

for more detail regarding our response to this specific issue. Given the vast number of factual 

and scientific issues addressed by these comprehensive assessment reports, the existence of only 

a very limited number of these kinds of errors does not show a failure to employ and implement 

a high degree of control on the scientific quality of the report. 

Comment (3-3): 

12
In support of its argument to Comment 3-2, the Southeastern Legal Foundation provides the 

announcement that the InterAcademy Council would conduct an independent review of the IPCC 

and its assessment report development process. The petitioner argues that “the IPCC itself is 

reconsidering its own work,” and claims that this investigation “impeach[es] the reporting” of the 

IPCC and undermines the science used in developing the Endangerment Finding. 

Response (3-3): 

On February 27, 2010, the IPCC announced that the InterAcademy Council is conducting an 

independent review of the policies and procedures of the IPCC (IPCC, 2010). Upon completion, 

the InterAcademy Council will issue a report with recommended measures and actions to 

strengthen the IPCC’s processes and procedures to better respond to future challenges and ensure 

the ongoing quality of its reports (InterAcademy Council, 2010). The IPCC’s (2010) 

announcement stated that: 

The IPCC strives to ensure that its procedures for use of published material in the 

preparation of its assessment reports are followed in all respects. But we recognize the 

criticism that has been leveled at us and the need to respond. While embarking on the 

preparation of its Fifth Assessment Report it was the intention of the IPCC that an 

independent committee of distinguished experts evaluate means by which IPCC 

procedures must be implemented fully and that they should also examine any changes in 

procedure that may be required. 

The petitioner improperly assumes that the IPCC is discredited because it has announced an 

evaluation of its report development process. In fact, the IPCC’s announcement also stated that: 

We stand firmly behind the rigour and robustness of the 4th Assessment Report’s 

conclusions, and are encouraged by the support demonstrated recently by scientists and 

governments around the world. The 4th Assessment Report’s key conclusions are based 

on an overwhelming body of evidence from thousands of peer-reviewed and independent 

scientific studies. Most significantly, they rest on multiple lines of analysis and datasets. 

The evidence provided by the petitioner does not show that the InterAcademy Council’s review 

was initiated based on a presumption of wrongdoing. EPA’s review of available information 

clearly reveals that the petitioner is wrong to assert that the IPCC is “reconsidering” its 

conclusions. We have addressed the specific scientific arguments raised by the petitions in the 

RTP document and find that the scientific evidence supporting the Endangerment Finding 

remains strong. Thus, as stated in the Findings, these reports continue to “represent the best 

reference materials for determining the general state of knowledge on the scientific and technical 

issues before the agency in making an endangerment decision,” and the petitioner has not 

provided evidence to suggest that EPA’s judgment was anything less than credible, objective, 

and robust. 

Comment (3-4): 

As evidence to support its argument that EPA delegated its duty and instead relied on the flawed 

IPCC assessment reports, the State of Texas states that “Dr. William Sprigg, who oversaw the 

IPCC’s first assessment report, recently commented at a climate change conference: ‘The IPCC 

is biased, conflicted, [and] pushing political agendas. We need to stick to our scientific 

13
principles. We need to improve our peer review process, and expand the stakeholders’ role to 

keep us all honest.’” 

Response (3-4): 

See Response 3-2 for our conclusion that we did not delegate our duty and that the petitioners are 

incorrect in alleging that the Administrator failed to exercise her own judgment in reaching the 

Endangerment Finding. 

In response to this specific evidence, the petitioner mischaracterizes who William Sprigg is and 

what his role was in the IPCC. The petitioner claims that Sprigg oversaw development of the 

IPCC’s First Assessment Report. However, after reviewing the reports of these Working 

Groups, there is no indication that Sprigg was involved in overseeing the development of any 

part of the entire report. The following people oversaw the development of the report: John 

Houghton, Chair of Working Group I; Yuri A. Izrael, Chair of Working Group II; and Frederick 

Bernthal, Chair of Working Group III. Sprigg is only mentioned as having been a contributing 

author on Chapter 6 (“World Oceans and Coastal Zones”) of the Working Group II report on 

impacts for the First Assessment, which was released in 1990. Clearly the petitioner did not take 

the time to determine Sprigg’s actual role in developing the IPCC’s First Assessment Report, and 

significantly overstated his involvement. 

 

Although the petitioner did not provide a transcript of Sprigg’s statement or a citation for it, the 

evidence provided indicates merely that Sprigg does not approve of the IPCC’s report 

development process. The petitioner provides this conclusion but provides no details about the 

basis for Sprigg’s concerns, nor any evidence to support them. Throughout this document and 

the overall record, we have responded to both general and specific comments and find that 

Sprigg’s comments do not provide any new information or evidence. The conclusory, 

unsupported statements of one former IPCC author, who has not been involved with the 

organization for almost two decades, do not provide evidence that the IPCC does not develop 

objective, sound, and unbiased assessments of climate change science. 

EPA Provided Sufficient Opportunities for Public Comment 

Comment (3-5): 

Peabody Energy describes that “a number of commenters sought an extension of the 60-day 

comment period for the Endangerment Finding, complaining that 60 days was insufficient to 

review and comment on the complex climatological and policy issues raised in the proposed 

finding.” The petitioner goes on to argue that in the Technical Support Document (TSD), “EPA 

elected to rely on secondary sources for which it has had no real scientific testing of any kind. It 

has used a rulemaking process that effectively permits no replies and no rebuttals.” Peabody 

Energy argues that “EPA’s use of the public comment periods in the processes that led to 

development of the ‘assessment literature’ as justification for the short comment period here [of 

the proposed findings] is further evidence of EPA’s near total reliance on that literature.”

Response (3-5): 

EPA received several requests to extend the 60-day public comment period for the Proposed 

Findings. The main justification for these requests was that the record for this rulemaking, 

14
which was made up of the assessment literature that EPA relied on in developing the TSD, was 

extensive and that additional time was needed to fully review all of the materials. In its denial of 

these requests, EPA noted, among other things, that a large majority of the underlying 

information and analysis supporting the Proposed Findings, and EPA’s intension of using this 

information, had been in the public domain for almost one year prior to publishing the Proposed 

Findings. This was because a very large part of the underlying information and analysis for the 

Proposed Findings were previously released for a public comment period of 120 days on July 11, 

2008, as part of the Advance Notice of Proposed Rulemaking: Regulating Greenhouse Gas 

Emissions under the Clean Air Act (73 FR 44353). EPA also noted that the major recent 

scientific assessments on which the Agency relied all had their own public review processes, and 

had been publicly available for some time. Under these circumstances, EPA determined that the 

60-day comment period provided adequate opportunity for the public to review and comment on 

the Proposed Findings. We maintain that the 60-day comment period was reasonable and we 

note that the petitioner is not asking that EPA reconsider the Findings based on the length of the 

comment period. 

Instead, Peabody Energy alleges that EPA’s justification for the length of the comment period on 

the Proposed Findings “is further evidence of EPA’s total reliance on that literature,” and that the 

Agency “did not independently judge the science and instead relied primarily on summary 

scientific reports produced by third parties.” The fact that EPA acknowledged the prior 

opportunity for public comment on the assessment reports does not evidence that EPA did not 

exercise independent scientific judgment. Rather, the evidence shows, as clearly stated in the 

proposed and final Findings, that EPA reviewed the major assessments of the USGCRP, the 

IPCC, and the NRC as the primary scientific and technical basis for the Administrator’s 

endangerment decision. As described in Response 3-2, EPA and the Administrator properly and 

carefully exercised our own judgment in all matters related to the Endangerment Finding. 

Finally, we note that was not impracticable to raise the objection during the public comment 

period and the reasons for the objection did not arise between June 24, 2009, and February 16, 

2010. In making their argument, the petitioners have provided no new evidence and have not 

shown why it would have been impracticable for them to raise this issue during the public 

comment period, especially given the fact that the public has been aware that EPA relied, in part, 

on the IPCC assessments since the July 2008 ANPR. 

EPA Complied With the Information Quality Act 

Comment (3-6):

The Coalition for Responsible Regulation, the State of Texas, and Peabody Energy allege that 

EPA violated the IQA and APA by failing to make underlying data and studies relied on by the 

assessment literature available for public review by placing them in the docket. Peabody Energy 

concludes that EPA’s approach to the science meant “there could be no genuine interchange 

between an open-minded EPA and the public on what EPA’s scientific judgment should be 

because the Agency did not intend to exercise any such judgment.” 

Response (3-6):

15
First, we note that the petitioners are re-raising this issue in the petitions for reconsideration 

because they believe that the CRU e-mails show that “IPCC authors deleted information and hid 

behind foreign laws to avoid disclosure of key data” (from petition of the Coalition for 

Responsible Regulation). EPA responds to allegations involving the behavior of CRU scientists, 

including the allegation that data were destroyed, in Volume 1 and also in Sections 3.3 and 3.4 of 

this Volume of the RTP document. As stated in these sections, the evidence submitted by the 

petitioners in the form of the CRU e-mails does not support their allegation that data were 

destroyed. Therefore, the “new” information presented by the petitioners does not call into 

question the overall integrity of the science, nor does it call into question the process EPA used 

in developing the Findings. 

As noted in Volume 1 of the RTC document, EPA is required to docket the information on which 

it relies, and, as explained in Section III.A of the Findings and in Volume 1 of the RTC 

document, the Administrator reasonably relied on the major assessments of the USGCRP, the 

IPCC, and the NRC as the primary scientific and technical basis of her endangerment decision.1

 

Where EPA used or described any data in the TSD, the source of the data is listed, including 

where it can be accessed and downloaded. Further, each report, study, or dataset we relied on 

was clearly identified in the TSD bibliography and was placed in the docket. Information 

regarding the underlying data, models, and studies used by the IPCC, the USGCRP, the U.S. 

Climate Change Science Program (CCSP), and the NRC in developing their assessment reports 

can be accessed by consulting these reports. EPA also made available all studies and other 

information submitted by commenters. Given that some of these reports relied on thousands of 

underlying studies, docketing every underlying study and the data that were used in their 

development would be unreasonable and unnecessary, and it is not required by the IQA or any 

other law. 

Cases cited by the petitioner do not indicate otherwise. In American Relay Radio League, Inc. v. 

FCC, 524 F.3d 227 (D.C. Cir. 2008), the D.C. Circuit held that the Federal Communications 

Commission (FCC) did not provide appropriate notice and comment when it redacted FCC staffproduced data integral to the basis for the rule. That is not the case for the Findings. EPA has 

provided and made available all studies relied on by the agency. American Relay Radio League

also indicates that failure to provide data must be “prejudicial” to the commenter (American 

Relay Radio League, 524 F.3d at 237-238). Petitioners have had multiple opportunities to 

engage in this process, and the Agency has fully addressed this issue throughout. The D.C. 

Circuit itself noted the “narrowness” of its holding in American Relay Radio League, indicating 

that agencies are free to choose which studies they credit, as long as the Agency itself does not 

“redact parts of those studies” necessary to support the Agency’s conclusion. EPA has provided 

and made available for comment all studies relied on for its final conclusion.2

 

 

1

 See, for example, American Trucking Ass’n v. EPA, 293 F.3d 355, 372 (D.C. Cir. 2002). (EPA is not required to 

obtain and publicize the data underlying all the studies on which it relies.); Coalition of Battery Recyclers Assn. v. 

EPA, 604 F.3d 613, 622-24 (D.C. Cir. 2010) (same). 2

 Petitioners cite a case, Solite Corp. v. EPA, 952 F.2d 473 (D.C. Cir. 1991), where the court rejected a claim that 

EPA did not appropriately disclose data. In fact, this case holds that courts will only strike down agency action 

based on lack of disclosure of data when the agency hides or disguises “the information it used, or otherwise 

conducted the rulemaking in bad faith” (Solite Corp., 952 F.2d at 484). That is certainly not the case here. 

16
The public was able to review all documents used by EPA in developing the TSD, including 

copyrighted material, by requesting a copy or visiting EPA’s Air Docket. There was a full 

opportunity to review and comment on every piece of data relied on by EPA. 

EPA’s Review Process for the TSD Was Appropriate 

Comment (3-7):

Several petitioners (the Coalition for Responsible Regulation, the Pacific Legal Foundation, and 

Peabody Energy) make the overarching argument that EPA’s TSD did not go through a truly 

independent peer-review process. The petitioners argue that past EPA peer review of the science 

is now insufficient in light of new information in the CRU e-mails, and that the SAB must be 

given an opportunity to conduct an independent review of the Findings. They argue that the 

“SAB has not been able to perform its statutory function as an independent scientific review 

panel.” More specifically, one petitioner states that review by the SAB is required under 42 

U.S.C. § 4365(c)(1), because the substantial uncertainty surrounding EPA’s scientific 

determination warrants reopening of the comment period. The Pacific Legal Foundation states 

that Section 4365(c) requires EPA to submit relevant technical information and data to the SAB 

for their review whenever the public comment period is open. 

Response (3-7):

The general issue raised by petitioners regarding review of the TSD is not new and, in fact, was 

raised and responded to through the public comment process (see Volume 1 of the RTC 

document). Thus, it was not impracticable to raise the objection during the public comment 

period and the reasons for the objection did not arise between June 24, 2009, and February 16, 

2010. To the extent petitioners argue that new information in the CRU e-mails calls into 

question the reasoning behind EPA’s position on this issue in the final Findings, the petitioners 

do not demonstrate that additional information has become available that merits reconsideration 

of the Findings. We have carefully reviewed the issue raised regarding the implications of the 

CRU e-mails, and considered whether information in the CRU e-mails calls for EPA to 

reconsider the procedural steps with respect to the scientific and technical information used as 

basis for the endangerment determination. We find nothing in the CRU e-mails that relates to 

EPA’s decision regarding peer review of the TSD. Also, and as explained in detail elsewhere in 

this document and the Denial, the e-mails and other “new” information provided by petitioners 

do not call into question the underlying science of climate change, nor the validity of the 

assessment reports. 

As stated in Volume 1 of the RTC document, the purpose of the federal expert review was to 

ensure that the TSD accurately summarized the conclusions and associated uncertainties from the 

assessment reports. This is reasonable given our approach to the scientific literature (described 

in Section III.A of the Findings and Volume 1 of the RTC document). We also note that the 

federal expert review was only one part of a much larger process of developing the TSD from 

2007 until the present. In addition to the three rounds of technical review by the 12 federal 

experts, the TSD has also gone through two rounds of public comment. The scope and depth of 

the record on the Endangerment Finding—including an 11-volume RTC document responding to 

comments on all aspects of the science, law, and procedure—demonstrate both the volume of 

information the Administrator considered in developing the Findings and the seriousness with 

17
which the task of assessing the science was approached. Based on this, EPA rejects the Pacific 

Legal Foundation’s allegation that the peer-review process EPA employed was insufficient in 

light of new information in the CRU e-mails. See other sections of this RTP document for our 

response to petitioner arguments regarding the implications of the CRU e-mails. 

The petitioner’s argument regarding the SAB is somewhat unclear. To the extent the petitioner 

is claiming that EPA was required to submit the proposed Endangerment Finding to the SAB 

when it was proposed, the petitioner clearly could have raised this objection during the comment 

period, and thus this objection is not a basis for reconsideration of the Endangerment Finding. 

To the extent that the petitioner is claiming that EPA is required to submit the Endangerment 

Finding to the SAB for review at this time, because the various other grounds raised in the 

petitions to reconsider warrant reopening of the public comment period, EPA interprets this as a 

claim that SAB review will be required under this provision if EPA grants the petition to 

reconsider and reopens the comment period. For all of the reasons discussed elsewhere in the 

Decision and the RTP document, EPA is not granting the petitions to reconsider and is not 

reopening the comment period. Thus, there is no reopening of the comment period to trigger the 

SAB review claimed by the petitioner. 

In addition, this statutory provision did not require EPA to submit the proposed Endangerment 

Finding to SAB for review. Under its terms, the provision calls for EPA to make a “proposed 

criteria document, standard, limitation, or regulation” available to the SAB for review. The 

proposed Endangerment Finding is not a criteria document, standard, limitation, or regulation, 

and is thus not in the scope of this provision. In addition, the requirement to submit the proposed 

document to the SAB applies when “any proposed criteria document, standard, limitation, or 

regulation ... is provided to any other Federal agency for formal review and comment.” It is not 

clear whether this includes the kind of informal interagency review conducted pursuant to 

Executive Order (E.O.) 12866, as compared to the more formal agency review envisioned in 

statutory provisions such as 49 U.S.C. 32902(j). 

Finally, the objection does not provide substantial support for the argument that the 

Endangerment Finding should be revised. In the Endangerment Finding the Administrator 

determined that the body of scientific evidence compellingly supports a positive endangerment 

finding. The major assessments by the USGCRP, the IPCC, and the NRC (published before 

2010) served as the primary scientific basis supporting the Administrator’s Endangerment 

Finding. The objections raised by the various petitioners have not changed EPA’s view of the 

science. In May 2010, the NRC of the U.S. National Academies published its comprehensive 

assessment, “Advancing the Science of Climate Change.” It concluded that “climate change is 

occurring, is caused largely by human activities, and poses significant risks for—and in many 

cases is already affecting—a broad range of human and natural systems.” Furthermore, the NRC 

stated that this conclusion is based on findings that are “consistent with the conclusions of recent 

assessments by the U.S. Global Change Research Program, the Intergovernmental Panel on 

Climate Change’s Fourth Assessment Report, and other assessments of the state of scientific 

knowledge on climate change.” These are the same assessments that served as the primary 

scientific references underlying the Administrator’s Endangerment Finding. Importantly, this 

recent NRC assessment represents another independent and critical scientific inquiry into the 

state of climate change science, separate and apart from the previous IPCC and USGCRP 

18
assessments. The NRC assessment is a clear affirmation that the scientific underpinnings of the 

Administrator’s Endangerment Finding are robust, credible, and appropriately characterized by 

EPA. Petitioners provide no basis to suggest that lack of review by the SAB undermines this 

scientific basis in any way. 

EPA Did Consider Positive Impacts of Elevated Carbon Dioxide Concentrations

Comment (3-8): 

Peabody Energy argues that “EPA fails to come to grips with the fact that CO2 [carbon dioxide] 

is a benign, naturally-occurring gas that is necessary for life on earth” and that the 

Administrator’s finding of endangerment to public health fails to recognize this fact. The 

petitioner goes on to describe that in making the endangerment determination, EPA did not 

account for the “wide variety of positive impacts for plant life, including agricultural crops.” 

Finally, referring to the IPCC reports, the petitioner argues that “EPA’s attempt to transform the 

benign naturally-occurring substance into a danger air pollutant is based on evidence it should 

never have used in the first place.” 

Response (3-8): 

First, we note that the issue raised by petitioner is not at all new and was raised and responded to 

at length through the public comment process after the Proposed Findings and very directly 

within the Endangerment Finding itself (see Sections I and IV of the Findings and Volume 1, 

Section 4, of the RTC document). Second, the petitioner is simply incorrect in claiming that 

EPA did not account for some of the beneficial effects of CO2, such as the fertilization effect on 

agricultural crops; these issues have been addressed at length by EPA in the RTC document and 

in the Findings. Thus, it was not impracticable to raise the objection during the public comment 

period and the reasons for the objection did not arise between June 24, 2009, and February 16, 

2010. 

To the extent petitioners argue that new information in the CRU e-mails calls into question the 

reasoning behind EPA’s position on this issue in the final Findings, the petitioners do not 

demonstrate that additional information has become available that merits reconsideration of the 

Findings. Based on our review of the CRU e-mails, we find that they do not contain information 

that should cause us to question the conclusions of the assessment literature as to the state of the 

science on GHGs, climate change, and the associated risks and impacts to public health and 

welfare. In the context of the allegation by Peabody Energy, the CRU e-mails also do not cause 

us to reconsider our consideration of net (adverse and beneficial) effects. We note that the 

petitioner did not provide any new information (e.g., peer-reviewed, published scientific studies) 

to support their argument regarding the CO2 fertilization issue. Rather, the petitioner refers to 

the comments they submitted on the Proposed Findings, which, as stated above, we have already 

responded to at length in the RTC document. 

3.1.4 Summary 

After reviewing the petitioners’ arguments, EPA finds that many of them are based on a either a 

mischaracterization of or a fundamental disagreement with our approach to the scientific 

literature in developing the TSD for the final Findings, or the Administrator’s consideration of 

19
that science in her Findings. Almost all of their arguments are not new, and we responded to 

them in the Findings and RTC document. None of the petitioners’ arguments regarding the 

approaches and processes EPA used to develop the scientific support for the Findings justifies 

reconsideration. 

EPA reasonably chose to rely on the existing assessment reports of the USGCRP, the IPCC, and 

the NRC as the primary sources for determining the current state of the science relating to 

climate change, and for determining the degree of scientific consensus on these issues, based on: 

1) the goals of these reports to provide such information, in the context of the broad scope and 

complexity of the climate science that would be considered in an Endangerment Finding; 

2) EPA’s review of the rigorous and transparent procedures for development of the various 

assessment reports; 3) EPA’s review of the contents of these reports; and 4) EPA’s use of the 

public comment process to test and evaluate its initial scientific conclusions and judgments based 

primarily on the assessment literature. It is our conclusion that by placing primary reliance on 

the major assessment reports, EPA ensured that the endangerment determinations are based on 

reports that have considered and weighed all views. Our review of the objections raised by 

petitioners to the process and the substance of the various assessment reports does not support 

changing this view. EPA fully exercised its judgment and discretion under section 202(a), as 

evidenced throughout the comprehensive and robust record supporting the Endangerment 

Finding. 

The petitioners appear to believe that there is a substantial likelihood that EPA would have 

drawn different conclusions had it conducted its own separate assessment instead of relying on 

the conclusions of the assessment literature. They further claim that the CRU e-mails and other 

new information prove that such separate assessment is absolutely necessary. After examining 

the breadth and quality of the USGCRP, IPCC, and NRC assessments, as well as the new 

information provided by petitioners, we disagree. Overall scientific understanding is not shaped 

by any single study; one must look across a range of studies that together serve to advance 

scientific knowledge. These assessment reports already reflect significant input from EPA’s 

scientists and the scientists of many other government agencies. They have been reviewed and 

formally accepted, commissioned, or in some cases authored by U.S. government agencies and 

individual government scientists. By relying on the assessment literature, EPA is benefitting 

from the confidence and strength of an entire federal research enterprise and a robust process 

involving the scientists from around the world, and we find no reason, for reasons described 

throughout this RTP document, to believe that these reports do not represent the best primary 

source material to determine the state of science on the issues central to making an 

Endangerment Finding for GHGs. 

3.2 Response to Claims That the Assessments by the USGCRP and NRC Are Not 

Separate and Independent Assessments 

3.2.1 Overview 

Two petitioners (the Competitive Enterprise Institute and the State of Texas) argue that EPA 

misled the public into thinking that the Agency relied on three separate and independent 

assessment reports when in reality, they contend, the assessment reports developed by two of the 

20
groups (USGCRP and NRC) are not separate and independent assessments of the available 

science because the USGCRP and NRC “regularly cite and rely on data, resources and 

conclusions in the IPCC reports.” These petitioners further argue that since the IPCC reports are 

unreliable, the USGCRP and NRC reports are also unreliable, and thus all of the assessment 

literature EPA relied on is flawed. Following this logic, the petitioners argue that the 

Endangerment Finding must thus be reconsidered. 

First, as explained in detail in this document and the Denial, the IPCC reports are not unreliable, 

and continue to provide a robust foundation for the Findings. Moreover, the IPCC, USGCRP, 

and NRC assessments are separate and independent of each other. The organizational and 

personnel differences, and the detailed and robust report development procedures employed by 

the IPCC, USGCRP, and NRC, demonstrate that these assessment reports are separate and 

independent, and petitioners’ claims to the contrary are insufficient and unsubstantiated. EPA’s 

reliance on these three sets of assessment reports was and is reasonable. The fact that different 

assessments, developed by different organizations using different report development 

procedures, refer to each other’s work and arrive at similar conclusions does not imply flawed 

work. To the contrary, when multiple independent sources arrive at similar conclusions, those 

findings are strengthened. 

3.2.2 EPA’s Response to Petitioners’ Arguments 

Comment (3-9): 

Both the Competitive Enterprise Institute and the State of Texas note that EPA relied on the 

findings of the assessment literature to serve as a basis for the Endangerment Finding. They 

argue that EPA misled the public into believing that the Agency relied on assessments from three 

independent climate science entities, when in fact the TSD discusses and references findings 

from IPCC assessment reports far more frequently and in greater depth than those of the 

USGCRP and NRC. For example, the State of Texas argues that “the Administrator attempts to 

justify outsourcing her scientific assessment by purporting to rely on three outside organizations 

– which creates the appearance of a more thorough review.” In discussing this issue, the 

Competitive Enterprise Institute claims that the USGCRP and NRC assessments “are actually 

extensions of the IPCC findings, incorporating its faults and errors. Contrary to EPA claims, 

they do not provide any independent scientific support whatsoever.” The petitioners argue that 

the Endangerment Finding must be reconsidered because the USGCRP and NRC assessments are 

as flawed as the IPCC reports because they are not separate and independent from the IPCC 

reports. 

Response (3-9): 

The issues of EPA’s reliance on the assessment literature and whether the assessments by IPCC, 

USGCRP, and NRC are independent are not new and not only could have been, but were, the 

subject of comment during the public comment period. Thus, it was not impracticable to raise 

the objection during the public comment period and the reasons for the objection did not arise 

between June 24, 2009, and February 16, 2010. As such, they do not justify reconsideration of 

the Findings. The Administrator’s rationale for relying on the major assessments of the 

USGCRP, IPCC, and NRC as the primary scientific and technical basis for making the 

endangerment decision is explained in detail in the Findings, and our responses on this issue are 

21
included in Section 1.1 of Volume 1 of the RTC document, as well as Section 3.1 of this volume 

and Section 2.2 of Volume 2 of this RTP document. 

To the extent petitioners are arguing that new evidence casts further doubt on a practice they 

already criticized during the public comment period, we disagree. As discussed in Volume 2 and 

the Denial, it is abundantly clear that the issues raised in the CRU e-mails and errors found in the 

IPCC report do not cast doubt on the EPA’s reliance on the IPCC and other assessment literature 

relied for the Endangerment Finding. 

Moreover, contrary to the arguments of the petitioners, the USGCRP, IPCC, and NRC are 

separate and independent of each other. Although we thoroughly addressed this issue 

previously in Volume 1 of the RTC document, we will respond again here. 

There can be no doubt that the USGCRP, the IPCC, and the NRC are distinct organizations, with 

separate report development procedures. Below, we summarize the differences in the 

organizations, the groups of scientists who developed the assessments, and scope of the 

assessments produced by each body. 

 The IPCC, created in 1988 by the United Nations Environment Programme and the 

World Meteorological Organization (WMO), is open to all member countries of the 

United Nations and the WMO. At regular intervals, the IPCC prepares comprehensive 

assessments of scientific, technical, and socio-economic information relevant for the 

understanding of human induced climate change, potential impacts of climate change, 

and options for mitigation and adaptation all at global and regional scales. The most 

recent assessment—the AR4—included thousands of scientists from all over the world, 

who participated on a voluntary basis as authors, contributors, and reviewers (IPCC, 

2007a). While many federal and nonfederal scientists from the United States were 

involved in the development of the AR4, the United States is just one of 194 countries 

that contribute to the assessments. 

 The USGCRP is part of the United States Executive Branch. Thirteen departments and 

agencies participate in the USGCRP, including EPA. A critical role of the interagency 

program is to coordinate research and integrate and synthesize information to achieve 

results that no single agency, or small group of agencies, could attain. Between 2004 and 

2009, the USGCRP produced 21 synthesis and assessment reports on a wide range of 

topics (e.g., temperature trends in the lower atmosphere; weather and climate extremes in 

a changing climate; and the effects of climate change on agriculture, land resources, 

water resources, and biodiversity). The USGCRP assessment reports are developed to 

enhance understanding of natural and human-induced changes in the Earth’s global 

environmental system; to monitor, understand, and predict global change in the United 

States; and to provide a sound scientific basis for national and international decisionmaking. Each of these reports had a unique team of authors, drawn from relevant 

disciplines. Many authors were federal scientists, and in some cases, nonfederal 

scientists contribute their expertise to the process. While some of the USGCRP authors 

participated in the development of the IPCC AR4, most did not. 

22
 The NRC is an independent scientific organization that is not affiliated with either the 

IPCC or USGCRP. As described in Appendix C of Volume 1 of the RTC document, the 

NRC: 

“enlist(s) the nation’s foremost scientists, engineers, health professionals, and other 

experts to address the scientific and technical aspects of society’s most pressing 

problems. Each year, more than 6,000 of these experts are selected to serve on hundreds 

of study committees that are convened to answer specific sets of questions. All serve 

without pay. Federal agencies are the primary financial sponsors of the Academies’ 

work. Additional studies are funded by state agencies, foundations, other private 

sponsors, and the National Academies endowment. The Academies provide independent 

advice; the external sponsors have no control over the conduct of a study once the 

statement of task and budget are finalized. Study committees gather information from 

many sources in public meetings but they carry out their deliberations in private in order 

to avoid political, special interest, and sponsor influence.” 

Ten NRC reports are cited in the Endangerment Finding and TSD. Each of these reports 

has a unique author committee, selected based on their areas of expertise. While some of 

the NRC study committee members have participated in either the IPCC or USGCRP 

report development processes, many have not. 

With this background on the three organizations and their report development processes, the 

flaws of the petitioners’ allegations become clear. Not only are the three organizations separate 

and distinct, but there is additional independence among the multiple reports that they each 

produce. Within the IPCC, each chapter has a unique, dedicated team of authors, and the same is 

true for each NRC and USGCRP report. It should be no surprise that some scientists participate 

in reports produced by more than one organization, but petitioners have provided no evidence 

that any scientists exerted influence on a number of the reports produced by these three 

organizations. Moreover, there is no overlap in the personnel at the IPCC, NRC, and USGCRP 

who supervised the review and preparation of the final reports. 

Finally, the petitioners state that EPA cited and referenced the IPCC AR4 more frequently and in 

more depth than the USGCRP and NRC assessment reports in the Findings and the TSD. While 

this is accurate, the TSD also references many of the USGCRP and NRC assessment 

conclusions. For example, the Chapter 15 of the TSD on “U.S. Regional Climate Change 

Impacts” primarily cited and referenced the USGCRP’s 2009 assessment (Karl et al., 2009) for 

its focus on impacts in the United States. Regardless, counting references is a misguided and 

trivial criterion to apply. As described in the Endangerment Finding, we relied on the IPCC AR4 

because it is a comprehensive synthesis of the latest science on: “(1) the amount of greenhouse 

gases being emitted by human activities; (2) how greenhouse gases have been and continue to 

accumulate in the atmosphere as a result of human activities; (3) changes to the Earth’s energy 

balance as a result of the buildup of atmospheric greenhouse gases; (4) observed temperature and 

other climatic changes at the global and regional scales; (5) observed changes in other climatesensitive sectors and systems of the human and natural environment; (6) the extent to which 

observed climate change and other changes in climate-sensitive systems can be attributed to the 

human-induced buildup of atmospheric greenhouse gases; (7) future projected climate change 

under a range of different scenarios of changing greenhouse gas emission rates; and (8) the 

23
projected risks and impacts to human health, society and the environment.” As discussed 

throughout this document, this statement still holds true. 

Our reliance on the IPCC is entirely reasonable given the breadth of the issues covered and the 

credibility and quality of the information presented in the AR4. As discussed in Volume 2 of 

this RTP document, the recent revelations about a small number of specific factual errors in the 

IPCC AR4 do not call into question the overall credibility of the report such that it would render 

EPA’s reliance on it unreasonable. Nor do the CRU e-mails call into question the scientific 

integrity of the IPCC report or the underlying studies considered therein. Importantly, during the 

public comment period, we received many comments on specific scientific issues and 

conclusions of the IPCC AR4 and the other reports on which we relied. These comments were 

fully responded to in the multiple volumes of the RTC document, and insights from the 

comments were reflected in the Administrator’s final determination. The scope and depth of the 

record on the Endangerment Finding—including an 11-volume RTC document responding to 

comments on all aspects of the science, law, and procedure—demonstrates both the volume of 

information the Administrator considered in developing the Findings and the seriousness with 

which EPA approached the task of assessing the science. The general claims by the petitioners 

that the IPCC is “unreliable” or “flawed” are not valid because, as discussed in Volume 2, 

Section 2.1, of the RTP document, they are not backed by specific evidence or credible scientific 

studies that support their views. 

Comment (3-10): 

The Competitive Enterprise Institute and the State of Texas argue that EPA misled the public 

into believing that the Agency relied on assessments from three independent climate science 

entities, when in fact the USGCRP and NRC reports regularly cite and rely on data, resources, 

and conclusions in the IPCC reports, thereby contradicting arguments that all three of the 

assessments are separate and independent. 

Response (3-10): 

These allegations are not new and not only could have been, but were, the subject of comment 

during the public comment period. It was not impracticable to raise the objection during the 

public comment period and the reasons for the objection did not arise between June 24, 2009, 

and February 16, 2010. 

In their recent assessment reports, the USGCRP and NRC relied on and referenced many 

conclusions from the IPCC AR4 chapters. All three bodies are tasked with identifying the best 

available scientific information on which to base their assessments. Therefore it is reasonable 

and expected that the NRC and USGCRP would cite the IPCC; this is a reflection of the 

confidence that the NRC and USGCRP place in the work of the IPCC, not evidence that there is 

a lack of separation and independence. We disagree with the petitioners’ conclusion that since 

the reports produced by the different organizations referenced many of the same studies, or each 

other, or arrived at consistent conclusions this means that these reports are not independent 

assessments of the available science related to climate change. Given the clear separation and 

independence in the organizations, the personnel performing supervision and review, and the 

differences in the groups of scientists working on the assessment, the appropriate conclusion to 

24
draw is that the consistency in the conclusions reached by multiple reports of the three 

organizations provides more, not less, weight and confidence in these conclusions. 

