CLIMATE SCIENCE: 

ASSUMPTIONS, POLICY IMPLICATIONS, 

AND THE SCIENTIFIC METHOD 

HEARING 

BEFORE THE

COMMITTEE ON SCIENCE, SPACE, AND 

TECHNOLOGY 

HOUSE OF REPRESENTATIVES 

ONE HUNDRED FIFTEENTH CONGRESS 

FIRST SESSION 

MARCH 29, 2017 

Serial No. 115–10 

Printed for the use of the Committee on Science, Space, and Technology 

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CLIMATE SCIENCE: ASSUMPTIONS, POLICY IMPLICATIONS, AND THE SCIENTIFIC METHOD 
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CLIMATE SCIENCE: 

ASSUMPTIONS, POLICY IMPLICATIONS, 

AND THE SCIENTIFIC METHOD 

HEARING 

BEFORE THE

COMMITTEE ON SCIENCE, SPACE, AND 

TECHNOLOGY 

HOUSE OF REPRESENTATIVES 

ONE HUNDRED FIFTEENTH CONGRESS 

FIRST SESSION 

MARCH 29, 2017 

Serial No. 115–10 

Printed for the use of the Committee on Science, Space, and Technology 

( 

Available via the World Wide Web: http://science.house.gov 
(II) 

COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY 

HON. LAMAR S. SMITH, Texas, Chair 

FRANK D. LUCAS, Oklahoma 

DANA ROHRABACHER, California 

MO BROOKS, Alabama 

RANDY HULTGREN, Illinois 

BILL POSEY, Florida 

THOMAS MASSIE, Kentucky 

JIM BRIDENSTINE, Oklahoma 

RANDY K. WEBER, Texas 

STEPHEN KNIGHT, California 

BRIAN BABIN, Texas 

BARBARA COMSTOCK, Virginia 

GARY PALMER, Alabama 

BARRY LOUDERMILK, Georgia 

RALPH LEE ABRAHAM, Louisiana 

DRAIN LAHOOD, Illinois 

DANIEL WEBSTER, Florida 

JIM BANKS, Indiana 

ANDY BIGGS, Arizona 

ROGER W. MARSHALL, Kansas 

NEAL P. DUNN, Florida 

CLAY HIGGINS, Louisiana 

EDDIE BERNICE JOHNSON, Texas 

ZOE LOFGREN, California 

DANIEL LIPINSKI, Illinois 

SUZANNE BONAMICI, Oregon 

ALAN GRAYSON, Florida 

AMI BERA, California 

ELIZABETH H. ESTY, Connecticut 

MARC A. VEASEY, Texas 

DONALD S. BEYER, JR., Virginia 

JACKY ROSEN, Nevada 

JERRY MCNERNEY, California 

ED PERLMUTTER, Colorado 

PAUL TONKO, New York 

BILL FOSTER, Illinois 

MARK TAKANO, California 

COLLEEN HANABUSA, Hawaii 

CHARLIE CRIST, Florida 
(III) 

C O N T E N T S 

March 29, 2017 

Page 

Witness List ............................................................................................................. 2 

Hearing Charter ...................................................................................................... 3 

Opening Statements 

Statement by Representative Lamar S. Smith, Chairman, Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 4 

Written Statement ............................................................................................ 6 

Statement by Representative Eddie Bernice Johnson, Ranking Member, Committee on Science, Space, and Technology, U.S. House of Representatives .... 8 

Written Statement ............................................................................................ 10 

Statement by Representative Andy Biggs, Committee on Science, Space, and 

Technology, U.S. House of Representatives ....................................................... 12 

Written Statement ............................................................................................ 13 

Statement by Representative Suzanne Bonamici, Committee on Science, 

Space, and Technology, U.S. House of Representatives .................................... 14 

Written Statement ............................................................................................ 16 

Witnesses 

Dr. Judith Curry, President, Climate Forecast Applications Network; Professor Emeritus, Georgia Institute of Technology 

Oral Statement ................................................................................................. 19 

Written Statement ............................................................................................ 21 

Dr. John Christy, Professor and Director, Earth System Science Center, 

NSSTC, University of Alabama at Huntsville; State Climatologist, Alabama 

Oral Statement ................................................................................................. 35 

Written Statement ............................................................................................ 37 

Dr. Michael Mann, Distinguished Professor of Atmospheric Science and Director, Earth System Science Center (ESSC), The Pennsylvania State University 

Oral Statement ................................................................................................. 51 

Written Statement ............................................................................................ 53 

Dr. Roger Pielke Jr., Professor, Environmental Studies Department, University of Colorado 

Oral Statement ................................................................................................. 71 

Written Statement ............................................................................................ 73 

Discussion ................................................................................................................. 97 

Appendix I: Answers to Post-Hearing Questions 

XDr. Michael Mann, Distinguished Professor of Atmospheric Science and 

Director, Earth System Science Center (ESSC), The Pennsylvania State 

University ............................................................................................................. 134 

Appendix II: Additional Material for the Record 

Documents submitted by Representative Eddie Bernice Johnson, Ranking 

Member, Committee on Science, Space, and Technology, U.S. House of 

Representatives .................................................................................................... 270 
Page

IV 

Document submitted by Representative Suzanne Bonamici, Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 304 

Documents submitted by Representative Lamar Smith, Chairman, Committee 

on Science, Space, and Technology, U.S. House of Representatives ................ 335 

Document submitted by Representative Paul Tonko, Committee on Science, 

Space, and Technology, U.S. House of Representatives .................................... 352 

Document submitted by Representative Dana Rohrabacher, Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 361 

Document submitted by Representative Clay Higgins, Committee on Science, 

Space, and Technology, U.S. House of Representatives .................................... 362 

Document submitted by Representative Mark Takano, Committee on Science, 

Space, and Technology, U.S. House of Representatives .................................... 371 

Document submitted by Representative Donald S. Beyer, Jr., Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 376 

Document submitted by Representative Daniel Webster, Committee on 

Science, Space, and Technology, U.S. House of Representatives ..................... 482 

Document submitted by Representative Darin LaHood, Committee on Science, 

Space, and Technology, U.S. House of Representatives .................................... 488 

Document submitted by Representative Neal P. Dunn, Committee on Science, 

Space, and Technology, U.S. House of Representatives .................................... 489 
(1) 

CLIMATE SCIENCE: ASSUMPTIONS, POLICY 

IMPLICATIONS, 

AND THE SCIENTIFIC METHOD 

WEDNESDAY, MARCH 29, 2017 

HOUSE OF REPRESENTATIVES, COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY, Washington, D.C. 

The Committee met, pursuant to call, at 10:03 a.m., in Room 

2318 of the Rayburn House Office Building, Hon. Lamar Smith 

[Chairman of the Committee] presiding. 
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Chairman SMITH. Good morning to everyone. The Committee on 

Science, Space, and Technology will come to order. 

Without objection, the Chair is authorized to declare recesses of 

the Committee at any time. 

Welcome to today’s hearing called ‘‘Climate Science: Assumptions, Policy Implications, and the Scientific Method.’’ I’ll recognize 

myself for five minutes for an opening statement, and then the 

Ranking Member. 

Today we will examine the scientific method as it relates to climate change. We must ensure that the underlying science that informs policy decisions is based on credible scientific methodology. 

I believe the climate is changing and that humans play a role. 

However, I also believe significant questions remain as to the extent. Our actions must be based on sound science. This is the only 

way we will be able to better address climate change. 

Before we impose costly government regulations, we should 

evaluate scientific uncertainties and ascertain the extent to which 

they make it difficult to quantify humans’ contribution to climate 

change. 

Far too often, alarmist theories on climate science originate with 

scientists who operate outside of the principles of the scientific 

method. The scientific method is a simple process that has been 

used for centuries. It involves identifying a question, developing a 

hypothesis, constructing an experiment, and analyzing the results. 

If the results do not align with the original hypothesis, the hypothesis must be reexamined. The scientific method welcomes critiques 

so theories can be refined, and it avoids speculation about distant 

events for which there is no hard proof. 

Alarmist predictions amount to nothing more than wild guesses. 

The ability to predict far into the future is impossible. Anyone stating what the climate will be in 500 years or even at the end of the 

century is not credible. 

All too often, scientists ignore the basic tenants of science in 

order to justify their claims. Their ultimate goal appears to be to 

promote a personal agenda, even if the evidence doesn’t support it. 

The scientific method is regarded as the foundation of modern 

science. It ensures that scientific experimentation is neither arbitrary nor subjective, and that results can be replicated. 

In the field of climate science, there is legitimate concern that 

scientists are biased in favor of reaching predetermined conclusions. This inevitably leads to alarmist findings that are wrongfully 

reported as facts. 

The scientific method also requires that for a hypothesis to become a theory, a repeated validation of the results, called reproducibility, should be possible. However, a recent survey found that 70 

percent of scientific researchers have tried and failed to reproduce 

the experiments conducted by other scientists. The lack of reproducibility is a warning that the scientific method is not being followed and that the theory may lack credibility. 

To restore faith in science, we must uphold the principles of scientific integrity. For example, the Science Committee heard from 

whistleblowers that National Oceanic and Atmospheric Administration (NOAA) employees put their ‘‘thumb on the scale’’ during the 

analysis of data. This was done to arrive at politically correct re-
5 

sults that would disprove the absence of global temperature increases from 1998 to 2012. 

More recently, NOAA admitted to Committee staff that there 

was no legal justification for not complying with the Committee’s 

lawfully issued subpoena requesting information. In fact, we 

learned that it was simply a political decision to halt any further 

debate on the subject. This is professional misconduct, if not worse. 

A similar event unfolded in 2009. Emails from East Anglia University scientists were uncovered and revealed that they frequently 

violated principles of scientific integrity and attempted to halt debate about climate science. 

Much of climate science today appears to be based more on exaggerations, personal agendas, and questionable predictions than on 

the scientific method. Those who engage in such actions do a disservice to the American people and to their own profession. Only 

when scientists follow the scientific method can policymakers be 

confident that they are making the right decisions. Until then, the 

debate should continue. 

[The prepared statement of Chairman Smith follows:] 
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Chairman SMITH. That concludes my opening statement, and the 

Ranking Member, the gentlewoman from Texas, Eddie Bernice 

Johnson, is recognized for hers. 

Ms. JOHNSON. Thank you very much, Mr. Chairman, and I thank 

you for calling today’s hearing on climate science. I also want to 

thank our witnesses for being here. 

I want to start off today by placing our current situation in some 

historical perspective. The existence of the greenhouse effect was 

first proposed in the early 1800s. By the late 1800s scientists began 

to theorize that increases in carbon dioxide in our atmosphere 

could lead to global warming. By 1960, scientists had shown that 

carbon dioxide was in fact increasing in the atmosphere and humans were at least in part responsible for the increase. 

Scientific evidence of human-induced climate change rapidly increased through the 1970s. By 1982, even oil giant Exxon’s own scientists were reporting to management that climate change due to 

carbon dioxide emissions was likely to occur, and that the effects 

of this climate change could be catastrophic. 

Since the early 1980s when Exxon internally acknowledged the 

reality of climate change, the scientific evidence confirming human 

caused climate change has piled up at an incredible rate. The current scientific consensus on human caused climate change is based 

on thousands of scientific studies conducted by thousands of scientists all across the globe. 

What does that word—consensus—actually mean? It means the 

Intergovernmental Panel on Climate Change, the IPCC, which is 

composed of scientists from around the world, has concluded that 

warming of the climate system is unequivocal, and that it is extremely likely that human influence was the dominant cause of 

global warming. 

The IPCC is not alone. The National Academies of Sciences has 

reached the same conclusion. In fact, the national academies of 

sciences in virtually every major country on Earth has endorsed 

the IPCC’s central conclusions on climate change. Most relevant 

scientific societies, including AAAS, the American Physical Society, 

the American Geophysical Union, the American Meteorological Society, and a host of others have also affirmed the overwhelming scientific evidence for human-caused climate change. 

Unfortunately, the long-established scientific understanding of 

the reality of climate change ends at the doorstep of the Republican 

National Committee. Republicans in Congress overwhelmingly reject or minimize the scientific consensus on climate change. In this, 

they follow the leader of the Republican Party, President Trump, 

who once claimed that climate change was a hoax perpetrated by 

China. Even on this Committee on Science, Republican Members 

have postulated sometimes unique theories about climate change, 

some of which have become punchlines on late night television. 

It saddens me, really, that Majority Members of Congress and of 

this Committee in particular, consistently ignore the thousands of 

scientists around the world who maintain mainstream climate 

science views, instead repeatedly calling a handful of preferred witnesses who are here today over and over again to testify. For instance, the three witnesses called by the Majority today have col-
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lectively appeared in front of Congress at least 20 times over the 

past decade. 