Petitioners appear to believe that EPA should conclude, from the fact that subsequent 

assessments of climate change science have reaffirmed and strengthened the core conclusions of 

previous reports, that the assessments are not separate and independent. However, the test of 

separation and independence is not whether one reaches a different result or conclusion, but 

rather whether independent discretion and judgment was exercised. For example, it is routine in 

science for different researchers to perform similar or related analyses or assessments. Reaching 

a similar result provides increased confidence in the entire set of results. The similarity in results 

does not prove, nor should it even suggest, that the researchers failed to be separate and 

independent. Petitioners’ logic fails, as it is driven by an inappropriate results-oriented criterion. 

The fact that each successive assessment report, performed by a different organization and group 

of scientists and reviewers, reexamines the work of previous reports in light of new scientific 

information, and in many cases cites them, results in greater confidence in the reliability and 

objectivity of the scientific conclusions on which the Endangerment Finding relies. In this 

manner, the USGCRP, the IPCC, and the NRC have all taken a fresh look at the literature and 

existing assessments and reached similar, consistent, and compelling conclusions regarding the 

threat of climate change. 

It is also reasonable and scientifically credible that the USGCRP and NRC would reference the 

IPCC AR4. Despite the allegations of petitioners, we have found no evidence that the IPCC 

processes do not produce credible reports or that the IPCC has reached flawed conclusions on 

specific scientific issues. Our response to petitioners’ claims regarding the IPCC processes are 

detailed in Volume 2, and our response on the science issues are in Volume 1 of this RTP 

document. Petitioners’ evidence does not support their claim that the USGCRP and NRC blindly 

accept the conclusions and assessments reports of the IPCC. To the contrary, the evidence 

shows that they independently reviewed the conclusions of the assessment reports, including in 

some cases the literature underlying the assessments, and also reviewed the more recent literature 

to determine the current state of the science. In some cases, USGCRP reviewed the underlying 

science and referenced the IPCC where they agreed with the conclusions and how they were 

developed. For example, in their assessments the USGCRP referenced IPCC findings for many 

context-setting issues such as global observations, attribution, and radiative forcing. In other 

cases, USGCRP reviewed the available literature, including any studies reviewed or referenced 

in the AR4, and made their own key conclusions regarding the state of the science. The 

USGCRP predominantly employed this approach in describing observed and projected impacts 

in the United States (Karl et al., 2009). A very similar approach was used by the NRC in their 

assessments (NRC, 2008). As a result, USGCRP’s and NRC’s assessments contain both 

references for the AR4 chapters and individual studies. 

The USCGRP and NRC also give the public opportunities to provide input and comment during 

report development (see Volume 1 of the RTC document for more information on USGCRP’s 

and NRC’s report development processes). Specifically, the USGCRP holds public comment 

periods when developing the prospectus for each assessment and again once the report has been 

drafted. The NRC employs a different, yet entirely robust and reasonable process. Informationgathering meetings of the NRC study committees are open to the public, and any written 

25
materials provided to the committee by individuals are maintained in a public access file that is 

available for examination. In developing the draft findings and recommendations for each 

report, the study committees deliberate in meetings closed to the public in order to maintain 

independence from outside influences. Finally, the NRC reports undergo a rigorous, 

independent external review by experts whose comments are provided anonymously to the 

committee members. 

Comment (3-11): 

Peabody Energy contends that the principal authority for EPA’s central conclusion that 

anthropogenic GHG emissions are causing deleterious climate change is the IPCC, rather than 

other “assessment literature” or any other studies. They note that of the 67 citations in the 

attribution section of the TSD (Section 5) that discusses the linkage between observed climate 

change and GHGs, 47 are from the IPCC. Additionally, Peabody Energy is critical of the fact 

that “only eight pages” of the TSD are devoted to this issue. 

Response (3-11):

Section 5 of the TSD addresses attributing observed changes in climate to anthropogenic GHGs, 

and the IPCC does serve as a core reference to the assessment literature for Section 5. The 

IPCC’s findings on attribution, as summarized in the TSD, draw from modeling experiments 

using 14 atmosphere-ocean general circulation models and scores of simulations, as well as 

literally hundreds of studies. The IPCC’s chapter on attribution is 80 pages long. It is therefore 

the most comprehensive resource on attribution available in the scientific literature on this 

subject. Peabody Energy provides no substantive comment on its content. 

While we reference the IPCC for large parts of our discussion of attribution, we also reviewed 

and cited several USGCRP assessments that cover attribution issues. These include: 

 CCSP 1.3: Reanalysis of Historical Climate Data for Key Atmospheric Features: 

Implications for Attribution of Causes of Observed Change (CCSP, 2008a) 

 Subsections on attribution in CCSP 3.3: Weather and Climate Extremes in a Changing 

Climate (CCSP, 2008b) 

 Global Change Impacts in the United States (Karl et al., 2009) 

While Peabody Energy’s points to the length in pages of the TSD discussion, it does not identify 

any general or specific issues that were omitted or inappropriately handled. Peabody Energy’s 

focus on counting references and pages is not a credible, science-based argument against the 

scientific information that supports the Endangerment Finding. We did receive many public 

comments on attribution, and our responses are provided in Volume 3 of the RTC document. 

Furthermore, the National Academy of Sciences recent report “Advancing the Science of 

Climate Change” (NRC, 2010) supports and reaffirms the conclusions from the earlier 

assessment literature synthesized in the TSD pertaining to attribution as mentioned in Section 

1.1.2.4 of this RTP document. 

EPA’s evaluation of the attribution issue relies on appropriate assessment literature, as well as 

any information or studies provided in the public comment process. EPA’s evaluation, and it’s 

26
responses to comments on the issue of attribution, provide a comprehensive and appropriate 

evaluation of this issue. Peabody Energy’s comment on citations and pages provides no 

scientific basis to believe otherwise. 

3.2.3 Summary 

The evidence provided by the petitioners does not support their allegations that the IPCC, 

USGCRP, and NRC assessments are not separate and independent, and the alleged flaws with 

the IPCC attach to the USGCRP and NRC reports as well. The organizational and personnel 

differences, and the detailed and robust report development procedures employed by the IPCC, 

USGCRP, and NRC, demonstrate that these assessment reports are separate and independent, 

and petitioners’ claims to the contrary are insufficient and unsubstantiated. Thus, the petitioners’ 

claims that EPA misled the public regarding the breadth and independence of the information 

relied on by the Administrator are unfounded. Contrary to petitioners’ allegation, the USGCRP 

and NRC are independent and separate assessments. Furthermore, the similarity of the 

conclusions among the assessment reports from the three bodies provides evidence of the 

strength of the underlying science and does not represent a lack of independence, as alleged by 

the petitioners. The evidence does not support changing EPA’s use of those assessments, or 

justify the reconsideration of the Findings. 

Separate and apart from the issue of the independence of these assessment reports, the petitioners 

provide no information to demonstrate that the scientific conclusions of the IPCC, USGCRP, and 

NRC are wrong or that EPA erred in relying on them. The specific science issues raised by 

petitioners are discussed in Volumes 1 and 2. Thus, whether or not the various assessment 

reports are separate and independent, EPA reasonably relied on them as reflecting the current 

state of the science and the degree of broad consensus within the science community on these 

issues. 

3.3 Issues Concerning the Integrity of Peer-Reviewed Literature 

3.3.1 Overview 

Several petitioners (the Coalition for Responsible Regulation, the Ohio Coal Association, the 

Pacific Legal Foundation, Peabody Energy, the Southeastern Legal Foundation, the State of 

Texas) argue that leading climate scientists associated with the CRU e-mails conspired to keep 

dissenting views of anthropogenic climate change out of the peer-reviewed literature. 

Specifically, petitioners claim that these scientists unfairly gave favorable reviews of each 

other’s manuscripts while providing negative reviews of manuscripts authored by those with 

opposing views, made efforts to unfairly expedite publication of their responses to papers by 

with opposing views, conspired to remove editors of prominent journals that had published 

dissenting views of climate change, and boycotted certain journals in reprisal for publication of 

articles with which they disagreed. The petitioners conclude that all of these actions advantaged 

the positions of the climate scientists associated with the CRU e-mails in getting their views 

published and legitimized, while making it very difficult if not impossible for dissenting views to 

27
be published. Thus, petitioners argue that the peer-reviewed climate change literature is 

unbalanced and reflects an artificial consensus about anthropogenic climate change. 

Our review of the petitioners’ claims and the evidence they rely upon shows many cases in 

which the petitioners make overly broad generalizations based on suggestions of inappropriate 

actions that are not supported by the information they provided. Most of the quotes from the emails that petitioners allege shows impropriety are taken out of context from the e-mails. 

Further, petitioners do not provide corroborating evidence that improper action actually 

occurred, let alone evidence that any alleged improper action led to biased or inaccurate science 

that was ultimately used by EPA to support the Findings. In addition, the petitioners make broad 

leaps in logic to impugn the overall integrity of the peer-reviewed climate change literature based 

on very limited examples and largely speculative assertions. Based on our review, the e-mails do 

not contain information that causes us to question the integrity of the assessment literature or its 

conclusions as to the state of the science on GHGs, climate change, and the associated risks and 

impacts to public health and welfare. 

The following sections provide our responses to the arguments made by petitioners regarding the 

integrity of peer-reviewed literature. Section 3.3.2 responds to allegations regarding reviews of 

manuscripts. Section 3.3.3 responds to allegations of unfair journal publications practices. 

Section 3.3.4 responds to allegations of efforts to remove editors and boycott journals. Section 

3.3.5 responds to allegations of intimidating junior scientists and those with opposing views. 

Finally, Section 3.3.6 summarizes our responses. 

3.3.2 Allegations Regarding Reviews of Manuscripts 

Comment (3-12): 

Peabody Energy cites one example from the CRU e-mails that it claims demonstrates that the 

scientists “bent the rules to ensure publication of papers that supported their position regardless 

of quality.” Specifically, the petitioner argues that Michael Mann (a professor at Pennsylvania 

State University and former editor for the Journal of Climate) inappropriately recommended that 

Phil Jones of CRU should review a manuscript submitted for publication by Ben Santer of 

Lawrence Livermore National Laboratory and Tom Wigley of the University Corporation for 

Atmospheric Research. Peabody Energy argues that Jones’ close association with the authors 

limited his ability to act as an impartial reviewer. In addition, Peabody Energy cites an e-mail 

written by Tom Wigley from September 22, 2000, on which Jones was copied and which shows 

Santer and Wigley discussing their submitted manuscript: 

Ben (or, really, everybody else), 

I don’t know whether you have all seen the paper analyzing the observed data that Ben 

and I sent to J. Climate ?? This is where the JGR [Journal of Geophysical Research] 

paper began, and it is useful to compare both papers. In the J. Climate paper we assessed 

the best fits using a subjective balance of raw and lowpass filtered results. The reason for 

this was because of the difficulty of setting up an automated procedure -- which is the 

problem that Ben is currently having to deal with. In the next iteration of the JGR paper, 

the reason for moving to a more automated procedure will be explained. Both the 

subjective and automated procedures have their advantages and disadvantages. The latter 

28
procedure, of course, is in no way ‘objective’. Many subjective choices have to be made 

in setting up the procedure. This is why the word ‘automated’ is used above, rather than 

‘objective’. 

If you have not seen the J. Climate paper, let me know and I will send you a copy. There 

is a companion paper that has been accepted by GRL [Geophysical Research Letters] that 

I will send at the same time.3

Peabody Energy argues that this e-mail gave Jones advance knowledge of the paper’s content 

and thus limited his ability to act as an impartial reviewer of their manuscript. The petitioner 

states that on October 24, 2000, Jones wrote a positive review with minimal comments: 

Dear Brendaw, 

My review of the paper JCL [Journal of Climate] 3435 is attached. My recommendation 

is to accept the paper subject to minor changes. I don’t wish to see it again. If there are 

any problems with the attachment, let me know and I can fax the 2 pages.4

Peabody Energy asserts that Jones did not act as an impartial, objective reviewer because he 

clearly had problems with the manuscript, but recommended the paper for publication anyway. 

As evidence of Jones’ problems with the manuscript, the petitioner cites the following excerpt of 

an e-mail written by Jones on October 25, 2000, to Santer: 

Also just sent back comments to Mike Mann on the paper by Tom and you factoring out 

ENSO [the El Niño Southern Oscillation] and Volcanoes. Felt like writing red ink all 

over it, but sent back a short publish subject to minor revision to Mike.5

 

Peabody Energy concludes that this exchange is evidence that “peer-review publication rules” 

were manipulated, and that “the peer-review process was tainted in favor of desired papers.” 

Peabody Energy argues that the Endangerment Finding should be reconsidered because it relies 

on biased peer-reviewed literature that published papers supporting anthropogenic climate 

change regardless of their scientific quality. 

Response (3-12): 

The emails do not support the petitioner’s arguments because the petitioner provides no evidence 

to support its claim that past collaborations among these climate researchers led Jones to skew 

his review. The petitioner makes much of Jones’ statement that he “felt like writing red ink all 

over it,” but the meaning of this statement is unclear from the e-mail. Jones does not say that he 

disagreed with the paper’s conclusions, and it is equally plausible the he thought the paper was 

poorly written or that he believed the conclusions could have been improved. The fact that he 

wanted to edit the paper (for an unknown reason) does not support the view that he should have 

rejected it for publication. 

 

3

 E-mail file 969652057.txt, (September 22, 2000), page 285, line 42 of PDF version entitled: CRU Emails 1996-

2009.pdf 

4

 E-mail file 972415204.txt, (October 24, 2000), page 295, line 33 of PDF version entitled: CRU Emails 1996-

2009.pdf 

5

 E-mail file 972499087.txt, (October 25, 2000), page 296, line 9 of PDF version entitled: CRU Emails 1996-

2009.pdf 

29
Petitioner alleges that Mann inappropriately asked Jones to review the paper and that Jones 

should have declined because he knew the authors and may have had prior knowledge of the 

paper’s content. Neither of these events is uncommon in scientific publishing; however, in a 

small field like paleoclimate research, there is often substantial interaction of this type. In order 

to demonstrate manipulation, petitioners need to prove that the paper was flawed, which they fail 

to do. In fact, they do not provide any discussion of the scientific merits of the paper. In 

addition, all peer-reviewed publications have multiple reviewers, so Jones was not in position to 

determine whether or not it would be approved for publication. 

In addition, this incident, even if it supported the claim petitioner alleges, does not support 

petitioners allegations of broad ranging efforts by multiple scientists to manipulate the entire 

spectrum of peer-reviewed literature. All this incident could possibly prove, if the petitioner’s 

claims were substantiated (which they are not) is that Phil Jones gave a favorable review to one 

paper published by people he interacted with professionally. 

These e-mails do not support the claim that Jones or others “bent the rules” on the peer review 

process for this specific paper, and they present no other evidence to support the petitioner’s 

claim of a broader effort by many scientists that affected an unknown number of other journal 

articles. Even if the allegations were corroborated for this one paper, they deal with only one of 

thousands of papers that make up the body of scientific literature on climate change. To claim, 

as the petitioner does, that one paper or the actions of one scientist could somehow bias the vast 

wealth of climate change studies or call into question the overall conclusions reached from those 

thousands of papers is unwarranted and unsupported. Finally, the petitioner fails to make any 

arguments as to why the paper at issue was scientifically flawed and should have been rejected 

for publication. Instead of arguing about the scientific merits of the paper, the petitioner relies 

upon speculation. 

Comment (3-13):

Petitioners claim that the CRU e-mails indicate that certain scientists unfairly wrote negative 

reviews of manuscripts authored by “climate skeptics” in order to keep opposing views out of the 

peer-reviewed literature. Peabody Energy argues that: 

As leading scientists in the climate field, several of the authors involved in AR4 were in a 

position to affect the types of papers that were published in the peer-reviewed 

literature...They abused their positions of influence, however, by manipulating the peerreview publication process to prevent publication of papers at odds with their own views 

and even to oust editors who had published such papers. 

More specifically, Peabody Energy claims that Tom Wigley of the University Corporation for 

Atmospheric Research unfairly reviewed and recommended rejecting a manuscript by Patrick 

Michaels of the University of Virginia. The petitioner suggests that Wigley was motivated by a 

desire to keep dissenting views out of the peer-reviewed climate change literature because “other 

peer reviewers not connected with the Jones et al. group had accepted it in the normal course and 

the refereeing process had been more rigorous than usual.” The petitioner cites an e-mail from 

Wigley in which he discusses his rejection of the manuscript: 

30
Danny Harvey [of the University of Toronto] and I refereed this and said it should be 

rejected. We questioned the editor (deFreitas again!) and he responded, saying... “The 

[manuscript] was reviewed initially by five referees...The other three referees, all 

reputable atmospheric scientists, agreed it should be published subject to minor revision. 

Even then I used a sixth person to help me decide. I took his advice and that of the three 

other referees and sent the [manuscript] back for revision. It was later accepted for 

publication. The refereeing process was more rigorous than usual.” 

On the surface this looks to be above board—although, as referees who advised rejection, 

it is clear that Danny and I should have been kept in the loop and seen how our criticisms 

were responded to.6

In a related example, Peabody Energy and the State of Texas quote an excerpt of an e-mail from 

Phil Jones to Michael Mann on March 31, 2004, in which he discusses his unfavorable reviews of 

two papers for Geophysical Research Letters and the Journal of Geophysical Research: 

Recently rejected two papers (one for JGR and for GRL) from people saying CRU has it 

wrong over Siberia. Went to town in both reviews, hopefully successfully. If either 

appears I will be very surprised, but you never know with GRL.7

 

The petitioners claim that Jones’ negative reviews attempted to “prevent a manuscript from 

being published that questioned the CRU’s research” and were motivated by a desire to keep 

dissenting views out of the peer-reviewed literature. The petitioner concludes that these 

examples provide evidence that “peer-review publication rules” were manipulated to suppress 

dissenting views of anthropogenic climate change. The petitioners argue that the Endangerment 

Finding should be reconsidered because it relied on biased peer-reviewed literature that does not 

reflect the true breadth of the science. 

Response (3-13): 

As part of the peer-review process, scientists are justified in recommending that any given 

manuscript not be published if, based on their expert scientific judgment, they determine that the 

manuscript does not meet a certain standard of methodological rigor or its conclusions are 

questionable, given the evidence presented. The petitioners assume that the papers at issue 

received unjustified unfavorable reviews by Wigley, Harvey, and Jones, and assume the 

unjustified views were motivated by a desire to suppress dissenting views about climate change. 

Regarding the paper reviewed by Wigley and Harvey, petitioners neither entertain nor address 

the most straightforward possibility: that these scientists, based on their expert judgment, 

concluded that the paper was not up to standards for publication, while the other reviewers 

simply came to a different conclusion. Disagreement among reviewers is extremely common in 

scientific publishing. This issue was examined by the Independent Climate-Change E-mail 

Review, which stated, “There is always the risk of group-think among experts which resists 

alternative perspectives. Editors try to reduce the risk of group-think by sending papers to 

 

6

 E-mail file 1051156418.txt, (April 23, 2003), page 486, line 27 of PDF version entitled: CRU Emails 1996-

2009.pdf 

7

 E-mail file 1051156418.txt, (March 31, 2004), page 664, line 1 of PDF version entitled: CRU Emails 1996-

2009.pdf 

31
different and widely dispersed reviewers, deliberately seeking or even provoking critical 

reviews” (Russell, 2010). 

Regarding the Jones review, the petitioners provide no evidence to support their claim that 

Jones’ actions were inappropriate or that his reviews of these two particular papers were not 

scientifically justified. In addition, all peer-reviewed publications have multiple reviewers, so 

Jones was not in position to determine whether or not these papers would be approved for 

publication. Thus, we find that the reviews by Wigley, Harvey, and Jones were completely 

within the norms of scientific practice. 

Beyond these e-mails, Peabody Energy provides no evidence to support their claim that these 

scientists “bent the rules” of the peer-review process to bias the peer-reviewed process for these 

papers or for the literature as a whole. Petitioners also provide no evidence that the papers were 

not in fact published, which would seem to be an important fact if they are concerned that the 

goals was to “keep opposing views out of the peer-reviewed literature.” It appears that at least 

one paper was published, and there is no information on the other two. So, petitioners fail to 

show any actual bias in the literature that might have occurred. Even if the allegations were 

supported for these papers, which they are not, the petitioner’s allegations involve only three out 

of thousands of papers that make up the body of scientific literature on climate change. To 

claim, as the petitioner does, that a few papers or the actions of a few scientists could somehow 

bias the vast wealth of climate change studies or call into question the overall conclusions 

reached from those many papers is unwarranted and unsupported. 

Comment (3-14):

In another example, Peabody Energy claims that on June 4, 2003, Keith Briffa of CRU asked 

Edward Cook of the Lamont-Doherty Earth Observatory at Columbia University to provide 

evidence for rejecting a manuscript because Briffa disagreed with its authors’ views on climate 

change. According to the petitioner, in making his request, Briffa apparently inappropriately 

disclosed the identity and recommendation of the other reviewer, Dave Stahle. 

I am really sorry but I have to nag about that review - Confidentially I now need a hard 

and if required extensive case for rejecting - to support Dave Stahle’s and really as soon 

as you can. Please 8

According to the petitioner, Cook replied to Briffa the same day to ask for help regarding a 

manuscript review for the Journal of Agricultural, Biological, and Environmental Sciences. 

Peabody Energy states that rather than providing his own independent analysis of the paper’s 

suitability for publication, Cook enlisted Briffa’s help to write an unfavorable review for the 

paper. The petitioner concludes that this provides evidence that “peer-review publication rules” 

were manipulated to suppress dissenting views of anthropogenic climate change. Peabody 

Energy argues that the Endangerment Finding should be reconsidered because it relies on biased 

peer-reviewed literature that did not reflect the true breadth of the science. 

 

8

 E-mail file 1054748574.txt, (June 4, 2003), page 514, line 1 of PDF version entitled: CRU Emails 1996-2009.pdf 

32
Response (3-14):

The Independent Climate-Change E-mail Review examined in detail the claims regarding the 

manuscript review Keith Briffa requested from Edward Cook. Based on the CRU e-mails and 

additional evidence submitted to the Independent Climate-Change E-mail Review panel, they 

concluded the following: 

Although much has been made of the e-mail in paragraph 15 as evidence of an 

unprincipled approach to the role of editor, we see nothing in these exchanges that 

supports the interpretations of subverting the peer review process that have been placed 

upon it. It appears to reflect an Editor with a strongly negative review in hand, and who 

presumably has read the paper, asking for confirmation that the paper should be rejected, 

possibly to reduce one of the many complications that assail an editor; and in view of the 

delay in communicating to authors, hoping for a strong decision from the referee. On 

receiving a second, more equivocal review, he offers the authors the opportunity to resubmit. These exchanges illustrate some of the complications of an Editor’s life ... They 

do not provide evidence of subversion of process in rejecting contradictory ideas as has 

been alleged. (Russell, 2010) 

Regarding the claim that Cook enlisted Briffa’s help in reviewing a manuscript, the petitioner 

does not quote Cook’s e-mail in its entirety. The full text of the e-mail provides important 

context: 

Hi Keith, 

Okay, today. Promise! Now something to ask from you. Actually somewhat important 

too. I got a paper to review (submitted to the Journal of Agricultural, Biological, and 

Environmental Sciences), written by a Korean guy and someone from Berkeley, that 

claims that the method of reconstruction that we use in dendroclimatology (reverse 

regression) is wrong, biased, lousy, horrible, etc. They use your Tornetrask recon as the 

main whipping boy. I have a file that you gave me in 1993 that comes from your 1992 

paper. Below is part of that file. Is this the right one? Also, is it possible to resurrect the 

column headings? I would like to play with it in an effort to refute their claims. If 

published as is, this paper could really do some damage. It is also an ugly paper to 

review because it is rather mathematical, with a lot of Box-Jenkins stuff in it. It won’t be 

easy to dismiss out of hand as the math appears to be correct theoretically, but it suffers 

from the classic problem of pointing out theoretical deficiencies, without showing that 

their improved inverse regression method is actually better in a practical sense. So they 

do lots of monte carlo stuff that shows the superiority of their method and the 

deficiencies of our way of doing things, but NEVER actually show how their method 

would change the Tornetrask reconstruction from what you produced. Your assistance 

here is greatly appreciated. Otherwise, I will let Tornetrask sink into the melting 

permafrost of northern Sweden (just kidding of course). 

Cheers, Ed 9

As is clearly stated in the e-mail, Cook only asks Briffa to confirm if a specific dataset was the 

same as the one Briffa used in an early paper (and which was the focus of the paper Cook was 

being asked to review) and to provide column headings for the data. Cook does not ask Briffa to 

 

9

 E-mail file 1054756929.txt, (June 4, 2003), page 514, line 44 of PDF version entitled: CRU Emails 1996-2009.pdf 

33
read the manuscript, nor does he ask for Briffa’s help in writing the review. These examples do 

not support the petitioner’s arguments that the peer-review process was manipulated. 

Comment (3-15): 

In another example, Peabody Energy claims that Jones influenced the editor of the International 

Journal of Climatology (IJC) to select reviewers who would be biased against a paper submitted 

by Stephen McIntyre, editor of the blog ClimateAudit, and Ross McKitrick of the University of 

Guelph. Peabody cites the following e-mail Jones wrote to Ben Santer on January 29, 2009: 

I’ve just seen that M+M [McIntyre and McKitrick] have submitted a paper to IJC 

on your H2 statistic - using more years, up to 2007... Anyway you’ll likely get this 

for review, or poor Francis will. Best if both Francis and Myles did this. If I get 

an email from Glenn I’ll suggest this.10

In a related example, the Coalition for Responsible Regulation claims that Jones encouraged his 

co-authors on a paper “to submit the names of five scientists as recommended peer reviewers 

because they ‘know the sort of things to say’.11” The petitioner provides no additional context 

about the title or content of paper, but asserts that true scientific scrutiny and close review 

“cannot be expected from hand-picked, wholly-supportive reviewers.” The petitioner argues that 

Jones’ actions bias the peer review process and “endors[e] findings that may prove to be 

scientifically erroneous or unsubstantiated.” The petitioners conclude that Jones acted 

unethically to manipulate the normal peer-review process in order to keep dissenting views out 

of the peer-reviewed literature, and that the Endangerment Finding should be reconsidered 

because it relies on biased peer-reviewed literature that did not reflect the true state of the 

science. 

Response (3-15): 

It is customary for scientific journal editors to ask authors or associates to provide names of 

recommended reviewers during the process of submitting a manuscript. Thus, Jones’ actions do 

not appear inappropriate and there is no explanation how this could have biased the peer 

reviewed literature, as alleged by the petitioners. Regarding the first example, it is clear from the 

e-mail that Jones had not yet been asked to provide any recommendations; rather, he was simply 

stating his intentions if the editor decided to contact him. The petitioner does not provide any 

evidence that Jones was ever contacted by the editor, or if he was, how he responded. Similarly, 

in the second example, petitioners again provide no evidence that Jones’ co-authors submitted 

names of peer-reviewers, or if they did, that the scientists they suggested were asked to peer 

review and that they then said “the sorts of things” Jones wanted. 

In both examples, the petitioners make an unsubstantiated assumption that the reviewers 

suggested by Jones would be biased, either against the McIntyre and McKitrick paper, or biased 

in favor of the paper Jones wrote with his co-authors. There is no evidence to support the 

petitioners’ claims that any reviewers suggested by Jones and selected by the editor would be 

 

10 E-mail file 1233249393.txt, (January 29, 2009), page 1626, line 33 of PDF version entitled: CRU Emails 1996-

2009.pdf 

11 E-mail file 1249503274.txt, (August 5, 2009), page 1722, line 32 of PDF version entitled: CRU Emails 1996-

2009.pdf 

34
unable or unwilling to provide objective critique of a manuscript. In addition, Jones was not in a 

position to “hand-pick” any reviewers because any decisions regarding the selection of peer 

reviewers are solely the purview of the journal editor. In sum, these examples do not support the 

petitioner’s arguments that the journal publication process was manipulated. 

In summary, the various claims by petitioners of biased peer review processes or bending of 

rules to achieve this result are not supported by the evidence they present. Their evidence shows 

only the typical peer review process being followed, with reviewers presenting their views pro or 

con. There is no evidence that any papers were not published and, if they were not, that the basis 

was any reason other than scientific inadequacy. There is no evidence or scientific argument that 

the literature is biased, even for the specific papers at issue, just unsupported allegations of an 

improper process. Petitioners’ claims and evidence do not provide a basis for EPA to question or 

change its view that the science supporting the Endangerment Finding is robust, is compelling, 

and has been appropriately characterized by EPA. 

3.3.3 Allegations Regarding Journal Publication Practices 

Comment (3-16): 

Peabody Energy argues that the CRU materials reveal that Ben Santer of Lawrence Livermore 

National Laboratory and various colleagues exerted improper influence to pressure IJC to delay 

publication of a paper by David Douglass of University of Rochester and his colleagues—

Douglass et al. (2007)—and to expedite publication of their response—Santer et al. (2008). 

According to Peabody Energy, the overall effect of these actions was to give Santer et al. the 

“last word” and prevent Douglass et al. from responding according to “customary conventions.” 

Peabody Energy asserts that a number of e-mails12 reveal inappropriate conduct on the part of 

the authors and journal editors, including: 

 

(a) unusual cooperation between authors and editor that undermined the independence of 

each, (b) misstatement of known facts, (c) outright character assassination, (d) avoidance 

of traditional scientific give-and-take, (e) use of confidential information, (f) 

misrepresentation, or at a minimum misunderstanding, of the scientific question posed by 

Douglass et al. (2007), [and] (g) withholding of material data. 

The Southeastern Legal Foundation also argues that the CRU e-mail authors engaged in 

improper actions with regard to the Douglass et al. paper, quoting an opinion article by David 

Douglass of the University of Rochester and John Christy of the University of Alabama 

published in the daily Internet publication American Thinker: “The CRU e-mails have revealed 

how the normal conventions of the peer review process appear to have been compromised by a 

12 E-mail file 1196795844.txt, (December 4, 2007), page 1360, line 4; e-mail file 1196877845.txt, (December 5, 

2007), page 1365, line 7; e-mail file 1196956362.txt, (December 6, 2007) page 1370, line 36; e-mail file 

1196964260.txt, (December 6, 2007) page 1371, line 22; e-mail file 1197325034.txt, (December 10, 2007) page 

1374, line 13; e-mail file 1197507092.txt, (December 12, 2007) page 1376, line 8; e-mail file 1199988028.txt, 

(January 10, 2008) page 1424, line 3; e-mail file 1199999668.txt, (January 10, 2008), page 1426, line 43 of PDF 

version entitled: CRU Emails 1996-2009.pdf; e-mail file 1200059003.txt, (January 11, 2008) page 1432, line 8; email file 1200076878.txt, (January 11, 2008) page 1432, line 46; and e-mail file 1215712600.txt, (July 10, 

2008),page 1531, line 29 of PDF version entitled: CRU Emails 1996-2009.pdf) 

35
team of global warming scientists, with the willing cooperation of the editor of the IJC, Glenn 

McGregor” (Douglass and Christy, 2009). 

Prior to submitting the Santer et al. article to IJC, Peabody Energy asserts, Santer strategized to 

get the study published “in a way that customary conventions are ignored and the authors are 

prevented from responding.” Peabody Energy refers to an e-mail from Santer to Peter Thorne, a 

climate scientist working at the UK Met Office, on December 5, 2007: 

Peter, I think you’ve done a nice job capturing some of my concerns about the Douglass et al. 

paper ... I don’t think it’s a good strategy to submit a response to the Douglass et al. paper to the 

International Journal of Climatology (IJC). As Phil [Jones] pointed out, IJC has a large backlog, 

so it might take some time to get a response published. Furthermore, Douglass et al. probably 

would be given the final word.13

Peabody Energy then describes how Tim Osborn, part of IJC’s editorial board , “inserted 

himself into the process” by recommending that Santer submit to the journal and by 

contacting IJC editor Glenn McGregor to “see what he can do” to ensure a quick turnaround 

in publishing the Santer et al. submission. Peabody Energy states that McGregor was “clearly 

not unbiased, and the journal was persuaded to disregard proper peer-review procedures in 

order to hurry the team’s [Santer et al.’s] response into print.” Peabody Energy quotes an email from Tim Osborn to Santer and Phil Jones on January 10, 2008: 

I just contacted the editor, Glenn McGregor, to see what he can do. He promises to 

do everything he can to achieve a quick turn-around time (he didn’t quantify this) 

and he will also “ask (the publishers) for priority in terms of getting the paper 

online asap after the authors have received proofs.” He genuinely seems keen to 

correct the scientific record as quickly as possible. 

He also said (and please treat this in confidence, which is why I e-mailed to you 

and Phil only) that he may be able to hold back the hardcopy (i.e. the print/paper 

version) appearance of Douglass et al., possibly so that any accepted Santer et al. 

comment could appear alongside it. Presumably depends on speed of the review 

process. 

If this does persuade you to go with IJC, Glenn suggested that I could help (because 

he is in Kathmandu at present) with achieving the quick turn-around time by 

identifying in advance reviewers who are both suitable and available. Obviously 

one reviewer could be someone who is already familiar with this discussion, 

because that would enable a fast review - i.e., someone on the e-mail list you’ve 

been using - though I don’t know which of these people you will be asking to be 

co-authors and hence which won’t be available as possible reviewers... 14

 

13 E-mail file 11968778451..txt, (December 5, 2007), page 1365, line 23 of PDF version entitled: CRU Emails 1996-

2009.pdf 

14 E-mail file 1199999668.txt, (January 10, 2008), page 1426, line 43 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

36
Peabody Energy then cites the following e-mail in which Santer states his conditions for 

submitting to IJC to Tim Osborn (copying Phil Jones), also in an e-mail from January 10, 

2008: 

1) Our paper should be regarded as an independent contribution, not as a comment on Douglass et 

al. ... 