Disturbingly, the Majority’s unwillingness to accept the strong 

scientific consensus on climate change has led them to harass scientists who disagree with them. For example, the Majority on this 

Committee has issued subpoenas for the emails of climate scientists at NOAA, taking a page out of the playbook of fossil industry funded front groups who have harassed climate scientists 

across the country. In the process our Majority has brought condemnation upon this once great committee from across the scientific community. 

Perhaps in retaliation for this inconvenient truths, climate scientists are now being targeted with massive budget cuts by Republicans in the White House and Congress. These cuts would devastate our ability to understand and mitigate the future effects of 

climate change. I sincerely hope that someday soon the Committee 

on Science will cease lecturing and harassing scientists, and instead return to listening to and supporting them. America will be 

far better off if we do. 

And finally, I’m attaching a report prepared by the Democratic 

staff to my opening statement. This report details the Majority’s 

nearly 2-year-long investigation into climate science paper that was 

prepared by NOAA scientists and published in the Journal of 

Science in June of 2015. 

I thank you, and yield back. 

[The prepared statement of Ms. Johnson follows:] 
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Chairman SMITH. Thank you, Ms. Johnson. Do you want that report made a part of the record? 

Ms. JOHNSON. Yes. 

Chairman SMITH. Okay. Without objection, that report will be 

made a part of the record, and I might also add that I know the 

Commerce Committee is conducting in their own investigation. If 

nothing else, it probably all proves that the science is not yet settled. 

[The information appears in Appendix II] 

Chairman SMITH. We’ll now recognize the gentleman from Arizona, Mr. Biggs, the Chairman of the Environment Subcommittee, 

for his opening statement. 

Mr. BIGGS. Thank you, Chairman Smith. Thank you, panelists, 

for being with us today. I appreciate it. Thank you for calling this 

important hearing. 

As we move forward as policymakers in this new Congress and 

with a new Administration, it is important that we have the best 

available data to make informed decisions. It is also important that 

this data is grounded in sound science that is not biased politically 

or part of a larger political agenda. 

Our nation’s climate change policy cannot be taken lightly, because the stakes are enormous. We simply must eliminate costly, 

unjustifiable regulations. For example, President Obama’s climate 

change actions, such as the Clean Power Plan, have been estimated 

to cost billions annually, while having a negligible impact on the 

environment. It is for this very reason that President Trump issued 

an Executive order yesterday requiring the EPA to revisit this regulation. 

Not only did the previous Administration mute honest discussions that went against Obama’s politicized climate change legacy, 

but it also perpetuated scandal in the industry. Dr. Bates’ concerns 

regarding the Karl Study at NOAA is one such instance. The 

American economy should not be trifled with. If we are to make 

farsighted laws and regulations, the findings of climate research 

need to be clear, not muddled with bad science, name-calling, or 

scandals. 

Unfortunately, this muddling has tarnished the reputation of 

science and made many Americans wary of supporting climate 

change regulations, understanding that the underlying science is 

subject to manipulation. Rigorous scientific debate should never be 

silenced, and we must vigorously confront instances in which scientific integrity falls short. 

I look forward to an honest, level-headed discussion today not 

just about what we know about climate change, but also about the 

uncertainties that still need to be addressed. 

Thank you, Chairman Smith. I yield back the balance of my 

time. 

[The prepared statement of Mr. Biggs follows:] 
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Chairman SMITH. Thank you, Mr. Biggs. 

And the gentlewoman from Oregon, Ms. Bonamici, the Ranking 

Member of the Environment Subcommittee, is recognized for an 

opening statement. 

Ms. BONAMICI. Thank you very much, Mr. Chairman. 

It’s truly unfortunate that the Science Committee is holding this 

hearing today. We’re spending valuable time on efforts to try to discredit science and question the scientific process when we should 

be looking for ways to advance scientific research. 

Climate change is not a partisan issue. People who fish in Oregon, farmers in Oklahoma, servicemen and women in Virginia and 

around the country are all living with the results of climate 

change, regardless of their political affiliation. The economic, 

human health, and environmental consequences of climate change 

are well known, and our understanding about how to address the 

causes of climate change continues to improve. 

At a time when people in the United States and around the 

world are facing threats from rising sea levels, oceans that are becoming more acidic, more frequent and severe weather events, 

record droughts and flooding, and rising global temperatures, it’s 

critical that we support scientific research about climate, and that 

we build on rather than break down decades worth of progress on 

this issue. 

Fortunately, 17 of my colleagues on the other side of the aisle 

have introduced legislation with a commitment to address climate 

change. The Science Committee should return to being a forum for 

robust discussions about our nation’s scientific priorities, celebration of our scientific achievements, and development of bipartisan 

legislation that improves our understanding of science. Over the 

years, these efforts have helped grow the economy and created new 

jobs and new industries. Let’s return to that Science Committee, 

rather than one where science is attacked and there is not enough 

focus on bipartisan work that benefits the millions of American 

people who are concerned that increased carbon emissions threaten 

our country and our planet. 

This hearing is going to follow a familiar pattern, with familiar 

faces offering fringe perspectives. We have heard from the three 

Majority witnesses in the past. Based on the testimony they’ve submitted, their positions on this issue have not changed. 

Science is not about trust or belief or personal agendas. Science 

is about knowledge and understanding. Scientists put their research and findings through rigorous peer review, and constantly 

seek to improve our understanding of the world through scientific 

process. Characterizing well-understood science as a trust exercise 

undermines the general principle of scientific integrity. 

There is a difference between a political position that denies the 

reality of climate change and scientific fact that climate change is 

real. Too often there is confusion about those distinctions in this 

room. Again, we should focus on solutions to the climate change 

problem not distractions from the reality. 

I look forward to hearing about possible solutions from Dr. Michael Mann today, a distinguished climate scientist who has been 

at the forefront of the international scientific community’s efforts 

to examine, understand and respond to global warming and the 
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consequences it has brought to our planet. And I hope that the day 

comes soon when we can all focus on and discuss solutions to climate change, and as the Chair of the Environment Subcommittee 

said, the stakes are enormous. I hope it’s not too late for our children, our grandchildren, and generations to come. 

Thank you, Mr. Chairman, and I yield back. 

[The prepared statement of Ms. Bonamici follows:] 
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Chairman SMITH. Thank you, Ms. Bonamici. 

We have a particularly distinguished panel today, and let me introduce our witnesses. Our first witness is Dr. Judith Curry, President of the Climate Forecast Applications Network, and Professor 

Emeritus at the Georgia Institute of Technology. Dr. Curry performs extensive research that focuses on air and sea interactions, 

climate feedback processes associated with clouds and sea ice, and 

the climate dynamics of hurricanes. Dr. Curry also recently served 

on the NASA Advisory Council Earth Science Subcommittee, the 

DOE Biological and Environmental Research Advisory Committee, 

the National Academies Climate Research Committee, the Space 

Studies Board, and the NOAA Climate Working Group. Dr. Curry 

received her Ph.D. in atmospheric science from the University of 

Chicago. 

Our second witness is Dr. John Christy, Professor and Director 

of the Earth Systems Science Center at the University of Alabama 

at Huntsville and Alabama’s State Climatologist. Dr. Christy has 

served as Lead Author, Contributing Author and Reviewer of the 

United Nations Intergovernmental Panel on Climate Change Assessments. In addition, he was awarded NASA’s Medal for Exceptional Scientific Achievement. In 2002, he was elected a Fellow of 

the American Meteorological Society. Dr. Christy received his master’s degree and Ph.D. in atmospheric sciences from the University 

of Illinois. 

Our third witness today is Dr. Michael Mann, Distinguished Professor of Atmospheric Science and Director of the Earth Systems 

Science Center at Pennsylvania State University. Dr. Mann’s research involves the use of theoretical models and observational 

data to understand Earth’s climate system. In addition, he was a 

Lead Author on the Observed Climate Variability and Change 

Chapter of the IPCC Third Scientific Assessment report in 2001. 

Dr. Mann is a Fellow of the American Geophysical Union, the 

American Meteorological Society, and the American Association for 

the Advancement of Science. Dr. Mann received his bachelor’s degree in physics and applied math from the University of California 

at Berkley, his master’s degree in physics from Yale University, 

and his Ph.D. in geology and geophysics from Yale University. 

Our final witness is Dr. Roger Pielke, Professor of the Environmental Studies Department at the University of Colorado. Dr. 

Pielke is the Founding Director and a Faculty Affiliate of the Center for Science and Technology Policy Research, and from 2001 to 

2016 was a Fellow of the Cooperative Institute for Research and 

Environmental Sciences. Dr. Pielke previously served as a Scientist 

at the National Center for Atmospheric Research. In addition, Dr. 

Pielke is a Senior Fellow of the Breakthrough Institute and has 

held several academic appointments. Dr. Pielke received his bachelor’s degree in mathematics, his master’s degree in public policy, 

and his Ph.D. in political science, all from the University of Colorado. 

We welcome you all, and Dr. Curry, we’ll begin with your testimony. 
19 

TESTIMONY OF DR. JUDITH CURRY, PRESIDENT, 

CLIMATE FORECAST APPLICATIONS NETWORK; 

PROFESSOR EMERITUS, GEORGIA INSTITUTE OF 

TECHNOLOGY 

Dr. CURRY. I thank the Chairman and the Committee for the opportunity to offer testimony on this important topic. 

Prior to 2010, I felt that supporting the IPCC consensus on 

human-caused climate change was the responsible thing to do. 

That all changed for me in November 2009 following the leaked 

Climategate emails that illustrated the sausage making and even 

bullying that went into building that consensus. 

I came to the growing realizing that I had fallen into the trap 

of groupthink in supporting the IPCC consensus. I began making 

an independent assessment of topics in climate science that had 

the most relevance to policy. I concluded that the high confidence 

of the IPCC’s conclusions were not justified and that there were 

substantial uncertainties in our understanding of how the climate 

system works. 

I realized that the premature consensus on human-caused climate change was harming scientific progress because of the questions that don’t get asked and the investigations that aren’t made. 

We therefore lack the kinds of information to more broadly understand climate variability and societal vulnerabilities. 

As a result of my analyses that challenge the IPCC consensus, 

I have been publicly called a serial climate disinformer, antiscience, and a denier by a prominent climate scientist. I’ve been 

publicly called a denier by a U.S. Senator. My motives have been 

questioned by a U.S. Congressman in a letter sent to the president 

of Georgia Tech. 

While there is much noise in the media and blogosphere and professional advocacy groups, I’m mostly concerned about the behavior 

of other scientists. A scientist’s job is to continually challenge their 

own biases and ask how could I be wrong? Scientists who demonize 

their opponents are behaving in a way that is antithetical to the 

scientific process. These are the tactics of enforcing a premature 

theory for political purpose. 

There is enormous pressure for climate scientists to conform to 

the so-called consensus. This pressure comes from federal funding 

agencies, universities and professional societies and scientists 

themselves. Reinforcing this consensus are strong monetary, 

reputational and authority interests. Owing to these pressures and 

the gutter tactics of the academic debate on climate change, I recently resigned by tenured faculty position at Georgia Tech. 

The pathology of both the public and scientific debates on climate 

change motivated me to research writings on the philosophy and 

sociology of science, argumentation from the legal perspective, the 

policy process, and decision-making under deep uncertainty. My 

analysis of the problems in climate science from these broader perspectives have been written in a series of posts in my blog, Climate 

Et Cetera, and also in four published journal articles. My reflections on these issues are summarized in my written testimony. 

The complexity of the climate change problem provides much 

scope for disagreement among reasonable and intelligent people. 
20 

Why do scientists disagree about the causes of climate change? The 

historical data is sparse and inadequate. There’s disagreement 

about the value of different classes of evidence, notably, the value 

of global climate models and paleoclimate reconstructions. There’s 

disagreement about the appropriate logical framework for linking 

and assessing the evidence. And scientists disagree over assessment of areas of ambiguity and ignorance. 

Policymakers bear the responsibility of the mandate that they 

give to panels of scientific experts. In the case of climate change, 

the U.N. Framework Convention on Climate Change framed the 

problem too narrowly. This narrow framing of the climate change 

problem essentially preordained the conclusions from the IPCC assessment process. 

There are much better ways to assess science for policymakers 

than a consensus-seeking process that serves to stifle disagreement 

and debate. Expert panels with diverse perspectives should handle 

controversies and uncertainties by assessing what we know, what 

we don’t know, and where the major areas of disagreement and uncertainties lie. Let’s make scientific debate about climate change 

great again. 

This concludes my testimony. 

[The prepared statement of Dr. Curry follows:] 
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Chairman SMITH. Thank you, Dr. Curry. 

Dr. Christy. 

TESTIMONY OF DR. JOHN CHRISTY, 

PROFESSOR AND DIRECTOR, 

EARTH SYSTEM SCIENCE CENTER, NSSTC, 

UNIVERSITY OF ALABAMA AT HUNTSVILLE; 

STATE CLIMATOLOGIST, ALABAMA 

Dr. CHRISTY. Thank you, Chairman Smith, and Committee Members for this opportunity to speak about climate change. 