2) If IJC agrees to 1), then Douglass et al. should have the opportunity to respond to our 

contribution, and we should be given the chance to reply. Any response and reply should be 

published side-by-side, in the same issue of IJC. 

I’d be grateful if you and Phil could provide me with some guidance on 1) and 2), and on whether 

you think we should submit to IJC. Feel free to forward my email to Glenn McGregor.15

Peabody Energy subsequently states: 

The final approval of the strategy (Santer’s conditions) to deny Douglass and his collaborators an 

opportunity to respond in the normal way was acknowledged by Osborn to Santer and Jones in 

that Osborn wrote that McGregor, as editor, is “prepared to treat it as a new submission rather 

than a comment on Douglass et al.” and “[McGregor’s] offer of a quick turn around time etc still 

stands.”16 

Peabody Energy concludes by arguing that the Santer et al. paper was published in print only 

36 days after it was published online, while Douglass et al. had waited more than 11 months for 

their print publication. In addition, the petitioner argues that Douglass and his co-authors were 

never informed of Santer’s intention to publish a response, nor were they contacted for an 

explanation at any point in the process regarding Santer et al.’s concerns with their paper. 

Peabody Energy concludes that “The strategy of preventing Douglass and his collaborators from 

having any opportunity for a simultaneous response to Santer et al. had been achieved. The 

gamesmanship behind this strategy diverted the process of scientific inquiry from its proper path 

and tainted the materials on which the Agency now seeks to rely.” Peabody Energy concludes 

that the CRU e-mail authors’ improper conduct places Santer et al.’s work on questionable 

footing and casts doubt on the credibility of their critique of Douglass et al. (2007). 

Response (3-16): 

As discussed in Volume 1, Section 1.2.1.2 , the petitioners’ complaint focuses on the timing of 

the hardcopy publication of the Douglass et al. (2007) paper (which was previously published 

on-line), and does not provide any substantive evaluation or analysis of the scientific content of 

Santer et al. (2008). Petitioner does not explain why the findings presented in Douglass et al. 

(2007) are correct despite the findings presented in Santer et al. (2008). Peabody Energy also 

offers no substantive evaluation of any of the assessment literature (i.e., Karl et al., 2009) or 

other studies relied on by EPA that provide evidence for an anthropogenic fingerprint in the 

 

15 E-mail file 1200076878.txt, (January 11, 2008), page 1433, line 41 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

16 E-mail file 1200076878.txt, (January 11, 2008), page 1433, line 9 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

37
tropics. In addition, Douglass and the other authors of the 2007 study have not provided a 

scientific response or rebuttal to the scientific position presented in the Santer et al. (2008) paper. 

In addition to the petitioner’s focus on the timing of the hard copy publication rather than 

scientific content, we note that Peabody Energy extensively quotes from an article entitled “A 

Climate Conspiracy” (Douglass and Christy, 2009), published in the daily Internet publication 

American Thinker. In this article, two authors of Douglass et al. (2007) (Douglass and 

University of Alabama–Huntsville scientist John Christy) discuss the CRU e-mails pertinent to 

the Santer et al. and Douglass et al. studies, and pose the following challenge to readers: 

We will let the reader judge whether this team effort [of Santer and colleagues], revealed 

in dozens of e-mails and taking nearly a year, involves inappropriate behavior, including 

(a) unusual cooperation between authors and editor, (b) misstatement of known facts, (c) 

character assassination, (d) avoidance of traditional scientific give-and-take, (e) using 

confidential information, (f) misrepresentation (or misunderstanding) of the scientific 

question posed by DCPS [the authors of Douglass et al. (2007): Douglass, David; 

Christy, John; Pearson, Benjamin; Singer, Fred], (g) withholding data, and more. 

(Douglass and Christy, 2009) 

Peabody Energy’s allegations of misconduct on the part of Santer and colleagues identically 

match the examples of “inappropriate behavior” put forward by Douglass and Christy in the 

American Thinker article though Peabody Energy does not cite this article as the underlying 

source. Peabody Energy has no independent basis for their allegations; they are uncritically 

repeating the objections of Douglass and Christy. 

In February (2010), Santer published lengthy counterarguments to Douglass and Christy (2009) 

on the blog RealClimate (Santer, 2010a) and, separately, in an open letter to the scientific 

community (Santer, 2010b). The following excerpt from Santer (2010a) describes his 

counterarguments to the allegations set out in Douglass and Christy (2009) and an article by Fred 

Pearce in the Guardian (Pearce, 2010): 

In December 2009, shortly after the public release of the stolen emails from the 

University of East Anglia’s Climatic Research Unit, Professors David Douglass and John 

Christy accused me of leading a conspiracy to delay publication of the print version of 

the Douglass et al. paper. This accusation was based on a selective analysis of the stolen 

emails. It is false. 

In Mr. Pearce’s account of this issue, he states that “There is no doubt the (sic) Santer and 

his colleagues sought to use the power they held to the utmost...” So what are the facts 

of this matter? What is the “power” Fred Pearce is referring to? 

 Fact 1: The only “power” that I had was the power to choose which scientific journal 

to submit our paper to. I chose the International Journal of Climatology. I did this 

because the International Journal of Climatology had published (in their online 

edition) the seriously flawed Douglass et al. paper. I wanted to give the journal the 

opportunity to set the scientific record straight. 

 Fact 2: I had never previously submitted a paper to the International Journal of 

Climatology. I had never met the editor of the journal (Professor Glenn McGregor). 

38
 Fact 3: Prior to submitting our paper, I wrote an email to Dr. Tim Osborn on January 

10, 2008. Tim Osborn was on the editorial board of the International Journal of 

Climatology. I told Dr. Osborn that, before deciding whether we would submit our 

paper to the International Journal of Climatology, I wanted to have some assurance 

that our paper would “be regarded as an independent contribution, not as a comment 

on Douglass et al.” This request was entirely reasonable in view of the substantial 

amount of new work that we had done. I have described this new work above. 

 Fact 4: I did not want to submit our paper to the International Journal of Climatology 

if there was a possibility that our submission would be regarded as a mere 

“comment” on Douglass et al. Under this scenario, Douglass et al. would have 

received the last word. Given the extraordinary claims they had made, I thought it 

unlikely that their “last word” would have acknowledged the serious statistical error 

in their original paper. As subsequent events showed, I was right to be concerned – 

they have not admitted any error in their work. 

 Fact 5: As I clearly stated in my email of January 10 to Dr. Tim Osborn, if the 

International Journal of Climatology agreed to classify our paper as an independent 

contribution, “Douglass et al. should have the opportunity to respond to our 

contribution, and we should be given the chance to reply. Any response and reply 

should be published side-by-side...” 

 Fact 6: The decision to hold back the print version of the Douglass et al. paper was 

not mine. It was the editor’s decision. I had no “power” over the publishing 

decisions of the International Journal of Climatology. 

This whole episode should be filed under the category “No good deed goes unpunished”. 

My colleagues and I were simply trying to set the scientific record straight. There was no 

conspiracy to subvert the peer-review process. Unfortunately, conspiracy theories are 

easy to disseminate. Many are willing to accept these theories at face value. The 

distribution of facts on complex scientific issues is a slower, more difficult process. 

Peabody Energy provides numerous quotations from the CRU e-mails and narrates its 

interpretations of events, but its examples do not materially change the narrow and limited nature 

of its overall argument, which is that the Santer et al. paper was improperly published in print at 

the same time as the Douglass et al. paper. Peabody makes no claims or arguments as to the 

validity of the science in the Santer et al. (2008) paper, just that its hard-copy publication date 

was advanced by the editor, and another paper’s was delayed. Decisions regarding the selection 

of peer reviewers, the timing of peer review, and whether and when a paper is published are 

solely the responsibility of the journal editor, not the study authors. 

Crucially, we also note that the Douglass et al. paper was freely available online for almost a 

year before it came out in print. Online publications are considered to be official records of 

publication and generally attract the majority of the scientific and media attention. At the point 

of online publication, the Douglass et al. paper was considered to be a legitimate contribution to 

the literature, which is why the year of citation is 2007 while the year of citation for the Santer et 

al. paper is 2008. Thus, Peabody Energy’s argument that the Douglass et al. paper was 

“improperly delayed” and Southeastern Legal Foundation’s argument that “the normal 

conventions of the peer review process appear to have been compromised” are without merit; 

39
when it was published online, Douglass et al. were “on the record” as part of the peer-reviewed 

academic literature. 

The decision of IJC editor Glenn McGregor to delay the print publication of Douglass et al. and 

expedite the review of Santer et al. so that they would be published simultaneously was 

motivated by McGregor’s desire to “correct the scientific record17” after the editor became 

aware of problems with the Douglass et al. paper. Santer had made the case for doing so when 

he e-mailed Tim Osborne at IJC stating his conditions for submittal on January 10, 2008—which 

the petitioner did not include in its summary of events: 

IJC published a paper with egregious statistical errors. Douglass et al. was essentially a 

commentary on work by myself and colleagues—work that had been previously published in 

Science in 2005 and in Chapter 5 of the first U.S. CCSP Report in 2006. To my knowledge, none 

of the authors or co-authors of the Santer et al. Science paper or of CCSP 1.1 Chapter 5 were used 

as reviewers of Douglass et al. I am assuming that, when he submitted his paper to IJC, Douglass 

specifically requested that certain scientists should be excluded from the review process. Such an 

approach is not defensible for a paper which is largely a comment on previously-published work. 

It would be fair and reasonable to give IJC the opportunity to “set the record straight”, and correct 

the harm they have done by publication of Douglass et al. I use the word “harm” advisedly. The 

author and coauthors of the Douglass et al. IJC paper are using this paper to argue that “Nature, 

not CO2, rules the climate”, and that the findings of Douglass et al. invalidate the “discernible 

human influence” conclusions of previous national and international scientific assessments. 

Quick publication of a response to Douglass et al. in IJC would go some way towards setting the 

record straight. I am troubled, however, by the very real possibility that Douglass et al. will have 

the last word on this subject. In my opinion (based on many years of interaction with these guys), 

neither Douglass, Christy or Singer are capable of admitting that their paper contained serious 

scientific errors. Their “last word” will be an attempt to obfuscate rather than illuminate. They 

are not interested in improving our scientific understanding of the nature and causes of recent 

changes in atmospheric temperature. They are solely interested in advancing their own agendas. 

It is telling and troubling that Douglass et al. ignored radiosonde data showing substantial 

warming of the tropical troposphere—data that were in accord with model results—even though 

such data were in their possession. Such behaviour constitutes intellectual dishonesty. I strongly 

believe that leaving these guys the last word is inherently unfair.18

Given Santer’s serious scientific concerns about the substance of the Douglass et al. paper, as 

well as the process for publishing it, McGregor clearly felt it was his prerogative as the journal 

editor to accept Santer’s request for a quick turn-around and inclusion as a new submission. This 

is demonstrated by the e-mail cited by the petitioner in which Osborne says to Santer on January 

11, 2008: 

 

17 E-mail file 1199999668.txt, (January 10, 2008), page 1427, line 43 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

18 E-mail file 1200076878.txt, (January 11, 2008), page 1433, line 18 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

40
just heard back from Glenn. He’s prepared to treat it as a new submission rather than a comment 

on Douglass et al. and he also reiterates that “Needless to say my offer of a quick turn around 

time etc still stands.”19

The petitioner is correct that the publication of Santer as a new submission, rather than a 

comment gave Santer the last word on the subject in that particular issue of the journal. 

However, as stated above, Santer had made clear to IJC “Douglass et al. should have the 

opportunity to respond to our contribution.” As discussed in Volume 1, Section 1.2.1.2, we note 

that to date, Douglass et al. have not published a peer reviewed rebuttal to Santer et al.’s study or 

other literature on the issue, although they have had ample time to do so. 

In summary, the evidence does not suggest and no logical conclusion can be drawn that two 

papers being printed simultaneously “tainted the materials on which the Agency now seeks to 

rely” or challenges the key conclusions of the totality of scientific literature on the issue of an 

anthropogenic fingerprint in the tropics—as discussed in Volume 1, Section 1.2.1.2. Peabody 

Energy makes no arguments that the scientific reasoning or conclusions in the Santer et al. 

(2008) paper were inappropriate in any way, and instead draws broad, unsupported conclusions 

solely based on the timing of the various articles, which is irrelevant to their scientific merit. 

Various additional allegations of misconduct on the part of Santer and colleagues from Peabody 

Energy are discussed in several subsequent responses in this section. 

Comment (3-17): 

Peabody Energy states that Glenn McGregor, editor of IJC, intended to: 

....identify in “advance reviewers who are both suitable and available [to review the Santer et al. 

submission],” perhaps including “someone on the email list you’ve been using.” 20

It concludes “this appears to be a flagrant abuse of the review process, where reviewers are not 

permitted to be close associates of the author.” 

Response (3-17): 

It is standard practice when submitting a journal article for journal editors to request from 

authors a list of appropriate reviewers. Reviewers should not be directly contributing to the 

research of the authors, but may be colleagues who are experts on matters related to the subject 

and/or have published on related work. 

As a matter of fact, Tim Osborn, an editor at IJC, stated criteria for suggesting co-authors in an 

e-mail (partially cited by Peabody Energy): 

Obviously one reviewer could be someone who is already familiar with this discussion, 

because that would enable a fast review - i.e., someone on the email list you’ve been 

using - though I don’t know which of these people you will be asking to be co-authors 

 

19 E-mail file 1200076878.txt, (January 11, 2008), page 1433, line 9 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

20 E-mail file 1200076878.txt, (January 11, 2008), page 1434, line 25 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

41
and hence which won’t be available as possible reviewers. For objectivity the other 

reviewer would need to be independent, but you could still suggest suitable names.21

And, in fact, on January 11, 2008, Santer submitted a list of names to Tim Osborn, with the 

following preface: 

Here are some suggestions for potential reviewers of a Santer et al. IJoC submission on 

issues related to the consistency between modeled and observed atmospheric temperature 

trends. None of the suggested reviewers have been involved in the recent “focus group” 

that has discussed problems with the Douglass et al. IJoC paper.22

Thus, Peabody Energy’s allegation of “flagrant abuse of the review process” is not supported. 

Comment (3-18): 

Peabody Energy states: 

On January 10, 2008, Jones told the team [i.e. many of the scientists Santer and his 

colleagues corresponded with on this issue] (Wigley, K. Taylor, Lanzante, Mears, Bader, 

Zwiers, Wentz, Haimberger, Free, MacCracken, Jones, Sherwood, Klein, Solomon, 

Thorne, Osborn, Schmidt, and Hack) a “secret” he had learned from Osborn: that one of 

the recipients on the Santer e-mail list was one of the original reviewers of Douglass et al. 

(2007) who did not reject the article. 

The problem !! The person who said they would leave it to the editor’s 

discretion is on your email list! I don’t know who it is - Tim does - maybe they 

have told you? I don’t want to put pressure on Tim. He doesn’t know I’m 

sending this. It isn’t me by the way - nor Tim ! Tim said it was someone who 

hasn’t contributed to the discussion - which does narrow the possibilities down!23

Response (3-18): 

The petitioner excerpts this e-mail with no comment as it to its significance or implications. It 

appears to be simply an example of scientists, in a private communication, trying to determine 

who among them might have approved publication of a paper (i.e., Douglass et al.) that many of 

them felt was substandard. It has no demonstrated relevance to the integrity of the publication of 

the Santer et al. paper or the underlying science. 

Comment (3-19): 

Peabody Energy claims that this statement in an e-mail from Osborn to Santer and Jones on 

January 11, 2008 demonstrates “the impropriety of the situation” in which the Douglass et al. 

paper publication is delayed: 

 

21 E-mail file 1199999668.txt, (January 10, 2008), page 1428, line 4 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

22 E-mail file 1200059003.txt, (January 11, 2008), page 1432, line 17 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

23 E-mail file 1199999668.txt, (January 10, 2008), page 1427, line 9 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

42
the only thing I didn’t want to make more generally known was the suggestion that print 

publication of Douglass et al. might be delayed ... all other aspects of this discussion are 

unrestricted.24

Response (3-19): 

The petitioner does not explain why it is improper or of any scientific relevance that Osborn, an 

editor of IJC, would want to keep quiet the possibility that the print publication of Douglass et al. 

might be delayed. It is also not clear why Osborn wanted to keep it quiet. Instead of arguing the 

merits of the science, the petitioner relies instead on speculation of motivations. There is not 

material evidence of “impropriety.” 

As stated in our response (3-16) above, the electronic version of Douglass et al.—an official 

record of the publication—had been available to the public for months 

Comment (3-20): 

Peabody Energy ends its narrative discussion of this issue by referencing a series of e-mails 

composed during the Santer et al. paper review process, suggesting the journal editor, McGregor, 

had made efforts to “accommodate” Santer: 

McGregor informed Santer that he had received one set of comments and though he “... 

would normally wait for all comments to come in before providing them to you, I thought 

in this case I would give you a head start in your preparation of revisions.”25 Later, 

Santer wrote to Jones on July 10, 2008, that the two subsequent reviews were in, but 

reviewer number two was “somewhat crankier.”26 Santer indicated that McGregor had 

told him that he would not resend the coming revised manuscript to the “crankier” 

reviewer in another apparent effort by McGregor to accommodate Santer.27

Response (3-20): 

The petitioner does not explain why or how McGregor’s actions are relevant to the scientific 

legitimacy of Santer et al.’s study. First, the petitioner does not demonstrate how McGregor 

providing Santer et al. with one reviewer’s comments before the other two has any effect on the 

substance of Santer’s study or the legitimacy of the review process. The following e-mail from 

Santer to his co-authors on April 24, 2008, details how seriously Santer considered the comments 

from this first reviewer and discusses at length Santer’s initial thoughts on how to be responsive: 

Dear folks, 

I’m forwarding an email from Prof. Glenn McGregor, the IJoC editor who is handling our paper. 

The email contains the comments of Reviewer #1, and notes that comments from two additional 

 

24 E-mail file 1200076878.txt, (January 11, 2008), page 1433, line 13 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

25 E-mail file 1209080077.txt, (April 24, 2008), page 1484, line 23 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

26 E-mail file 1215712600.txt, (July 10, 2008), page 1536, line 12 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

27 E-mail file 1215712600.txt, (July 10, 2008), page 1536, line 12 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

43
Reviewers will be available shortly. Reviewer #1 read the paper very thoroughly, and makes a 

number of useful comments. The Reviewer also makes some comments that I disagree with. 

The good news is that Reviewer #1 begins his review (I use this personal pronoun because I’m 

pretty sure I know the Reviewer’s identity!) by affirming the existence of serious statistical errors 

in DCPS07 [Douglass, Christy, Pearson, and Singer, 2007] 

“I’ve read the paper under review, and also DCPS07, and I think the present authors are entirely 

correct in their main point. DCPS07 failed to account for the sampling variability in the 

individual model trends and, especially, in the observational trend. This was, as I see it, a clearcut statistical error, and the authors deserve the opportunity to present their counter-argument in 

print.” 

Reviewer #1 has two major concerns about our statistical analysis. Here is my initial reaction to 

these concerns. 

CONCERN #1: Assumption of an AR-1 [autoregressive] model for regression residuals. 

In calculating our “adjusted” standard errors, we assume that the persistence of the regression 

residuals is well-described by an AR-1 model. This assumption is not unique to our analysis, and 

has been made in a number of other investigations. The Reviewer would “like to see at least 

some sensitivity check of the standard error formula against alternative model assumptions.” 

Effectively, the Reviewer is asking whether a more complex time series model is required to 

describe the persistence. 

Estimating the order of a more complex AR model is a tricky business. Typically, something like 

the BIC (Bayesian Information Criterion) or AIC (Akaike Information Criterion) is used to do 

this. We could, of course, use the BIC or AIC to estimate the order of the AR model that best fits 

the regression residuals. This would be a non-trivial undertaking. I think we would find that, for 

different time series, we would obtain different estimates of the “best-fit” AR model. For 

example, 20c3m runs without volcanic forcing might yield a different AR model order than 

20c3m runs with volcanic forcing. It’s also entirely likely (based on Rick ’Katz’s experience 

with such AR model-fitting exercises) that the AIC- and BIC-based estimates of the AR model 

order could differ in some cases. 

As the Reviewer himself points out, DCPS07 “didn’t make any attempt to calculate the standard 

error of individual trend estimates and this remains the major difference between the two papers.” 

In other words, our paired trends test incorporates statistical uncertainties for both simulated and 

observed trends. In estimating these uncertainties, we account for non-independence of the 

regression residuals. In contrast, the DCPS07 trend “consistency test” does not incorporate ANY 

statistical uncertainties in either observed or simulated trends. This difference in treatment of 

trend uncertainties is the primary issue. The issue of whether an AR-1 model is the most 

appropriate model to use for the purpose of calculating adjusted standard errors is really a 

subsidiary issue. My concern is that we could waste a lot of time looking at this issue, without 

really enlightening the reader about key differences between our significance testing procedure 

and the DCPS07 approach. 

One solution is to calculate (for each model and observational time series used in our paper) the 

parameters of an AR(K) model, where K is the total number of time lags, and then apply equation 

8.39 in Wilks (1995) to estimate the effective sample size. We could do this for several different 

44
K values (e.g., K=2, K=3, and K=4; we’ve already done the K=1 case). We could then very 

briefly mention the sensitivity of our “paired trend” test results to choice of order K of the AR 

model. This would involve some work, but would be easier to explain than use of the AIC and 

BIC to determine, for each time series, the best-estimate of the order of the AR model. 

CONCERN #2: No “attempt to combine data across model runs” 

The Reviewer is claiming that none of our model-vs-observed trend tests made use of data that 

had been combined (averaged) across model runs. This is incorrect. In fact, our two modified 

versions of the DCPS07 test (page 29, equation 12, and page 30, equation 13) both make use of 

the multi-model ensemble-mean trend. 

The Reviewer argues that our paired trends test should involve the ensemble-mean trends for each 

model (something which we have not done) rather than the trends for each of 49 individual 

20c3m realizations. I’m not sure whether the rationale for doing this is as “clear-cut” as the 

Reviewer contends. 

Furthermore, there are at least two different ways of performing the paired trends tests with the 

ensemble-mean model trends. One way (which seems to be what the Reviewer is advocating) 

involves replacing in our equation (3) the standard error of the trend for an individual realization 

performed with model A with model A’s intra-ensemble standard deviation of trends. I’m a little 

concerned about mixing an estimate of the statistical uncertainty of the observed trend with an 

estimate of the sampling uncertainty of model A’s trend. 

Alternately, one could use the average (over different realizations) of model A’s adjusted 

standard errors, or the adjusted standard error calculated from the ensemble-mean model A time 

series. I’m willing to try some of these things, but I’m not sure how much they will enlighten the 

reader. And they will not help to make an already-lengthy manuscript any shorter. 

The Reviewer seems to be arguing that the main advantage of his approach #2 (use of ensemblemean model trends in significance testing) relative to our paired trends test (his approach #1) is 

that non-independence of tests is less of an issue with approach #2. I’m not sure whether I agree. 

Are results from tests involving GFDL CM2.0 and GFDL CM2.0 temperature data truly 

“independent” given that both models were forced with the same historical changes in 

anthropogenic and natural external forcings? The same concerns apply to the high- and lowresolution versions of the MIROC model, the GISS models, etc. 

I am puzzled by some of the comments the Reviewer has made at the top of page 3 of his review.

I guess the Reviewer is making these comments in the context of the pair-wise tests described on 

page 2. Crucially, the comment that we should use “...the standard error if testing the average 

model trend” (and by “standard error” he means ’DCPS07’s sigma{SE}) IS INCONSISTENT 

with the Reviewer’s approach #3, which involves use of the inter-model standard deviation in 

testing the average model trend. 

And I disagree with the Reviewer’s comments regarding the superfluous nature of Section 6.

The Reviewer states that, “when simulating from a known (statistical) model... the test statistics 

should by definition give the correct answer. The whole point of Section 6 is that the DCPS07 

consistency test does NOT give the correct answer when applied to randomly-generated data! 

45
In order to satisfy the Reviewer’s curiosity, I’m perfectly willing to repeat the simulations 

described in Section 6 with a higher-order AR model. However, I don’t like the idea of 

simulation of synthetic volcanoes, etc. This would be a huge time sink, and would not help to 

illustrate or clarify the statistical mistakes in DCPS07. 

It’s obvious that Reviewer #1 has put a substantial amount of effort into reading and commenting 

on our paper (and even performing some simple simulations). I’m grateful for the effort and the 

constructive comments, but feel that a number of comments are off-base. Am I misinterpreting 

the Reviewer’s comments? 

With best regards, 

Ben28

As evidenced by this detailed and substantive scientific discussion of the reviewers comments, 

Santer treated the peer review process seriously and focused carefully on the scientific merits of 

the reviewer’s comments. Petitioners, however, have raised no scientific arguments or 

objections, and instead rely solely on speculation concerning motivations. 

Concerning the second review, the petitioner does not discuss why McGregor’s decision not to 

send Santer’s revised manuscript back to the second reviewer is an accommodation or somehow 

irregular. Santer’s e-mail to his co-authors about the second reviewer’s comments simply 

indicates that McGregor—as journal editor—had communicated to Santer that he was not 

sending the next draft of the manuscript back to this reviewer. The CRU e-mails do not explain 

McGregor’s reasoning, and the petitioner relies on speculation. 

Although Santer was told the second reviewer would not see the manuscript again, he was 

diligent in describing to McGregor why one of the second reviewer’s criticisms was not of 

central relevance. Santer wrote to McGregor on July 10, 2008: 

Dear Glenn, 

I thought you might be interested in this email exchange with Francis Zwiers [one of 

Santer’s co-authors]. It’s directly relevant to the third criticism raised by Reviewer 2. 

With best regards, 

Ben29

Santer attached a detailed, highly technical discussion from Zwiers pertaining to this third 

criticism and his response to Zwiers in which he stated his agreement. 

Thanks - this information will be extremely helpful in responding to Reviewer 2. I really 

do feel that the Reviewer is getting overly exercised about a relatively minor technical 

point.30

 

28 E-mail file 1209080077.txt, (April 24, 2008), page 1482, line 1 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

29 E-mail file 1215713915.txt, (July 10, 2008), page 1537, line 25 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

46
To summarize, the petitioner does not substantiate any improper procedures on the part of either 

Santer or McGregor in this process, nor does the petitioner present any scientific basis to 

question the scientific validity of the analysis and conclusions contained in the Santer et al. 

(2008) paper. 

Comment (3-21): 

Peabody Energy states that it appears that Glenn McGregor, editor of IJC, breached 

confidentiality obligations by disclosing the page proofs of Douglass et al. (2007) to New York 

Times reporter Andrew Revkin, who then disclosed them to Santer and two other unnamed 

scientists a week before initial publication online. The petitioner makes a general claim that “use 

of confidential information” should cause EPA to question Santer et al.’s work. Peabody Energy 

quotes Revkin’s e-mail: “Sorry to take your time up, but really do need a scrub of 

singer/christy/etc effort.”31 

Response (3-21): 

It is customary for journals to provide embargoed versions of articles to journalists prior to 

publication. Thus, it does not appear that confidentiality was breached by McGregor. 

Furthermore, the petitioner does not discuss how the alleged breach of confidentiality bears on 

the legitimacy of the publication process of either the Douglass et al. or Santer et al. papers, or 

on the scientific validity of the analyses and concussion in either paper. Our evaluation of the 

scientific issues involved with the Douglass and Santer papers is provided in Volume 1, Section 

1.2.1.2 of this RTP document. 

Petitioners’ evidence does not support their claim that the journal publication process was 

manipulated or improper, nor do the petitioners provide any other evidence that would cause 

EPA to question the conclusions drawn about the scientific merits of the issues involved in these 

papers. 

Comment (3-22): 

Peabody Energy argues that Michael Mann and Kevin Trenberth (of the National Center for 

Atmospheric Research) improperly sought special treatment to get their comment (Foster et al. 

2010) on a paper by McLean et al. (2009) published immediately in the Journal of Geophysical 

Research. According to the petitioner, their improper actions included violating the journal’s 

policy that reviewers recommended by the authors could not be their close associates, and giving 

a copy of their manuscript to Michael McPhaden, president of the American Geophysical Union 

(AGU), which publishes the journal. The petitioner concludes that these examples provide 

evidence that “peer-review publication rules” were manipulated in an attempt to favor 

publication of supporting views of anthropogenic climate change. Peabody Energy argues that 

the Endangerment Finding should be reconsidered because it relied on biased peer-reviewed 

literature that does not reflect the true breadth of the science. 

 30 E-mail file 1215713915.txt, (July 10, 2008), page 1538, line 18 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

31 E-mail file 1196795844.txt, (December 4, 2007). page 1360, line 4 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

47
Response (3-22): 

First, we note that McLean et al. (2009) was published on July 23, 2009, and Foster et al. (2010) 

was published about 10 months later on May 14, 2010. This fact alone refutes the petitioner’s 

claim that there was any “special treatment” that resulted in immediate publication of Foster et 

al. (2010). Furthermore, the petitioner’s argument does not discuss the merits of the science in 

either paper, or any alleged harm to the McLean et al. (2009) paper resulting from the 

publication of Foster et al. (2010). It is well within the norms of the scientific community to 

write and attempt to publish rebuttals to published journal articles if one can demonstrate that 

there are scientific insufficiencies. Responses can be submitted either as separate manuscripts or 

as “comments” on a given paper. There is no credible evidence to suggest that the authors of 

Foster et al. (2010) overstepped the bounds of common practice in submitting their response and 

asking that it be reviewed expeditiously. In addition, the petitioner makes an unsubstantiated 

assumption that the reviewers suggested by the authors of Foster et al. (2010) would be biased in 

favor of the paper. There is no evidence to support the petitioner’s claim that these 

recommended reviewers would be unable or unwilling to provide objective critique of a 

manuscript. Ultimately, any decisions as to the timing of review, the selection of peer reviewers, 

and whether and when a paper is published are solely the responsibility of the journal editor. 

This example does not support the petitioner’s argument that the journal publication process was 

manipulated, nor does the petitioner provide any other evidence that would cause EPA to change 

its view on the scientific issues involved in these papers. Petitioner has failed to provide any 

arguments based on the science. 

To summarize Section 3.3.3, petitioners argue that the scientific record for the Endangerment 

Finding is biased because of improper practices in publication of certain journal articles. Their 

evidence is limited to only a few articles. They focus on claims of when the hard copy of one 

article was published, as well as changes in the editorial board at one journal. Their claims of 

improper practices are broad and sweeping, but are not supported by the evidence they present. 

Their claims are based largely on speculation, and they fail to provide any scientific argument to 

contest the scientific analysis or conclusions of the articles they object to. They fail to show 

improper action, whether for the articles at issue or more broadly. They fail provide a basis to 

question EPA’s views on the scientific issues involved in the papers. 

3.3.4 Allegations Regarding Efforts to Remove Editors and Boycott Journals 

Comment (3-23): 

The Coalition for Responsible Regulation, the Ohio Coal Association, Peabody Energy, the 

Southeastern Legal Foundation, and the State of Texas argue that the CRU e-mail authors 

threatened to boycott the journal Climate Research and endeavored to have one of its editors, 

Chris de Freitas, removed because the journal had published a paper by Soon and Baliunas 

(2003) with which that they did not agree. The Southeastern Legal Foundation asserts that 

“After Messrs. Jones and Mann threatened a boycott of publications and reviews, half of the 

editorial board of Climate Research resigned.” Peabody Energy claims that “[i]n response to 

these protests, wholesale changes were made in the editorial staff at Climate Research.” The 

State of Texas argues that when “the group learned that Climate Research planned to publish so48
called skeptical literature, the climatologists responded less like objective scientists eager to let 

the science determine the answer, and more like activists working to advance their preferred 

result.” The Southeastern Legal Foundation claims that this is an example of “a concerted effort 

to purge dissenting views from the scientific literature.” The Pacific Legal Foundation also 

references this example, stating that the CRU e-mails “...appear to show attempts to ‘discipline’ 

scientists and journalists who published skeptical information.” The petitioners quote a number 

of CRU e-mails in support of their arguments. 

More specifically, the Ohio Coal Association and Peabody Energy quote a statement from Phil 

Jones: “I will be e-mailing the journal to tell them I’m having nothing more to do with it until they 

rid themselves of this troublesome editor.32” The Southeastern Legal Foundation and Peabody 

Energy quote the following e-mail from Michael Mann: 

I think we have to stop considering ‘Climate Research’ as a legitimate peer-reviewed journal. We 

would also need to consider what we tell or request of our more reasonable colleagues who 

currently sit on the editorial board. Perhaps we should encourage our colleagues in the climate 

research community to no longer submit to, or cite papers in, this journal.33 

Peabody Energy quotes an e-mail from Tom Wigley, characterizing his words as “urging a fullscale assault on the editorial board”: 

PS Re CR [Climate Research], I do not know the best way to handle the 

specifics of the editoring [sic]. Hans von Storch [another editor at Climate 

Research] is partly to blame -- he encourages the publication of crap science ‘in 

order to stimulate debate’. One approach is to go direct to the publishers and point 

out the fact that their journal is perceived as being a medium for disseminating 

misinformation under the guise of refereed work. I use the word ‘perceived’ here, 

since whether it is true or not is not what the publishers care about -- it is how the 

journal is seen by the community that counts. 

I think we could get a large group of highly credentialed scientists to sign such a 

letter -- 50+ people. Note that I am copying this view only to Mike Hulme and 

Phil Jones. Mike’s idea to get editorial board members to resign will probably not 

work -- must get rid of von Storch too, otherwise holes will eventually fill up with 

people like Legates, Balling, Lindzen, Michaels, Singer, etc. I have heard that the 

publishers are not happy with von Storch, so the above approach might remove that 

hurdle too34.”