I’m John Christy, Professor of Atmospheric Science at the University of Alabama in Huntsville, and Alabama State Climatologist. 

I have served in many climate roles including Lead Author of the 

United Nations IPCC. My main research is building data sets from 

scratch to help understand what the climate is doing. 

Of concern today is the proposition that the traditional scientific 

method has not been consistently followed in today’s pronouncements about climate change made by so-called official panels. 

Science is simply a method that describes a pathway to discover information. In the method, the scientist makes a claim or a hypothesis about something and then proceeds to test that claim against 

independent data to see if the claim is false or not. 

In the first figure next, I show a vertical cross-section of the atmospheric temperature trends. Surface is at the bottom, stratosphere at the top, and the poles on either end, tropics in the middle. This figure is simply a claim common to climate models that 

the bulk atmosphere in the last 38 years should show considerable 

atmospheric warming due to extra greenhouse gases, especially in 

the outlined tropical section. So here we have a testable claim because we have observations with which to compare. 

In the next figure, I show the temperature progression from 32 

model groups with their average in red of that tropical section. We 

are interested in the red curve because that is the consensus upon 

which claims of future climate change are based. But don’t overlook 

the widespread of model results in the dash lines. They’re all over 

the place. There is no clear certainty on what the climate might do 

in the future. 

I also show observations on this chart of the bulk atmospheric 

trend you see with symbols, circles, squares and diamonds based 

upon three different types of measuring systems: balloons, satellites and merged product used in weather forecasting called re 

analyses. Each of these methods has three or four different groups 

contributing a result. This figure looks confusing, so to simplify the 

test of the claim, I show the next figure, which is just the trend 

lines that are being compared. What is obvious is that the warming 

hypothesized and claimed by climate models to have already occurred has not. The warming is clearly overstated. When these 

trends are formally tested, the scientific conclusion is that the consensus of the climate models—the red line—fails to represent reality of the actual changes in the bulk atmosphere, and that’s a 

foundational climate metric. 
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Little known to many is that this result was displayed in the 

most recent IPCC buried deep and without comment in chapter 10, 

supplementary information. In my written testimony, is how that 

using that IPCC diagram, the same result as shown here, occurs. 

The warming rate of models on which policy is based can be scientifically falsified as representing reality. 

Interestingly, the IPCC result, in that result, the models without 

extra greenhouse gases reproduce the actual observations very 

well. Indeed, I am a co-author of a report in which we used a statistical model to reproduce to a large degree the atmospheric temperature trends without the need for extra greenhouse gases. In 

other words, it seems that Mother Nature can cause such temperature trends on her own, which should be no surprise. 

It is astounding and disturbing that such contradictory evidence 

to the IPCC’s main model-based conclusion that humans caused 

most of the recent warming could be ignored so gallantly and willfully. In my view, the dispassionate analysis of scientific results on 

which policy decisions are based was sidetracked by those in control of the IPCC documents. 

This problem is pervasive in climate science. Grand compilations 

such as the IPCC, the National Climate Assessment, pronouncements from scientific societies, who never do any scientific work on 

the problem, by the way, for their results and even EPA’s 

endangerment finding are on the whole written by those who are 

not scientifically dispassionate, and as such, the traditional method 

of science was circumvented, in my opinion. 

I’ll close by noting that when someone says that precisely measuring the role of ‘‘human activity on the climate is something very 

challenging to do and there’s tremendous disagreement about the 

degree of impact’’ that person is making a scientifically defensible 

statement as demonstrated by my testimony. 

Thank you. 

[The prepared statement of Dr. Christy follows:] 
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Chairman SMITH. Thank you, Dr. Christy. 

And Dr. Mann. 

TESTIMONY OF DR. MICHAEL MANN, 

DISTINGUISHED PROFESSOR OF 

ATMOSPHERIC SCIENCE AND DIRECTOR, 

EARTH SYSTEM SCIENCE CENTER (ESSC), 

THE PENNSYLVANIA STATE UNIVERSITY 

Dr. MANN. Thank you, Mr. Chairman and Members of the Committee. My name is Michael Mann. I am Distinguished Professor 

of Atmospheric Science at Penn State University, where I also direct the Earth System Science Center at Penn State. My research 

interests are in understanding the behavior of the Earth’s climate 

system. I have served on several National Academy panels and 

committees. I’m a Fellow of the American Geophysical Union, the 

American Meteorological Science, and the Association—American 

Association for the Advancement of Science. I received numerous 

prestigious awards. I have authored more than 200 publications 

and several books. 

It is important to make clear at the outset that there is extremely broad agreement among the world’s scientists on the basic 

facts of human-caused climate change. The U.S. National Academy 

of Sciences, all of the scientific societies of all the industrial nations, more than 30 scientific societies around the United States, 

at least 97 percent of scientists publishing in the field, all of these 

have concluded based on the evidence that climate change is real, 

is human caused, and is having adverse impacts on us, our economy, and our planet. 

Yet we find ourselves at this hearing today with three individuals who represent that tiny minority that reject this consensus or 

downplay its significance, and only one, myself, who is in the mainstream. That’s 25 percent. That’s a far cry from 97 percent, an inauspicious start for an honest discussion about science. 

I have devoted my life to understanding the natural world. In the 

case of climate science, it turns out that this lifelong journal of scientific discovery has also enormous societal implications. Earlier 

this week, for example, my colleagues and I published a study demonstrating that climate change is altering the jet stream in a way 

that is making extreme weather events—droughts, floods, heat 

waves—more likely, events like the 2011 Texas and Oklahoma heat 

wave and drought, the 2015 California wildfires that affected the 

lives so many Americans. Other recent studies have shown the fingerprints of human-caused climate change on extreme events like 

the fires that devastated America’s heartland earlier this month, 

burning cattle alive. One local called these wildfires ‘‘Our Hurricane Katrina.’’ February’s record warmth was made three times 

more likely by human-caused climate change, and that record 

warmth fueled the drought that set up these fires. 

Continuing to pose important questions and seeking to answer 

them using scientific tools and observations, as a scientist, that’s 

what I love doing, but I’m here today because I’m also passionate 

about communicating what we know to the public and to policymakers. In my view, nothing could be more noble. 
52 

Anti-science forces have launched a series of bad-faith assaults 

on climate science and climate scientists. I should know. I found 

myself at the center of these episodes more than once. 

We’ve recently seen the latest in this perpetual series of attacks, 

and the story is eerily familiar. As always, they focused on a particular individual, in this case, Tom Karl, who in 2015 led a study 

published in the premier journal Science that put the final nail in 

the coffin of the contrarian myth du jour that global warming had 

supposedly stopped. Never mind that we’ve now broken all-time 

records for three consecutive years and various published studies 

have convincingly demonstrated that human-caused global warming continues unabated, this Committee’s Chairman, Chairman 

Smith, attacked Karl, aided by contrarian bloggers and the tabloid 

press. Smith even misrepresented an article I was co-author on, 

claiming it supported his attacks on Karl and NOAA. While we disagreed over some details, precisely the sort of healthy debate that 

many in this room would like to pretend doesn’t exist in the scientific community, both papers agree that human-caused global 

warming continues unabated while natural variations continue as 

well. 

While such political theater plays out in Congress, the process of 

real science plays out in the peer-reviewed literature and at scientific meetings where scientists continuously challenge each other’s findings. But just as our critics have intentionally ignored the 

many independent studies reaffirming the hockey stick curve for 

which I was attacked, so too have Karl’s critics ignored the fact 

that his findings have been confirmed by the Berkeley Earth 

Project, a project funded by the Koch Brothers. 

When I was attacked by Joe Barton a decade ago over the hockey 

stick, I found support from moderate pro-science Republicans like 

John McCain and Sherwood Boehlert, the former Chair of this 

Committee, I would add. I am deeply appreciative of the efforts 

today by Republicans like Bob Inglis of South Carolina and former 

Reagan Administration officials James Baker and George Schultz 

to promote conservative climate solutions. It is time for other Republicans to put aside the anti-science and engage instead in the 

worthy debate to be had about how we solve this great challenge 

to all of humanity. 

Thank you. 

[The prepared statement of Dr. Mann follows:] 
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Chairman SMITH. Thank you, Dr. Mann. 

And Dr. Pielke. 

TESTIMONY OF DR. ROGER PIELKE JR., PROFESSOR, 

ENVIRONMENTAL STUDIES DEPARTMENT, 

UNIVERSITY OF COLORADO 

Dr. PIELKE. Thank you. 

I started my career in science and policy working for Chairman 

George Brown, who’s in the red sweater to my left looking down 

on us, at this Committee 26 years ago. It’s always a privilege to 

come back, and I know how hard the members and the staff work 

on all our behalf. 

My testimony focuses on how Members of Congress can better 

support scientific integrity and climate research. Let me tell you a 

story. 

Several months after I testified before this Committee in December of 2013, the White House posted on its website a six-page essay 

by the President’s Science Advisor, which claimed falsely that my 

testimony before this Committee was not representative of mainstream views and was seriously misleading. Now, we’ve all come to 

learn that no good happens when the White House releases false 

information, and my case was no different. 

One year later, Congressman Raul Grijalva opened a formal investigation of me and six other professors, three of whom are testifying here today. In his letter to my university’s president, Mr. Grijalva justified the investigation of me by relying on the Science Advisor’s false claims. In his letter, he introduced another false implication, that I and the other academics had potential conflicts of interest in failures to disclose corporate funding sources. He cited 

ExxonMobil and the Koch Foundations as possible sources of undisclosed funding that I might have received. My university conducted 

the investigation, and no surprise to me found I’ve never received 

any fossil fuel or Koch Foundation funding. 

In 2016, the University of Colorado’s elected Board of Regents 

issued a unanimous bipartisan statement in support of me and academic freedom more generally. 

Despite being ultimately vindicated about the integrity of my research and my funding sources, as well as receiving the strong support of my university leadership, the investigation proved extremely harmful to my ability to work in the field of climate, yet 

scientific evidence in support of the conclusions I presented to this 

Committee in 2013 is stronger today. There is little scientific basis 

in support of claims that extreme weather events and specifically 

hurricanes, floods, drought and tornados and their economic damage has increased in recent decades due to the emissions of greenhouse gases. In fact, since 2013, when I last appeared here, the 

world and the United States have had a remarkable stretch of good 

fortune with respect to extreme weather as compared to the past. 

The lack of evidence to support claims of increasing frequency or 

intensity of hurricanes, floods, drought or tornados on climate time 

scales is also supported by the most recent assessments of the 

IPCC and the broader peer-reviewed literature on which the IPCC 

is based. 
72 

My experience as an inconvenient academic is not unique. Politicians, including elected officials in Congress, and enthusiastic advocates from both sides of the aisle have targeted climate researchers 

whose peer-reviewed research they do not like including all four 

witnesses testifying here today. 

Such dynamics of delegitimatization are not unique to the climate issue. Drawing on my experiences, my research and that of 

the broader community focused on science advice, I offer several 

recommendations focused on how Members of Congress can improve the state of science integrity and climate science. 

Policymakers and scientists have developed well-established 

processes for assessing the state of scientific knowledge on subjects 

of relevance. Such process include federal advisory committees, 

those of the National Academies, the assessments of the IPCC, and 

many other nationally and internationally. Such processes work 

best when they are populated by a diversity of experts including 

those who may hold minority or even unpopular perspectives. 

Members of Congress have the standing and authority to call for 

such assessments to ensure through oversight that they are conducted with integrity and responsive to their information requests. 

In contrast, while the legislative process can be extremely effective in highlighting partisan differences on policy, it is not wellsuited to provide an accurate characterization of the state of scientific understandings. 

Sometimes debates over science serve as a proxy for debates 

about policy preferences or political orientation. When Members of 

Congress and scientists participate in such proxy debates, it contributes to the pathological politicization of science. 

Oversight of the integrity of scientific assessments is an important and appropriate role for Congressional committees. However, 

the investigation of individual researchers is not an appropriate 

role for Congress and is unlikely to contribute positively to the upholding of scientific integrity. A bipartisan truce ending such investigations of individual researchers should start immediately. 

Congress should support the role of scientific assessments in providing an accurate perspective on questions asked by policymakers. 

We have plenty of knowledge and experience about how to arrive 

at accurate represents of the state of scientific understandings on 

any topic. It’s a choice whether or not to use that knowledge and 

experience. 

Thanks again for the opportunity to share these views. 

[The prepared statement of Dr. Pielke follows:] 
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Chairman SMITH. Thank you, Dr. Pielke, and I’ll recognize myself for questions, and let me address my first question to Dr. 

Curry. 

Dr. Curry, let me say at the outset, I know you could take an 

hour to answer this question. Unfortunately, you’ll have to give me 

a summary, and the question is this: what are the uncertainties, 

complexities, biases involved with climate science or the study of 

climate science that need to be considered before we can actually 

make informed decisions about what to do about climate science? 

Dr. CURRY. Well, the greatest uncertainties in both our understanding and our ability to model the climate system relate to 

these items. The first is what I call the thermodynamic feedbacks 

related to clouds and water vapor. Climate models have a large 

amplifying effect from clouds and water vapor. The magnitude of 

this amplifying effect and even the sine are in dispute. A lot about 

the oceans that we don’t understand, how the ocean transports 

heat and carbon in the vertical is not well represented in the climate models. We also have these very large-scale long-term ocean 

oscillations, which play a huge role in determining our climate. 

These are not well simulated, and we don’t have good documentation of the really long time period oscillations. The effects of the 

sun on climate, particularly the indirect solar effects, and I could 

go on and on, but I think those are the key issues. 

Chairman SMITH. And you didn’t even get into the biases and 

other uncertainties, but that’s a good start, and that gives us an 

idea. Thank you, Dr. Curry. 

Dr. Christy, the PowerPoints you put up on the flat screens a 

while ago I thought were absolutely riveting, and at least to me 

very persuasive. My question is, why are both the satellite and surface temperature measurements so far below the climate model 

predictions? In other words, there’s a conflict between the data and 

the predictions. Why is that? 

Dr. CHRISTY. Well, there are a lot of answers, I suppose. I can 

speculate about some. What we’ve seen is that the models tend to 

be too sensitive to greenhouse gases, likely related to the fact the 

models tend to shrink clouds more than in reality so that more 

sunlight gets in and heats up the Earth more, so that’s one idea 

that may be the reason. But overall, the basic answer is that models are too sensitive to extra greenhouse gases. The Earth has a 

way to release the heat that greenhouse gases try to build up. 

Chairman SMITH. I think most constructive was the line that 

showed the actual observations as opposed to the modeling and 

how big of a discrepancy there was between the two. Thank you for 

pointing that out. 

Dr. Pielke, you in your testimony today mentioned that extreme 

weather events are not necessarily caused by climate change. In 

fact, the IPCC has said there’s low confidence that there’s any connection between climate change and extreme weather events. Why 

are some climate scientists claiming that there’s a connection when 

you and other scientists and the IPCC all says there’s likely not a 

connection? 

Dr. PIELKE. Yeah, when you talk about trends and extreme 

events, it’s really important to focus on the phenomena you’re talking about—hurricanes, floods, drought—and look at those individ-
98 

ually. It’s long been a puzzle to me why there would be any controversy over this topic since something like a hurricane is pretty 

big. It’s easy to see when it occurs. We have very good data on it. 

In the United States, the number of hurricanes and the intensity 

of hurricanes is down by 20 percent since 1900. I don’t put a lot 

of stock into that because you can start at different dates and get 

different trends, but the point is, there’s no evidence to suggest 

that hurricanes either in the United States or globally are increasing, and the same goes for floods, drought and tornado. And don’t 

believe me, you can look at the appendix that I provided with data 

from the IPCC. So why people would hang their hat on long-term 

trends in extreme weather is a puzzle. 

Chairman SMITH. Thank you, Dr. Pielke. 

That concludes my questions, and the gentlewoman from Texas, 

the Ranking Member, is recognized for hers. 

Ms. JOHNSON. Thank you, Mr. Smith. 

We have seen some Congressional Republicans be critical of individuals scientists because the scientist’s research does not align 

with their personal and political beliefs. 

Dr. Mann, what kind of effect does criticism of this type have on 

individual scientists, research institutions or even the entire fields 

of research? 

Dr. MANN. I think the attacks against scientists by individuals, 

groups, many of them allied with fossil fuel interests and fossil fuel 

front groups, are aimed at several goals. One of them is to silence 

climate scientists. If you get attacked every time you publish an article that demonstrates the reality and threat of human-caused climate change, if that causes you to become subject to Congressional 

inquiries and Freedom of Information Act requests, obviously that’s 

very stifling, and I think the intention is to cause scientists to retreat. I also think that the intention of these very public attacks 

on climate scientists like Tom Karl is meant to send a chilling signal to the entire research community that if you too publish and 

speak about the threat of human-caused climate change, we’re 

going to come after you too. 

Science and the progress of science that we have relied upon as 

a nation for our prosperity, science relies on the ability of researchers to carry out unfettered investigations into the natural world, 

and any time you start trying to game that system, it becomes very 

problematic. 

I would like to speak to one example from history. This is the 

example. Trofim Lysenko was a Russian agronomist, and it became 

Leninist doctrine to impose his views about heredity, which were 

crackpot theories completely at odds with the world’s scientists. 

Under Stalin, scientists were being jailed if they disagreed with his 

theories about agriculture, and Russian agriculture actually suffered. Scientists were jailed. They died in their jail cells. And potentially millions of people suffered from the disastrous agricultural policies that followed from that. So that’s what happens when 

fringe scientific views that might support a particular ideology are 

allowed to trump actual mainstream science. 

Ms. JOHNSON. Thank you. 

How do we make sure that political influence does not negatively 

influence the scientific process? 
99 

Dr. MANN. Say that again, please. 

Ms. JOHNSON. How can we make sure that political influence 

does not negatively influence the scientific process? 

Dr. MANN. Well, you know, I agree with Roger Pielke, Jr., that 

we have to discourage investigations that are aimed at discrediting 

and threatening individual climate scientists about their research. 

Now, asking for a scientist’s source of funding to me is fair game, 

and I’m more than—always more than happy to provide details 

about where my funding comes from. I think any scientist should 

be willing to do that, and Congress has a right to know that information as well. 

But going after scientists simply because you don’t like the implications of their research, not because their science is bad but because you find the implications of their research inconvenient to 

the special interests who fund your campaigns, I would hope we 

could all agree that that is completely inappropriate. It’s a threat 

to science, it’s a threat to our prosperity as a nation, which relies 

on scientific research—unfettered, honest, scientific research. 

Ms. JOHNSON. Thank you. 

Very quickly, Dr. Pielke has accused you and other climate researchers of being bullies toward individuals who don’t agree with 

you. Have you been a target of personal attacks based on your research? 

Dr. MANN. Well, I have. As I just mentioned the hockey stick 

graph became a focus of attacks by Congressional Republicans like 

Congressman Joe Barton, Ken Kuncinelli, the Attorney General of 

Virginia. Of course, our research ultimately has been validated 

time and again and yet the attacks continue because it was an 

iconic research result. But I would like—and it spoke to the obvious 

fact that our globe is warming and it’s due to human activity. 

But I would like to speak to this other point you raised about Dr. 

Pielke and others accusing climate scientists like myself of being 

bullies. I do think that’s rather rich coming from Roger. He does 

have a history of bullying other scientists who criticize him and 

then sort of points to himself as the victim. Three years ago, he 

wrote a piece for Nate Silver’s new FiveThirtyEight website that 

rejected the connection between climate change and extreme 

weather. Keep in mind, Roger isn’t an actual climate scientist. A 

number of actual climate scientists including Kevin Trenberth, who 

is a distinguished researcher at the National Center for Atmospheric Research, challenged, publically challenged his statements 

in his article, and was the subject along with me of threatening 

emails from Roger. In fact, Kevin Trenberth’s boss received a 

threatening email that implied potential legal action if he didn’t 

apologize and retract his criticisms. Well, the emails were reviewed 

by FiveThirtyEight, by Nate Silver, and he decided that they were 

not in keeping with the values of the organization. He terminated 

Roger’s involvement with FiveThirtyEight. Roger then presented 

himself as the victim. And so in this case, clearly Roger was the 

bully, sending these bullying emails to me and Kevin Trenberth 

and our bosses, and then trying to paint himself as the victim, and 

that just doesn’t serve the discourse. 

Ms. JOHNSON. Thank you very much. 

Chairman SMITH. The gentlewoman’s time is expired. 
100 

The gentleman from Alabama, Mr. Brooks, is recognized. 

Mr. BROOKS. Thank you, Mr. Chairman. As an overview, so 

many questions, so little time. I’m going to direct my question to 

Dr. Christy from my hometown at University of Alabama in Huntsville, but if anyone else wants to add any comments, please feel 

free. 

When I say ‘‘so many questions,’’ first we’ve got the issue of 

whether global warming exists, and if so, to what degree, and if so, 

is it cyclical or manmade. But we’ve also got the question about if 

it is noncyclical, if it is manmade, what are the effects, and in that 

vein, I’d like to get your insight on some information that I received while I was in Antarctica about 15 or 16 months ago. The 

question focuses on sea-level rise or fall. What we generally see in 

the news media is if there’s global warming and it makes sense at 

first blush, well, you’re going to see ice melt and you’re going to 

see the sea levels rise and we’re going to have all sorts of damage 

done to our coastal areas as a consequence. But while I was in Antarctica, I met with a number of national science foundations who 

all contended that there was some degree of global warming but 

they added that if there was a slight or a modest global warming, 

that the sea levels will fall, not rise. Let me emphasize that: that 

the sea levels if there is slight or modest global warming will fall, 

not rise. And of course, that was somewhat perplexing because 

that’s the exact opposite of what we hear in the news media on a 

regular basis, and this is what they said, and Dr. Christy, if you’d 

please share your insight as to whether you think their argument 

is legitimate or not, first, that the principal amount of ice on the 

planet is in Antarctica, roughly 85 percent, more or less, of the 

total amount of ice on the planet; second, that if the temperatures 

rise a little bit, then that air is going to carry more moisture, which 

in Antarctica is going to be deposited on a huge land mass that is 

larger than the size of the United States of America, by way of example, some levels of ice, I think the mean is around 6,000 feet 

deep, at the South Pole it’s more than that, and some places in 

Antarctica as much as 3 miles thick, and that it takes hundreds 

of years for that ice that has fallen in Antarctica to actually reach 

the coastline, which means that if the temperature goes up a little 

bit because of this effect, you’re actually looking at more snow and 

ice being deposited on Antarctica and water being taken from the 

oceans, more than offsetting whatever melt there may be in Greenland or the Arctic. 

So what are your thoughts on that theory or argument that they 

were raising to us in Antarctica? 

Dr. CHRISTY. Well, thank you for the question, Congressman. I 

will yield to our polar expert here, Dr. Curry, for the answer. 

Mr. BROOKS. Well, dadgummit, I wanted to do something with a 

local boy, but go ahead, Dr. Curry. 

Dr. CHRISTY. It’s pretty hot in Alabama. 

Dr. CURRY. Thank you, John. 

Well, the math balance of glaciers is a complicated topic, and we 

have, you know, new satellite technologies that are trying to measure this from laser altimetry and so on and so forth. But you see 

glacier accumulation in some regions due to increased snowfall and 

then there’s a few regions where you see it melting, and this is true 
101 

both for Greenland and Antarctica. The idea of warmer oceans 

translating into more snowfall seems to be a real one but then 

there’s glacier dynamics. It’s a very complex situation so there is 

something to what you heard, you know, that is a real mechanism, 

but how all this plays out for the glacier mass balance remains, 

you know, a topic of research, and it’s really only, you know, the 

last decade or so that we have had really, really good measurements of glacier topography, and we can really track the mass balance. So we do need the observations from satellite and also field 

experiments to sort out this issue. 

Mr. BROOKS. Well, moving to a NASA study from 1992 to 2008, 

they concluded that in Antarctica, you were seeing, while there’s 

this global warming going on, a net addition of about 100 billion 

tons of ice per year, and you talk about over the last decade. Is that 

1992 to 2008 data accurate in your judgment or inaccurate? 

Dr. CURRY. There’s uncertainty but you’ve seen the accumulation 

over east Antarctic where on the west Antarctic ice shelves you’re 

seeing net melting. So there’s some spatial variability, and there is 

significant uncertainties in our estimates of all this, particularly 

the further back you go. 

Mr. BROOKS. Anybody else want to add any comments to that 

issue? Dr. Mann? 

Dr. MANN. Yes. So we have widespread measurements now from 

satellites, direct measurements of the total ice mass contained in 

the ice sheets, and there is no question that the two main potential 

contributors to global sea-level rise, the Greenland ice sheet and 

the west Antarctic ice sheet, are losing ice, and we know that that 

loss of ice means that the ice sheets are contributing to sea-level 

rise already. Now, we hear so much about uncertainty as if uncertainty is a reason for inaction, but in this case, the uncertainties 

are breaking against us because we are actually seeing more rapid 

loss of ice from those ice sheets than the climate models that many 

here criticize had predicted in the past. That means that we are 

going to see more sea-level rise in the near term than the models 

had predicted. In this case, uncertainty is not our friend. It’s breaking against us. 

Mr. BROOKS. Dr. Mann, Dr. Curry, thank you. 

Dr. Christy, next time. 

Thank you, Mr. Chairman. 

Chairman SMITH. Thank you, Mr. Brooks. 

The gentlewoman from Oregon, Ms. Bonamici, is recognized. 