Peabody Energy then quotes a statement from the publisher of Climate Research, Otto Kinne, 

which attempts to defend de Freitas’ decision to publish the Soon and Baliunas paper: 

 

32 E-mail file 1047388489.txt, (March 11, 2003), page 456, line 30 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

33 E-mail file 1047388489.txt, (March 11, 2003), page 457, line 13 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

34 E-mail file 1051190249.txt, (April 24, 2003), page 488, line 11 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

49
Dear colleagues, In my [June, 20 2003] e-mail to you I stated, among other 

things, that I would ask C[limate] R[esearch] editor Chris de Freitas to present to 

me copies of the reviewers’ evaluations for the 2 Soon et al. papers. I have 

received and studied the material requested. Conclusions: 1) The reviewers 

consulted (4 for each ms) by the editor presented detailed, critical and helpful 

evaluations. 2) The editor properly analyzed the evaluations and requested 

appropriate revisions. 3) The authors revised their manuscripts accordingly. 

Summary: Chris de Freitas has done a good and correct job as editor.35 

As further evidence of the CRU e-mail authors’ protests against this editor and journal, Peabody 

Energy quotes Mann’s response that Kinne’s words were “disingenuous” and said “I think that 

the community should, as previously suggested in this eventuality, terminate its involvement with 

this journal at all levels--reviewing, editing, and submitting, and leave it to wither way into 

oblivion and disrepute.”36

Peabody Energy then quotes Wigley’s response: “I agree that Kinne seems like he could be a 

deFreitas clone. However, what would be our legal position if we were to openly and extensively 

tell people to avoid the journal?”37 The petitioner also quotes Santer’s response: “Based on 

Kinne’s editorial, I see little hope for more enlightened editorial decision making at Climate 

Research. Tom, Richard Smith and I will eventually publish a rebuttal to the Douglass et al. paper. 

We’ll publish this rebuttal in JGR - not in Climate Research.”38

The petitioner concludes that these e-mails provide evidence that the e-mail authors interfered 

with journal editorial boards in an attempt to suppress publication of dissenting views about 

anthropogenic climate change. Peabody Energy argues that the Endangerment Finding should be 

reconsidered because it relied on biased peer-reviewed literature that does not reflect the true 

breadth of the science. 

Response (3-23):

The context to the petitioners’ arguments is the Soon and Baliunas (2003) paper published in the 

journal Climate Research. This paper was subsequently heavily and broadly criticized by the 

scientific community in peer-reviewed journals. A scientific rebuttal to Soon and Baliunas 

(2003) was published in the AGU journal Eos (Mann et al., 2003). 

The publication of this paper revealed problems with the peer review process at Climate 

Research, which eventually resulted in the resignation of three people on the editorial board 

when they could not come to an agreement with the publisher on how to revamp the peer-review 

process in the wake of the controversy (Kinne, 2003). Petitioners assume that because the 

resignations occurred after the CRU e-mail authors threatened to boycott the journal, the 

 

35 E-mail file 1057941657.txt, (July 11, 2003), page 546, line 13 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

36 E-mail file 1057941657.txt (July 11, 2003), page 547, line 18 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

37 E-mail file 1057941657.txt (July 11, 2003), page 547, line 12 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

38 E-mail file 1057941657.txt (July 11, 2003), page 547, line 1 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

50
resignations must be a result of that threat. However, Climate Research publisher Otto Kinne 

later admitted in a statement published in the journal that the Soon and Baliunas paper was 

flawed and should not have been published, expressed regret that the journal had lost three 

editors due to the controversy, and promised to strengthen the journals’ peer review policies 

(Kinne, 2003). Thus, the petitioners’ claims that it was the actions of the CRU e-mail authors 

that resulted in changes to the editorial board of Climate Research are without merit. 

It is clear from the quoted e-mails that the CRU scientists and their colleagues believed that there 

was a failure of the peer review process at Climate Research that allowed a scientifically flawed 

paper to be published. Subsequent events have demonstrated that their views were justified; as 

shown by the publication of Mann et al.’s (2003) scientific rebuttal. It is not inappropriate or 

uncommon for scientists to challenge the validity of each ’others work. It is well within the 

norms of the scientific community to write and publish comments or responses and otherwise 

challenge published journal articles if one can demonstrate that there are scientific 

insufficiencies. Such challenges are indeed essential to the progress of science. The critical 

issue is that such challenges should be focused on scientific and factual grounds. The scientists 

reacted reasonably by publishing a rebuttal to the Soon and Baliunas paper in a different peerreviewed journal (Mann et al., 2003). 

Science is a community-based professional enterprise in which it is expected and appropriate that 

researchers choose in which journals to publish, as well as recommend to their peers journals in 

which to publish or not publish. In this case, the bottom line is that the underlying science at 

issue has been shown to be flawed. The scientists’ actions were focused on this lack of scientific 

merit and the process that lead to it, and not an attempt to distort the science or the scientific 

literature. We disagree with the petitioner’s claim that the CRU e-mail authors acted like 

“activists” and not like scientists. Their focus was clearly on the scientific merits of the study at 

issue and the scientific integrity of the peer review process. There is no evidence to suggest that 

the CRU e-mail authors were attempting to manipulate the peer-reviewed literature. If anything, 

their actions aimed to police the peer review process and rectify a problem that threatened its 

scientific integrity. 

We also note that the e-mails cited by the petitioner are simply statements of displeasure, not 

indications that any actions were undertaken. It is legitimate and entirely reasonable that these 

scientists expressed their opinions about a situation that concerned them. There is no evidence 

that the CRU e-mail authors engaged in any actions that were unethical, or otherwise outside the 

norms of scientific practice. Moreover, there are hundreds of journals relevant to climate science 

and many editors at each, so to claim that any change in the editorial board at one journal 

somehow biased the vast wealth of climate change studies or called into question the overall 

conclusions reached from those thousands of papers is unwarranted and unsupported. 

Comment (3-24):

The State of Texas and the Coalition for Responsible Regulation claim that the CRU e-mail 

authors sought to remove an editor from Geophysical Research Letters (GRL) because they did 

not agree with his views on climate science. They quote the following e-mail from Tom Wigley: 

This is truly awful. GRL has gone downhill rapidly in recent years...Proving bad 

behavior here is very difficult. If you think that [the objectionable editor] is in the 

51
greenhouse skeptics camp, then, if we can find documentary evidence of this, we could 

go through official AGU channels to get him ousted.39

The Pacific Legal Foundation also references this example, stating that the CRU e-mails 

“...appear to show attempts to ‘discipline’ scientists and journalists who published skeptical 

information.” The State of Texas argues that the CRU e-mail authors’ language reflects an “us 

versus them” attitude more commonly associated with legal advocacy or team sports than the 

scientific method. The petitioner quotes an e-mail from Michael Mann: “What a shame that 

would be. It’s one thing to lose ‘Climate Research’ [sic]. We can’t afford to lose GRL.” 

The State of Texas states that “Wigley’s goal of removing the editor” was successful, quoting a 

statement from Pat Michaels of the Cato Institute, who said that the departure of the GRL editor, 

James Saiers, “coincided with Mann, Wigley, and Dr. Jones’s plan to ‘get him ousted’” 

[Michaels, 2009a]. The State of Texas and the Coalition for Responsible Regulation also quote 

an e-mail from Michael Mann: “the GRL leak may have been plugged up now w/ new editorial 

leadership there.”40

The petitioners conclude that these e-mails provide evidence that their authors interfered with 

journal editorial boards in an attempt to suppress publication of dissenting views about 

anthropogenic climate change. The petitioners argue that the Endangerment Finding should be 

reconsidered because it relied on biased peer-reviewed literature that does not reflect the true 

state of the science. 

Response (3-24):

First, we note that there is no evidence that any actions by the CRU e-mail authors were taken or 

they resulted in the dismissal or replacement of the editor, and there is also no evidence that they 

took inappropriate actions. The e-mails show the scientists discussing plans to record evidence 

of potential political bias by one of the journal’s editors. Michael Mann states, “If there is a clear 

body of evidence that something is amiss, it could be taken through the proper channels” 41 The 

e-mails depict scientists’ reaction to what they believed was bias within the peer review process. 

Again, petitioners assume that because the resignation occurred after the CRU e-mail authors 

talked among themselves, it must be a result of actions by the e-mail authors. This claim is 

unsupported by any evidence provided by the petitioners, however, and they do not show that the 

scientists engaged in improper behavior or claimed sabotage of the journal or its editors. There 

is also no evidence that any action by the scientists resulted in the replacement of the journal 

editor. To the contrary, we note that the GRL editor in question was James Saiers, who was 

quoted in an article in the Guardian newspaper saying simply that “his three-year term was up” 

(Pearce, 2010). Saiers also stated, “My departure had nothing to do with attempts by Wigley or 

 

39 E-mail file 1106322460.txt (January 20, 2005), page 809, line 14 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

40 E-mail file 1132094873.txt, (November 15, 2005), page 989, line 25 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

41 E-mail file 1106322460.txt, (January 20, 2005), page 809, line 7 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

52
anyone else to have me sacked...nor was I censured, as I have seen suggested on a blog posting 

written by McKitrick.” Thus, it appears that Saiers left voluntarily when his term ended, and that 

his departure was unrelated to any actions of the CRU e-mail authors. 

As stated in our previous response (3-23), it is not unethical or inappropriate for scientists to 

challenge or oppose—on scientific and factual grounds—the actions of a journal editor that 

approved the publication of research that they believe is flawed. Just as they were concerned for 

editorial integrity at Climate Research, the CRU scientists and their colleagues were concerned 

about what they viewed as a failure of the peer review process at GRL. The evidence does not 

suggest that the CRU e-mail authors were attempting to manipulate the peer-reviewed literature, 

nor that they engaged in any actions that were unethical or otherwise outside the norms of 

scientific practice. Moreover, there are hundreds of journals relevant to climate science and 

many editors at each, so to claim that any change in the editorial board at one journal somehow 

biased the vast wealth of climate change studies or called into question the overall conclusions 

reached from those thousands of papers is unwarranted and unsupported. 

Comment (3-25): 

The Coalition for Responsible Regulation claims that the CRU e-mails show that Phil Jones and 

Ben Santer “went over the head of the editor of Weather, with Jones threatening the Royal 

Meteorological Society [RMS] Chief Executive that he would no longer submit information to 

Royal Meteorological Society journals if the Weather editor refused to ‘back down’ 

[1237496573.txt].” The Coalition for Responsible Regulation provides no additional context for 

this exchange, but claims that it is another example of the CRU scientists and their colleagues 

interfering with the editorial boards of scientific journals in order to publish only those papers 

that agreed with their positions. 

The petitioners conclude that these e-mails provide evidence that their authors interfered with 

journal editorial boards in an attempt to favor publication of papers that supported their views 

about anthropogenic climate change. The petitioners argue that the Endangerment Finding 

should be reconsidered because it relied on biased peer-reviewed literature that does not reflect 

the true breadth of the science. 

Response (3-25): 

From our review of the CRU e-mails, the context for the petitioner’s quote is that Phil Jones 

submitted a paper with fellow CRU scientist David Lister on urban heat islands (UHI) to the 

journal Weather—i.e., Jones and Lister (2009). Contrary to what the petitioner implies, Ben 

Santer was not involved with the paper; he simply received an e-mail about it from Jones. It 

appears that Jones received comments back from the editor at Weather with which he did not 

agree. Jones states: 

I’ve written up the London paper for the RMS journal Weather, but having trouble with 

their new editor. He’s coming up with the same naive comments that these responders 

are. He can’t understand that London has a UHI of X, but that X has got no bigger since 

1900.42 

 

42 E-mail file 1237474374.txt, (March 19, 2009), page 1647, line 37 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

53
In another e-mail, Jones states: 

In my 2 slides worth at Bethesda I will be showing London’s UHI and the effect that it 

hasn’t got any bigger since 1900. It’s easy to do with 3 long time series. It is only one 

urban site (St James Park), but that is where the measurements are from. Heathrow has a 

bit of a UHI and it has go[t] bigger. I’m having a dispute with the new editor of 

Weather. I’ve complained about him to the RMS Chief Exec. If I don’t get him to back 

down, I won’t be sending any more papers to any RMS journals and I’ll be resigning 

from the RMS. The paper is about London and its UHI!43

First, we note that the science of UHIs and their relationship to climate change is addressed in 

Volume 1, Section 1.3.4 of this RTP document. However, the petitioner does not argue based on 

the scientific information presented in the manuscript in question, which was eventually accepted 

and published in Weather (Jones and Lister, 2009). Rather, the petitioner takes issue with the 

fact that Jones complained about the editor and made statements about boycotting the journal in 

the future, which the petitioner claims is evidence that Jones inappropriately interfered with the 

peer review and publication process at Weather. Phil Jones is within his rights as a scientist and 

author to choose the journals to which he submits his papers. We disagree with the petitioner 

that Jones’ statements constitute “interference” or inappropriate action. 

The Independent Climate Change E-mails Review examined this general issue and reached a 

similar conclusion: 

In conclusion, it is common for editors to have multiple, intense, and sometimes sharp 

and passionate interactions with authors and reviewers. The tone of their exchanges and 

communications with editors can be attacking, accusatory, aggressive, and even personal. 

If a research paper is especially controversial and word of it is circulating in a particular 

scientific community, third-party scientists or critics with an interest in the work may get 

to hear of it and decide to contact the journal. They might wish to warn or encourage 

editors. This kind of intervention is entirely normal. It is the task of editors to weigh up 

the passionate opinions of authors and reviewers, and to reflect on the comments (and 

motivations) of third parties. 

This example does not support the petitioner’s arguments that the journal publication process 

was manipulated. 

To summarize Section 3.3.4, petitioners’ evidence does not support their claims that the journal 

publication process was improperly influenced. Their evidence shows scientists with strong 

scientific opinions on the scientific merits of various papers, and opinions about the scientific 

integrity of the peer review process at certain journals. It appears that in one case the journal 

determined that mistakes had been made in publishing a flawed paper. In another case an editor 

resigned and publicly stated it had nothing to do with the scientists that petitioners point to. 

 

43 E-mail file 1237496573.txt, (March 19, 2009), page 1649, line 21 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

54
Petitioners’ broad, sweeping conclusions about improper actions by the scientists are speculative 

and not supported by the evidence. 

As in other claims discussed above, petitioners do not base their claims on scientific arguments. 

They do not argue that the scientists at issue here were wrong in their scientific analyses or 

conclusions, or in their critiques of other studies. They do not provide evidence of any scientific 

paper or research that was not but should have been published. Their broad claim that EPA 

relied upon a body of peer reviewed literature that was biased and did not reflect the true breadth 

of the science is not supported by the evidence they present. Their assertions are not based on 

any scientific arguments or evidence, but instead rely upon unwarranted speculation. 

3.3.5 Allegations Regarding Objectivity of the Peer-Reviewed Literature 

Comment (3-26):

Peabody Energy argues that “Michael Mann and his collaborators engaged in a decade-long 

campaign of preventing dissenting scientific voices from being heard.” Peabody Energy states 

that one of Mann’s former collaborators, Raymond Bradley, disassociated himself from 

comments made to the editor of the journal Science after it published a paper with which Mann 

disagreed. Peabody Energy quotes part of an e-mail written by Bradley on April 19, 1999 to the 

editor at Science: 

As for thinking that it is “Better that nothing appear, than something 

unacceptable to us”...as though we are the gatekeepers of all that is acceptable in 

the world of paleoclimatology seems amazingly arrogant. Science moves forward 

whether we agree with individual articles or not.44

Peabody Energy asserts that in the end, Mann and his colleagues acted as gatekeepers to the 

peer-reviewed literature, in marked contrast to Mann’s stance in his 2009 letter to the editor of 

The Wall Street Journal. Peabody Energy provides the following excerpt from the letter: 

Society relies upon the integrity of the scientific literature to inform sound policy. 

It is thus a serious offense to compromise the peer-review system in such a way as 

to allow anyone—including proponents of climate change science—to promote 

unsubstantiated claims and distortions[Mann, 2009]. 

Peabody Energy argues that the Endangerment Finding should be reconsidered because it relied 

on peer-reviewed literature that is biased in favor of views supporting anthropogenic climate 

change and does not reflect the true breadth of the science. 

Response (3-26):

The petitioner quotes only one part of one e-mail from Bradley, and fails to provide the context 

for the incident they are describing, which occurred more than 10 years ago. In context, it 

appears Mann is referring to specific language he objected to in a draft article he was reviewing 

for the journal Science. This drafting issue was later resolved to the satisfaction of the author of 

 

44 E-mail file 0924532891.txt (April 19, 1999), page 155, line 16 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

55
the article, and does not indicate any attempt to suppress opposing views or some “decades long” 

attempt to do so. To understand Mann’s statement in context, we include three relevant e-mails 

below, in full. The first is the full text of Bradley’s e-mail to the editor at Science, sent April 19, 

1999. The second is an e-mail from Phil Jones to Michael Mann regarding Mann’s reaction to 

the draft article in Science, sent May 6, 1999. The third is an e-mail from Mann to Jones and 

others involved in writing, reviewing, or editing the draft article in Science, sent on May 12, 

1999. 

Date: Mon, 19 Apr 1999 10:06:52 -0400 

To: juppenbrink@science-int.co.uk [editor at Science] 

From: “Raymond S. Bradley” rbradley@geo.umass.edu 

Subject: Climate warming prespctives article 

Cc: mann@snow.geo.umass.edu, mhughes@ltrr.arizona.edu 

I have just returned from Finland and have now read all the correspondence regarding 

the Science perspectives article you asked Keith Briffa & Tim Osborn to write. I’ve sent 

Tim Osborn & Keith Briffa a few suggestions re their perspectives article. If you would 

like to see them, let me know. I would like to diasassociate myself from Mike Mann’s 

view that “xxxxxxxxxxx” [original text x’ed out in released e-mails] and that they 

“xxxxxxxxxxxxx” [original text x’ed out in released e-mails]. I find this notion quite 

absurd. I have worked with the UEA [University of East Anglia] group for 20+ years and 

have great respect for them and for their work. Of course, I don’t agree with everything 

they write, and we often have long (but cordial) arguments about what they think versus 

my views, but that is life. Indeed, I know that they have broad disagreements among 

themselves, so to refer to them as “the UEA group”, as though they all march in lock-step 

seems bizarre. As for thinking that it is “Better that nothing appear, than something 

unnacceptable to us” .....as though we are the gatekeepers of all that is acceptable in the 

world of paleoclimatology seems amazingly arrogant. Science moves forward whether 

we agree with individiual articles or not.... Sincerely, Raymond S. Bradley45 

From: Phil Jones <p.jones@xxxxxxxxx.xxx> 

To: mann@xxxxxxxxx.xxx 

Subject: Straight to the Point 

Date: Thu, 06 May 1999 17:37:34 +0100 

Cc: k.briffa@xxxxxxxxx.xxx,t.osborn@xxxxxxxxx.xxx,mhughes@xxxxxxxxx.xxx, 

rbradley@xxxxxxxxx.xxx 

Mike, 

Just back from two weeks away and from discussions with Keith and Tim and some 

e-mails you seem quite pissed off with us all in CRU. I am somewhat at a loss to 

understand why. It is clear from the e-mails that this relates to the emphasis placed on a 

few words/phrases in Keith/Tim’s Science piece. These may not be fully resolved but the 

piece comes out tomorrow. I don’t want to open more wounds but I might by the end of 

the e-mail. I’ve not seen the censored e-mail that Ray has mentioned but this doesn’t, to 

my way of working, seem to be the way you should be responding - ie slanging us all off 

 

45 E-mail file 0924532891.txt (April 19, 1999), page 155, line 16 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

56
to Science. We are all trying to work together for the good of the ‘Science’. We have 

disagreements - Ray, Malcolm, Keith and me have in the past, but they get aired and 

eventually forgotten. We have never resorted to slanging one another off to a journal (as 

in this case) or in reviewing papers or proposals. You may think Keith or I have 

reviewed some of your papers but we haven’t. I’ve reviewed Ray’s and Malcolm’s - 

constructively I hope where I thought something could have been done better. I also 

know you’ve reviewed my paper with Gabi very constructively. 

So why all the beef now? Maybe it started with my Science piece last summer. 

When asked to do this it was stressed to that I should discuss how your Nature paper 

fitted in to the current issues in paleoclimatology. This is what I thought I was doing. 

Julia Uppenbrink asked me to do the same with your GRL paper but I was too busy and 

passed it on to Keith. Again it seems a very reasoned comment. 

I would suspect that you’ve been unhappy about us coming out with a paper going 

back 1000 years only a few months after your Nature paper (back to 1400). Ray knew all 

about this as he was one of the reviewers. Then the second Science comment has come 

out with a tentative series going back 2000 years. Both Science pieces give us a chance 

to discuss issues highly relevant to the ‘science’, which is what we have both tried to do. 

Anyway that’s enough for now - I’ll see how you’ll respond, if at all. There are two 

things I’m going to say though: 

1) Keith didn’t mention in his Science piece but both of us think that you’re on very 

dodgy ground with this long-term decline in temperatures on the 1000 year timescale. 

What the real world has done over the last 6000 years and what it ought to have done 

given our understanding of Milankovic forcing are two very different things. I don’t 

think the world was much warmer 6000 years ago - in a global sense compared to the 

average of the last 1000 years, but this is my opinion and I may change it given more 

evidence. 

2) The errors don’t include all the possible factors. Even though the tree-ring 

chronologies used have robust rbar statistics for the whole 1000 years (ie they lose 

nothing because core numbers stay high throughout), they have lost low frequency 

because of standardization. We’ve all tried with RCS [regional curve standardized]/very 

stiff splines/hardly any detrending to keep this to a minimum, but until we know it is 

minimal it is still worth mentioning. It is better we (I mean all of us here) put the caveats 

in ourselves than let others put them in for us. 

3) None of us here are trying to get material into IPCC. I’ve given you my input 

through the review of the chapter in Asheville. I may get a chance to see the whole thing 

again at some stage, but I won’t be worried if I don’t. 

I can’t think of a good ending, but hoping for a favourable response, so we can still 

work together. Cheers, Phil46

From: mann@xxxxxxxxx.xxx 

Date: Wed, 12 May 1999 13:00:09 -0400 (EDT) 

To: juppenbrink@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx, 

t.osborn@xxxxxxxxx.xxx 

Cc: mann@xxxxxxxxx.xxx, mhughes@xxxxxxxxx.xxx, p.jones@xxxxxxxxx.xxx, 

 rbradley@xxxxxxxxx.xxx 

 

46 E-mail file 0926026654.txt (May 6, 1999), page 164, line 18 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

57
Dear all, 

Thanks for working so hard to insure a final product that was acceptable to all. I 

think that Keith and Tim are to be commended on a fine job w/ the final version of the 

Perspectives piece that appeared, and I thank Julia for her especially difficult editorial 

task. I appreciate having had the opportunity to respond to the original draft. I think this 

opportunity is very important in such cases (ie, where a particular author/groups work is 

the focus of a commentary by someone else), and hope that this would be considered 

standard procedure in the future in such instances. 

I think we have some honest disagreements amonst us about some of the underlying 

issues, but these were fairly treated in the piece and that’s what is important (The choice 

of wording in the final version was much better too. Wording matters!). Thanks all for 

the hard work and a job well done. I like to think that may feedback helped here--so I 

take some pride here as well. 

best regards, 

mike47

We first note that the statement attributed to Michael Mann—“Better that nothing appear, than 

something unacceptable to us”—is actually just inferred from Raymond Bradley’s email, which 

does not specifically identify Mann as the source of the quote. Regardless of its origin, however, 

the petitioner mischaracterizes and misinterprets this statement attributed to Michael Mann by 

Bradley. The petitioner mistakenly assumes that Mann was arguing that it would be better that 

nothing was published in the peer-reviewed literature, rather than dissenting viewpoints that 

differed from his own. In actuality, Mann was specifically commenting on a draft article written 

by Keith Briffa and Tim Osborn (Briffa and Osborn, 1999) for the journal Science. The Briffa 

and Osborn article was commissioned by an editor at Science and represents a review or 

synthesis, not original research. As the e-mails make clear, the background for their 

disagreement stems from a negative review of the Briffa and Osborn article that Mann sent to an 

editor at Science. We do not have access to the review Mann sent to the editor at Science

because it was not included in the released CRU e-mails, but it can be observed from other CRU 

e-mails that Mann disagreed with some of the language and descriptions used in the article.48 

For example, in one of his comments to Briffa and Osborn, Mann states, “One additional new 

comment: 0) 1st page, ‘In attemping [sic] to do this...Mann at al...exemplifies’ is unacceptable 

language to us. We confront the very problems that are being discussed here, so it is a disservice 

to us to say our paper ‘exemplifies’ these problems. It ‘exposes’ or ‘confronts’ would be fair 

language, but ‘exmemplifies’[sic] is unacceptable.” 49 

The e-mails also make it clear that the disagreements were amicably resolved; in the final e-mail, 

Mann states, “Thanks for working so hard to insure a final product that was acceptable to all.”50

 

47 E-mail file 0924532891.txt (April 20, 1999), page 155, line 46 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

48 e.g., E-mail file 0924030302.txt (April 13, 1999), page 146, line 45, e-mail file 0924120405.txt (April 14, 1999), 

page 153, line 15, and e-mail file 0924613924.txt (April 20, 1999), page 155, line 46 of the PDF version 

entitled: CRU Emails 1996-2009.pdf. 

49 E-mail file 0924120405.txt (April 14, 1999), page 153, line 15 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

50 E-mail file 0926681134.txt (May 14, 1999), page 166, line 45 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

58
The most reasonable conclusion is that the statement “Better that nothing appear, than something 

unacceptable to us” apparently referred to specific language in the paper with which Mann 

strongly disagreed. We find no evidence to suggest that the statement had anything to do with 

suppressing dissenting scientific views on climate change or their publication, much less a 

“decade-long campaign” to keep them out of the peer-reviewed literature. 

The petitioner’s evidence does not show that Mann’s actions were inconsistent with his views on 

the peer review process, as described in his letter to the editor of The Wall Street Journal. 

Although the petitioner only quotes part of the letter, we provide it here in full: 

In his Dec. 18 op-ed “How to Manufacture a Climate Consensus,” Patrick J. Michaels of 

the Cato Institute falsely claims that work by him (and other fossil-fuel-funded climate 

change contrarians) has been unfairly blocked by me and others from appearing in 

mainstream science journals because the peer review process is supposedly biased against 

climate science deniers. 

In truth, the only bias that exists at such publications is for well-reasoned writing that is 

buttressed by facts. 

That is why climate skeptics such as Richard Lindzen of MIT [Massachusetts Institute of 

Technology] or John Christy of the University of Alabama—who are widely regarded as 

credible and whose work contributes meaningfully to the scientific discourse—have no 

problem publishing their work in mainstream scientific journals. 

And what about those who are not being published? Every scientist dealing with a major 

public issue must decide if he or she is going to be a scientist or a de facto politician. 

Mr. Michaels and many climate science deniers have opted for the latter course of action. 

For example, presidential science adviser John Holdren notes that Mr. Michaels “has 

published little if anything of distinction . . . being noted rather for his shrill op-ed pieces 

and indiscriminate denunciations of virtually every finding of mainstream climate 

science.” This makes Mr. Michaels a perfect candidate for a Wall Street Journal op-ed 

and a decidedly poor submitter to a serious scientific journal. 

Society relies upon the integrity of the scientific literature to inform sound policy. It is 

thus a serious offense to compromise the peer-review system in such a way as to allow 

anyone—including proponents of climate change science—to promote unsubstantiated 

claims and distortions. 

The good news is that it is not happening today in relation to either climate scientists or 

the deniers of climate science. Men and women who have dedicated their lives to 

advancing science need not apologize for keeping their rigorous professional journals 

free of the pollution of what is purely politics. 

Thus, we conclude that the petitioner leaps from the Bradley quote to an unsupported 

conclusions regarding Mann’s actions with respect to the specific issue in the e-mails and in 

general. The petitioner’s claim that Mann wanted to suppress the article is unsupported by the 

 

59
text they reference, and their claim that these e-mails somehow prove that Mann had a “decadeslong agenda” to suppress dissenting views is baseless. Mann’s letter to the editor of The Wall 

Street Journal further clarifies that he supports ensuring high standards of rigor and quality in the 

peer-reviewed literature. This example does not support the petitioner’s arguments that the 

journal publication process was manipulated. The claim of a “gatekeeper” to the peer-reviewed 

literature is not supported by their evidence, and the petitioner provides no evidence of any paper 

that it believes was not, but should have been, published as a result of the claimed “gatekeeping.” 

They make no arguments based on science, and instead rely on unwarranted speculation. 

Comment (3-27): 

The Coalition for Responsible Regulation and the Southeastern Legal Foundation argue that 

various actions by the CRU e-mail authors made it difficult or impossible for scientists with 

differing views to successfully publish their research in peer-reviewed journals. The Coalition 

for Responsible Regulation claims that the CRU e-mail authors “tried mightily to allow only one 

perspective on the global warming debate to be published and legitimized.” In support of this 

argument, petitioners repeat their allegations regarding reviews of manuscripts, journal 

publication practices, and efforts to remove editors and boycott journals that are discussed in 

sections 3.3.2, 3.3.3, and 3.3.4 of this Volume. In addition, the Coalition for Responsible 

Regulation quotes part of an e-mail written by Roger Pielke, Sr., of Colorado State University on 

November 19, 2004: 

There has been, however, in my view an unfortunate change over time where reviewers 

who disagree with already published work recommend rejection of subsequent work 

rather than letting the community view and assess the different perspectives on a science 

issue.51

The Coalition for Responsible Regulation claims that “[t]his systemic suppression of differing 

viewpoints, in turn, has dissuaded prominent scientists from seeking publication in peerreviewed journals,” quoting as evidence an e-mail from Phil Jones: “Even here they [climate 

change skeptics] don’t seem to be bothering with journals at all recently.”52 The Southeastern 

Legal Foundation provides a quote supporting this argument from Pat Michaels: 

Mr. Wigley repeatedly tells news reporters not to listen to ‘skeptics’ (or even nonskeptics 

like me), because they didn’t publish enough in the peer-reviewed literature— even as he 

and his friends sought to make it difficult or impossible to do so. [Michaels, 2009] 

Thus, the petitioners argue, scientists with dissenting views were only able to publish their 

work in formats other than peer-reviewed journals, which both EPA and the IPCC ignored or 

downplayed. On this basis, the petitioners argue that the Endangerment Finding should be 

reconsidered because it relies on peer-reviewed literature, which is biased in favor of views 

supporting anthropogenic climate change and does not reflect the true state of the science. 

Response (3-27):

 

51 E-mail file 1101133749.txt (November 18, 2004), page 752 lines 30-46 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

52 E-mail file 1256765544.txt (October 28, 2009), page 1837 , lines 28-29 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

60
We respond to petitioners’ allegations regarding reviews of manuscripts, journal publication 

practices, and efforts to remove editors and boycott journals in sections 3.3.2, 3.3.3, and 3.3.4 of 

this volume. As discussed there, the petitioners’ broad, sweeping conclusions about improper 

actions by the scientists are speculative and not supported by the evidence. The petitioners jump 

to the conclusion that papers with opposing views were systematically suppressed but do not 

provide any evidence of actions taken to prevent publication of otherwise acceptable research. 

The petitioners quote the opinions of Roger Pielke, Sr., and Pat Michaels as support for the 

proposition that research with opposing views of anthropogenic climate change cannot get 

published. The petitioners assume that such research should have been or would have been 

published in peer-reviewed literature if not for the opposition of the CRU e-mail authors, without 

providing any science-based analysis to support this argument. The petitioners assume, with no 

basis, that the CRU e-mail authors had the power both to influence the peer-review process for 

the many journals that publish research related to climate-change, and to prevent publication of 

manuscripts with opposing views of anthropogenic climate change. 

The petitioner’s characterization of the scientific literature as biased and one-sided is incorrect. 

The Coalition for Responsible Regulation argues that it has been “difficult or impossible” for 

climate “skeptics” to get their research published in professional journals. However, EPA 

reviewed numerous publications representing a wide range of views on climate change, both here 

in the RTP document and in the RTC document for the Endangerment Finding. As Michael 

Mann stated in his letter to the editor of The Wall Street Journal (reproduced in full in response 

3-26 above): “[C]limate skeptics such as Richard Lindzen of MIT or John Christy of the 

University of Alabama—who are widely regarded as credible and whose work contributes 

meaningfully to the scientific discourse—have no problem publishing their work in mainstream 

scientific journals.” Petitioners’ evidence does not support their claims of “systematic 

suppression of differing viewpoints” in the literature. 

EPA disagrees with the petitioners’ argument that the Findings were based on a false consensus 

regarding anthropogenic global warming, and that the IPCC (and by extension EPA) disregarded 

contrary views or evidence because they were not represented in the peer-reviewed literature. 

Contrary to the petitioners’ implication, there are many perspectives on climate change present in 

the peer-reviewed literature. In reality, many diverging viewpoints and a vast array of findings 

are represented in the scientific literature on climate change. There is no single view in the 

literature as petitioners seem to claim, instead there are myriad examples in the literature of the 

robust back and forth process of scientific research for the broad range of scientific issues have 

been explored by many different scientists around the world. It is precisely this diversity in 

research results that the IPCC describes in its assessment reports when it provides uncertainty 

ranges for its major conclusions. The assessment reports synthesize literally thousands of 

individual studies and look at the range of conclusions across multiple disciplines. The 

assessment reports comprehensively reviewed the science; their scientific conclusions routinely 

identified the degree of certainty around any conclusion, driven by the degree of consistency and 

the depth of the science. These conclusions reflected a broad consensus of the scientific 

community, and recognized the existence of ongoing debate within the scientific community on 

all of these issues, as is the norm in all science endeavors. We thoroughly address issues related 

to the use of consensus literature and the major assessment reports in Volume 1 of the RTC 

61
document for the Endangerment Finding and again in Volume 2, Section 2.2 of this RTP 

document. Thus we find no merit in the argument that the Endangerment Finding did not fully 

consider scientific evidence representing a full range of views. 

The Endangerment Finding was based on a careful consideration of the full weight of scientific 

evidence and a thorough review of hundreds of thousands of public comments. The major 

scientific conclusions that support the Endangerment Finding are themselves the product of 

decades of research, reflected in thousands of studies by numerous scientists, with varying 

opinions about how best to interpret the results. EPA relied on these assessment reports 

precisely to avoid an over-reliance on and narrow consideration of individual studies from a 

limited subset of scientific disciplines or perspectives and to ensure that the Administrator’s 

decision would be based on a comprehensive assessment of the scientific literature. Even if 

something was missed in an assessment report, our notice and comment on the Endangerment 

Finding was designed to ensure that EPA received information from all points of view. We 

received over 380,000 comments, including hundreds of references to literature and reports for 

our consideration. This material was reviewed and responded to in the 11 volumes of the RTC 

document for the Endangerment Finding. The notion that EPA did not consider the full range of 

scientific views is thus simply incorrect. We find that the objections raised by the petitioner 

have not changed EPA’s conclusion that the science supporting the Endangerment Finding is 

robust, is compelling, and has been appropriately characterized by EPA. 

Comment (3-28):

Petitioners question the credibility of the peer review process and the validity of the scientific 

consensus regarding anthropogenic climate change. The Southeastern Legal Foundation claims 

that the numerous examples (discussed in sections 3.3.2–3.3.4 above) of “persecution and blackballing of journals, editors, and reviewers” by the CRU e-mail authors provide evidence that “the 

normal processes of peer review and objective scientific evaluation that might ordinarily lead to 

‘consensus’ have been shown to be so fundamentally degraded by collusion, intimidation, and 

deception that no one can seriously contend that any consensus [about anthropogenic climate 

change] exists at this time.” 

The Southeastern Legal Foundation argues that the CRU e-mail authors’ intimidation tactics 

have caused other journal editors to be concerned about the risk to their careers from allowing 

publication of anything contrary to the views of these scientists. The Southeastern Legal 

Foundation states that “it can be difficult to distinguish ‘consensus’ from enforced doctrinal 

orthodoxy,” quoting John Christy of the University of Alabama: 

These people act in concert to diminish, reject, and otherwise denigrate findings with 

which they do not agree -- and they are able to do so because of their “establishment” 

positions. This is the preservation of “group think” at its most serious level.... The group 

represented by the bulk of these e-mails does indeed have a message to defend. Those of 

us who see problems with that message are aware of how the data are manufactured and 

interpreted to support that message -- and worse, how these establishment scientists act as 

gatekeepers for the “consensus” reports to suppress alternative findings.[Hake, 2009] 

The Southeastern Legal Foundation asserts that the CRU e-mail authors “manipulated the 

scientific literature to purge any and all contrary opinions” and that this suppression of contrary 

62
opinions has resulted in bias in the type of papers cited in the IPCC reports and other major 

assessments, and which were relied upon by EPA in making the Endangerment Finding. The 

petitioner quotes Pat Michaels in support of this argument: 

When scientists make putative compendia of that literature, such as is done by the U.N. 

climate change panel every six years, the writers assume that the peer-reviewed literature 

is a true and unbiased sample of the state of climate science. That can no longer be the 

case. The alliance of scientists at East Anglia, Penn State, and the University 

Corporation for Atmospheric Research (in Boulder, Colo.) has done its best to bias it. 

[Michaels, 2009] 

The Pacific Legal Foundation claims that the CRU e-mails “appear to call into question the 

credibility of the peer review process” and argues that that EPA’s Scientific Advisory Board 

should be given the opportunity to examine the CRU e-mails and determine if there was 

scientific misconduct that would undermine the science on which the Endangerment Finding was 

based. The Competitive Enterprise Institute claims that “the IPCC scientific review process 

has a systematic bias of an unknowable magnitude in favor of human-induced warming. 

Consequently, the EPA Endangerment Finding is severely undermined by a systematic bias of an 

unknowable magnitude in favor of human-induced warming.” 

The petitioners argue that the Endangerment Finding should be reconsidered because the peerreviewed literature on which it relies has been biased in favor of views supporting 

anthropogenic climate change and does not reflect a true consensus regarding anthropogenic 

climate change. 

Response (3-28):

We respond to petitioners’ specific arguments regarding the peer review process, journal editors, 

and journal publication practices in Sections 3.3.2–3.3.4 of this Volume of the RTP document. 

In our responses, we discuss the fact the evidence relied upon by petitioner is limited in nature, 

involves at most a few articles and the journals involved, that this evidence is often taken out of 

context and does not support the claims made by petitioners of unethical, or inappropriate actions 

taken against journals or their editors, or an attempt to prevent contrary opinions from entering 

the literature. Petitioners do not identify papers that were not, but should have been, published 

because of their scientific merit, and petitioners do not make any scientific arguments about the 

limited number of papers at issue. Southeastern Legal Foundation’s claim that journal editors 

would be concerned about the risk to their careers from publishing opposing science is not 

substantiated by the evidence. Southeastern Legal Foundation’s sole support for this allegation 

is the personal opinions of Pat Michaels and John Christy. These statements of opinion, 

however, do not demonstrate or substantiate the petitioner’s claim that CRU scientists 

“manipulated the scientific literature.” In addition, as discussed in the preceding response (3-

27), the scientific literature is not one-sided and includes a wide variety of perspectives about 

climate change. 

The evidence presented by petitioners does not support the claims that the CRU e-mail authors 

acted as “gatekeepers” to the literature to advance their views or were motivated by an activist 

agenda. As discussed in detail in our previous response (3-23), the CRU scientists identified 

what they believed was flawed science in specific papers, and responded by publishing peer63
reviewed, scientific rebuttals in professional journals. This is standard practice in the scientific 

community and in no way constitutes bias in the literature. The evidence does not support the 

claims that the content and substance of the body of peer-reviewed literature on climate change 

was manipulated by the CRU email authors. 

The statement from John Christy provided by the Southeastern Legal Foundation (that “data are 

manufactured and interpreted to support [a] message [of anthropogenic climate change]”) is an 

assertion; it contains no evidence of the claimed data manipulation. We respond to similar 

arguments that question the accuracy and credibility of the science in Volume 1 of this RTP 

document. The scientific issues petitioners claim were hidden or presented in a biased manner 

were in fact fully and comprehensively discussed in the assessment reports. Our responses to the 

science issues contained in Volume 1 make this clear. The evidence we have examined does not 

call into question any of the fundamental conclusions of climate science research. 

Finally, our notice and comment process on the Endangerment Finding was designed to ensure 

that EPA received information from all points of view. We received over 380,000 comments, 

including hundreds of references to literature and reports for our consideration. This material 

was reviewed and responded to in the 11 volumes of the RTC document for the Endangerment 

Finding. The notion that EPA did not consider the full range of scientific views is thus simply 

incorrect. The objections raised by the petitioner do not support changing EPA’s conclusion that 

the science supporting the Endangerment Finding is robust, is compelling, and has been 

appropriately characterized by EPA. 

Comment (3-29):

The State of Texas claims that the CRU e-mails “reveal a cadre of activist scientists colluding 

and scheming to advance what they want the science to be, even where the empirical data 

suggest a different outcome.” The State of Texas concludes that the CRU e-mails “reflect a 

concerted effort to advance a specific scientific theory—or perhaps more appropriately a 

scientific cause—rather than to reach the objective truth. That is, the e-mails that have been 

released indicate that the scientists were more concerned with advancing their agenda than with 

obtaining the objective results required by the OMB and EPA guidelines.” 

The State of Texas also claims that the CRU e-mail authors were opposed to the publication of 

dissenting views because they “had long maligned their skeptical opponents’ positions by 

arguing that the opposition’s research had not been published by a peer-reviewed journal and 

could therefore not be trusted.” The State of Texas argues that the CRU e-mail authors were 

worried that any publication of dissenting views gave support to “skeptics”, quoting as evidence 

an e-mail from Phil Jones: “I think the skeptics will use this paper to their own ends and it will 

set paleo [climate science] back a number of years if it goes unchallenged.53” The petitioner 

argues that the Endangerment Finding should be reconsidered because it relies on peer-reviewed 

literature, which is biased in favor of views supporting anthropogenic climate change and does 

not reflect the true state of the science. 

 

53 E-mail file 1047388489.txt (March 11, 2003), page 456, line 30 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

64
Response (3-29): 

The State of Texas claims that the CRU e-mail authors’ scientific judgments regarding 

anthropogenic climate change are unsupported by “empirical data.” We respond to similar 

arguments that question the accuracy and credibility of the science in Volume 1 of this RTP 

document. The scientific issues petitioners claim were hidden or presented in a biased manner 

were in fact fully and comprehensively discussed in the assessment reports, and include 

appropriate characterization of the degree of certainty around any conclusion. The evidence 

EPA has examined does not call into question any of the fundamental conclusions of climate 

science research. 

The State of Texas argues that the CRU scientists were opposed to certain publications 

solely on ideological grounds, but the evidence does not support the petitioner’s claim. 

The petitioner quotes an e-mail from Phil Jones that refers to the controversial Soon and 

Baliunas (2003) paper published in the journal Climate Research. As described in our 

response (3-23) above, the publication of this paper revealed problems with the journal’s 

peer review process, which eventually resulted in the resignation of three people on the 

editorial board. The publisher of Climate Research later admitted that the Soon and 

Baliunas paper was flawed and should not have been published (Kinne, 2003). Scientists, 

including Jones, did no more than challenge the scientific validity of the Soon and 

Baliunas (2003) paper, which is an appropriate response within the scientific community 

and appears scientifically warranted in this case. Petitioners make no arguments that the 

scientific challenges were incorrect. 

As stated in the above responses (3-23 and 3-24), scientists are justified in challenging or 

opposing—on scientific and factual grounds—any research that they believe is flawed. This is 

true regardless of whether the research had been published in a peer-reviewed journal, but is 

particularly so if a scientist has reason to believe that flawed science made it through the peer 

review process, which exists for the express purpose of ensuring scientific integrity of published 

research. It is well within the norms of the scientific community to write comments or responses 

and otherwise challenge published journal articles if one can demonstrate that there are scientific 

insufficiencies. The State of Texas implies that the CRU e-mail authors did not have scientific 

and factual grounds on which to oppose the publication of dissenting views; however, the 

petitioner does not provide evidence or even attempt to show that the critiques of “skeptics’” 

research were scientifically unjustified. In addition, the State of Texas implies that “skeptics’” 

research should have been or would have been published in peer-reviewed literature if not for the 

opposition of the CRU e-mail authors, but it does not provide any evidence or science-based 

analysis to support this argument. 

In sum, the petitioners’ evidence does not support their claim of actions to manipulate the 

content and substance of the peer-reviewed literature on climate change, nor does the evidence 

provided by the petitioner warrant EPA to question the conclusion that the science supporting the 

Endangerment Finding is robust, is compelling, and has been appropriately characterized by 

EPA. 

Comment (3-30): 

65
The Coalition for Responsible Regulation argues that “[p]rominent scientists have stated for 

years that their efforts to publish contrary science have been stifled and that they have seen their 

grant money dry up and research positions become unavailable to them. These same scientists 

claim they have been publicly ridiculed and their reputations made to suffer if they take issue 

with the supposed ‘consensus’ on the science (Carter, 2008).” The petitioner argues that because 

certain researchers have been unable to publish their research, the peer-reviewed literature is 

biased in favor of views supporting anthropogenic climate change and does not reflect the true 

state of the science. 

Response (3-30): 

The petitioner’s evidence does not support its claim of broad, concerted efforts to exclude 

dissenting viewpoints that would in any way change our understanding of key climate change 

science. The petitioner makes accusations of “public ridicule” and harm to “skeptics’” 

professional reputations, citing an article by Robert Carter, an Australian professor at James 

Cook University, in which he argues against the evidence for anthropogenic climate change. It 

appears that the petitioner bases its claim on the following statement in Carter’s article: “At the 

same time, unsolicited ad hominem attacks are made on qualified persons who espouse different 

views, and who are often disparaged as ‘sceptics’, ‘deniers’, or worse.” Carter does not 

elaborate beyond this one statement, and there is no evidence presented to substantiate either 

Carter’s or the Coalition for Responsible Regulation’s claims. 

The petitioner claims that scientists with opposing views of anthropogenic climate change faced 

difficulties securing grant money and research positions; however, these are common challenges 

faced by research scientists in all disciplines of scientific research. The existence of such 

challenges does not mean the body of scientific literature on climate change, which spans 

multiple scientific disciplines and reflects the research of thousands of scientists worldwide, is 

flawed or biased. The evidence does not support the petitioner’s broad and sweeping 

conclusions about the merits of the broader body of scientific literature, and the arguments do not 

support changing EPA’s conclusion that the science supporting the Endangerment Finding is 

robust, is compelling, and has been appropriately characterized by EPA. 

3.3.6 Allegations of Intimidating Scientists and Those With Dissenting Views 

Comment (3-31): 

Peabody Energy claims that “The politics of climate research was enough to make at least one 

scientist contemplate leaving the field completely.” The petitioner claims that Mann and other 

CRU colleagues engaged in “constant haranguing” about a manuscript submitted by Ed Cook 

regarding the Medieval Warm Period. The petitioner quotes part of an e-mail from Ed Cook to 

Keith Briffa, sent on September 10, 2001: 

I never wanted to get involved in this quixotic game of producing the next great 

NH [Northern Hemisphere] temperature reconstruction because of the 

professional politics and sensitivities involved. ... This all reinforces my 

determination to leave this NH/global temperature reconstruction junk behind 

66
me once I get this paper submitted. It’s not worth the aggravation. However, the 

paper is something that I need to do for Jan. And I still think it is a good paper.54

Peabody Energy concludes that the goal of the CRU e-mail authors’ “intimidation/bad-mouthing 

[was] to influence scientific development” and effectively prevent “dissenting scientific voices 

from being heard” in the climate science literature. Peabody Energy argues that the 

Endangerment Finding should be reconsidered because it relies on peer-reviewed literature, 

which is biased in favor of views supporting anthropogenic climate change and does not reflect 

the true breadth of the science. 

Response (3-31):

We disagree with the petitioner’s interpretation of this e-mail. Our review indicates that the 

context for this e-mail, which is not discussed by petitioner, was an e-mail discussion between 

Cook and Michael Mann and Keith Briffa, in which Mann and Briffa provided scientific 

feedback on a paper Cook was completing. The e-mails are provided below, and do not support 

the petitioner’s charge that Cook suffered “constant haranguing.” To the contrary, the e-mails 

reflect a professional exchange on how best to characterize a complex scientific issue:55 

Ed 

I still believe you are not showing sufficient comparisons with series besides the MBH 

[Mann, Bradley, and Hughes]; necessary to demonstrate the true extent of “new” 

information in this work. At the very least this needs to acknowledge that other (and other 

tree-ring-based ) series are out there , that use at least some of the data you employ , and 

use the RCS method to process may of their constituent series - i.e. the Northern 

chronology series shown in my QSR [Quaternary Science Reviews] paper. What is 

similar and what is different in your series and this one? You give the impression here 

that you are using the RCS and new data to demonstrate the possibility of getting more 

low frequency signal from tree-ring data - but then you base this on a comparison with 

MBH only. Surely what is needed here is to establish WHY MBH don’t get as much LIA 

[Little Ice Age]for example. By not showing that other tree-ring data that have also 

shown a LIA , and not exploring why MBH does not (despite using some of the same -

and note -already RCS standardised data) is perhaps confusing rather than clarifying the 

issue. When we discussed this here, I also suggested the need to show separate “north” 

and more “south” curves ,separated in your data set, to try to get at least some handle on 

the independent expression of the centennial trends in a region south of the overexploited northern network. At the very least it should be clearly stated that many of the 

site data used here and in previous work (see our Science perspectives piece) are common 

and other series already produce more low-frequency signal than is implied in MBH. 

Sorry for this rushed comment but I wanted to get this point over as we had talked about 

it before but you don’t seem to have taken it on board. 

Cheers Keith 56

 

54 E-mail file 1000154718.txt (September 10, 2001), page 389, line 17 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

55 e.g., E-mail file 1000132513.txt (September 10, 2001), page 386, line 15, e-mail file 1000140042.txt (September 

10, 2001), page 388, line 45, and e-mail file 1000168453.txt (September 10, 2001), page 390, line 26 of the PDF 

version entitled: CRU Emails 1996-2009.pdf. 

56 E-mail file 1000168453.txt (September 10, 2001), page 390, line 26 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

67
Hi Ed, 

Just to reiterate one more key point---Superimposing the two series and their 

uncertainties is not the whole story (although it is a definite improvement over just 

showing the two reconstructions on top of each other w/ know assessment of 

uncertainty). However, doing the above still only poses the question: apple +/- 

[uncertainty in apple] =? orange +/- [uncertainty in orange] 

As we discussed in a previous e-mail exchange (based on the correlations you calculated 

between instrumental series w/ the trend removed) , the two reconstructions should 

probably only share about 60% or so variance in common in the best case scenario, where 

there is no uncertainty at all, owing simply to the differing target regions/season... So we 

need to be very careful w/ the following statement which you made in your previous email: “If so, this would not mean that the series are not significantly different from each 

other. One can’t dismiss the highly systematic differences at multi-centennial timescales 

quite so easily.” I’m not sure you can justify that statement based on sound statistical 

reasoning! I agree w/ your following statement “Why these differences are there is the 

crux question.” 

However, I hope the discussion will accurately reflect the fact that the leading hypotheses 

to be rejected in answering that question are 1) random uncertainty in the two series 

owing to differing data quality and sampling, etc. can explain the difference and 2) 

systematic differences owing to differing target region and seasonality can explain any 

residual differences after (1). That may be a tough standard to beat, but it *is* the 

approach that Tom, Phil, Keith, and I have all been taking in addressing the issue of 

whether our different reconstructions are or are not inconsistent and the conclusion has in 

general been (see e.g. IPCC which was really a consensus of many of us, though 

admittedly only I was a lead author) that, despite notable differences in the low-frequency 

variability, the different reconstructions probably cannot be considered inconsistent given 

the uncertainties and differences in seasonality/spatial sampling. I have a hard time 

understanding why the same standard should not be applied to comparisons w/ your 

current reconstruction? Does your RCS reconstruction really not fall in the mix of all the 

other reconstructions? Is it truly an outlier w/ respect to Phil’s, Tom’s, MBH, and other 

existing N. hem reconstructions that are based on different seasonality and regional 

sampling??? 

We’ve probably had enough discussion now on this point, so I’ll leave it to you to discuss 

the results in the way you see most fit, but I really hope you take the above points into 

account, in fairness to the previous work... I look forward to seeing the final manuscript 

in one form or another, in any case, 

cheers, 

mike57

These e-mails provide no basis for the petitioner’s charges of intimidation, bad mouthing, and 

constant haranguing, or that these drove Cook out of this area of research. Cook has not left the 

field; he currently serves as the director of the Tree-Ring Laboratory at the Lamont-Doherty 

Earth Observatory at Columbia University. Although Cook may no longer work on this 

 

57 E-mail file 1000132513.txt (September 10, 2001), page 386, line 15 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

68
particular type of temperature reconstruction, there is no basis for the petitioner’s assertion that 

this was because of improper actions by Mann and Briffa. 

We disagree that the comments and critiques from Keith Briffa, Michael Mann, and others 

constitute “haranguing” or indicate that politics were tainting climate research. It is evident from 

the e-mails that the CRU scientists and their colleagues were providing detailed, science-based 

critiques of Cook’s manuscript in an attempt to improve it. There is no indication that they were 

pressuring or threatening Cook. In fact, Mann clearly tells Cook, “I’ll leave it to you to discuss 

the results in the way you see most fit”.58 We respond to the petitioner’s scientific arguments 

regarding the paleoclimate reconstructions in the RTC document for the Endangerment Finding 

and in Volume 1 of this RTP document. 

Comment (3-32):

Peabody Energy claims that “[d]iverging opinions were also left out of conferences and 

professional events” and that Michael Mann and Phil Jones acted to exclude “skeptic” scientists 

from such events. Peabody Energy quotes an e-mail sent by Mann to Jones on August 25, 2005, 

in which he refers to a conference invitee list that he has been sent, saying, “The last two on the 

list (w/ question marks) would be unwise choices because they are likely to cause conflict than to 

contribute to consensus and progress,” to which Phil Jones responds, “I agree with Mike that the 

last two names on the list should be removed”.59 Peabody Energy then quotes another e-mail 

from Mann describing why he did not want to invite Zorita: 

I’m afraid I don’t agree on Zorita. He has engaged in some very nasty, and in my 

opinion unprofessional e-mail exchanges with some close colleagues of mine 

who have established some fundamental undisclosed errors in work he copublished with von Storch. Given this, I don’t believe he can be involved in 

constructive dialogue of the sort we’re looking for at this workshop. There are 

some similarly problematic issues w/ Cubasch, who like von Storch, who has 

engaged in inflammatory and ad hominem public commentary. There is no room 

for that on any side of the debate.60

Peabody Energy concludes that the goal of the CRU e-mail authors’ “intimidation/bad-mouthing 

[was] to influence scientific development” and effectively prevent “dissenting scientific voices 

from being heard” at conferences or in the climate science literature. Peabody Energy argues 

that the Endangerment Finding should be reconsidered because it relies on peer-reviewed 

literature, which is biased in favor of views supporting anthropogenic climate change and does 

not reflect the true breadth of the science. 

Response (3-32):

 

58 E-mail file 1000132513.txt (September 10, 2001), page 386, line 15 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

59 E-mail file 1124994521.txt (August 25, 2005), page 980, line 23 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

60 E-mail file 1125067952.txt (August 26, 2005), page 981, line 19 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

69
Peabody Energy’s claim that there is a pattern of behavior of excluding “skeptic” scientists from 

conferences and professional events is based on a speculative interpretation of one e-mail chain 

involving one apparently by-invitation-only workshop. As conveners of the workshop, Mann, 

Jones, and the other workshop planners have every right to decide who to invite and why, based 

on their goals for the workshop. Peabody Energy claims that Zorita and Cubasch were not 

invited because they were “skeptic scientists,” but Mann and Jones do not characterize them as 

such. Rather, the e-mail from Mann clearly indicates that he had concerns regarding the quality 

of their scientific work and their professional behavior. Mann makes a substantive comment that 

Zorita had “fundamental undisclosed errors” in a paper he co-authored, and that he was 

concerned neither of them would be constructive at the workshop. 

The petitioner does not make any arguments based on the science, but projects a claim of bias to 

the breadth of the scientific literature based on one e-mail involving one invitation-only 

workshop. There is no discussion of the validity of the scientific work of the individuals at issue, 

or whether their work is reflected in the peer reviewed literature, or whether their work shows 

that the body of scientific evidence, when viewed as a whole, does not support the conclusions 

reached by EPA. Instead of basing arguments on the science, the petitioner relies on very limited 

evidence of one workshop to draw an unwarranted assumption of bias across the body of the 

scientific literature. 

Comment (3-33):

Peabody Energy argues that Michael Mann engaged in “a pattern of scholarly intimidation” 

against those whose research challenged his own, and that this affected the way other 

researchers presented their results in journal articles. Peabody Energy quotes an e-mail sent 

on November 30, 2001, from Keith Briffa to an editor at the journal Science regarding a 

manuscript he reviewed: 

You will see that I think the work is genuinely interesting and potentially of wide 

significance. The bottom line is that you should publish this but the way the 

authors have chosen to present their results smacks of a lack of clarity of thought 

(and a lot of fudging!). I believe that they are more concerned with trying to 

temper their ideas so as not to “offend” Mann et al.61

The petitioner describes an e-mail exchange between Briffa and the authors of the manuscript, 

which Peabody Energy characterizes as “some less established paleoclimate researchers.” Briffa 

states in this e-mail, “I think you will start a minor explosion - but that is what science needs.62“ 

The researchers wrote back to offer Briffa a co-authorship on the paper; Peabody Energy asserts 

that they made this offer for protection from Mann, because Briffa, as a more well-established 

scientist, “could better shield them from” any backlash from Mann. Peabody Energy argues that 

this example demonstrates that scientists felt a “fear of reprisal from Mann.” 

 

61 E-mail file 1014240346.txt (February 20, 2002), page 398, line 17 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

62 E-mail file 1066075033.txt (October 13, 2003), page 603, line 25 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

70
Peabody Energy concludes that the goal of the CRU e-mail authors’ “intimidation/bad-mouthing 

[was] to influence scientific development” and effectively prevent “dissenting scientific voices 

from being heard” in the climate science literature. Peabody Energy argues that the 

Endangerment Finding should be reconsidered because it relies on peer-reviewed literature 

which is biased in favor of views supporting anthropogenic climate change and does not reflect 

the true breadth of the science. 

Response (3-33):

This is another instance of the petitioner claiming that there is a pattern of behavior based on 

speculation and innuendo. The first e-mail offers one scientist’s opinion on a manuscript, which 

he concludes has scientific merit and ought to be published. He offers his opinion that the 

research results could have been presented differently, but it is clear from the e-mail that he is 

not questioning the validity of the research findings themselves. The petitioner provides no 

analysis of the scientific content in the manuscript in question or evidence that Michael Mann 

played a material role in the decision to present the research findings any particular way. In fact, 

there is no evidence whatsoever that Mann had anything to do with the paper either before or 

after it was published. The petitioner quote parts of the e-mail exchange between Briffa and the 

authors of the manuscript in question (Jan Esper of the Swiss Federal Research Institute and Rob 

Wilson of the University of St. Andrews), but here we provide the e-mails in full to provide 

important context: 

Date: Mon, 13 Oct 2003 15:21:03 +0200 

To: Keith Briffa <k.briffa@xxxxxxxxx.xxx> 

From: Jan Esper <esper@xxxxxxxxx.xxx> 

Subject: minor explosion 

Cc: Wilson Rob <rjwilson_dendro@xxxxxxxxx.xxx> 

Hi Keith 

thank you for the message and the comments to the Siberia draft. We are intending to 

finalize a draft when Rob is coming over and we go on a sampling trip to the Bavarian 

Forest and E-Germany. We will then also discuss of data-overlap issue again and might 

include some extra figure with our record re-calculated (without Tornetraesk and Polar 

Ural). However, I (Jan) an not sure that we should have another figure with only the 

Mann and the (reduced) Esper series. Second, it seems that Mann used the density 

records from these two sites only (not ring width). Lets see. We would really like to 

send you the final draft, and ask you to become the fourth author? We ask this not only 

because of the “minor explosion” that might happen, but also because some of the 

arguments in the draft were made earlier by you anyway. What do you think? 

Take care 

Jan and Dave 

Jan 

with respect to the overlap problem we could agree to differ for now -I think the problem 

is much more in the earlier period anyway but I suggest you go ahead and submit it 

anyway. There are some minor wording points but nothing that affects the meaning. You 

know that in my opinion the recent similarity in the records is driven by instrumental data 

inclusion (or calibration against instrumental data) and that Mann’s earlier data are 

strongly biased towards summer and northern land signals. I think you will start a minor 

explosion - but that is what science needs. I looked at your tree-line data and thought 

them very interesting. In my opinion the way you directed the interpretation was what 

71
drew your criticisms. For a climate journal you should have been pointing out the 

complicated regional responses (to the temperature record) rather than trying to state a 

simple overall response. The data are clearly important and you should have no trouble 

publishing them if you rethink the approach to the description (no work needed). I think 

Boreas or Arctic and Alpine Res. are better targets though. I enjoyed the discussions also 

and it is frustrating not to be able to get up to speed with your other projects. I will get 

back to you when I have looked more at the idea of the big review paper. 

the very best to you and all 

Keith 

At 09:55 AM 10/8/03 +0200, Jan Esper wrote: 

Hi Keith 

with respect to our EOS draft, I am still thinking about the data overlap argument you 

made. 

1. I still believe that the overlap is not that significant, and that the significance is 

changing dramatically with time (less in more recent centuries). 

2. With respect to the aim of the paper, we do NOT intend to explain the similarity 

between the records. We rather address that the recons differ in the lower frequency 

domains AND are much more similar in the higher frequency domains. I believe that this 

is crucial. (One could also say that we only address the dissimilarity, and the arguments 

related to that.) 

I appreciated the discussions we had very, very much (especially the one in the night 

before the official meeting). 

Take care 

Jan63

This e-mail exchange clearly shows that Briffa made substantive contributions to the manuscript, 

which would warrant the courtesy of offering co-authorship. As the petitioner acknowledges, 

Briffa did not accept the co-authorship, the paper was published, and there is no evidence of any 

“backlash” from Mann. These subsequent events demonstrate that the petitioner’s speculative 

claim of “fear of reprisal” was unfounded. 

Beyond these e-mails, Peabody Energy provides no evidence to support their claim that Mann 

engaged in a “pattern of scholarly intimidation,” implying that an unknown number of journal 

articles may have been affected by one scientist’s purported actions. This allegation is not 

supported by evidence, but relies on unwarranted speculation and assumptions based on this email exchange involving only one of thousands of papers that compose the body of scientific 

literature on climate change, and for this one paper there was publication and no apparent 

reprisal or other activity. To claim, as the petitioner does, that concerns raised concerning this 

one paper could somehow bias the vast wealth of climate change studies or call into question the 

overall conclusions reached from those thousands of papers is unwarranted speculation and 

unsupported. This example and the objections raised by the petitioner provide no basis for 

changing EPA’s conclusion that the science supporting the Endangerment Finding is robust, is 

compelling, and has been appropriately characterized by EPA. 

 

63 E-mail file 1066075033.txt (October 13, 2003), page 603, line 25 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

72
Comment (3-34): 

Peabody Energy claims that Michael Mann and Tom Wigley in particular “resorted to 

admonishment of those they disagreed with.” Peabody Energy cites the example of Mexican 

climate researcher Jorge Sánchez-Sesma, who, in an e-mail to Phil Jones sent December 3, 2004, 

said that he met Mann at a conference. According to Peabody Energy, “at first Mann was ‘very 

kind,’ but when Mann found out Sánchez-Sesma’s work ran counter to some of Mann’s 

conclusions, Mann ‘changed his attitude.’”64

In addition, Peabody Energy claims that Michael Mann “continued his battle” against climate 

change “skeptics” like Stephen McIntyre and Ross McKitrick in the press, quoting an e-mail from 

Mann to New York Times reporter Andy Revkin, sent on February 8, 2005: 

The McIntyre and McKitrick paper is pure scientific fraud. I think you’ll find 

this reinforced by just about any legitimate scientist in our field you discuss this 

with. To recap, I hope you don’t mention MM [McIntyre and McKitrick] at all. 

It really doesn’t deserve any additional publicity.65

Peabody Energy also claims that Tom Wigley engaged in character assassination of two 

highly credentialed scientists—John Christy and Chris de Freitas—in an attempt to ruin 

their careers. As evidence, Peabody Energy quotes the following e-mail from Wigley, sent 

on August 19, 2003: 

Jim Titus mentioned to me that in the legal profession here people are disbarred for 

behavior like that of De Freitas (and even John Christy -- although this is a more 

subtle case). We cannot do that of course, but we can alert the community of 

honest scientists to such behavior and formally discredit these people.66

Peabody Energy concludes that the goal of the CRU e-mail authors’ “intimidation/bad-mouthing 

[was] to influence scientific development” and effectively prevent “dissenting scientific voices 

from being heard” at conferences or in the climate science literature. Peabody Energy argues 

that the Endangerment Finding should be reconsidered because it relies on peer-reviewed 

literature, which is biased in favor of views supporting anthropogenic climate change and does 

not reflect the true breadth of the science. 

Response (3-34):

The petitioner uses language such as “admonished,” “battled,” “engaged in character 

assassination,” and “intimidation/bad mouthing” in an attempt to demonstrate that two scientists, 

Michael Mann and Tom Wigley, improperly biased the peer reviewed literature, making the 

body of peer reviewed literature unreliable. Examination of the petitioner’s argument does not 

support their claims. With respect to interaction between Mann and Jorge Sánchez-Sesma, we 

 

64 E-mail file 1079384474.txt (March 15, 2004), page 661, line 45 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

65 E-mail file 1107899057.txt (February 8, 2005), page 825, line 31 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

66 E-mail file 1061298033.txt (August 19, 2003), page 566, line 15 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

73
provide the full e-mail that Sánchez-Sesma sent to Phil Jones, in which he described his 

interaction with Michael Mann: 

Dear Dr. Jones: I am very happy because I went to a Workshop in Kona Hawaii (with 

support of NASA-CRCES [National Aeronautics and Space Administration–Center for 

Research on the Changing Earth System] after to gain a contest with a review paper about 

global temperature reconstructions, it was a different version of the paper that you have 

read). There I met with Dr. Michael Mann. Mann was very kind with me, however when 

he did know my work he changed his attitude. I met there also Dr. Hans von Starch who 

presented a global temperature reconstructions with a AOCGCM [atmosphere-ocean 

coupled general circulation model] with natural and anthropogenic forcings. His results 

agree more or less with ECS, and my results. i am in contact with the GKSS group in 

order to compare and share information. However, the key point of my studies, as you 

have pointed out, is to justify that the background Ice Acidity (without volcanic activity) 

from polar caps could be considered as a proxy. I have contacted Dr. Hammer and Dr. 

Crowley to have information and advice. In order continue this kind of studies I would 

like to propose you again (as we have tried last year) to ask support the AMC (Mexican 

Academy of Sciences) to support a visit to CRU UEA next year to continue my work, 

with your help and advice, about global temperature for the Holocene. I will need only an 

official invitation for my visit. It would be in March 2005 for 3 or 4 weeks. Also, I am 

asking support to travel to Japan this year (this fall), however I would like to stop in 

England a week, in order to visit CRU-UEA and to continue our collaboration. I would 

like to know your opinion, cheers, Jorge67

The quote from Sánchez-Sesma”Jorge—”he changed his attitude”—is unclear; there is no 

substantive information in the e-mail to determine what it means. Assuming Mann did change 

his attitude to some degree, the petitioners’ evidence does not show that he acted in a way that 

had any negative consequences for Sánchez-Sesma. In fact, it is clear from the full e-mail that 

Sánchez-Sesma was “very happy” with the workshop, and it appears that his brief contact with 

Mann did not adversely affect his experience there. 