Ms. BONAMICI. Thank you very much, Mr. Chairman. 

There have been many studies that have confirmed that of the 

thousands of peer-reviewed papers that have taken a position on 

the cause of global warming, 97 percent recognize the influence humans have on global warming, and only three percent reject or 

minimize the connection between humans and climate change. So 

the witness panel does not really represent the vast majority of climate scientists who have concluded that there is a connection between human activity and climate change. So sort of visualize 96 

more climate scientists who agree that climate change is driven by 

human activity. I know we don’t have that many seats at the dais 

but I just want to put that out there. For a balanced panel, we’d 

need 96 more Dr. Manns. 
102 

So we know that human contributions to climate change have 

vast and alarming effects including rising sea levels, ocean acidification, melting glaciers. We just got the alarming report recently 

about the Great Barrier Reef. Climate change is damaging our environment, our economy, our food sources, and fossil fuel emissions 

also contribute to higher rates of asthma, lung and heart disease, 

threatening the lives of our children and grandchildren. 

So I’m proud to say that my home State of Oregon is taking action. In January of 2016, the Nature Conservancy convened the Oregon Business Leaders Greenhouse Gas Emission Task Force, and 

it’s a coalition of business leaders who recently produced a report 

with strategies to reduce greenhouse gas emissions and at the 

same time maintain our business competitiveness. The action items 

include calling for Oregon building codes to promote energy efficiency, increasing federal investment in low-carbon technologies, 

addressing congestion in the metropolitan areas, and I applaud the 

Nature Conservancy and our business leaders in Oregon for rising 

to the challenge and coming up with commonsense solutions that 

benefit the environment and also help our businesses succeed in a 

changing world. We understand that it is not mutually exclusive 

that we can protect the environment and grow our economy. 

So Mr. Chairman, I request unanimous consent to enter the Nature Conservancy report into the record. 

Chairman SMITH. Without objection. 

[The information appears in Appendix II] 

Ms. BONAMICI. Dr. Mann, science continues to prove the connection between human activity and our changing climate, so instead 

of holding this unproductive hearing, what would be better for this 

Committee to do? How could we further scientific inquiry and investigate actions that we could take to respond to the current and 

future risks of climate change? 

Dr. MANN. Well, thanks very much for the question, and as I 

often like to say, actually scientists—science doesn’t prove anything. Proof is for mathematical theorems and alcoholic beverages. 

But what science does do is establish at high levels of confidence, 

just like the theory of gravity. We haven’t proved it but we don’t 

jump off a cliff. We understand that it’s real. And the same thing 

is true with climate change. In fact, by some measures, there is as 

deep a consensus about human-caused climate change as there is 

about gravity. It literally goes back two centuries to Joseph Fourier 

in the early 1880s. 

So as I’ve said before, what I would like to see, what I would 

hope we would see in Congress is a good-faith debate between politicians on both sides of the aisle advocating for solutions to this 

problem that are consistent with their ideologies, and I think it’s 

great that they’re Republicans and conservatives today who are out 

there saying to their fellow Republicans, let’s put aside the antiscience. This is about U.S. competitiveness. The rest of the world 

is moving ahead. They’re transitioning to renewable energy. 

They’re actually tackling this problem, and we stand to get left behind. 

Ms. BONAMICI. Thank you. I’m going to get another question. I 

did want to note that Mr. Pielke’s testimony indicates he might 

support a carbon tax. I wish we were having a hearing about that. 
103 

So we’ve also heard in the Committee and elsewhere in Congress 

criticisms of the climate models used by the National Oceanic and 

Atmospheric Administration, the IPCC and other bodies that understand and discuss responses to climate change. So there have 

been some like Dr. Christy who claim that the satellite data somehow disproves our understanding of climate change. So would you 

respond to that claim, and how should we consider the value of satellite and in situ observations as we work to better understanding 

our Earth’s climate? 

Dr. MANN. Well, thanks for the question, and I would say, you 

know, that statement that the satellite data somehow disprove 

human-caused climate change, it’s what I can an RUS. It’s a ridiculously untrue statement. And the surface and near-surface temperature records—in fact, if we can show Exhibit A from my written statement here, it shows that all of the surface and near-surface temperature records agree that there’s a steady long-term pattern of warming. That’s true for the temperatures measured by 

thermometers at the surface, the balloon measurements in the 

lower atmosphere, and both John’s satellite data set and other estimates from the same satellite data. 

Now, I should point out that that’s John’s satellite data set after 

it’s been corrected for numerous errors that he had made over the 

years and which came to light because of other attempts by other 

researchers to reproduce his results, and ultimately now with those 

corrections, his satellite record is basically consistent with these 

other records. They all show long-term warming, and I would add, 

by the way, that if he is right, that the mid and upper troposphere 

are not warming as fast as the models say, and there’s a paper just 

out a week ago by Ben Santer, Susan Solomon, Presidential Medal 

of Science winner, a very austere team of climate scientists that 

has shown that his claim of the observations not showing the 

model predicted warming in the mid and upper troposphere is 

largely an artifact, an artifact of the fact that he’s mixing in stratospheric temperatures. The stratosphere actually cools. In global 

warming, the lower part of the atmosphere including where we 

live, the troposphere warms, the stratosphere cools. His satellite estimates actually smear some of that cooling stratosphere into what 

he’s calling the upper troposphere, and that’s the reason for the 

discrepancy, and if he was right that it was warming less quickly 

than the models predict, it would actually imply the opposite of 

what he claimed earlier. It would imply a higher climate sensitivity 

because it turns out that one of the negative feedback, one of the 

ameliorating effects, so-called lapse rate feedback, would not be as 

strong as we think it is, so it would actually mean that the climate 

is even more sensitive to increasing greenhouse gas concentrations. 

Chairman SMITH. The gentlewoman’s time has expired. 

Ms. BONAMICI. I’m out of time. Yield back. Thank you, Mr. Chairman. 

Chairman SMITH. The gentleman from Arizona, Mr. Biggs, is recognized for his questions. 

Mr. BIGGS. Thanks, Mr. Chairman, and I guess I’ll go back to 

you and this ping pong ball discussion, Dr. Christy. You know, it 

was very interesting. Would you like to respond to Dr. Mann’s explanation of your—— 
104 

Dr. CHRISTY. Absolutely. What he said was incorrect. The satellites, balloons and reanalyses, 12—10 different measuring systems, show the same thing. All include the stratospheric portion, 

which is very tiny in the tropics. The models included it as well. 

And so it was an apples-apples comparison. What I showed was a 

legitimate scientific test. 

And I would just like to say one other thing. Science is not done 

by polling, it’s done by numbers, and I showed numbers that can 

stand up, you know, under cross-examination. Those are the numbers that are out there and that we see the climate models do fail 

when compared against real data. 

Mr. BIGGS. And Dr. Christy, continuing with you, we’ve heard referred to any basically if you don’t toe to the consensus view on climate here that you’re practicing anti-science, and I was wondering 

what your comment would be on that. 

Dr. CHRISTY. I would just say I don’t practice anti-science. People 

can say what—something you should understand. Scientists are 

people and they say crazy things all the time. They are people and 

human. 

Mr. BIGGS. Sounds like Congress is really what it sounds like. 

Well, this hearing is really focusing on scientific method and 

some of our recent discourse might have gotten a little bit away 

from strictly scientific method but a lot of research on climate 

change receives significant funding from governments, and by extension, that means the American taxpayer. 

So my next question is focusing on us really trying to get at 

funding and how it might impact outcomes in research and potential biases. So the Congressional Research Service has estimated 

that between 2008 and 2013, the United States government spent 

$77 billion on climate change, and it’s my understanding that the 

Government Accountability Office is also working on a similar indepth report. 

So I’ll go with you, Dr. Curry. Are there concerns that climate 

change funding across many federal agencies may be duplicative or 

even sometimes wasteful? 

Dr. CURRY. Well, I think that the funding for observing systems, 

particularly satellite observing systems, is money very, very well 

spent, also for our ocean observing systems. I mean, this is critical 

information that we need, and I urge you to support continued 

funding of these. 

My concern is that too many announcements of opportunity from 

funding agents, you know, implicitly assume that climate change is 

caused by humans and that it’s dangerous, and as a result, what 

we get is what a lot of research that I would call climate model taxonomy where scientists just analyze the output of the IPCC production runs and, you know, make claims that, you know, climate 

change causes syphilis or will stop growing grapes in California, or 

whatever. You’ve seen all these claims. And these are not useful 

studies. What we need is more fundamental climate dynamics research to understand how the climate system works on decadal to 

century time scales and uses understanding to develop new structural forms for our climate models. That’s what I think we need to 

do to move all this forward. 
105 

Mr. BIGGS. And Dr. Pielke, is there any way to determine how 

much of the funding that we see going to support this, what has 

been called the consensus of science or those who question the consensus or perhaps may be skeptical? Is there any way to track 

that? 

Dr. PIELKE. Let me say at the outset that the findings related to 

climate science have been largely consistent since the 1980s. Yeah, 

there’s a lot of details but there is fundamental risk, it’s not going 

away, and there are fundamental legitimate disagreements as you 

heard here. 

What has happened in climate science is that this idea of a 97 

percent consensus went from characterizing what the research 

looked like to characterizing what views were legitimately allowed 

to be aired. The fact that a scientist as distinguished as John 

Christy is excoriated in the media by politicians on social media on 

a daily basis for doing legitimate science tells us something about 

the pressures to conform to a particular point of view. 

But let me say, you can fund billions and billions of dollars more 

of climate research and the findings will be very much the same. 

There’s fundamental risks, the future’s uncertain, and we have 

choices about whether and how we might want to mitigate those 

risks. 

Mr. BIGGS. Thank you. I’ll yield back. 

Chairman SMITH. Thank you, Mr. Biggs. 

The gentleman from California, Dr. Bera, is recognized. 

Mr. BERA. Thank you, Mr. Chairman. 

So a lot of people talked about the scientific method, and I am 

a scientist. I’m a doctor. I’ve spent a lot of time in the lab, a lot 

of time doing research, and as a physician, how I interpret the scientific method is to discover cause-and-effect relationships by asking questions, gathering and examining the evidence, and seeing if 

all available information can bring me to a logical conclusion. So 

let’s do that. Let’s actually go through the scientific method here 

and gather information. 

The temperature is rising. You know, Dr. Mann, what was the 

hottest year on record? Twenty sixteen, second, 2015; third, 2014; 

fourth, 2010. So we see this trend. Even Dr. Christy’s graphs show, 

you know, while there’s variation show a trend line of warming 

temperature. 

Dr. Mann, is the polar ice melting? 

Dr. MANN. Yes. 

Mr. BERA. Does ice melt when it gets colder or hotter? I’m a simple person—— 

Dr. MANN. I’m pretty sure about that one. 

Mr. BERA. Exactly. So—and is ocean temperature rising? 

Dr. MANN. Equally sure about that one. 

Mr. BERA. Okay. So we’ve gathered the facts. Now let’s start to 

think about okay, what’s—you know, those are the—what’s causing 

this. So we can agree that we ought to move the conversation towards what’s causing it, and even Dr. Pielke, you said we can talk 

about how we mitigate those causes. Yes, no one’s going to disagree 

there’s variation in weather patterns. In my home State of California, we’ve gone through dramatic droughts in the past few years, 

not this year, though. We’re having if not the wettest year on 
106 

record, one of the wettest years on record. So there is variation. 

But that doesn’t mean we ought not to be thinking about what’s 

causing this and move the conversation. 

And we ought not to—whether you deny the climate change or 

deny that the Earth is getting hotter or you agree with that, as the 

vast majority of scientists do, we ought not to be persecuting our 

scientists. We ought to be having an open dialogue, and there’s no 

problem with varying opinions but we ought to have an honest conversation about it. 

You know, do any of you think the—do any of you disagree with 

the fact that the Earth rotates around the sun? Pretty given 

science. But in 1633, Galileo was persecuted for putting forth that 

theory. Again, let’s not go back to that time. Let’s actually move 

this conversation forward. This is the Science and Technology Committee. Let’s have an honest conversation about what’s happening. 

We all agree the Earth is warming. We all agree that we’re seeing 

more extremes of climate. Let’s start mitigating that. 

Again, you could argue whether humans are causing this or if it’s 

natural. I seem to think, you know, there’s a human cause of this. 

So Dr. Mann, where would you proceed if you were to again advise 

this Committee? 

Dr. MANN. Well, let me first say the scientific method—we’ve 

heard this term quite a bit. The Chairman keeps using this term. 

I do not think it means what he thinks it means. 

According to an article that came out a few days ago in the Journal of Science, Chairman Smith was on record at the Heartland Institute. This is a climate change-denying Koch Brothers-funded 

outlet that has a climate change denier conference every year, and 

Chairman Smith spoke at that conference—— 

Chairman SMITH. Dr. Mann, don’t mischaracterize that. 