Regarding the e-mail from Michael Mann to Andy Revkin, Mann’s statements reflect his 

scientific judgment that the McIntyre and McKitrick (2005) paper was flawed. As discussed 

thoroughly in our previous responses (e.g., 3-23), it is entirely acceptable and appropriate for 

scientists to express their opinions and challenge papers that they believe are scientifically 

flawed. It was on this basis that Mann recommended that McIntyre and McKitrick were not 

worth interviewing because their paper was flawed. In any case this e-mail concerns discussions 

with a journalist, and have no bearing on the publication of peer-reviewed literature in journals. 

We note that we have responded to the scientific arguments presented in McIntyre and 

McKitrick (2005) as well as numerous other issues related to paleoclimatic reconstructions, both 

in the RTC document for the Endangerment Finding and in Volume 1 of this RTP document. 

Regarding the allegations of “character assassination,” the full e-mail sent on August 19, 2003, 

by Tom Wigley provides context for his statements: 

 

67 E-mail file 1079384474.txt (March 15, 2004), page 661, line 45 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

74
 Andre, I have been closely involved in the CR [Climate Research] fiasco. I have had 

papers that I refereed (and soundly rejected), under De Freitas’s editorship, appear later 

in the journal -- without me seeing any response from the authors. As I have said before 

to others, his strategy is first to use mainly referees that are in the anti-greenhouse 

community, and second, if a paper is rejected, to ignore that review and seek another 

more ‘sympathic’ reviewer. In the second case he can then (with enough reviews) claim 

that the honest review was an outlier. I agree that an ethics committee is needed and I 

would be happy to serve on such a committee. It would have to have endorsement by 

international societies, like Roy. Soc., US Nat. Acad., Acad. Europ., plus RMS, AMS 

[American Meteorological Society], AGU, etc. Jim Titus mentioned to me that in the 

legal profession here people are disbarred for behavior like that of De Freitas (and even 

John Christy -- although this is a more subtle case). We cannot do that of course, but we 

can alert the community of honest scientists to such behavior and formally discredit these 

people. The Danish Acad. did something like this recently, but were not entirely 

successful. In the meantime, I urge people to dissociate themselves from Climate 

Research. The residual ‘editorial’ (a word I use almost tongue in cheek) board is looking 

like a rogues’ gallery of skeptics. Those remaining who are credible scientists should 

resign. 

Tom.68 

Wigely’s e-mail refers to the decision by an editor at Climate Research, Chris de Freitas, to 

publish the controversial Soon and Baliunas (2003) paper. As described in our response (3-23) 

above, the publication of this paper revealed problems with the journal’s peer review process. 

The publisher of Climate Research later admitted that the Soon and Baliunas paper was flawed 

and should not have been published (Kinne, 2003). Clearly, scientists, including Wigley, were 

justified in challenging the scientific merit of the Soon and Baliunas (2003) paper and to 

question the process that enabled such a paper to be published. It is clear from the e-mail that 

Wigley believed that Chris de Freitas acted in a way that was contrary to the practice of good 

science. Like anyone else, Wigley is entitled to speak his mind in personal communications to 

colleagues. To raise legitimate questions of scientific validity is not “character assassination,” 

nor are such actions unethical, or otherwise outside the norms of scientific practice. In sum, the 

evidence presented does not support the arguments and broad conclusions drawn by petitioners. 

3.3.7 Summary 

The petitioners rely upon a small number of papers and other circumstances to claim that leading 

climate scientists successfully conspired to keep dissenting views of climate change out of the 

broad body of peer-reviewed literature and create an artificial consensus about anthropogenic 

climate change. They claim these e-mails show the broad body of scientific literature is biased 

and can not credibly be relied upon to make an Endangerment Finding. The examples proved by 

petitioners are extremely limited, and involve a small number of papers and a few specific 

situations. In all cases it appears the scientists involved were basically making their scientific 

objections known, and were basing their objections on the science and not on assumptions or 

speculation. The evidence presented by petitioners does not support their claims of bias, either 

 

68 E-mail file 1061298033.txt (August 19, 2003), page 566, line 15 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

75
for the specific papers and individuals at issue, or for the much broader and sweeping challenges 

made concerning the integrity of all peer-reviewed climate literature. 

The arguments made of a biased peer review process relies on speculation and subjective 

interpretations of quotes from the CRU e-mails, which are typically taken out of context, and 

involve a very small number of papers and situations. The e-mails themselves do not support the 

claims and conclusions drawn by petitioners, either for those specific papers and situations, or 

for the broader peer reviewed literature petitioners contest. Petitioners’ claims are not based on 

scientific analysis or arguments, and their evidence does not support changing or revising EPA’s 

use of the major assessments of peer-reviewed literature or the overall scientific conclusions 

about climate change reached from the thousands of papers considered in the assessments. The 

objections raised by the petitioner have not called into question or changed EPA’s conclusion 

that the science supporting the Endangerment Finding is robust, is compelling, and has been 

appropriately characterized by EPA. 

3.4 Issues Concerning Freedom of Information Act Requests 

3.4.1 Overview 

Several petitioners (the Coalition for Responsible Regulation, the Ohio Coal Association, the 

Pacific Legal Foundation, Peabody Energy, the Southeastern Legal Foundation, the State of 

Texas) claim that the CRU e-mails provide evidence that leading climate scientists did not 

conduct their research in a fully transparent manner and did not appropriately respond to UK 

Freedom of Information (FOI) and U.S. Freedom of Information Act (FOIA) requests. 

Specifically, the petitioners argue that these scientists deliberately withheld key data and 

computer programming codes and attempted to obstruct or avoid FOI/FOIA requests from 

“climate skeptics.” 

Our review of the CRU emails indicates that in many cases, the data at issue were released by the 

scientists, including data concerning a human “fingerprint” in the tropics, data underlying the 

HadCRUT temperature record, and data concerning historic temperature reconstructions. In 

addition, significant data were also publicly available. Petitioners have not explained or shown 

why the amount of data and other information that was available was not adequate for 

researchers to replicate or otherwise evaluate key findings, or to conduct other research. In 

addition, there was a robust and public process to submit, review, and publicly respond to 

comments on the scientific issues involved in all parts of the IPCC AR4. Petitioners do not rely 

on science or science based arguments to support their claim that the assessment report resulting 

from this robust process should not be relied upon by EPA. Instead, they rely on unsupported 

conclusions drawn from e-mails concerning a FOI request for personal communications between 

various scientists, where it appears that the appropriate University FOI officers had determined 

that these emails were exempt from release. This evidence does not support petitioners’ claims 

that the IPCC AR4 should not be considered as part of the scientific basis for the Endangerment 

Finding. 

EPA agrees with the results of the various investigations, which found that the scientists at issue 

conducted their research with scientific integrity and rigor, the research utilized methods which 

are fair and satisfactory, and that their actions were consistent with the common practice in 

76
climate research at that time. EPA also agrees with the recommendations of the Independent 

Climate Change E-mails Review supporting greater transparency in the future in this area of 

climate research. Petitioners’ evidence, however, does not support their conclusions that the 

research produced by these scientists was suspect, flawed, or biased, or that the AR4 or other 

assessment reports were suspect, flawed, or biased. Their evidence does not support the 

conclusion that the science at issue should not be relied upon by EPA. Greater transparency in 

the future will facilitate scientific research; however, concluding that greater transparency would 

be helpful for a particular element of climate change science is not the equivalent of providing 

evidence that the scientific basis for EPA’s Endangerment Finding is flawed. 

The following sections provide our response to petitioners’ specific arguments. Section 3.4.2 

deals with claims that the CRU e-mail authors refused requests to make their data, computer 

programming codes, and other information on which some of their research was based publicly 

available, and inappropriately limited other researchers’ ability to replicate and verify results. 

Section 3.4.3 addresses claims of improper conduct with regard to UK FOI and U.S. FOIA laws, 

including general non-compliance allegations, allegations regarding a specific FOI request 

related to the IPCC, and allegations of improperly influencing University FOI officials. Finally, 

Section 3.4.4 summarizes our response to these issues. 

3.4.2 Allegations of Withholding Key Data and Information 

Comment (3-35):

The Southeastern Legal Foundation claims that “three prominent British scientific organizations 

have condemned the practices of top IPCC climate scientists as revealed by the Climategate 

documents [i.e., the CRU e-mails].” The group provides quotes from the Institute of Physics, the 

Royal Society of Chemistry (RSC), and the Royal Statistical Society (RSS) taken from 

statements submitted to the UK House of Commons Science and Technology Committee (2010a) 

during its investigation of the CRU e-mails. The Southeastern Legal Foundation states that these 

three organizations “concluded that the refusal of the CRU researchers to disclose their data and 

methods was contrary to the scientific method and cast doubt on the integrity of their research.” 

In addition, the petitioner highlights the organizations’ statements regarding data availability, 

stating that they call for the “data and methods of climate research to be made freely available as 

required by the canons of the scientific method.” On the basis of these statements, the 

Southeastern Legal Foundation concludes that the CRU e-mails have “grave implications for the 

integrity of the science upon which the IPCC’s reporting is based” and that “EPA cannot dismiss 

the conclusions of institutions having the prestige and reputation of the Institute of Physics, the 

Royal Society of Chemistry, and the Royal Statistical Society.” 

Response (3-35): 

During the UK House of Commons Science and Technology Committee’s investigation of the 

CRU e-mails, it accepted written evidence regarding the following questions: 

1. What are the implications of the disclosures for the integrity of scientific research? 

2. Are the terms of reference and scope of the Independent Review announced on 3 

December 2009 by UEA adequate? 

3. How independent are the other two international datasets? 

77
In addition, the UK House of Commons Science and Technology Committee held one oral 

evidence session to take information from the following five panels: 

1. The Right Honourable Lord Lawson of Blaby, Chairman, and Dr. Benny Peiser, Director, 

Global Warming Policy Foundation. 

2. Richard Thomas Commander of the Order of the British Empire, former Information 

Commissioner. 

3. Professor Edward Acton, Vice-Chancellor at UEA, and Professor Phil Jones, Director of 

CRU. 

4. Sir Muir Russell, Head of the Independent Climate Change E-Mails Review. 

5. Professor John Beddington, Government Chief Scientific Adviser; Professor Julia Slingo 

Officer of the Order of the British Empire, Chief Scientist, UK Met Office; and Professor 

Bob Watson, Chief Scientist, Department for Environment, Food and Rural Affairs. 

The Committee received 57 submissions of written evidence (see UK House of Commons 

Science and Technology Committee, 2010a). The petitioner cites selective quotes from only 

three of these submissions. The full transcripts of the three statements discussed by the 

petitioner are provided in the reference document entitled, “Memoranda Submitted to the UK 

House of Commons Science and Technology Committee Investigation” in the docket 

(http://www.regulations.gov, Docket ID EPA-HQ-OAR-2009-0171). We respond to the 

petitioner’s allegations with regard to the three submissions below. 

First, the petitioner mischaracterizes or exaggerates the statements from the Institute of Physics, 

the RSC, and the RSS to claim that they “condemned the practices of top IPCC climate 

scientists.” The Institute of Physics states that there is “reason for concern” as well as “a need 

for a review of [the] adequacy and objectivity” of the peer-review process (Institute of Physics, 

2010). The institute also states its opinion that further inquiry into the implications of the CRU 

e-mails on scientific integrity is warranted. Contrary to the petitioner’s claims, however, the 

institute does not assume misconduct or wrongdoing on the part of the CRU e-mail authors, nor 

does it “condemn” their work. 

The RSC states that the CRU e-mails have been “widely portrayed as an indication of a lack of 

integrity in scientific research,” but the RSC itself does not state or conclude that there has been 

lack of integrity in climate science research (RSC, 2010). The RSC statement does not have 

language that represents a condemnation of IPCC climate scientists. Similarly, the RSS 

discusses in detail its arguments for placing climate change data, analysis methods, and models 

in the public domain, but does not condemn the work of IPCC scientists nor allege a lack of 

integrity in climate science research. 

Second, the petitioner exaggerates the organizations’ statements when it states that the 

organizations agree that the CRU e-mails “cast doubt on the integrity of their research.” The 

Institute of Physics states that questions have been raised about the integrity of some historic 

temperature reconstructions and the way in which they have been graphically represented by 

entities such as the IPCC. It is misleading and inaccurate to interpret this statement—which 

states that “questions have been raised” but does not take a position on the merits of the issue—

as casting doubt on all of the research conducted throughout the years by the CRU e-mail 

authors. 

78
The RSC describes the implications of “[a] lack of willingness to disseminate scientific 

information” in general or hypothetical terms, without making claims or drawing conclusions 

about CRU researchers or their work. In addition, in part of the statement not quoted by the 

petitioner, the RSC highlights the importance of transparency and valid science on both sides of 

the climate change debate (point 10 in their submission): 

10. The issue of misinformation in the public domain must also be tackled. Just as the 

scientific community must be open with regard to their evidence base, those who disagree 

must also provide a clear and verifiable backing for their argument, if they wish their 

opinions to be given weight. When disagreements occur, the validity of the analysis must 

be established before credence can be given to any opinion. Increased understanding of 

the process of scientific research, firstly in the government, but also within the media and 

general public, is vital in order to foster a more open sharing of information. 

Similarly, the RSS makes broad statements and recommendations about the importance of 

open access to data without making claims or drawing conclusions about CRU researchers 

or their work. In part of the statement not quoted by the petitioner, the RSS also discusses 

important caveats to its position that raw data and associated metadata used for scientific 

analyses should be publicly available within reason (point 8 in their statement): 

8. It is also clearly unreasonable to require that any given scientist having published some 

research is then condemned to answer each and every question that might possibly arise 

from it. For example, requests under the Freedom of Information act or the 

Environmental Information Regulations could overwhelm small groups of scientists. To 

avoid this it is best if data are stored in data centres that are professionally run and 

properly funded. 

These statements from the Institute of Physics, RSC, or RSS do not constitute agreement that the 

integrity of CRU e-mail authors’ research is now in question. We note that the Institute of 

Physics, the RSC, and the RSS are offering their opinions on the questions posed to them by the 

UK House of Commons Science and Technology Committee. Neither the Institute of Physics, 

the RSC, nor the RSS have been involved in the three recent inquiries and investigations into the 

CRU e-mails that carefully examined the full body of evidence with regard to the allegations 

against CRU: 1) the UK House of Commons Science and Technology Committee investigation; 

2) the Scientific Appraisal Panel review; and 3) the Independent Climate Change E-mails 

Review. 

Beyond reading the text of the e-mails, none of the organizations indicated that they had 

conducted any detailed review of the broader context for the events described in the CRU emails. These organizations’ statements were written in February 2010, before the conclusions of 

any of the three recent investigations were published. The petitioner claims that the statements 

from the Institute of Physics, RSC, and RSS challenge the scientific research advanced by CRU 

scientists and by extension the science on which EPA relied, but does not cite any of the 

conclusions of the independent investigations that carefully examined the full body of evidence. 

In contrast to the general statements from the Institute of Physics, RSC, and RSS, the UK House 

of Commons Science and Technology Committee investigation examined written and oral 

79
evidence from numerous witnesses on both sides of the issue and examined the facts of the 

issues. Their report made the following broad conclusions: 

 The focus on Professor Jones and CRU has been largely misplaced. On the accusations relating 

to Professor Jones’s refusal to share raw data and computer codes, we consider that his actions 

were in line with common practice in the climate science community. We have suggested that 

the community consider becoming more transparent by publishing raw data and detailed 

methodologies. On accusations relating to Freedom of Information, we consider that much of 

the responsibility should lie with UEA, not CRU. 

 In addition, insofar as we have been able to consider accusations of dishonesty—for example, 

Professor Jones’s alleged attempt to “hide the decline”—we consider that there is no case to 

answer. Within our limited inquiry and the evidence we took, the scientific reputation of 

Professor Jones and CRU remains intact. We have found no reason in this unfortunate episode 

to challenge the scientific consensus as expressed by Professor Beddington, that “global 

warming is happening [and] that it is induced by human activity”. It was not our purpose to 

examine, nor did we seek evidence on, the science produced by CRU. It will be for the 

Scientific Appraisal Panel to look in detail into all the evidence to determine whether or not the 

consensus view remains valid (UK House of Commons Science Technology Committee, 

2010b). 

The Scientific Appraisal Panel conducted a review of the science, examining criticism of CRU 

that “climatic data had been dishonestly selected, manipulated and/or presented to arrive at predetermined conclusions that were not compatible with a fair interpretation of the original data.” 

The inquiry involved an international panel of experts headed by Lord Oxburgh, and drew the 

following key conclusions: 

 We saw no evidence of any deliberate scientific malpractice in any of the work of the 

Climatic Research Unit and had it been there we believe that it is likely that we 

would have detected it. Rather we found a small group of dedicated if slightly 

disorganised researchers who were ill-prepared for being the focus of public 

attention. As with many small research groups their internal procedures were rather 

informal. 

 After reading publications and interviewing the senior staff of CRU in depth, we are 

satisfied that the CRU tree-ring work has been carried out with integrity, and that 

allegations of deliberate misrepresentation and unjustified selection of data are not 

valid. In the event CRU scientists were able to give convincing answers to our 

detailed questions about data choice, data handling and statistical methodology. The 

Unit freely admits that many data analyses they made in the past are superseded and 

they would not do things that way today. 

 Like the work on tree rings, this work [temperatures from historical instrumental 

records] is strongly dependent on statistical analysis and our comments are 

essentially the same. Although there are certainly different ways of handling the 

data, some of which might be superior, as far as we can judge the methods which 

CRU has employed are fair and satisfactory. Particular attention was given to 

records that seemed anomalous and to establishing whether the anomaly was an 

artefact or the result of some natural process. There was also the challenge of dealing 

with gaps in otherwise high quality data series. In detailed discussion with the 

researchers we found them to be objective and dispassionate in their view of the data 

and their results, and there was no hint of tailoring results to a particular agenda. 

Their sole aim was to establish as robust a record of temperatures in recent centuries 

80
In addition, the Independent Climate Change E-mails Review found: 

Climate science is a matter of such global importance, that the highest standards of 

honesty, rigour and openness are needed in its conduct. On the specific allegations made 

against the behaviour of CRU scientists, we find that their rigour and honesty as scientists 

are not in doubt. In addition, we do not find that their behaviour has prejudiced the 

balance of advice given to policy makers. In particular, we did not find any evidence of 

behaviour that might undermine the conclusions of the IPCC assessments (Russell, 

2010). 

The three general statements selected by the petitioner do not support what they claim, and 

do not undermine the conclusions of the independent investigations quoted above that 

weighed substantially more information and evidence. We find that evidence provided by 

the petitioner does not contradict the conclusions of these investigations, which found that 

the CRU research was conducted with integrity and scientific rigor, without dishonesty, 

and their release of data was consistent with the common practices of the scientific 

community at that time. 

Comment (3-36): 

The State of Texas and Peabody Energy reference an article in The Times newspaper discussing 

the reaction of Professor John Beddington (Chief Scientific Advisor to the British Government) 

to the CRU e-mails. The State of Texas provides the following quote from Beddington: “I don’t 

think it’s healthy to dismiss proper skepticism. Science grows and improves in the light of 

criticism. There is a fundamental uncertainty about climate change prediction that can’t be 

changed” (Webster, 2010). Peabody Energy provides the following quote from Beddington: “I 

think, wherever possible, we should try to ensure there is openness and that source material is 

available for the whole scientific community” (Webster, 2010). The petitioners use these quotes 

to substantiate their claim that the CRU e-mail authors obstructed the normal process of 

scientific inquiry by withholding information necessary for replicating key studies, so that by 

extension, the science on which EPA relied for the Endangerment Findings has been called into 

question. 

Response (3-36): 

Professor John Beddington’s opinions as quoted from a newspaper article do not provide 

evidence that supports the petitioner’s allegation that the CRU e-mail authors withheld data 

necessary for replicating key studies. Beddington is simply stating his view that the climate 

scientists, in addition to the whole scientific community, should make more concerted efforts to 

ensure data availability. The petitioners’ evidence does not show that the CRU e-mail authors 

engaged in any actions that were unethical or outside of the norms of scientific practice. As 

discussed in our response (3-35) above, the CRU e-mail authors acted in line with common 

practice in the climate science community. 

81
In addition, we note that Professor Beddington elaborated more fully on his views in his written 

evidence to the UK House of Commons Science and Technology Committee investigating the 

CRU e-mails. The relevant portion of his submission stated: 

Not withstanding the need for scientists to maintain a competitive position amongst their 

peers, protect intellectual property and in some cases protect confidentiality, scientists 

should, as a general principle, aim to ensure openness and transparency of their data, 

methods and results at the point of peer-reviewed publication. This allows independent 

expert scrutiny, challenge and repetition to confirm the validity of findings, all of which 

are fundamental to furthering scientific understanding. Equally, scientists should feel 

free to openly debate their work, as this process is also essential for the furthering of 

robust research (UK House of Commons Science and Technology Committee, 2010b). 

In another relevant portion of Professor Beddington’s written evidence, he states that the CRU emails have not altered our understanding of the basic science and the human contribution to 

climate change: 

It is important to emphasise that the evidence that the world is warming and that human 

activities are driving this change does not rest on the robustness or otherwise of a single 

temperature record. Basic physics shows that greenhouse gases absorb and re-emit long 

wave radiation emitted by the Earth, which warms the surface and lower atmosphere. 

The science underpinning this knowledge was performed over a century ago. We also 

know that human activities are releasing billions of tonnes of greenhouse gases - 

including carbon dioxide, methane, nitrous oxide and halocarbons - each year, which is 

increasing their concentration in the atmosphere. 

The petitioners’ evidence does not support their claim that the CRU scientists and their 

colleagues obstructed the normal process of scientific inquiry, nor does the article relied upon by 

the petitioners provide any other evidence that would cause EPA to question the scientific merits 

of these scientists’ work. The evidence indicates that scientists commonly weigh several policies 

in deciding issues of release of data, such as the need for transparency, protection of intellectual 

property, and protection of confidentiality. As discussed below, in many cases data were already 

publicly available or were released by the scientists, and the scientific issues involved were the 

subject of robust and serious scientific debate, as explained in Volume 1 of the RTP document. 

Petitioners’ evidence does not show that the scientific research produced by these scientists is in 

any way flawed or unreliable, and they make no science-based arguments to that effect. 

Comment (3-37): 

The Ohio Coal Association, Peabody Energy, and the Southeastern Legal Foundation point to 

CRU scientists’ attempts to refuse an FOI request by scientist Willis Eschenbach to obtain land 

station data for the HadCRUT3 dataset (Eschenbach, 2009), which is a global surface 

temperature dataset based on measurements from both land stations and ships. The petitioners 

state that the request was first met with evasion, and only later it was eventually revealed that the 

CRU no longer had access to the raw data for their dataset. The Southeastern Legal Foundation 

goes one step further, claiming that the CRU e-mails “prove that the conspiracy to obstruct his 

requests went to the highest levels of climate science.” 

Response (3-37): 

82
The petitioners claim that the CRU scientists stonewalled FOI requests in order to prevent public 

access to critical climate information like the HadCRUT dataset. An extensive discussion of the 

availability of HadCRUT data was provided in Volume 2 of EPA’s RTC document for the 

Endangerment Findings, and this issue is also discussed in Volume 1, Section 1.3.3.1 of this RTP 

document. As stated in those discussions, a limited amount of raw data from the HadCRUT 

dataset is no longer in CRU’s possession; however, this does not impede the ability to check if 

the publically available data give the same results as the HadCRUT analysis, or that it changes 

the scientific validity of the analyses performed by the CRU. The HadCRUT dataset is publicly 

available as a value-added (i.e., quality-controlled and homogenized) dataset of global surface 

temperature data. Regarding the availability of the HadCRUT data, the Independent Climate 

Change E-mails Review (Russell, 2010) found that: 

On the allegation of withholding temperature data, we find that CRU was not in a 

position to withhold access to such data or tamper with it. We demonstrated that any 

independent researcher can download station data directly from primary sources and 

undertake their own temperature trend analysis. 

The Independent Climate Change E-mails Review also noted that CRU eventually provided a list 

of station identifiers pursuant to the FOI request referenced by petitioners. Although the review 

notes this could have been accomplished in a more timely manner, the evidence does not support 

the argument of a “conspiracy to obstruct [Eschenbach’s] requests.” Petitioners’ evidence 

provides no basis to question the reliability or integrity of the scientific research involving the 

HadCRUT dataset. 

 

Comment (3-38): 

Peabody Energy claims that Benjamin Santer of Lawrence Livermore National Laboratory 

attempted to avoid repeated informal requests for data as well as a formal U.S. FOIA request by 

Stephen McIntyre for data that were used in one of his papers. The data in question depicted 

evidence for a human “fingerprint” in the tropics, essentially showing that the tropical 

troposphere was warming as predicted by models. The petitioner claims that the lack of access 

to this data hampered efforts by other researchers to replicate and verify Santer’s work, which 

was a key attribution study used in the IPCC AR4. Peabody Energy states that the data were 

eventually made public, but questions why “Santer could not have just released his data when 

McIntyre first requested it rather than attempting to stonewall it.” 

Response (3-38): 

We respond to comments on the scientific validity of Santer’s study regarding a human 

“fingerprint” in the tropics and the existence of multiple lines of evidence for human attribution 

of climate change in Section 1.2.1 of this RTP document. 

The petitioner acknowledges that Santer subsequently provided the requested datasets and 

information, as well as additional information. In an e-mail written in December 2008 and sent 

to various colleagues, Santer states: 

...Over the past several weeks, I’ve had a number of discussions about the “FOIA issue” 

with PCMDI’s [Program for Climate Model Diagnosis and Intercomparison] Director 

(Dave Bader), with other LLNL [Lawrence Livermore National Laboratory] colleagues, 

83
and with colleagues outside of the Lab. Based on these discussions, I have decided to 

“publish” all of the climate model surface temperature time series and synthetic MSU 

time series (for the tropical lower troposphere [T2LT] and the tropical mid- to uppertroposphere [T2]) that we used in our International Journal of Climatology (IJoC) paper. 

This will involve putting these datasets through an internal “Review and Release” 

procedure, and then placing the datasets on PCMDI’s publicly-accessible website. The 

website will also provide information on how synthetic Microwave Sounding Unit 

(MSU) temperatures were calculated, anomaly definition, analysis periods, etc. After 

publication of the model data, we will inform the “FOIA Point of Contact” that the 

information requested by McIntyre is publicly available for bona fide scientific research. 

Unfortunately, we cannot guard against intentional or unintentional misuse of these 

datasets by McIntyre or others. By publishing the T2, T2LT, and surface temperature 

data, we will be providing far more than the “Monthly average T2LT values” mentioned 

in McIntyre’s FOIA request to DOE. This will make it difficult for McIntyre to continue 

making the bogus claim that he is being denied access to the climate model data 

necessary to evaluate the validity of our findings. All of the raw model output used in 

our IJoC paper are already available to Mr. McIntyre (as I informed him several months 

ago), as are the algorithms required to calculate synthetic MSU temperatures from raw 

model temperature data. I hope that “publication” of the synthetic MSU temperatures 

resolves this matter to the satisfaction of NNSA [National Nuclear Security 

Administration], DOE Headquarters, and LLNL. With best regards, Ben 69 

Petitioner makes no argument based on the science that Santer’s analysis was incorrect 

scientifically. They do not claim that there has been any inability to use the released information 

for their research. Their sole argument concerns the timing of the release, and not the merits of 

the science. The petitioners’ evidence does not provide any reason to question the scientific 

merits of these scientists’ work. 

Comment (3-39):

Peabody Energy argues that CRU scientists and their colleagues “hid from public view” 

information pertaining to key studies used in the IPCC AR4. The petitioner describes four 

examples in which it claims that authors of CRU e-mails refused to release requested information 

because they feared scientific criticism of their work. Two of the examples—the data underlying 

the HadCRUT temperature record and the data regarding a human “fingerprint” in the tropics—

are discussed and responded to in the preceding comments (3-37 and 3-38). The two other 

examples are discussed below. 

According to the petitioner, the first example of “stonewalling” requests for data occurred in the 

spring of 2003, when Michael Mann, professor at Pennsylvania State University, allegedly 

provided Stephen McIntyre, editor of the blog “Climate Audit,” with an incorrect or incomplete 

dataset of the information used in Mann’s “hockey stick” temperature reconstruction paper. 

McIntyre used the dataset to publish a paper in October 2003 with Ross McKitrick, professor at 

University of Guelph, which described errors in Mann’s analysis. According to Peabody Energy, 

Mann responded in a tone that was “harshly negative” and accused McIntyre and McKitrick of 

making numerous errors and using some data other than what was used in the original analysis. 

 

69 E-mail file 1229468467.txt (December 16, 2008), page 1598, line 38 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

84
Peabody Energy quotes an e-mail from November 12, 2003, in which Tim Osborn, academic 

fellow at CRU, writes to Keith Briffa and Phil Jones of CRU and states that he wished Mann had 

waited to respond to the McIntyre and McKitrick paper by submitting a formal comment to a 

peer-reviewed journal. 

Peabody Energy states that McIntyre and McKitrick then requested Mann’s original source code, 

but their request was not granted. Peabody Energy notes that Mann referred to their requests as 

“intimidation tactics” in a February 14, 2005, Wall Street Journal article (Regalado, 2005). The 

petitioner also highlights a series of e-mails from Phil Jones to multiple colleagues, from which 

Peabody Energy draws the conclusion that Jones and his colleagues discussed providing 

“information that could not be used or not providing any information at all.” In one of the emails quoted by Peabody Energy, Jones writes his opinions about the request from McIntyre and 

McKitrick: 

If the code is sent, there needs to be conditions. We don’t want MM [McIntyre 

and McKitrick] to come out and say he can’t get it to work after a few days. So, 

it is far some simple. I’m still against the code being given out. Mike has made 

the data available. That is all they should need. The method is detailed in the 

original paper - in the online (methods) and also in several other papers Mike has 

written.70

The petitioner cites a second example of “stonewalling” requests for data in the winter of 2004, 

when Stephen McIntyre made a request to Phil Jones for data underlying the Jones and Mann 

(2003) paper, which created a proxy temperature reconstruction that was cited in Chapter 6 of the 

IPCC AR4 (Jansen et al., 2007). Peabody Energy describes Jones as refusing the request despite 

obtaining approval from a colleague, Tas van Ommen of the Australian Arctic Division, to 

release his part of the dataset. The petitioner also cites an e-mail exchange between Jones and 

Mann about McIntyre’s request, in which Mann stated that he would not provide information to 

McIntyre and encouraged Jones to do the same. Peabody Energy also quotes an e-mail from 

Jones to Mann from about a year later: 

I got this e-mail from McIntyre a few days ago. As far as I’m concerned he has the data 

— sent ages ago. I’ll tell him this, but that’s all — no code. If I can find it, it is likely to 

be hundreds of lines of uncommented fortran! I recall the program did a lot more that 

just average the series. I know why he can’t replicate the results early on — it is because 

there was a variance correction for fewer series.71 

The petitioner argues that these examples of ignoring data requests, in addition to other 

statements made by CRU scientists and their colleagues, are indicative of a pattern or typical 

practice of refusing to provide access to their data. Peabody Energy cites the following e-mail 

from Phil Jones to Tas van Ommen on February 9, 2004 as further evidence: 

 

70 E-mail file 1076083097.txt, (February 6, 2004), page 650, line 42 of the PDF version 

entitled: CRU Emails 1996-2009.pdf. 

71 E-mail file 1114607213.txt, (April 27, 2005), page 866, line 31 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

85
I had some e-mails with him a few years ago when he wanted to get all the station 

temperature data we use here in CRU. At that time, I hid behind the fact that some of the 

data had been received from individuals and not directly from Met Services through the 

Global Telecommunications Service (GTS) or through GCOS [Global Climate Observing 

System ]... I’ll just sit tight here and do nothing. Mike will likely do the same, but we’ll 

expect another publication in the nearish future.72

Peabody Energy also cites the following e-mail from Phil Jones to Tas van Ommen and 

Caspar Ammann on May 7, 2004: 

Many of us in the paleo field get requests from skeptics (mainly a guy called Steve 

McIntyre in Canada) asking us for series. Mike and I are not sending anything, partly 

because we don’t have some of the series he wants, also partly as we’ve got the data 

through contacts like you, but mostly because he’ll distort and misuse them.73

Peabody Energy asserts that “the reason why these scientists refused to divulge underlying 

information was to avoid criticism of their work” and “Jones and Mann and their colleagues were 

obviously hostile to McIntyre and other ‘skeptics’ because of their disagreement with the 

conclusions those ‘skeptics’ might draw, saying the ‘skeptics’ would ‘misuse’ and ‘distort’ the 

data.” As evidence, the petitioner quotes a comment Phil Jones made to Janice Lough of the 

Australian Institute of Marine Science: “Mike Mann refuses to talk to these people and I can 

understand why. They are just trying to find if we’ve done anything wrong.” As further 

evidence, Peabody Energy also quotes two e-mails from Mann to Osborn as examples of CRU 

scientists’ “acute hostility” to anyone associated with ClimateAudit: 

I’m saddened to hear that this bozo is bothering you too, in addition to NCAR 

[National Center for Atmospheric Research], NSF [National Science 

Foundation], NAS [National Academies of Science], IPCC and everyone else.

Rest assured that I won’t ever respond to McIntyre should he ever contact me, 

but I will forward you any e-mail he sends related to this. I assume Scott feels 

the same way... 74

hi tim. personally, I don’t see why you should make any concessions for this 

moron.75

Peabody Energy states that “[T]his attitude is not consistent with good science...Research, 

particularly research of this immense importance, should be amenable to replication by anyone, 

regardless of whether they will draw different conclusions from the research than those 

producing the research would like.” In support of this argument, Peabody Energy references the 

conclusions of a report commissioned by the U.S. House Committee on Energy and Commerce, 

 

72 E-mail file 1076336623.txt, (February 9, 2004), page 652, line 6 of the PDF version entitled: CRU 

Emails 1996-2009.pdf. 

73 E-mail file 1083962601.txt, (May 7, 2004), page 665, line 12 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

74 E-mail file 1146062963.txt, (April 26, 2006), page 1126, line 8 of the PDF version entitled: CRU Emails 1996-

2009.pdf 

75 E-mail file 1147435800.txt, (May 12, 2006), page 1129, line 27 of the PDF version 

entitled: CRU Emails 1996-2009.pdf. 

86
known as the “Wegman Report” (Wegman et al., 2006). Peabody quotes the following 

conclusion from the report: 

Sharing of research materials, data, and results is haphazard and often grudgingly done.

We were especially struck by Dr. Mann’s insistence that the code he developed was his 

intellectual property and that he could legally hold it personally without disclosing it to 

peers. When code and data are not shared and methodology is not disclosed, peers do not 

have the ability to replicate the work and thus independent verification is impossible.

Response (3-39): 

First, the petitioner describes at length four interactions between the CRU e-mail authors and 

people requesting information. On the basis of these four examples, the petitioner concludes that 

CRU scientists and their colleagues repeatedly and consistently ignored data requests because 

they feared scientific review and critiques of their work. For two of these examples—the raw 

CRU temperature data and the tropical “fingerprint” data—we address the petitioner’s concerns 

on this issue in responses 3-37 and 3-38 above, which shows that these information requests 

were not ignored and data was made or was available to the requestors. Regarding the other two 

examples—claims that Mike Mann and Phil Jones withheld paleoclimate data—we address the 

petitioner’s concerns here. 

The e-mails cited by the petitioner indicate that the scientists believed they had already provided 

enough data and information for others to be able to replicate their work by making the basic 

data publicly available and publishing the methodology for replicating a particular study in the 

literature. For example, Phil Jones states that “Mike [Mann] has made the data available. That is 

all they should need. The method is detailed in the original paper - in the online (methods) and 

also in several other papers Mike has written”76. The UK House of Commons Science and 

Technology Committee inquiry (2010b) found that this type of approach was considered 

common practice at the time. They stated: 

The focus on Professor Jones and CRU has been largely misplaced. On the accusations 

relating to Professor Jones’s refusal to share raw data and computer codes, we consider 

that his actions were in line with common practice in the climate science community. We 

have suggested that the community consider becoming more transparent by publishing 

raw data and detailed methodologies. 

From our review of the e-mails, it is clear that the scientists expressed significant frustration at 

repeated requests for specific explanations and computer codes, and that their attitudes toward 

some requestors were not always complimentary. This is consistent with the findings of the 

Independent Climate Change E-mails Review, which stated that the CRU scientists had an 

“overly defensive approach” and a tendency to provide unhelpful responses to requests for 

information (Russell, 2010). This is regrettable, and EPA agrees with the recommendations of 

the UK House of Commons Science and Technology Committee investigation and the 

Independent Climate Change E-mails Review that both CRU and the greater scientific 

 

76 E-mail file 1076083097.txt, (February 6, 2004), page 650, line 42 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

87
community should make more of an effort to provide public access to raw data and detailed 

methodologies. 

However, we also find that the petitioner greatly exaggerates the implications of the alleged 

conduct of two scientists. The evidence they point to does not support their claims that the 

ability of other researchers to independently review or replicate paleoclimate studies has been 

limited, that their scientific conclusions are unsupported, or that these specific incidents are a 

sound basis on which to characterize the practices of hundreds, if not thousands, of scientists 

across the much broader body of climate science. These leaps of logic are not supported by 

sound reasoning or evidence. The evidence indicates the exercise of scientific rigor and honesty, 

and the release of information in accord with then common scientific practice. The petitioner has 

not explained why the data and methodology that was released or was otherwise available was 

inadequate for further research, and have not provided scientific arguments to support their 

claims. In addition, the “hockey stick” papers are more than a decade old. Since their 

publication, numerous studies have been published that improved on the original methodology 

and that include newer and different sources of data. Given this body of newer work, petitioner’s 

concern over the construction of a decade old figure are of little if any scientific relevance. As 

discussed in Volume 1 of the RTP and elsewhere, there has been significant research and debate 

in the scientific community over a variety of proxy temperature reconstructions, and petitioner 

has not argued or shown here that this research was in error or that research opposing it was not 

performed or could not be performed because of data or coding allegedly withheld. 

EPA agrees with the Independent Climate Change E-mails Review’s recommendation of greater 

transparency in the future in this area of scientific research, but the evidence presented by the 

petitioner does not support the view that the scientific research in this area and the conclusions 

drawn from it, including conclusions about the uncertainty involved in areas of research such as 

proxy temperature reconstructions, was flawed or improperly characterized by EPA in the 

Endangerment Finding. 

In addition, the body of paleoclimate research—that is, the specific research at issue in the emails related to these two examples cited by the petitioner—underwent extensive scientific 

review and scrutiny by the NRC in 2006 in response to a request from the U.S. House of 

Representatives Committee on Science. The NRC committee was tasked with assessing “the 

state of scientific efforts to reconstruct surface temperature records for the Earth over 

approximately the last 2,000 years and the implications of these efforts for our understanding of 

global climate change” (NRC, 2006). A key conclusion from the NRC report supported the 

methods and general conclusions of the paleoclimate community, stating: 

It can be said with a high level of confidence that global mean surface temperature was 

higher during the last few decades of the 20th century than during any comparable period 

during the preceding four centuries. This statement is justified by the consistency of the 

evidence from a wide variety of geographically diverse proxies. 

Thus, we find that the petitioner’s evidence does not support their conclusion that 

paleoclimate studies could not be replicated and results verified, nor any reason to question 

the fundamental conclusions of the climate change research conducted by the CRU 

researchers. 

88
Comment (3-40): 

Peabody Energy claims that in response to a HadCRUT data request from Warwick Hughes, an 

Australian scientist, Phil Jones replied on February 8, 2005, “We have 25 years or so invested in 

the work. Why should I make the data available to you, when your aim is to try and find 

something wrong with it?” (Jones, 2005). On this basis, the petitioner argues that the 

Endangerment Finding should be reconsidered because lack of data sharing and accessibility 

prevented key climate science studies from being replicated and critiqued. 

Response (3-40): 

Although Jones denies Hughes’ request, we note that he points Hughes to another expert (Hans 

Teunisson) to assist with his request, as well as to various sources of data while describing that 

some countries restrict access to data. Jones’ full response to Hughes’ email is as follows (Jones, 

2005): 

Warwick, 

Hans Teunisson will reply. ’He’ll tell you which other people should reply. Hans is 

“Hans Teunissen” <HTeunissen@wmo.int> . I should warn you that some data we have 

we are not supposed top pass on to others. We can pass on the gridded data - which we 

do. Even if WMO [the World Meteorological Organization] agrees, I will still not pass on 

the data. We have 25 or so years invested in the work. Why should I make the data 

available to you, when your aim is to try and find something wrong with it. There is IPR 

to consider. 

You can get similar data from GHCN at NCDC. Australia ’isn’t restricted there. Several 

European countries are. Basically because, for example, France ’doesn’t want the 

French picking up data on France from Asheville. Meteo France wants to supply data to 

the French on France. Same story in most of the others. 

Cheers 

Phil 

The petitioners exaggerate the implications of this one unfulfilled data request for the validity of 

the science. We note that the methods used to generate the HadCRUT temperature record are 

well described in the literature and the data necessary to replicate the HadCRUT record are 

publically available, as described in Volume 1, Section 1.3.3.1. Working with publically 

accessible data, the Independent Climate Change E-mails Review (Russell, 2010) was able to 

write computer code from scratch in a space of two days that produced results similar to the 

HadCRUT and other independent analyses. Furthermore, Volume 1 demonstrates that 

temperature reconstructions from publically available data such as NOAA’s temperature record, 

the Global Historical Climatology Network (GHCN), look very similar to temperature 

reconstructions from HadCRUT. Therefore, the petitioner’s allegation that key climate science 

studies could not be replicated and critiqued is not accurate. It remains the case that the 

HadCRUT temperature record is legitimized by peer reviewed methodology, its replicability, and 

its similarity with other global temperature records. 

As noted in our response (3-39) above, the Independent Climate Change E-mails Review found a 

tendency to provide unhelpful responses to requests for information and the need for a culture 

89
shift to emphasize the importance of transparency. EPA agrees with the recommendations of the 

UK House of Commons Science and Technology Committee investigation and the Independent 

Climate Change E-mails Review that both CRU and the greater scientific community should 

make more of an effort to provide public access to raw data and detailed methodologies. 

However, the petitioners’ broad and sweeping claims are not warranted given the data that was 

clearly available and the ready ability to do research using the publicly available data and 

methodology provided by the CRU. 

Comment (3-41): 

The petitioners draw various conclusions about the effect of the scientists’ alleged actions 

discussed in the e-mails. Peabody Energy argues that leading climate scientists have worked 

under a “veil of secrecy” and that their actions “[do] not comport with U.S. scientific norms.” 

Peabody Energy asserts that this is suggestive that they may have been “hiding” something. 

Peabody Energy also claims that without the underlying data and related information, CRU and 

associated scientists’ studies “could not be replicated or critiqued,” which calls into question 

their validity. The Coalition for Responsible Regulation goes one step further, alleging that “It is 

doubtful EPA can disclose the technical studies and data upon which it so heavily relies, not only 

because Phil Jones and his colleagues at CRU deliberately withheld data from both EPA’s and 

the public’s review, but also because some of that raw data has now been destroyed.” 

Response (3-41): 

Our responses to the specific e-mails petitioners rely upon in reaching these conclusions are 

addressed above. Responses 3-37 through 3-40 address claims regarding availability of data, 

including data concerning a human “fingerprint” in the tropics, data underlying the HadCRUT 

temperature record, and data concerning historic temperature reconstructions. Volume 1 of this 

RTP document addresses claims regarding the scientific validity and other scientific aspects of 

these data. As we have explained, based on our review of the e-mails, the evidence does not 

support the broad claims of misfeasance or poor science, or of attempts to hide any such science. 

Instead the scientists at issue performed their research honestly and with scientific rigour, and 

they released information in accord with the common scientific practice at that time. 

Further, the e-mails show that the scientists believed that enough data and information were 

available for independent review, replication, and verification, while also expressing frustration 

with the ongoing inquiries from certain individuals. It is clear that the e-mail authors were 

particularly frustrated by repeated requests for specific explanations and computer programming 

codes when the base data had already been made available and the methodology for replicating a 

particular study had already been published in the literature. As we note in our previous 

responses (e.g., 3-35), this view of the e-mail authors represented the common approach toward 

data release at the time. Petitioners do not explain why the data that was available was 

inadequate for the purposes of such research. 

The petitioners claim that the CRU scientists and their colleagues ignored requests for data 

in order to avoid revealing their biased or flawed science, implying that they did not 

operate according to good scientific practice. However petitioner’s evidence does not 

support their suggestion that the scientists manipulated their analyses to reach desired 

results, withheld data with an aim of hiding the alleged manipulation, and ultimately 

90
reached flawed their scientific conclusions are flawed. 

EPA is not alone in reaching these conclusions. As stated in our response (3-35) above, 

the UK House of Commons Science and Technology Committee investigation concluded 

that “On the accusations relating to Professor Jones’s refusal to share raw data and 

computer codes, we consider that his actions were in line with common practice in the 

climate science community.” The Scientific Appraisal Panel review examined criticism 

toward CRU and found “no evidence of any deliberate scientific malpractice in any of the 

work of the Climatic Research Unit and had it been there we believe that it is likely that we 

would have detected it” (Oxburgh, 2010). In addition, the Independent Climate Change Emails Review concluded, “On the specific allegations made against the behaviour of CRU 

scientists, we find that their rigour and honesty as scientists are not in doubt” (Russell, 

2010). We find that the petitioner’s evidence does not suggest otherwise or show that the 

CRU scientists and their colleagues utilized methods other than those which are “fair and 

satisfactory” according to the Scientific Appraisal Panel, and conducted their research with 

integrity and rigor. 

Comment (3-42): 

Peabody Energy states that the CRU e-mails provide evidence that top climate scientists 

refused to provide access to key data underlying their studies, and that this practice is 

“especially alarming both because many of these scientists were either government employees 

or government-funded and because they were so highly influential in the IPCC.” Peabody 

Energy quotes the following conclusion from the “Wegman Report” (Wegman et al., 2006). 

Federally funded work including code should be made available to other researchers upon 

reasonable request, especially if the intellectual property has no commercial value. Some 

consideration should be granted to data collectors to have exclusive use of their data for 

one or two years, prior to publication. But data collected under federal support should be 

made publicly available. 

Response (3-42): 

The petitioner’s quote from the Wegman Report does not support the petitioner’s allegation that 

the CRU e-mail authors refused to share key data underlying their studies. It is simply a 

statement of the opinion of Dr. Wegman, author of the referenced report. We have already 

addressed public comments regarding the Wegman Report in Volume 2 of the RTC document 

supporting the Endangerment Findings. We address the petitioners’ claims regarding the alleged 

withholding of data—including data concerning a human “fingerprint” in the tropics, data 

underlying the HadCRUT temperature record, and data concerning historic temperature 

reconstructions—in Responses 3-37 through 3-40 above. 

Comment (3-43): 

Peabody Energy states that the CRU e-mail authors finally acknowledged the importance of 

public disclosure of their data for maintaining good scientific practices only after they were 

forced to admit they had made mistakes in their research. According to Peabody Energy, the 

authors of a paper published in Science were forced to admit that they had flipped a dataset 

upside down as a result of Stephen McIntyre’s requests for data. Peabody Energy quotes the 

91
following e-mail from Jonathan Overpeck, professor at University of Arizona, sent to multiple 

colleagues on September 5, 2009: 

D [Darrell Kaufman, professor at Northern Arizona University] et al.—

Please write all e-mails as though they will be made public. I would not rush 

and I would not respond to any of them until the best strategy is 

developed—don’t want to waste anyone’s time, including yours or Mc’s 

[Stephen McIntyre’s]. Since the recon in Science has an error, I think you do 

need to publish a correction in Science...I don’t think you have a choice 

here... 

# 5 is tricky. Giving him the data would be good, but only if it is yours to give. 

You can’t give him data that you got from others and are not allowed to share. But 

it would be nice if he could have access to all the data that we used—that’s the 

way science is supposed to work.77 

Peabody Energy also states that Tom Wigley of the University Corporation for Atmospheric 

Research was forced to admit there were problems with datasets used in proxy temperature 

reconstructions by Keith Briffa of CRU, when Stephen McIntyre raised questions about them. 

According to the petitioner, Briffa, at least initially, “declined to respond to McIntyre’s requests 

for information.” The petitioner quotes the following e-mail excerpt from Tom Wigley to Phil 

Jones on October 5, 2009: 

...Keith does seem to have got himself into a mess...And the issue of with-holding data 

is still a hot potato, one that affects both you and Keith (and Mann). Yes, there are 

reasons— but many *good* scientists appear to be unsympathetic to these. The trouble 

here is that with-holding data looks like hiding something, and hiding means (in some 

eyes) that it is bogus science that is being hidden.78

Response (3-43): 

Peabody Energy implies that because of Stephen McIntyre’s requests for data, mistakes 

were found in a paper published in Science, which the petitioner did not identify but that 

we believe to be Kaufman et al. (2009) based on context given in the e-mails. However, 

the evidence does not show what the catalyst was for the authors’ decision to publish a 

correction. In the “corrections and clarifications” update written by Kaufman et al. 

responding to critiques of their original paper, they thanked “H. McCulloch and others who 

have pointed out errors and have offered suggestions” (Kaufman et al. 2010). To the 

extent that Peabody Energy is arguing that the results of Kaufman et al. (2009) are invalid 

given the errors that necessitated publishing a correction, we respond in Volume 1, Section 

1.1.3 of the RTP document to the allegation about “flipping datasets” (1-10) and related 

paleoclimate temperature reconstruction issues. 

Peabody Energy also implies that Wigley admitted there were problems with Keith 

 

77 E-mail file 1252164302.txt, (September 5, 2009), page 1734, line 12 of the PDF version 

entitled: CRU Emails 1996-2009.pdf. 

78 E-mail file 1254756944.txt, (October 5, 2009), page 1782, line 6 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

92
Briffa’s proxy temperature reconstructions after Stephen McIntyre questioned their 

validity. The e-mail does not support this allegation. The text of the e-mails says nothing 

that would indicate that Wigley “admitted” or believed there were errors in Briffa’s work, 

or that any errors were being “hidden.” To the contrary, Wigley states that there can be 

valid reasons for not publishing data, but voices concern that others would misinterpret 

such actions as trying to hide poor science. 

As before, the petitioner claims that these incidents are proof that the science was flawed 

and unreliable. Through our review of the scientific issues, in response to petitioners’ 

arguments and throughout the notice and comment period on the Endangerment Findings, 

EPA has determined that the paleoclimate science is appropriately characterized and 

weighed in the Administrator’s decision. Our review of the issues related to the release of 

data indicates that the scientists did make data and information available, even if sometime 

later and sometimes not to the satisfaction of requestors, that raw data was also publicly 

available, that the scientists at issue conducted their work with scientific integrity and 

rigour, and their actions in releasing data was consistent with common and accepted 

scientific practice. While EPA supports increased transparency in this area of research, 

petitioners arguments are not based on science and do not support their claims that the 

research at issue was flawed. Their claim is based on concerns over data availability, and 

they do not show why the data that was available was not adequate for the research 

purposes claimed. The evidence they present does not support the broad scientific and 

other conclusions they draw. 

3.4.3 Allegations of Improper Conduct With Regard to UK FOI and U.S. FOIA Laws 

3.4.3.1 General Allegations 

Comment (3-44): 

The Coalition for Responsible Regulation, the Pacific Legal Foundation, Peabody Energy, and 

the State of Texas claim that a quote from the Deputy Information Commissioner of the UK 

Information Commissioner’s Office (ICO)—”Requests under the Freedom of Information Act 

were not dealt with as they should have been under the legislation”—provides evidence that 

CRU scientists violated the law by refusing to comply with requests for data. Peabody Energy 

states that “these efforts by CRU to evade FOIA have now been determined to have been 

illegal.” Peabody Energy further opines that “Destruction of public records to avoid disclosure 

under FOIA unquestionably violates U.S. and U.K. law.” The State of Texas quotes a 

newspaper article (Kinver, 2010) that states that the UK ICO is reviewing whether the UK FOI 

law needs to be revised in light of the CRU’s refusal to disclose public information. 

Response (3-44): 

The petitioners base their allegations that CRU violated the UK FOI law solely on a statement 

to the press made by Deputy Information Commissioner Graham Smith, which suggested that 

at least some of the requested information should have been disclosed. Contrary to the 

petitioners’ claims, this statement was not an official finding of the UK ICO. The recent 

inquiry by the UK House of Commons Science and Technology Committee (2010b) puts 

Smith’s statement into proper context: 

93
88. On 29 January there was an exchange between UEA [University of East Anglia] and 

Mr. Smith, the Deputy Commissioner. Brian Summers, the Registrar and Secretary of 

UEA responded forcibly to Mr Smith’s 22 January press statement, which asserted that 

UEA had not dealt with FOIA requests “as they should have been under the legislation”. 

He did not consider it was “acceptable that such a statement which has led to an 

extremely damaging commentary on the University [was] first communicated to the 

University by a journalist”. His letter goes on to defend UEA’s actions in detail and to 

ask that, if the Information Commissioner’s Office (ICO) cannot retract the 22 January 

statement, it issue a clarification regarding the alleged breaches of the FOIA. A response 

from the ICO was issued the same day. It did not retract the original statement but 

offered clarification: 

1. [No] decision notice has yet been issued and no alleged breaches have yet been put 

to the University for comment. That matter has yet to be addressed, but it will be 

over coming months. 

2. The fact that the elements of a section 77 offence may have been found here, but 

cannot be acted on because of the elapsed time, is a very serious matter. The ICO 

is not resiling from its position on this. 

3. The ICO’s position is as stated in point 2 above. The statement may be read to 

indicate that. Under section 77, an offence may be committed by an individual, not 

necessarily the public authority itself. 

4. Errors like this are frequently made in press reports and the ICO cannot be 

expected to correct them, particularly when the ICO has not itself referred to 

penalties or sanctions in its own statement. 

89. UEA responded on 1 February thanking the ICO for the clarification but setting out 

its concerns relating to the press coverage of the ICO’s original statement: 

Your clarification that the press cannot infer from your statement to the 

Sunday Times that it has been established that the University (or indeed 

any individual associated with the University) has breached the terms of 

the Freedom of Information Act is welcome. [UEA’s] reputation which has 

been subjected to these damaging and incorrect assertions claiming to be 

based on your statement and we must take some steps to put this right. We 

will be writing to the media which carried reports based on your statement, 

pointing out the inaccuracies and asking them to rectify the position. 

90. In his oral evidence Professor Acton [Vice-Chancellor at UEA] questioned the ICO 

statement of 22 January: 

Our principle is that prima facie evidence is evidence which on the face of 

it and without investigation suggests that there is a case to answer. To my 

mind if there is prima facie evidence; why did I set up the Muir Russell 

independent review? Prima facie evidence is not the same as, you have 

been found to breach. [...] If it is sub judice, if, as we had in the letter ten 

days ago from the ICO, the investigation has not even begun, I am puzzled 

how we could have been found to breach if there has been no investigation. 

91. The ICO’s most recent letter, dated 3 March, in UEA’s view, “makes plain that there 

is no assumption by the ICO, prior to investigation, that UEA has breached the Act; and 

that no investigation has yet been completed.” The ICO’s letter confirmed that the “ICO 

is not pursuing any investigation under section 77 of the Act. That matter is closed as far 

as the ICO is concerned, given the statutory time limits for action”. It added that: 

94
The ICO acknowledges your concern about the statement made and the 

subsequent media and blog reports. Given that the Deputy Commissioner 

has already been publicly associated with the matter, any Decision Notice 

will be reviewed and signed off by another authorised signatory. 

The UK House of Commons Science and Technology Committee (2010b) concluded the 

following: 

We regret that the ICO made a statement to the press that went beyond that which it 

could substantiate and that it took over a month for the ICO properly to put the record 

straight. We recommend that the ICO develop procedures to ensure that its public 

comments are checked and that mechanisms exist to swiftly correct any mis-statements or 

misinterpretations of such statements. 

Based on the evidence submitted to the UK House of Commons Science and Technology by 

UEA and the UK ICO, it is clear that Deputy Information Commissioner Smith’s January 22nd

press statement was not based on the results of a formal investigation and his opinions about 

CRU do not represent the conclusions of a comprehensive government investigation. The 

statement from Smith does not support the petitioner’s allegations that CRU scientists acted 

illegally. In addition, regarding the comment from the State of Texas that the UK ICO is 

reviewing whether the UK FOI law needs to be revised, we note that the existence of a possible 

review of the law does not provide evidence that CRU scientists acted illegally or 

inappropriately. 

For all of the above reasons, the petitioners evidence does not show whether there was a 

violation of UK law, and does not contradict the conclusions of the three independent 

investigations into the CRU e-mails. These investigations found that the CRU e-mail 

authors conducted their research in accordance with common practice in the climate 

science community at the time, utilized methods which are “fair and satisfactory” 

according to the Scientific Appraisal Panel (Oxburgh, 2010), and maintained scientific 

integrity and rigor in their work. EPA supports the recommendations for greater 

transparency in this area of climate research; however petitioners’ evidence does not 

support their claim that the science underlying the Endangerment Finding was suspect or 

flawed, or that it was mischaracterized in any way in the Endangerment Finding. 

Petitioners’ arguments are not based on an analysis of the science, but on unsupported 

assertions of inadequate science. 

Comment (3-45):

The Coalition for Responsible Regulation, Peabody Energy, and the Southeastern Legal 

Foundation claim that the CRU e-mail authors, particularly Phil Jones and Michael Mann, 

avoided compliance with FOI laws. Peabody Energy argues that the CRU e-mail authors 

concealed information as a means to frustrate the work of researchers like Stephen McIntyre 

and Ross McKitrick who might criticize their work. Peabody Energy states that the 

paleoclimate community “decided that McIntyre and anyone associated with him was 

essentially their enemy and that they would refuse to cooperate entirely with any effort to 

provide him with information, including under the U.S. and British FOIAs.” Peabody Energy 

further claims that CRU scientists and their associates “accelerated their highly-contentious 

95
struggle against so-called ‘skeptics’” by creating the RealClimate website in order to “counter” 

Stephen McIntyre’s ClimateAudit website. 

The petitioners highlight numerous statements taken from the CRU e-mails in support of their 

arguments that CRU scientists and their colleagues withheld data and ignored FOI requests. In 

one example, Coalition for Responsible Regulation and Peabody Energy quote an e-mail from 

Phil Jones to Tom Wigley and Ben Santer on January 21, 2005: 

As for FOIA Sarah isn’t technically employed by UEA and she will likely be paid 

by Manchester Metropolitan University. I wouldn’t worry about the code. If 

FOIA does ever get used by anyone, there is also IPR [intellectual property rights] 

to consider as well. Data is covered by all the agreements we sign with people, so 

I will be hiding behind them. I’ll be passing any requests onto the person at UEA 

who has been given a post to deal with them.79

In another example, Peabody Energy, the Southeastern Legal Foundation, and the Coalition for 

Responsible Regulation quote the following e-mail excerpt from Jones to Mann on February 3, 

2005: 

Just sent loads of station data to Scott. Make sure he documents everything better this 

time! And don’t leave stuff lying around on ftp sites — you never know who is trawling 

them. The two MMs [Stephen McIntyre and Ross McKitrick] have been after the CRU 

station data for years. If they ever hear there is a Freedom of Information Act now in the 

UK, I think I’ll delete the file rather than send to anyone. Does your similar act in the US 

force you to respond to enquiries within 20 days? — our does ! The UK works on 

precedents, so the first request will test it. We also have a data protection act, which I will 

hide behind. Tom Wigley has sent me a worried e-mail when he heard about it — thought 

people could ask him for his model code. He has retired officially from UEA so he can 

hide behind that. IPR [intellectual property rights] should be relevant here, but I can see 

me getting into an argument with someone at UEA who’ll say we must adhere to it!...80 

Peabody Energy and Southeastern Legal Foundation quote Mann’s response (the Southeastern 

Legal Foundation erroneously attributes this quote to Phil Jones): 

Yes, we’ve learned out [sic] lesson about FTP. We’re going to be very careful in the 

future what gets put there. Scott really screwed up big time when he established that 

directory so that Tim could access the data. Yeah, there is a freedom of information act 

in the U.S., and the contrarians are going to try to use it for all its worth. But there are 

also intellectual property rights issues, so it isn’t clear how these sorts of things will play 

out ultimately in the U.S.81

 

79 E-mail file 1106338806.txt, (January 21, 2005), page 810, line 38 of the PDF version 

entitled: CRU Emails 1996-2009.pdf. 

80 E-mail file 1107454306.txt, (February 3, 2005), page 821, line 22 of the PDF version entitled: CRU 

Emails 1996-2009.pdf.

81 E-mail file 1107454306.txt, (February 3, 2005) page 821, line 12 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

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Peabody Energy quotes another e-mail excerpt from Phil Jones to Michael Mann, Raymond 

Bradley, and Malcolm Hughes on February 21, 2005: 

PS I’m getting hassled by a couple of people to release the CRU station temperature data.

Don’t any of you three tell anybody that the UK has a Freedom of Information Act !”82

Peabody Energy quotes another e-mail excerpt from Phil Jones to Ben Santer that was 

forwarded on December 4, 2008: 

In response to FOI and EIR [Environmental Information Regulations] requests, 

we’ve put up some data - mainly paleo data. Each request generally leads to more 

— to explain what we’ve put up. Every time, so far, that hasn’t led to anything 

being added — instead just statements saying read what is in the papers and what 

is on the web site! Tim Osborn sent one such response (via the FOI person) earlier 

this week. We’ve never sent programs, any codes and manuals.83 

Response (3-45): 

The quoted e-mails show the authors’ opinions and questions about the applicability of the FOI 

law to their various datasets. As discussed in our previous responses in this Volume, scientists 

can and do state their opinions and express frustration in personal communications with 

colleagues. Although Jones makes sometimes flippant statements regarding FOI laws, this does 

not show that he deleted files, destroyed data, or otherwise attempted to obstruct FOI requests. 

In addition, the petitioner’s claim that the paleoclimate community refused to cooperate entirely 

with McIntyre and anyone associated with him is without merit. Two of the e-mails quoted by 

Peabody Energy 84 clearly indicate that Jones and other CRU scientists provided data in response 

to FOI requests. As discussed throughout this section, our review of the issues related to the 

release of data indicates that in many cases the data were already publicly available or were 

released by the scientists, and that the scientists conducted their work with scientific rigor and 

honesty and consistent with common and accepted scientific practice. 

Regarding Peabody Energy’s claims that the CRU scientists perpetuated a “highly-contentious 

struggle” against “climate skeptics,” we find that the petitioner’s assertions concerning the 

RealClimate blog of no relevance. The reasons for creating the site are irrelevant to the issues of 

whether the scientists were complying with FOI laws, and to the issue of the scientific validity of 

their research. 

Comment (3-46):

Peabody Energy quotes the following e-mail excerpt written by Phil Jones to Kevin Trenberth of 

the University Corporation for Atmospheric Research on June 20, 2007, claiming that it provides 

evidence that CRU scientists and their colleagues withheld data and ignored FOI requests: 

 

82 E-mail file 1109021312.txt, (February 21, 2005), page 834, line 25 of the PDF version entitled: CRU 

Emails 1996-2009.pdf. 

83 E-mail file 1228412429.txt, (December 4, 2008), page 1593, line 22 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

84 E-mail file 1182346299.txt, (June 20, 2007), page 1335, line 9 and e-mail file 1228412429.txt, (December 4, 

2008), page 1593, line 22 of the PDF version entitled: CRU Emails 1996-2009.pdf. 

97
I won’t be replying to either of the e-mails below, nor to any of the accusations on the 

Climate Audit website. I’ve sent them on to someone here at UEA to see if we should be 

discussing anything with our legal staff. The second letter seems an attempt to be nice to 

me, and somehow split up the original author team. I do now wish I’d never sent them the 

data after their FOIA request 85

Peabody Energy cites this example as further evidence of the CRU e-mail authors ignored FOI 

requests as part of their “highly-contentious struggle” against anyone affiliated with Stephen 

McIntyre or the Climate Audit blog. 

Response (3-46): 

The petitioner selectively quotes part of an e-mail chain to support its argument and does not 

provide larger context for Jones’ statement. The e-mail chain at issue here was sent in response 

to the following e-mail from Douglas Keenan (private UK citizen) to Stephen McIntyre (editor 

of the blog Climate Audit). The subject of the e-mail relates to a paper on urban heat islands that 

Jones co-authored with Wei-Chyung Wang of the University at Albany in New York (i.e., Jones 

et al., 1990). 

From: “D.J. Keenan” doug.keenan@informath.org 

To: “Steve McIntyre” stephen.mcintyre@utoronto.ca 

Cc: “Phil Jones” p.jones@uea.ac.uk 

Subject: Wang fabrications 

Date: Tue, 19 Jun 2007 20:45:15 +0100 

Steve, 

I thought that I should summarize what has happened with the Wang case First, I 

concluded that the claims made about Chinese stations by Jones et al. [Nature, 1990] and 

Wang et al. [GRL, 1990] were very probably fabricated. (You very likely came to the 

same conclusion.) Second, some investigation showed that Phil Jones was wholly 

blameless and that responsibility almost certainly lay with Wang. Third, I contacted 

Wang, told him that I had caught him, and asked him to retract his fabricated claims. My 

e-mails were addressed to him only, and I told no one about them. In ’Wang’s reply, 

though, Jones, Karl, Zeng, etc. were Cc’d. Fourth, I explained to Wang that I would 

publicly accuse him of fraud if he did not retract. Wang seemed to not take me seriously. 

So I drafted what would be the text of a formal accusation and sent it to him. Wang 

replied that if I wanted to make the accusation, that was up to me. Fifth, I put a draft on 

my web site-- http://www.informath.org/apprise/a5620.htm-- and e-mailed a few people, 

asking if they had any recommendations for improvement. 

I intend to send the final version to Wang’s university, and to demand a formal 

investigation into fraud. I will also notify the media. Separately, I have had a 

preliminary discussion with the FBI--because Wang likely used government funds to 

commit his fraud; it seems that it might be possible to prosecute Wang under the same 

statute as was used in the Eric Poehlman case. The simplicity of the case makes this 

 

85 E-mail file 1182346299.txt, (June 20, 2007). page 1335, line 9 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

98
easier--no scientific knowledge is required to understand things. I saw that you have now 

e-mailed Phil (Cc’d above), asking Phil to publish a retraction of Wang’s claims: 

http://www.climateaudit.org/?p=1741#comment-115879 There could be a couple 

problems with that. One problem is that it would be difficult for Phil to publish anything 

without the agreement of Wang and the other co-authors (Nature would simply say “no”). 

Another problem is that your e-mail says that you presume Phil was “unaware of the 

incorrectness” of Wang’s work. I do not see how that could be true. Although the 

evidence that Phil was innocent in 1990 seems entirely conclusive, there is also the paper 

of Yan et al. [Advances in Atmospheric Sciences, 18: 309 (2001)], which is cited on my 

web page. Phil is a co-author of that paper. Phil, this proves that you knew there were 

serious problems with Wang’s claims back in 2001; yet some of your work since then 

has continued to rely on those claims, most notably in the latest report from the IPCC. It 

would be nice to hear the explanation for this. Phil? 

Kind wishes, 

Doug86

This e-mail shows Douglas Keenan making serious accusations of fraud and data fabrication 

against Wei-Chyung Wang, and accusing Jones of knowingly using Wang’s alleged faulty data 

in his research. Keenan goes even further, stating that he contacted the Federal Bureau of 

Investigation about prosecuting Wang for fraud, and threatening that if Wang does not publish a 

retraction, Keenan will make formal accusations of fraud to Wang’s university and the media. 