Dr. MANN. Let me finish my—— 

Chairman SMITH. No, they do not say that they are deniers, and 

you should not say that they are either. 

Dr. MANN. Well, we can have that discussion. I’d be happy to. 

Let me finish my statement. 

Chairman SMITH. Well, be accurate in your description. 

Dr. MANN. I stand by my statements. Can I finish my point? 

Mr. BERA. I’d like to reclaim my time. 

Dr. MANN. Yes. So he indicated at this conference that he, according to Science, and I’m quoting from them, he sees his role on 

this Committee as a tool to advance his political agenda rather 

than a forum to examine important issues facing the U.S. research 

community. As a scientist, I find that deeply disturbing. 

Chairman SMITH. Dr. Mann, who said that? 

Dr. MANN. This is according to Science magazine, one of the most 

respected outlets when it comes to science. 

Chairman SMITH. And who are they quoting? 

Dr. MANN. This is the author, Jeffrey Mervis, who wrote that article. I’d be happy to send to Committee the article. 

Chairman SMITH. That is not known as an objective writer or 

magazine. 

Dr. MANN. Well, it’s Science magazine. 

Mr. BERA. I’d like to reclaim my time. 
107 

Chairman SMITH. And the gentleman from California reclaims 

his time. 

Mr. BERA. Dr. Mann, if you could submit that paper to me, you 

know—— 

Dr. MANN. Absolutely. 

Mr. BERA. —we’d love to submit that for the record. 

Dr. MANN. Yes, it would be my pleasure. 

So just to continue, so science involves an objective search for 

truth, and that’s what scientists do, and we challenge each other. 

It’s not the lovefest that some would like to make it sound like. My 

good friend, who’s no longer with us, Steve Schneider, used to characterize climate—or science in general as a contact sport because 

scientists are constantly contesting in the peer-reviewed literature, 

at meetings. The way you get ahead in science isn’t by saying yes, 

I agree with everything, I agree with all the others. The way you 

get an article in the journals Nature and Science is by showing 

something different, something new, and so that’s the self-correcting machinery that keeps—using the language of Carl Sagan, 

that keeps science on a path towards truth. What we stand to be 

in danger of here is to have that machinery basically destroyed by 

the politicization of science. 

Mr. BERA. I couldn’t agree with you more. So let’s not persecute 

our scientists. We can disagree, we can have robust debate, but 

let’s actually have an honest, robust debate. 

Thank you. 

Chairman SMITH. Thank you, Dr. Bera. 

And without objection, I’d like to enter into the record three articles on the so-called 97 percent consensus, which shows that there 

was no consensus. The 97 percent was derived from a small sample 

of a small sample, and the question wasn’t whether humans contributed most of the change in climate but whether they contributed any part at all. The surprise is that it’s not more than 97 percent. 

Anyway, the 97 percent figure has been misused today a number 

of times, and without objection, those articles are made a part of 

the record. 

[The information appears in Appendix II] 

Chairman SMITH. The gentleman from Louisiana, Mr. Higgins, is 

recognized for his questions. 

Mr. HIGGINS. Thank you, Mr. Chairman. 

Dr. Mann, are you affiliated or associated with an organization 

called the Union of Concerned Scientists? 

Dr. MANN. No. I—— 

Mr. HIGGINS. You’re not affiliated nor associated with them? 

Dr. MANN. Am I associated with them? I know people who 

are—— 

Mr. HIGGINS. Are you affiliated or associated with an organization called the Climate Accountability Institute? 

Dr. MANN. No. I mean, may—— 

Mr. HIGGINS. You’re not affiliated—— 

Dr. MANN. —correspond with—— 

Mr. HIGGINS. —or associated with them? 

Dr. MANN. I can provide—I’ve submitted my CV. You can see 

who I’m associated with and who I’m not. 
108 

Mr. HIGGINS. These two organizations, are they connected directly with organized efforts to prosecute manned influence climate 

skeptics via RICO statutes? 

Dr. MANN. The way you’ve phrased it, I would find it extremely 

surprising if what you said was true. 

Mr. HIGGINS. Dr. Pielke, I’m going to ask you a series of short 

questions, please. Are hurricanes increasing? 

Dr. PIELKE. It depends on what date you want to start, but on 

climate time scales in the United States and globally, no. 

Mr. HIGGINS. Are tornados increasing? 

Dr. PIELKE. There’s a lot of uncertainty about tornados but 

there’s no evidence to suggest that they’ve been increasing. 

Mr. HIGGINS. Are floods increasing? 

Dr. PIELKE. As the IPCC concluded, there’s not really good data 

worldwide to know if they’re going up or down. 

Mr. HIGGINS. Are droughts increasing? 

Dr. PIELKE. Globally and in the United States, according to the 

EPA and according to the IPCC, the answer is no. 

Mr. HIGGINS. Why would you—can you explain why some would 

say that with such certainty that extreme weather events will increase given the fact that they have not? 

Dr. PIELKE. Well, they may increase yet in the future, and 

there’s a number of projections made by the IPCC that suggest that 

they might, and that’s part of the uncertainty associated with 

science, but looking from the past to today, we have good evidence 

to be able to answer the question whether these phenomena have 

increased on climate time scales. 

Mr. HIGGINS. And some scientists have a hypothesis that extreme weather events will increase because of climate change, and 

how do they—how do those scientists, how would you explain they 

square that hypothesis with the reality that these extreme weather 

events have not increased? 

Dr. PIELKE. Yeah, most—if you look at the IPCC and mainstream 

science, we shouldn’t expect to see the signal of human-caused climate change and increasing extreme events for decades, and many 

decades into the future. So there’s often a conflation of what’s predicted, say, in 2100 with what we’re observing today, and if we’re 

seeing an increase in extreme events today, that would actually 

show that the models are wrong because they suggest we won’t see 

it for many decades. 

Mr. HIGGINS. Thank you, sir. 

Dr. Mann, would you be able to at some future date provide to 

this Committee evidence of your lack of association with the organization Union of Concerned Scientists and lack of your association 

with the organization called Climate Accountability Institute? Can 

you provide that documentation to this Committee, sir? 

Dr. MANN. Yeah, so you haven’t defined what ‘‘association’’ even 

means here, but it’s all in my CV, which has already been provided 

to Committee. 

Mr. HIGGINS. Would you provide a statement—— 

Dr. MANN. I’ll send it again. 

Mr. HIGGINS. —to this Committee regarding your assertion? 

Dr. MANN. I will send it again. 

Mr. HIGGINS. Thank you, sir. 
109 

Mr. Chairman, I yield back. 

Chairman SMITH. Thank you, Mr. Higgins. 

The gentleman from New York, Mr. Tonko, is recognized. 

Mr. TONKO. Thank you, Mr. Chair. 

As an engineer, I know a few things about uncertainty. I know, 

for example, that everything from a steel beam to a parachute has 

a certain very small probability of failure. We have to account for 

uncertainty to be able to build large buildings and great structures 

that last for generations. We do the math, we check out our work, 

and we test it. We go back over time and shore up any weak spots. 

And when everyone does their part to build and maintain and test 

them, these structures remain strong. 

Science works in a similar way: thriving on the uncertainty that 

lives between evidence and conclusions. So when a few individuals 

express doubt about climate change, scientists listen, check their 

theories against the available data, and continue to observe and 

improve. But like the failure rate of that steel beam, the uncertainty in climate change science is known and negligible. 

For every one scientist who disputes the fact that human activity 

is driving climate change, there are 17,352 who acknowledge 

human activity is the main driver of climate change. So if we have 

a handful of scientists here in this room today who are skeptical 

about the human role in climate change, there are tens of thousands more credible, trained scientists out in the world standing up 

for the scientific fact that humans are the major driver of climate 

change. 

It is notable that those tens of thousands of scientists are represented here solely by Dr. Mann. I want to thank Dr. Mann for 

being here today, and representing this overwhelming consensus. 

The scientific community thrives on skepticism and uncertainty 

but denial is something different. Unlike healthy scientific skepticism, climate change denial stands today as one of the great pillars in the pantheon of political manipulation. Decades ago, major 

players in the fossil fuel industry saw the issue of climate change 

gaining popular attention. They also realized that any serious effort to reduce carbon pollution and greenhouse gases could be a 

death blow for their industry. So instead of embracing the clear 

evidence in front of them that fossil fuels contribute to climate 

change, they launched one of the most successful misinformation 

campaigns in our American history, right up there with the tobacco 

industry lying about cancer risks. 

In 1998, the fossil fuel industry laid out its misinformation strategy and tactics in something they called the Global Climate Science 

Communications Action Plan. Mr. Chair, I ask to enter this document into the record. 

Chairman SMITH. Without objection. 

[The information appears in Appendix II] 

Mr. TONKO. Thank you. 

This action plan said, and I quote, ‘‘Victory will be achieved when 

average citizens understand and recognize uncertainties in climate 

science; media understands, recognizes uncertainties in climate 

science.’’ The plan also called for identifying, recruiting and training a team of independent scientists to participate in media outreach. Their cause was not to better science or public education; it 
110 

was to undermine the ability of science to inform our public and 

private decisions. 

The plan was devised by one dozen people from the oil and gas 

industry along with communications strategists—PR professionals. 

One of those individuals was Myron Ebell, whose name has recently surfaced again because he led President Trump’s transition 

team at the EPA, and it seems certain from EPA Administrator 

Scott Pruitt’s recent actions that he will be more interested in strategic communications and parlor tricks to distract the public from 

the reality of climate change than actually attempting to address 

these serious problems. 

So Dr. Mann, a question. Can you talk a little bit about how you 

see these sort of tactics and distractive techniques being played out 

in the discussions about climate change, please? 

Dr. MANN. Yeah. Thanks for the question. And indeed, we do see 

these attacks against climate scientists orchestrated in many cases 

by organizations and individuals tied to fossil fuel interests. You 

mentioned specifically Scott Pruitt, and of course, Scott Pruitt is on 

record saying that—this is his quote: ‘‘I would not agree that 

human activity is a primary contributor to the global warming that 

we see,’’ which is completely at odds with what the world’s scientists have determined. 

Now, what is particularly concerning to me is that one of our witnesses here today, Judith Curry, supported that statement. She 

said, ‘‘I do not find anything to disagree with in what he said,’’ 

which means that she’s clearly going against what the U.S. National Academy of Sciences has said, what every academic scientific 

organization in the U.S. that has weighed in on the matter has 

said, and I find that distressing. 

Now, to have an EPA Administrator who has such a position 

that’s so at odds with the scientific evidence, there is no precedent, 

even in past Republican Administrations, under Nixon, under 

Reagan, under George H.W. Bush, they each had EPA Administrators that embraced science and actually that’s where market-driven 

solutions to dealing with environmental problems came about. 

Nixon founded the EPA. George H.W. Bush under his wonderful 

EPA Administrator, William K. Riley, signed the Montreal— 

sorry—passed cap-and-trade legislation. Remember cap and trade? 

That came from Bush Administration as a market-driven mechanism, a market-driven mechanism for dealing with an environmental problem. 

So what we have today with an EPA Administrator who rejects 

the overwhelming opinion of the world’s scientists is completely at 

odds with what we have ever seen before in both Democratic and 

Republican Administrations. 

Mr. TONKO. Dr. Mann, thank you so much. 

And Mr. Chair, I yield back. 

Chairman SMITH. Thank you. 

The gentleman from California, Mr. Rohrabacher, is recognized. 

Mr. ROHRABACHER. Yes. I’d like to thank the Chairman for calling this hearing today because it exposes people to different ideas, 

and it exposes people and especially at a time when those who disagree with the mainstream are being brutalized into silence, this 

type of hearing is vital to hear the fundamental arguments. 
111 

Unfortunately, from get-go, we have heard personal attack after 

personal attack after personal attack coming from those who are 

claiming to represent the mainstream of science, even to the point 

that our Chairman is attacked with a non-quote with an analysis 

of somebody else’s interpretation of what he said, and we have our 

Chairman attacked like that. That is ridiculous. People should be 

ashamed of yourselves for people who continue to attack other people because they disagree. You call people deniers all you want. 

You can use every kind of name you want. You’re not standing up 

to consensus. When we talk about how Mr. Lysenko was promoted 

by Stalin, that’s the type of thing they did to the scientists in Russia because you don’t agree with Mr. Lysenko, and now you can bet 

nobody except those who agree with Lysenko are going to be able 

to get a government research contract in Russia, the same as we’ve 

heard here in the United States from scientists who have great credentials who aren’t able to get their—who haven’t been able to get 

research grants because they’re now labeled deniers and attacked 

personally. This is a disgrace to the scientific community. 

And let me just go into some thing here. Now, CO2, the theory 

of CO2 changing the temperature of the climate, that is what basically we’re talking about when we talk about manmade climate 

change. That’s the theory. It’s not whether or not we’ve cut down 

the forest in order to produce farmland, et cetera. It’s CO2 production. That’s what they’re talking about when they’re proposing 

United Nations restrictions on our activities based on that theory 

because the globe is going to be affected by it. 

Now, was there a pause or wasn’t there a pause in the increase 

of temperature of the climate at a time when there was massive 

increases in CO2? That seems to be a fundamental question of 

whether or not—now, the fact that today the pause is—it should 

be evident that at one point at least those people who are attacking 

this side admitted that there was a pause, and you can tell that 

by the very discussion. That is, we remember when the issue was 

global warming. We remember over and over again global warming, and now just some evolution, that now we call it climate 

change. Well, what that is, is a recognition, is there was a pause 

in the heating of the planet even by those people who are advocating the opposite now. That’s why they call it climate change. 

Every time you call it climate change, you are admitting that yes, 

there was a pause, a major pause in temperature increase because 

before that, it was global warming over and over and over again. 

We heard that global warming. 

Let me ask Ms. Curry. You in particular, your testimony today 

was, I think, perhaps the most important testimony, and that is 

from someone who felt that she had to go along with the consensus 

and ignore facts that would lead—that would then lead to an honest conclusion. Could you give me your reaction to what I just said 

in terms of the way you’re getting treated? 

Dr. CURRY. Well, the issue—okay. You know, what advocacy 

groups say, what the media say, what anonymous bloggers say, you 

know, it’s noise, but what I’m concerned about is the behavior of 

scientists, and you know, I’ve been called a denier per the Congressional record from Michael Mann’s testimony. Judith Curry, the denier is now in the Congressional record. What kind of a behavior 
112 

is that? This is not the behavior of scientists who are respectfully 

disagreeing and open to debate. I mean, I am not out there in the 

fringes. My main point is that I think there are a lot of uncertainties and that the climate models and the data et cetera are not fit 

for the purpose for drawing highly confident conclusions about 

what has been causing the recent warming. 

It’s been warming for hundreds of years, and we can’t explain all 

of that, you know, due to human causes. So I’m saying we need to 

think more broadly about this problem, and that’s what I’m saying—— 

Mr. ROHRABACHER. Right. 

Dr. CURRY. —and I get called a denier and who knows what else. 

Mr. ROHRABACHER. Well, we’ve seen cycles. There have been cycles throughout the history of the planet of warming and cooling 

cycles. Whether or not man’s use of CO2 is now creating a warming 

cycle is what this is all about, and for scientists on either side to 

try to call names and try to beat somebody into submission, that’s 

a Stalinist tactic. Those using the words ‘‘denier’’ are using a Stalinist tactic—— 

Chairman SMITH. The gentleman—— 

Mr. ROHRABACHER. —and it is just incredible for me to hear others trying to claim that the basis of their discussion is what all scientists and the rest of everybody else who disagrees is in some way 

not worthy of being called a scientist, they’re deniers. 

Chairman SMITH. Thank you. 

Mr. ROHRABACHER. Mr. Chairman, I want to place on the record 

very quickly 300 names of 300 major scientists given—who signed 

on to a letter by of course the head of the science, Dr. Linzen from 

MIT, asking us to get out of the convention for climate change—— 

Chairman SMITH. Without objection, so ordered. 

[The information appears in Appendix II] 

Mr. ROHRABACHER. —300 prominent scientists. I’d like to also 

put for the record an in-depth study by a professor—and I don’t 

know how to pronounce his name—Neals Alex Werner talking 

about sea level, a man who has spent a massive amount of time 

studying sea-level rise and shows what we are getting—— 

Chairman SMITH. Without objection, that’ll be made a part of the 

record. 

[The information appears in Appendix II] 

Mr. ROHRABACHER. Thank you very much, Mr. Chairman. 

Chairman SMITH. Thank you, Mr. Rohrabacher, and the gentleman from Louisiana is recognized for unanimous consent as 

well. 

Mr. HIGGINS. Thank you, Mr. Chairman. 

My research has clarified that the organization called the Climate Accountability Institute is the primary—is a primary organization calling for criminal prosecution of climate skeptics under 

RICO statutes. I’d like to enter it into the record, sir, from their 

website, from the Climate Accountability website, listed as one of 

the Climate Accountability Institute council of advisors, Mr. Michael E. Mann. I would like this entered into the record, Mr. Chairman. 

Chairman SMITH. Without objection. 

[The information appears in Appendix II] 
113 

Chairman SMITH. The gentleman from California, Mr. Takano, is 

recognized for questions. 

Mr. TAKANO. Thank you, Mr. Chairman. 

Chairman SMITH. I’m sorry. Mr. McNerney has returned, and he 

was ahead of you. The gentleman from California, Mr. McNerney, 

is recognized for questions. 

Mr. MCNERNEY. I didn’t know I was going to be so controversial 

here, Mr. Chairman. 

I want to thank my friend from California for his opinion on this 

issue. Mr. Rohrabacher, thank you. 

Mr. Mann—Dr. Mann, I’m looking at the Exhibit B, and I was 

hoping that this could be brought to the screen, and it’s the socalled hockey curve. Now, what interests me about this is the way 

the shaded area diminishes over time. Could you explain that a little bit, how the shaded blue area diminishes as we get closer to the 

current day? 

Dr. MANN. Absolutely, and I’m glad you’re showing that plot here 

because one thing it shows, our hockey stick curve, that’s the blue 

curve that was published near two decades ago along with its uncertainties, the blue shading, you’ll notice it’s near identical to that 

green curve. That green curve is from a team of 78 scientists who 

published in the premier journal Nature Geoscience a few years 

ago using the most widespread database of proxy data ever brought 

to bear on a problem like this, and they got virtually an identical 

result to the one we had published decades ago. So to those who 

claim that the hockey stick has been discredited, just the opposite 

is true. The reason it’s accepted is because other scientists using 

different methods, different data, coming at the problem from different angles have all come up with the same result, and that’s 

how science works. 

Mr. MCNERNEY. And that’s consistent with the scientific method? 

Dr. MANN. Exactly. That’s how science works. If your result is 

wrong, it’s going to be discovered pretty quickly, and that’s what 

happened with John’s satellite records, which he originally claimed 

showed cooling. Ultimately it was discovered that there was an algebraic error in their code and a sine error like a minus where 

there’s supposed to be a plus, and now we have a consensus where 

John’s updated estimates are more or less in keeping with the 

other estimates. That’s how science works. 

Now, you ask why does the uncertainty become so large back in 

time? So let me add, by the way, that the word ‘‘uncertainties’’ appeared in the original article. To those who claim that we are trying to hide uncertainty, that we don’t want to talk about uncertainty, the words ‘‘uncertainties’’ and ‘‘limitations’’ appeared in the 

title of this original article, and that’s something we focused on. 

You can see those uncertainties do get quite large as you go back 

in time because you have less data, you have less paleo data as you 

go farther back into the past. 

Now, with some of these newer efforts like this pages 2K estimate, the green estimate, they have much more widespread data, 

the uncertainties are now smaller, and that’s how science works. 

You refine a result, you get a better estimate. Other scientists continually challenge each other, and that’s Carl Sagan’s self-correcting machinery. 
114 

Mr. MCNERNEY. Thank you. Why is it so narrow now in the current time, the uncertainty region? 

Dr. MANN. Yeah, because we’ve got widespread thermometer 

data over the last century and a half, so as we get more data, the 

uncertainties get smaller, and the red curve shows the instrumental record. We don’t need paleo data to tell us what’s happened 

to temperatures over the past century and a half. We’ve got widespread thermometer measurements for that. 

Mr. MCNERNEY. And these are measurements in the ocean and 

the atmosphere and all over the whole planet? 

Dr. MANN. That’s right, and to people who say, you know, they 

don’t trust a surface temperature record, well, we’ve got measurements from the ocean surface, we’ve got measurements of the land 

and for all the continents. We’ve got the southern hemisphere, 

we’ve got the northern hemisphere. They all point in the same direction. We’ve got a lot of independent information from holes in 

the ground, bore holes, an independent way of estimating surface 

temperatures back in time, dozens of independent lines of evidence 

that all come together telling us the same thing. That’s how science 

works. That’s why there’s a consensus, not because we’re standing 

around holding hands because independent teams of scientists coming at the problem from different angles arriving at the same consistent answer over and over again. 

Mr. MCNERNEY. Thank you. In his testimony, Dr. Pielke asserts 

that since 2013, the world and the United States have had a remarkable stretch of good fortune with respect to extreme weather 

as compared to the past. Would you respond to that, please? 

Dr. MANN. Yes. So Roger is, you know, pointing to outdated reports, outdated data. Three years ago, he actually posted the following on his blog. He said, ‘‘I am no longer conducting research 

or academic writing related to climate. I am not available for talks, 

and on the climate interest, I have no interest in speaking with reporters or giving testimony before Congress.’’ That’s what he said 

back in 2015. Well, that’s, you know, three years ago. There has 

been a lot of progress over the past three years. We just published 

an article in the Journal of Scientific Reports a few days ago that 

reaffirms what scientists are now finding. There are teams of scientists now, whole teams of scientists, when there’s an extreme 

event, they can use what’s known as detection and attribution. 

They can actually compare models and observations and estimate 

how much more likely that event might have been made by humancaused climate change, and in many of the extreme droughts and 

flooding events that we’ve seen in recent years, those groups have 

positively attributed those events. They’ve said that those events 

were sufficiently unlikely to have happened without human-caused 

global warming that we can say at a relatively high level of certainty that climate change did impact the event, not that it created 

the event; it made it worse, it made it bigger. 

Mr. MCNERNEY. Thank you, Mr. Chairman. 

Chairman SMITH. Thank you, Mr. McNerney. 

The gentleman from Texas, Mr. Weber, is recognized. 

Mr. WEBER. Thank you, Mr. Chairman. 

I think it’s a sad day when one of our witnesses lectures us about 

the number of witnesses we have and how many times that they’ve 
115 

been here to testify. It’s odd to me that he can remember how 

many times they’ve testified but he cannot remember being associated with Climate Accountability Institute. That certainly seems to 

be a lack of—a convenient lack of memory. 

So having said that, I’m going to go ahead and get to my questions. This will be for you, Dr. Curry, and I’m sorry that you’ve 

been demonized and it’s been written in the Congressional record 

that you are a climate denier. You shouldn’t have to endure that, 

you know, just because you might have a differing opinion, what 

we would call a minority report. I don’t think that you should have 

to endure that. 

I also remember, by the way, that if I remember correctly, Mark 

Twain said that sometimes a majority means all the fools are on 

one side. So there is that. 

Dr. Curry, would you characterize any of the climate policies discussed in the United States such as major industrial CO2 restrictions as flexible and adaptive? 

Dr. CURRY. No. I’m concerned about—you know, we’re facing a 

problem with—characterized by deep uncertainty and trying to fit 

this into a command-and-control kind of solution with climate models I think is a mismatch to this extremely complex and wicked 

problem. 

Mr. WEBER. So they’re not—in your opinion, they’re not flexible 

and adaptive, but scientists—science is supposed to be about the 

ongoing investigational study and adapting when necessary. Is that 

correct? 

Dr. CURRY. That would certainly be one approach that I think is 

consistent with the kinds of deep uncertainty we’re facing with this 

problem. 

Mr. WEBER. Sure. Okay. 

How about you, Dr. Christy? Would you describe those major industrial CO2 restrictions being discussed as flexible and adaptive? 

Dr. CHRISTY. Well, what I understand is that those regulations 

are based upon knowing how the system operates, how the climate 

system operates. One of the fundamental things about science is 

that when you understand a system, you can predict its behavior. 

I’ve demonstrated that the climate models we have now cannot predict even predict from the past a major climate metric, the bulk 

temperature of the atmosphere. 

Mr. WEBER. So they’re not flexible and adaptive? 

Dr. CHRISTY. Well, we don’t know what’s going to happen in the 

future so how can you then say well, this regulation is going to 

have this consequence. We don’t have confidence there. 

Mr. WEBER. Dr. Mann, I’ll give you a shot at that. Are they flexible and adaptive, those restrictions that we’re discussing on CO2? 

Dr. MANN. I’m not sure why you’re asking me that question. Obviously—— 

Mr. WEBER. Because you’re a learned scientist and you’re here 

to participate in the discussion. 

Dr. MANN. Yeah, that’s a matter of policy that you’re asking 

about, and I’ve tried to be quite clear in my view that there is a 

worthy debate to be had about what policies we invoke to deal with 

the problem—— 
116 

Mr. WEBER. So now it’s worthy and it’s not climate deniers. 

You—— 

Dr. MANN. No, you misunderstood what I’m saying. There’s a 

worthy debate to be had about the solutions to this problem. There 

is no longer a worthy debate to be had about whether the problem 

exists. 

Mr. WEBER. That is your opinion. 

Dr. MANN. That’s the opinion of the overwhelming community of 

scientists around the world. 

Mr. WEBER. And yet the EPA won’t release that data. 