We respond to the petitioners’ claims that Jones and Wang committed fraud and knowingly 

used faulty Chinese weather station data in Volume 1, Section 1.3.4 of the RTP document. 

There, we show that the claims of Keenan and McIntyre are groundless and that Wang was 

cleared of any misconduct. Given this larger context, Jones’ statement, “I do now wish I’d 

never sent them the data after their FOIA request,” is more understandable. Rather than being 

an indication of Jones’ reluctance to comply with FOIA requests, it appears that he is reacting 

to the fact that CRU data were misused to make aggressive and personal attacks on one of his 

colleagues. In addition, his e-mail basically says he is referring the request to the UEA, instead 

of making decisions himself on this issue. As the UK House of Commons Science and 

Technology Committee investigation found, “The focus on Professor Jones and CRU has been 

largely misplaced. On the accusations relating to Professor Jones’s refusal to share raw data 

and computer codes, we consider that his actions were in line with common practice in the 

climate science community. We have suggested that the community consider becoming more 

transparent by publishing raw data and detailed methodologies. On accusations relating to 

Freedom of Information, we consider that much of the responsibility should lie with UEA, not 

CRU” (UK House of Commons Science and Technology Committee, 2010b). 

Our review of the larger context for the CRU e-mails in question, as well as issues related to the 

release of data in general, indicates that the scientists did make data and information available, 

and conducted their work consistent with common and accepted scientific practice. 

Comment (3-47): 

 

86 E-mail file 1182346299.txt, (June 29, 2007), page 1336, line 22 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

99
The Southeastern Legal Foundation argues that “E-mails were apparently altered or deleted to 

cover up wrongdoing.” The petitioner quotes part of an e-mail from Phil Jones of CRU to 

Eugene Wahl of NOAA and Caspar Amman of the National Center for Atmospheric Research: 

“[T]ry and change the Received date. Don’t give those skeptics something to amuse themselves 

with.” The Southeastern Legal Foundation argues that even if there is no evidence that e-mails 

were tampered with in response to the request from Jones, the apparent willingness of these 

parties to engage in such actions should cause EPA to question its reliance on their work. 

Response (3-47): 

Petitioner makes a number of unsubstantiated assumptions in their argument. First, the petitioner 

assumes that Jones was asking Wahl and Ammann to alter their e-mail records. Although the 

petitioner only quotes part of the e-mail, we provide the full text to provide important context: 

Gene/Caspar, 

Good to see these two out. Wahl/Ammann doesn’t appear to be in ’CC’s [the journal 

Climatic Change] online first, but comes up if you search. You likely know that McIntyre 

will check this one to make sure it hasn’t changed since the IPCC close-off date July 

2006! Hard copies of the WG1 [IPCC Working Group 1] report from CUP have arrived 

here today. Ammann/Wahl - try and change the Received date! Don’t give those skeptics 

something to amuse themselves with. 

Cheers 

Phil 87 

Based on our review of the issue, we note that in his e-mail, Jones is referring to two distinct 

journal articles written by the same authors, Wahl and Ammann (2007) and Ammann and Wahl 

(2007), both published in the journal Climatic Change. The rationale for Jones’ statement, 

“Ammann/Wahl - try and change the Received date! Don’t give those skeptics something to 

amuse themselves with,” is that the journal Climatic Change had made an error in listing a 

received date of August 2000, which was several years earlier than the paper was written 

(Ammann and Wahl, 2007). Therefore, Phil Jones was apparently suggesting that they should try 

to get the journal to correct its website to list the actual date the Ammann and Wahl paper was 

received, rather than an obviously incorrect date of August 2000. There is no evidence that 

Ammann and Wahl followed up on Jones’ suggestion, but even if they had, this would not be an 

inappropriate action. 

Second, the petitioner assumes Jones’ statement was part of some kind of “cover up” of “wrongdoing,” without specifying what that means or providing any further context for their allegation. 

It is unclear on what basis the petitioner concludes that there was “apparent willingness of these 

parties” to tamper with e-mails. Jones suggestion is benign when the context is considered and 

receiving this e-mail in no way implies “willingness” on the part of Wahl and Amman to engage 

in inappropriate action. Subsequent replies from Wahl and Amman in the same e-mail chain88

discuss only their papers and provide no indication that they engaged in any inappropriate 

 

87 E-mail file 1189722851.txt, (September 12, 2007), page 1357, line 18 of the PDF version entitled: CRU 

Emails 1996-2009.pdf. 

88 E-mail file 1189722851.txt, (September 12, 2007). page 1356, line 33 of the PDF version entitled: CRU 

Emails 1996-2009.pdf. 

100
actions. The petitioners’ evidence does not support their claim that the CRU scientists and their 

colleagues altered e-mail information or withheld key data needed for replicating key climate 

change studies, nor do the petitioners provide any other evidence that would cause EPA to 

question the scientific merits of these scientists’ work. 

Comment (3-48): 

The Pacific Legal Foundation and the State of Texas claim that the CRU e-mails demonstrate 

that EPA was incorrect in asserting that the science on which the Administrator has based her 

endangerment determinations has been fully open and transparent. The Pacific Legal Foundation 

and the State of Texas state that a separate inquiry funded by the University of East Anglia will 

investigate CRU’s policies and practices for “disseminating data and research findings” to see if 

any of their actions were “at odds with acceptable scientific practice” or “call into question any 

of the research outcomes.” The Pacific Legal Foundation argues that this lack of transparency 

evident in the CRU e-mails casts doubt on the reliability of CRU’s work, and that EPA’s 

Scientific Advisory Board should be granted an opportunity to review and comment on whether 

the CRU data can be relied on by EPA. 

Peabody Energy argues that in a January 23, 2009, memorandum to EPA employees (U.S. EPA, 

2009b) and in a March 9, 2009, Presidential Memorandum for the Heads of Executive 

Departments (U.S. EPA, 2009c), Administrator Jackson stated her commitment that the EPA will 

rely on open and transparent science. Peabody Energy states that the CRU scientists and their 

colleagues, which includes “government-funded scientists involved in hugely important 

scientific research,” were not “fully willing to make available for public scrutiny all of the 

information they use and produce, no matter the political, policy or scientific consequence.” 

Peabody Energy concludes that: 

[S]cience advances only when research is exposed to critical analysis; that is the entire purpose of 

the scientific process. The practice of science in the shadows as reflected in the CRU material is 

directly contrary to the Administrator’s undertaking that science relied on by EPA will be subject 

to the highest standards of transparency and openness. The Administrator cannot, consistent with 

these undertakings, rely on the AR4 material prepared by these authors. 

In other words, the petitioner concludes that the work of the CRU e-mail authors, including their 

contributions to the IPCC AR4, violates EPA’s commitment to transparency and thus cannot be 

relied upon for the Endangerment Findings. 

Response (3-48): 

The Pacific Legal Foundation and the State of Texas reference the existence of the Independent 

Climate Change E-mails Review as evidence to call into question the reliability and validity of 

CRU’s work. In so doing, the petitioners inappropriately assume wrongdoing based solely on 

the existence—not the conclusions—of an investigation. With regard to the CRU scientists’ 

actions involving research and science, the Independent Climate Change E-mails Review issued 

its report on July 7, 2010. This report concluded: 

Climate science is a matter of such global importance, that the highest standards of 

honesty, rigour and openness are needed in its conduct. On the specific allegations made 

against the behaviour of CRU scientists, we find that their rigour and honesty as scientists 

101
are not in doubt. In addition, we do not find that their behaviour has prejudiced the 

balance of advice given to policy makers. In particular, we did not find any evidence of 

behaviour that might undermine the conclusions of the IPCC assessments. 

Regarding CRU’s data management policies and practices, the Independent Climate Change Emails Review identified issues with the way the CRU has handled requests for information in the 

past and the need for more transparency. As stated in our responses (e.g., 3-39) above, we agree 

with the recommendations of the UK House of Commons Science and Technology Committee 

and the Independent Climate Change E-mails Review that both CRU and the greater climate 

science community can improve its efforts in terms of transparency. However, we also find that 

the petitioners greatly exaggerate the implications of the e-mails concerning the release of certain 

data on the validity of the specific science issues they addressed, not to mention the petitioners’ 

much more expansive claim that the e-mails raise questions about the credibility of unrelated 

scientific issues not addressed in the materials they cite. Our review of the issues related to the 

release of data indicates that the scientists did make data and information available, that they 

conducted their work with scientific rigor and integrity, and that they acted in a manner 

consistent with common and accepted scientific practice. Data were also publicly available for 

use by researchers. We reiterate that we have found no evidence that other researchers were not 

able to access adequate data in order to replicate key findings or conduct their research. 

Petitioners have not explained why the data that was available was inadequate for these 

purposes. The petitioners’ evidence does not support their claim that the CRU scientists and 

their colleagues withheld key data needed for replicating key climate change studies, nor do the 

petitioners provide any other evidence that would cause EPA to question the scientific merits of 

these scientists’ work. 

The petitioners’ claim that the assessment reports can not be relied upon are not based on 

arguments or analysis of the scientific merits of the research at issue. Their arguments do not 

support a conclusion that the body of scientific research on climate change or the scientific basis 

for the Endangerment Finding is scientifically inappropriate or flawed. 

3.4.3.2 Specific FOI Request Regarding the IPCC’s Fourth Assessment Report 

The following comments and responses in this section address the petitioners’ specific allegation 

that the CRU e-mail authors obstructed one particular FOI request for e-mails and information 

pertaining to the creation of the IPCC’s AR4. 

Comment (3-49): 

The State of Texas alleges that the CRU e-mail authors ignored legal requirements when 

discussing how to respond to a FOI request for their e-mails relating to the drafting of the IPCC 

AR4. The petitioner argues that “At no time in the exchange did any of them suggest what state 

or federal laws might have governed how the request needed to be treated.” The State of Texas 

first quotes an e-mail from Bryan Lynch (private UK citizen) to Caspar Ammann of the National 

Center for Atmospheric Research on June 23, 2008, which references an FOI request submitted 

by David Holland of the UK-based think tank Global Warming Policy Foundation: 

I have read correspondence on web about your letter to the in relation [sic] to 

expert comments on IPCC chapter 6 sent directly by you to Keith Briffa, sent 

102
outside the formal review process. The refusal to give these documents tends to 

discredit you and the IPCC in the eyes of the public.89

Ammann apparently forwarded Lynch’s e-mail to Keith Briffa, Phil Jones, and Tim Osborn, and 

the State of Texas quotes their replies. Phil Jones states, “It doesn’t discredit IPCC!” .

90 Tim 

Osborn states: 

I’d ignore this guy’s request anyway. If we aren’t consistent in keeping our discussions 

out of the public domain, then it might be argued that none of them can be kept private.

Apparently, consistency of our actions is important91

Keith Briffa states: 

I have been of the opinion right from the start of these FOI requests, that our private, 

inter-collegial discussion is just thatPRIVATE. Your communication with individual 

colleagues was on the same basis as that for any other person and it discredits the IPCC 

process not one iota not to reveal the details. On the contrary, submitting to these 

“demands” undermines the wider scientific expectation of personal confidentiality. It is 

for this reason, and not because we have or have not got anything to hide, that I believe 

none of us should submit to these “requests.”92 

As a second example, the State of Texas alleges that Jones “...destroyed information in order to 

avoid the possibility of having to produce it.” As evidence, the petitioner quotes an e-mail in 

which Phil Jones states, “About 2 months ago I deleted loads of e-mails, so have very little - if 

anything at all”.93 

In a third example, the State of Texas cites one e-mail in which Gavin Schmidt of NASA 

compares the actions of global warming “skeptics” requesting information under FOI or FOIA 

laws to “Somali pirates”.94 The petitioner claims that this remark “took the climate scientists’ 

disdain for citizens who file open records requests to a whole new level.” The State of Texas 

concludes from these examples that the CRU e-mail authors “have been the antithesis of 

transparent,” displaying not only “a total disregard for open government-but worse, affirmative 

disdain for transparency and utter contempt for citizens who exercise their right to obtain public 

information.” 

 

89 E-mail file 1214228874.txt, (June 23, 2008) page 1533, line 5 of the PDF version entitled: CRU 

Emails 1996-2009.pdf. 

90 E-mail file 1214228874.txt, (June 23, 2008) page 1533, line 5 of the PDF version entitled: CRU 

Emails 1996-2009.pdf. 

91 E-mail file 1214228874.txt, (June 23, 2008) page 1533, line 25 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

92 E-mail file 1214228874.txt, (June 23, 2008) page 1533, line 13 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

93 E-mail file 1228412429.txt, (December 4, 2008), page 1593, line 22 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

94 E-mail file 1228258714.txt, (December 2, 2008), page 1590, line 44 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

103
Response (3-49): 

We have reviewed the e-mails at issue in the petitioner’s objection and disagree that they are 

evidence that the scientists ignored legal requests or that they “have been the antithesis of 

transparent.” We address each issue below. 

From our review of the e-mails related to the quote from Bryan Lynch, it appears that the subject 

of the FOI request was for personal communications between authors of IPCC Chapter 6 

(“Palaeoclimate”) regarding expert review comments on chapter 6.95 The request appears to be 

for e-mails that were not part of the formal review process—in other words, for personal 

conversations written privately between colleagues. This type of information is tangential at best 

to the scientific assessment of the AR4 or the workings of the IPCC as a whole, or for this one 

chapter. The IPCC maintains an open and transparent formal process by which expert comments 

are responded to and incorporated into the IPCC reports. The public can access drafts, expert 

and government review comments, and author responses used to prepare the Working Group I 

report (IPCC, 2007b), which includes chapter 6 on paleoclimate, on the Internet (IPCC, 2006). 

We provide further discussion of the transparency of IPCC review processes in Volume 2, 

Section 2.2. The petitioners’ evidence does not show that this formal, public process was 

hindered or disrupted in any way, or that the opinions expressed on how to respond to this FOI 

request produced any less robust or scientifically valid comment review process for the 

assessment report. 

Regarding the second example, we note that Phil Jones’ statement is taken out of context from 

the e-mails. We provide the following supporting context excerpted from the e-mail: 

The inadvertent email I sent last month has led to a Data Protection Act request sent by a 

certain Canadian, saying that the email maligned his scientific credibility with his peers!

If he pays 10 pounds (which he hasn’t yet) I am supposed to go through my emails and he 

can get anything I’ve written about him. About 2 months ago I deleted loads of emails, 

so have very little - if anything at all. This legislation is different from the FOI - it is 

supposed to be used to find put [sic] why you might have a poor credit rating!96 

Phil Jones does not discuss, as the petitioners have asserted, deleting e-mails to “avoid the 

possibility of having to produce it.” He also does not discuss deleting e-mails to avoid complying 

with requests (whether Data Protection Act or FOI); he simply states that he happened to delete a 

portion of his e-mails two months prior to receiving this request. The evidence does not support 

their conclusion that any information was deliberately deleted to avoid making it public. 

Regarding the third example, it is clear that the authors of the e-mails voiced significant 

frustration about the increasing numbers of FOI requests, which they viewed as frivolous and 

which were taking significant time away from their research. EPA does not agree that these 

examples or any statements in the quoted e-mails are indicative of “affirmative disdain” or “utter 

contempt” for transparency. As stated in our responses above, in many cases large amounts of 

data were in fact released or were publicly available. Although we agree that there is room for 

 

95 E-mail file 1214228874.txt, (June 23, 2008), page 1533, line 13 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

96 E-mail file 1228412429.txt, (December 4, 2008), page 1594, line 6 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

104
improvement in terms of transparency, we also find that the petitioners greatly exaggerate the 

implications of these process issues for the validity of the science in this area. Petitioners have 

not explained why the data available was not adequate data in order for researchers to replicate 

or otherwise evaluate key findings, or to conduct other research. We find that the CRU e-mail 

authors conducted their research in accordance with common practice in the climate science 

community at the time, utilized methods which are “fair and satisfactory” according to the 

Scientific Appraisal Panel, and maintained scientific integrity and rigor in their work. 

Comment (3-50): 

Peabody Energy, the Southeastern Legal Foundation, the Coalition for Responsible Regulation, 

the Pacific Legal Foundation, and the State of Texas allege that the CRU scientists and their 

colleagues deleted or otherwise attempted to avoid disclosing information pertaining to the 

drafting of the IPCC AR4, which was the subject of an active FOI request. Peabody Energy, the 

Southeastern Legal Foundation, and the State of Texas quote the following e-mail from Jones to 

Tom Wigley of the University Corporation for Atmospheric Research on December 4, 2008: 

You can delete this attachment if you want. Keep this quiet also, but this is the person 

who is putting in FOI requests for all emails Keith and Tim have written and received re 

Ch 6 of AR4. We think ’we’ve found a way around this...This message will self destruct 

in 10 seconds!97

Peabody Energy, the Southeastern Legal Foundation, and the Coalition for Responsible 

Regulation quote the following e-mail from Jones to Michael Mann on May 29, 2008: 

Can you delete any emails you may have had with Keith re AR4? Keith will do likewise.

He’s not in at the moment – minor family crisis. Can you also email Gene and get him to 

do the same? I don’t have his new email address. We will be getting Caspar to do 

likewise. I see that CA [Climate Audit blog] claim they discovered the 1945 problem in 

the Nature paper!!98 

Peabody Energy describes an e-mail exchange from May 27, 2008 between Tim Osborn of CRU 

and Caspar Amman of the National Center for Atmospheric Research about whether Amman 

viewed e-mails related to the IPCC AR4 as “confidential”.99 From these e-mails, Peabody 

Energy concludes that Osborn “was not looking for a good faith statement from Amman”; rather, 

he was “clearly seeking an excuse for refusing to disclose information that was being sought.” 

As further evidence that CRU scientists deleted information pertaining to the IPCC AR4, 

Peabody Energy cites the following e-mail excerpt from Phil Jones to Tom Wigley on March 12, 

2008: 

 

97 E-mail file 1210341221.txt, (May 9, 2008), page 1494, line 1 of PDF version entitled: CRU Emails 

1996-2009.pdf). 

98 E-mail file 1212063122.txt, (May 29, 2008), page 1514, line 45 of PDF version entitled: CRU Emails 1996-

2009.pdf). 

99 E-mail file 1211924186.txt, (May 27, 2008), page 1509, line 22, e-mail file 1212156886.txt, page 1519, line 12, 

and e-mail file 1212166714.txt, (May 30, 2008), page 1520, line 3 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

105
The inadvertent e-mail I sent last month has led to a Data Protection Act request 

sent by a certain Canadian, saying that the e-mail maligned his scientific 

credibility with his peers! If he pays 10 pounds (which he hasn’t yet) I am 

supposed to go through my e-mails and he can get anything I’ve written about 

him. About 2 months ago I deleted loads of e-mails, so have very little — if 

anything at all. This legislation is different from the FOI — it is supposed to be 

used to find put why you might have a poor credit rating!100

Peabody Energy also cites the following e-mail excerpt from Phil Jones to Ben 

Santer of Lawrence Livermore National Laboratory on December 10, 2008: 

Haven’t got a reply from the FOI person here at UEA. So I’m not entirely 

confident the numbers are correct. One way of checking would be to look on 

CA [Climate Audit], but I’m not doing that. I did get an e-mail from the FOI 

person here early yesterday to tell me I shouldn’t be deleting e-mails – unless 

this was ‘normal’ deleting to keep e-mails manageable!101 

Peabody Energy claims that “the material that they [the CRU e-mail authors] destroyed pertained 

directly to their work for the IPCC...” and that the “scientists’ concern about what they 

communicated with each other about preparation of AR4 was so serious that they undertook to 

delete the e-mails rather than have them subject to public scrutiny.” Peabody Energy contends 

that the refusal to provide information about the process of writing the IPCC reports contradicts 

EPA’s view of the transparency of that process. The Southeastern Legal Foundation argues that 

even if there is no evidence that e-mails were deleted in response to the request from Jones, the 

apparent willingness of the CRU scientists and their colleagues to destroy evidence should cause 

EPA to question its reliance on their work. 

Response (3-50): 

We note that the petitioner ascribes negative motives to CRU e-mail author Tim Osborn—e.g., 

“not looking for a good faith statement,” “clearly seeking an excuse”—which are based on 

conjecture and innuendo. We find that the petitioner bases its argument on a speculative 

interpretation of the following e-mail from Osborn to Caspar Amman: 

I don’t think it is necessary for you to dig through any e-mails you may have 

sent us to determine your answer. Our question is a more general one, which is 

whether you generally consider e-mails that you sent us to have been sent in 

confidence. If you do, then we will use this as a reason to decline the request.102

The petitioner does not provide evidence or reasons why EPA should not interpret this 

statement at face value—that Osborn was sincere in asking for only a general answer as to 

whether or not Amman considered their private communications to be confidential. It is 

reasonable for Osborn to tell Amman not to waste time digging through his e-mails, as he 

 

100 E-mail file 1228412429.txt, (March 12, 2008), page 1594, line 6 of the PDF version 

entitled: CRU Emails 1996-2009.pdf. 

101 E-mail file 1228922050.txt, (December 10, 2008), page 1596, line 20 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

102 E-mail file 1212166714.txt, (May 30, 2008), page 1520, line 3 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

106
meant for his question to be a general one. We find that the petitioner has no basis for its 

negative characterization of Osborn’s intentions. 

We also note that the second e-mail quoting Phil Jones [1228412429.txt], in which Jones 

discusses deleting some e-mails, does not pertain to the FOI request for IPCC AR4 information. 

Contrary to the petitioner’s assertions that Jones deliberately deleted information to avoid 

complying with the FOI request, the first sentence of the quoted e-mail [1228412429.txt] clearly 

refers to a Data Protection Act request, not an FOI request, for Jones’ personal communications 

about a specific person (i.e., “a certain Canadian,” presumably Stephen McIntyre). We also note 

that Phil Jones does not discuss, as the petitioners have asserted, deleting e-mails to avoid 

revealing something “serious” about preparation of AR4. In fact, he does not state any intentions 

whatsoever to avoid complying with any requests (whether Data Protection Act or FOI) by 

deleting e-mails; he simply states that he happened to delete a portion of his e-mails two months 

ago prior to receiving the Data Protection Act request. These e-mails may or may not have had 

anything to do with the drafting of the AR4; it is not clear from the e-mails themselves. 

The petitioners exaggerate the importance of the requested information pertaining to the IPCC 

AR4, implying that the information requested was central to the workings of the IPCC report 

writing process. We respond to this issue in our response (3-49) above. We provide further 

discussion of the transparency of IPCC review processes in Volume 2, Section 2.2. As described 

above, the petitioners’ evidence does not show that the formal, public process for submissions 

and review of comments was not fully robust or was hindered or disrupted, or that the opinions 

expressed in the e-mails produced any less robust or scientifically valid public comment review 

process on the science for the assessment report. 

As described above, the investigations of the CRU scientists found that they conducted their 

research with scientific integrity and rigor, and with no indications of scientific malpractice. 

Although we agree that there is room for improvement in terms of transparency, we also find that 

the petitioners greatly exaggerate the implications of these process issues for the validity of the 

science in this area. We find that the CRU e-mail authors conducted their research in accordance 

with common practice in the climate science community at the time and utilized methods which 

are “fair and satisfactory” according to the Scientific Appraisal Panel. Petitioners’ evidence 

concerning a request for information on e-mails considered to be informal communications does 

not change this conclusion. 

Comment (3-51): 

The Coalition for Responsible Regulation, Peabody Energy, and the State of Texas cite e-mails 

allegedly showing scientists attempting to avoid complying with a FOI request by saying that the 

IPCC, as an international institution, was not subject to the UK FOI law. As evidence, the 

Coalition for Responsible Regulation, the State of Texas, and Peabody Energy quote the 

following e-mail from Phil Jones: 

The skeptics will try to hang on to something, but I don’t want to give them 

something clearly tangible. Keith/Tim still getting FOI requests as well as 

MOHC [Met Office Hadley Center] and Reading. All our FOI officers have been 

in discussions and are now using the same exceptions not to respond — advice 

they got from the Information Commissioner. As an aside and just between us, 

107
it seems that Brian Hoskins has withdrawn himself from the WG1 Lead 

nominations. It seems he doesn’t want to have to deal with this hassle. The FOI 

line we’re all using is this. IPCC is exempt from any countries FOI – the 

skeptics have been told this. Even though we (MOHC, CRU/UEA) possibly hold 

relevant info the IPCC is not part our remit (mission statement, aims etc) therefore 

we don’t have an obligation to pass it on.103

Response (3-51): 

Regarding this argument, we find that the same e-mail quoted by the petitioner indicates that Phil 

Jones believed that CRU/UEA received advice from the Information Commissioner that the 

IPCC, as an international organization, was excepted from the UK FOI. Jones makes a similar 

statement in another e-mail: “According to the FOI Commissioner’s Office, IPCC is an 

international organization, so is above any national FOI. Even if UEA holds anything about 

IPCC, we are not obliged to pass it on, unless it has anything to do with our core business - and it 

doesn’t!”104 We disagree, therefore, that the CRU e-mails show any attempt by the CRU 

scientists to avoid compliance with FOI; if anything, it shows that the scientists consulting with 

and following the advice of the UK ICO. 

Comment (3-52): 

The Coalition for Responsible Regulation argues that the CRU e-mail authors deliberately 

concealed information pertaining to the IPCC AR4. The petitioner claims that Gavin Schmidt, a 

manager of the National Aeronautics and Space Administration’s (NASA’s) temperature 

database and who participated in the review of EPA’s Technical Support Document (TSD) for 

the Endangerment Finding, was aware that data supporting EPA’s conclusions were being 

hidden from the Agency. The petitioner concludes that “EPA’s Findings therefore rely on the 

input of at least one scientist who knew data were being withheld from review by EPA and the 

public.” As evidence of his involvement, the Coalition for Responsible Regulation quotes an email from Phil Jones to Schmidt: 

The FOI line we’re all using is this. IPCC is exempt from any countries FOI - the skeptics 

have been told this. Even though we (MOHC [Met Office Hadley Center], CRU/UEA) 

possibly hold relevant info the IPCC is not part our remit (mission statement, aims etc) 

therefore we don’t have an obligation to pass it on.105

Response (3-52): 

The petitioner’s claim that Gavin Schmidt was aware of a “cover up” and deliberate withholding 

of “data supporting EPA’s conclusions” is unsupported.” As stated in our response above, it 

appears that the subject of the FOI request was for personal e-mail communications between 

authors of IPCC chapter 6 (paleoclimate) regarding expert review comments. There is no 

mention within the e-mail exchange on this issue, nor does the petitioner present evidence, that 

 

103 E-mail file 1219239172.txt, (August 20, 2008), page 1547, line 31 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

104 E-mail file 1228922050.txt, (December 10, 2008), page 1596, line 34 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

105 E-mail file 1219239172.txt, (August 20, 2008), page 1547, line 18 of the PDF version entitled: CRU Emails 

1996-2009.pdf. See also 1210341221.txt, (May 9, 2008), page 1493, line 14; and 1228330629.txt, (December 3, 

2008), page 1591, line 41. 

108
the request involved any type of “data” that was withheld form EPA or would affect EPA’s 

review of the science in its Endangerment Finding. As noted above, the e-mail refers to advice 

received from their respective FOI office as the exemption from FOI, not to any cover-up. 

In sum, petitioners’ evidence concerning a FOI on communications related to the AR4 does not 

support their claims concerning the validity of the science underlying the AR4. The evidence 

indicates that personal communications were at issue, and that it appears that the respective FOI 

office determined that these were exempt from release. There was a robust and public process 

for review of comments on the science for the IPCC AR4, and petitioners’ claims are not based 

on scientific arguments or studies showing that this public process failed to achieve its goal, or 

that the resulting AR4 was scientifically inappropriate or flawed in any way. EPA agrees with 

the Independent Climate Change E-mails Review’s recommendation of greater transparency in 

the future in this area of research, but petitioners’ evidence does not support a conclusion that the 

science underlying the AR4 and the Endangerment Finding was flawed or mischaracterized. 

3.4.3.3 Allegations of Improperly Influencing University FOIA Officials 

Comment (3-53): 

The State of Texas and Peabody Energy cite an e-mail from Phil Jones of the CRU indicating his 

hope that university officials and potential requestors might be unaware of UK FOI laws. The 

State of Texas, the Southeastern Legal Foundation, and Peabody Energy claim that Phil Jones 

encouraged university officials to ignore FOI requests from people affiliated with the blog 

ClimateAudit. They quote the following e-mail: 

When the FOI requests began here, the FOI person said we had to abide by the requests.

It took a couple of half hour sessions — one at a screen, to convince them otherwise 

showing them what CA was all about. Once they became aware of the types of people we 

were dealing with, everyone at UEA (in the registry and in the Environmental Sciences 

school — the head of school and a few others) became very supportive. I’ve got to know 

the FOI person quite well and the Chief Librarian — who deals with appeals. The VC 

[Vice-Chancellor] is also aware of what is going on — at least for one of the requests, but 

probably doesn’t know the number we’re dealing with. We are in double figures.106

In a second example, the State of Texas and Peabody Energy quote the following e-mail 

from Jones as proof that Jones and his colleagues convinced University of East Anglia 

officials to agree to ignore requests for information from anyone associated with the 

ClimateAudit blog. The State of Texas claims that the second sentence in the e-mail shows 

that Jones urged a colleague in Australia to disregard requests for information. 

Nothing much else to say except: 

1. Think I’ve managed to persuade UEA to ignore all further FOIA requests if the 

people have anything to do with Climate Audit [CA]. 

2. Had an e-mail from David Jones of BMRC [Bureau of Meteorology Research 

Centre], Melbourne. He said they are ignoring anybody who has dealings with CA, as 

 

106 E-mail file 1228412429.txt, (December 4, 2008), page 1593, line 39 of the PDF version entitled: CRU Emails 

1996-2009.pdf. 

109
there are threads on it about Australian sites. 

3. CA is in dispute with IPCC (Susan Solomon and Martin Manning) about the availability of 

the responses to reviewer’s [sic] at the various stages of the AR4 drafts. They are most 

interested here re Ch 6 on paleo.107

Response (3-53): 

First, we note that in the first example the petitioners quote only part of the e-mail and that later 

in the same e-mail, Phil Jones states: 

In response to FOI and EIR [Environmental Information Regulations] requests, we’ve put 

up some data - mainly paleo data. Each request generally leads to more - to explain what 

we’ve put up. Every time, so far, that hasn’t led to anything being added - instead just 

statements saying read what is in the papers and what is on the web site! Tim Osborn 

sent one such response (via the FOI person) earlier this week. We’ve never sent 

programs, any codes and manuals.108 

The e-mails demonstrate that Phil Jones was not obstructing FOI requests; rather, he clearly 

indicates that he and his CRU colleagues made data available in response to FOI and other 

requests. He and others were working with the FOI officer and other university officials to 

determine the appropriate way to respond to these requests. As noted in our previous responses 

(e.g., 3-39) above, at the time it was not typical in climate science for authors to publish 

computer codes or detailed explanations beyond that which was described in the literature. 

Given this context, Jones’ statement—”We’ve never sent programs, any codes and 

manuals”109—demonstrates his belief that having the raw data is sufficient to be able to replicate 

CRU’s work because the methodologies are freely available in the published literature. 

Regarding the second example, the e-mail is written in factual terms, it does not indicate the 

basis for the BMRC’s interactions with persons affiliated with the CA. We also note that the 

Independent Climate Change E-mails Review spoke to these issues, as described in our previous 

responses (e.g., 3-39) in this volume. As discussed above, EPA agrees with their 

recommendation of greater transparency, but disagrees that the evidence presented by petitioners 

warrants any less reliance on the scientific assessment provided by the AR4. 

3.4.4 Summary 

Volumes 1 and 2 of this RTP document respond to scientific issues raised by petitioners in these 

e-mails and affirm that the science and assessment literature on which the Findings are based is 

sound. As noted in many places in this RTP document, the petitioners’ arguments are not based 

on the body of the scientific evidence and include only a limited discussion of the science itself. 

 

107 E-mail file 1182255717.txt, (June 19, 2007), page 1330, line 34 of the PDF version entitled: CRU Emails 1996-

2009.pdf. 

108 E-mail file 1228412429.txt, (December 4, 2008), page 1594, line 11 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

109 E-mail file 1228412429.txt, (December 4, 2008), page 1594, line 15 of the PDF version entitled: CRU Emails 

1996-2009.pdf 

110
Instead, the petitioners’ arguments rely on broad claims based on the e-mails and jump to 

conclusions about implications for the science that are not supported by evidence. 

Petitioners do not rely on science or science based arguments to support their claim that the 

assessment report resulting from this robust process should not be relied upon by EPA. Instead, 

petitioners claim that key climate data were withheld from the public when, in fact, our review of 

the CRU emails indicates that in many cases, the data were already publicly available or were 

released by the scientists. Petitioners have not explained or shown why the amount of data and 

other information that was available was not adequate for researchers to replicate or otherwise 

evaluate key findings, or to conduct other research. They also rely on unsupported conclusions 

drawn from e-mails concerning a FOI request for personal communications between various 

scientists, where it appears that the appropriate University FOI officers had determined that these 

emails were exempt from release. This evidence does not support petitioners’ claims that the 

IPCC AR4 should not be considered as part of the scientific basis for the Endangerment Finding. 

EPA agrees with the results of the various independent investigations into the CRU e-mails, 

which found that the scientists at issue conducted their research with scientific integrity and 

rigor, the research utilized methods which are fair and satisfactory, and that their actions were 

consistent with the common practice in climate research at that time. EPA also agrees with the 

recommendations of the Independent Climate Change E-mails Review supporting greater 

transparency in the future in this area of climate research; however, concluding that greater 

transparency would be helpful for a particular element of climate change science is not the 

equivalent of providing evidence that the scientific basis for EPA’s Endangerment Finding is 

flawed. Petitioners’ claims and evidence do not provide a basis for EPA to question or change 

its view that the science supporting the Endangerment Findings is robust, compelling, and has 

been appropriately characterized by EPA. 

111
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