I’m going to move on to you, Doctor. Is it Pielke? Is that how you 

say it? 

Dr. PIELKE. Yes. 

Mr. WEBER. In your opinion—you’re watching this. This is important to you, I’m sure. You all are watching this. Are the restrictions 

being discussed flexible and adaptive in your opinion? Do you have 

an opinion? 

Dr. PIELKE. Yes, I do. I’ve written a book on climate policy. And 

regulation has a very important role to play in bringing mature or 

near-mature technologies into deployment. Regulation itself is not 

a very good tool in stimulating R&D or fundamental innovation to 

create new technologies and so if in the absence of energy system 

innovation regulations will have marginal effects but they won’t 

have transformative effects like are being called for with the—— 

Mr. WEBER. So I’ll continue with you then and go back the other 

way. So in your opinion, before we make these kinds of major, 

major restrictive regulations, wouldn’t we want to be absolutely 

sure about the data, have the EPA release it, and why in the world 

would we demonize people who want that? Wouldn’t we want 

transparency from our own government? 

Dr. PIELKE. Well, my view, which may not be popular among 

anyone here, is that scientific uncertainty is not going to be eliminated on this topic before we have to act. If we want to improve 

energy technology, energy innovation for reasons of competitiveness, for air pollution benefits, for energy access around the world, 

we have plenty of justification for the U.S. to be a leader. Regulation plays a part in that but so too does investment in new technologies. To fund that, you guys might think about a low-carbon 

tax, one that’s maybe 2 or 3 pennies on a gallon of gas, raises hundreds of billions of dollars to bring those new technologies, and if 

the technologies exist, it’ll be a lot easier for you guys to regulate 

it because it won’t have costs that will affect people. 

Mr. WEBER. Well, now that he’s uttered blasphemy, Mr. Chairman, my time is expired and I’ll yield back. 

Chairman SMITH. Thank you, Mr. Weber. 

Back to the gentleman from California, Mr. Takano. 

Mr. TAKANO. Thank you, Mr. Chairman. 

Dr. Mann, last year Chairman Smith cited one of your papers in 

an attempt to contradict the findings of a NOAA study that disproved the theory of a global warming hiatus. In questioning thenAdministrator Kathy Sullivan, he asked ‘‘Do you still stand by the 

Karl study’s conclusions or do you now recognize that these conclusions might have been weak and agree with the Nature scientists?’’ 

Well, Dr. Mann, you are one of those Nature scientists, correct? 
117 

Dr. MANN. That’s absolutely correct. 

Mr. TAKANO. By Nature, I mean the Nature magazine. How do 

you respond? 

Dr. MANN. Yeah, well, I find it unfortunate that our work was 

misrepresented in that way. Our work in no way challenged the integrity of Tom Karl’s work. I have the utmost respect for Tom Karl 

as a scientist and as a human being, and he has the utmost integrity as a scientist. Our paper expressed an honest scientific difference of opinion. Yes, that’s what scientists do. We fight over interpretations and details, precisely the sort of challenges again that 

the critics like to pretend doesn’t take place, and in this case, it 

was a good-faith disagreement over how to characterize long-term 

warming trend. We weren’t disagreeing about whether there’s a 

long-term human-caused warming trend; we were simply contesting the interpretation, is it sort of a step-like trend like that or 

is it a more wavy trend like that, and what we weren’t disagreeing 

about was that there’s a long-term trend and that it’s caused by increasing greenhouse gas concentrations. 

Finally, let me say that other independent scientists including 

scientists, I’ll say it again, funded by the Koch Brothers have come 

up with precisely the same result that Tom Karl came up with and 

they said that they were able to download online all of the required 

raw data that was necessary to reproduce his findings, so the claim 

that he hadn’t archived and provided the data necessary for other 

scientists is just false. 

Mr. TAKANO. Well, in fact here, I have a letter, actually two letters signed by all 11 of those Nature scientists including one from 

my own home State of California rejecting the Chairman’s interpretation of their work. I would like to have these letters included into 

the record. 

Chairman SMITH. Without objection. 

[The information appears in Appendix II] 

Mr. TAKANO. Dr. Mann, I think it’s important to take a moment 

and address those who suggest that those of us who believe and 

know that climate change is occurring are somehow asking others 

simply to trust us. Science is not about trust or belief. It is the pursuit of knowledge and understanding. Sweeping statements and allegations about climate change and other issues that are not supported by any accepted scientific knowledge or often facts may be 

the calling card of this new Administration. But it is imperative 

that we not let such irrational rhetoric distract people from understanding how science works. The American people know that our 

climate is changing and they understand that we need policies to 

protect our health and environment. 

Dr. Mann, is this distinction between trust and understanding 

important? 

Dr. MANN. It absolutely is, and you know, when it comes to trust, 

I trust the U.S. National Academy of Sciences, which I might add 

was founded by a Republican President, Abraham Lincoln, in the 

19th century to inform Congress about matters of policy-relevant 

science, and they have weighed in. The world’s scientists have 

weighed in. And you know what? It doesn’t matter if individual scientists are bad persons. We all have faults as human beings. If our 

understanding depended on one or a small number of individuals, 
118 

their opinions, then of course we would not accept these findings 

as valid. It’s the fact that the entire community of climate scientists around the world arguing back and forth in the peer-reviewed literature contesting each other at meetings have all from 

different directions come to the same conclusion and all of the scientific assessments that have been done including the U.S. National Academy of Sciences back in the Bush Administration— 

George W. Bush in his first term—when the IPCC had just published their finding that climate change is real and human-caused, 

the Bush Administration was skeptical about that finding so they 

wanted an independent assessment. They asked the U.S. National 

Academy of Sciences to assess what the IPCC had said. The U.S. 

National Academy of Science after independently reviewing the literature and soliciting independent reviewers with a variety of perspectives came back and said well, you know, the IPCC, what they 

said was basically right. 

That’s—those are the facts, and we can’t dispute the facts, and 

it doesn’t matter—you know, the individual personalities of scientists, each of whom are human beings and have their own personal flaws, if that mattered, it would be a problem. The scientific 

process works because that doesn’t matter. Regardless of how good 

or bad a person you are, your claims will be independently tested 

by other scientists. 

Mr. TAKANO. Its reproducibility—— 

Chairman SMITH. The gentleman’s time has expired. 

Mr. TAKANO. —reproduction and corroboration by peers. 

Dr. MANN. Absolutely. 

Mr. TAKANO. Thank you. 

Chairman SMITH. Thank you, Mr. Takano. 

Before recognizing the gentleman from Florida, Mr. Webster, 

without objection, I’ll put into the record an op-ed from the Wall 

Street Journal called Keeping Cool about Hot Temperatures, which 

points out that even though it is claimed that 2016 was the hottest 

year in record and 2015 the hottest year on record before that, 

2014 the hottest year before that, all three instances, the temperatures were within the margin of error and that in fact in 2014, 

NASA admitted that they were only 38 percent confident of that 

temperature. That’s less than half. 

[The information appears in Appendix II] 

Chairman SMITH. The gentleman from Florida, Mr. Webster, is 

recognized. 

Mr. WEBSTER. Thank you, Mr. Chair, and thank you for holding 

this hearing. It’s been very informative. 

Dr. Curry, I’ll ask you. You were a professor at my alma mater 

so I did talk to Dr. Peterson here on Monday about some things, 

not about climate change, but anyway, I’d like to ask you what 

caused the Ice Age? 

Dr. CURRY. Well, the Ice— I mean, the big Ice Ages, the very big 

Ice Ages? 

Mr. WEBSTER. Yes. 

Dr. CURRY. Well, it has to do with—— 

Mr. WEBSTER. I know you weren’t there but—— 

Dr. CURRY. —yeah. The prevailing theory, the so-called 

Milankovitch theory, that it has—it’s related to the orbital vari-
119 

ations, changes in the tilt of the Earth’s axis, and then there’s complex feedbacks with ocean circulations and the carbon cycle. So do 

we—are we at a point where we have complete predictive understanding of the Ice Ages? The answer is no, but that—you know, 

our current understanding relates to Earth-sun geometry, longterm deep circulations in the ocean and the Earth’s carbon cycle. 

All these things are—— 

Mr. WEBSTER. So number one, all of those were natural causes. 

Dr. CURRY. Yes. 

Mr. WEBSTER. Number two, it just proves the point that there is 

a lot we don’t know about what goes on in years whether it be 40 

years or thousands of years or whatever. 

So when I first ran for office, which is many years ago, long before this issue was an issue, there was another issue, and it was 

called the coming Ice Age. There was a big article in one of the 

magazines, I think it was Time magazine, when I was running for 

office. I read everything. I just wanted to know as much as I could 

in case some question came up, so I read and read and read. Well, 

anyway, this article was by the—this was the standard belief of 

most scientists at the time in the late 1970s, and it talked about 

the coming Ice Age. So you kind of wonder, we had some charts up 

there that started in late 1979. I don’t know, maybe those before 

that were the other way, and so the only growth in the temperature was a re-energizing what the temperature used to be before 

it was cooling. 

And so it just seems like there is such a short period of time. 

We’re looking at this data. It’s calculated within, you know, down 

to maybe four-tenths of a degree, and if we look back thousands of 

years, there might be a better pattern to see, and granted, we may 

not have that data but it seems like we’re basing a lot of things 

on current data, not on necessarily what’s happened in the world 

in general, and we’re blaming it on one set of circumstances, which 

may or may not have been the case for other things that occurred 

and in some cases there weren’t any humans. 

Dr. CURRY. Well, if you look at the climate of the 20th century, 

you saw a pretty steep warming trend in the early part of the century up until about 1940, 1945, and this is at a time when there 

was very little human input of carbon dioxide, and then we saw a 

cooling trend from the mid-1940s to the mid-1970s, and this is 

what I guess triggered concerns about the Ice Age. And then there 

was a massive reorganization of ocean circulations in the Pacific in 

the mid-1970s, the so-called, you know, great climate shift, and 

then we saw increasing temperatures following that. And so trying 

to sort out what caused the early warming period and then the 

mid-century cooling period, I’ve argued that we end to understand 

this before we have highly confident attribution arguments about 

the warming since the mid-1970s. So there’s a lot of natural variability, largely associated with the multidecadal and longer ocean 

oscillations that are not well represented in the climate models, 

and this is why I’ve argued for fundamental climate dynamics research to try to better understand this. 

Mr. WEBSTER. So if the scientists of that day just not too long 

ago believed that there was a possibility of a coming Ice Age and 

then all of a sudden it changes, is that—— 
120 

Dr. CURRY. Well, that—— 

Mr. WEBSTER. It seems like some of the data’s being left out. 

Dr. CURRY. Well, that was before we had, you know, climate, you 

know, climate modeling. Global climate modeling was in its infancy, you know, in the 1970s, so we really didn’t have that as a 

tool to help us understand but, you know, we understand a lot 

more now than we did in the 1970s. 

Mr. WEBSTER. But the point is—— 

Chairman SMITH. The gentleman’s time—— 

Mr. WEBSTER. —if there was—— 

Chairman SMITH. The gentleman’s time has expired. 

Mr. WEBSTER. —if the scientists of that day with the amount of 

information that they had at that time believed this for a certainty 

and now today we believe something for a certainty, we don’t know 

what kind of technology is going to be available 40 years from now. 

Dr. CURRY. That’s the unknown unknowns. 

Mr. WEBSTER. So all I can say is, it seems to me like the more 

I hear, the more I believe that there—this is an embezzlement and 

flow, not necessarily a constant among even those if they are the 

majority of scientists, it’s going back and forth, not necessarily 

stagnant. 

Dr. CURRY. There’s definitely oscillations. 

Mr. WEBSTER. I yield back. 

Chairman SMITH. Thank you, Mr. Webster. 

The gentleman from Virginia, Mr. Beyer, is recognized. 

Mr. BEYER. Yeah, thank you, Mr. Chairman, very much. I’d like 

to begin just by welcoming a constituent who is shadowing me 

today, Jairo Medrano, who is a history buff and attending George 

Washington Middle School in Alexandria. Jairo, thank you for 

being with us. 

Thank you very much for being—testifying. I have this great 

sense of a food fight among scientists, and I guess each one of you 

in different ways has talked about what Dr. Curry called was gutter politics. And I apologize for that, and I was trying to think why 

can’t we all just get along, and realized it’s because the stakes are 

so high. You know, if the vast majority of scientists are correct 

about the human impact from global warming, you have 55 million 

people in Bangladesh that will be displaced, or many countries, including the Maldives, that disappear from the planet. 

I was just in India with Congresswoman Esty, and they talked 

about how climate change there already is dramatically changing 

agricultural patterns and their ability to feed 1.3 billion people. Or 

the demonstrated increased from CDC and lung disease and in 

tropical diseases here in the United States. Or on a more trivial 

measure, not for them, the outdoor industries are in a panic about 

what it’s doing to climbing and skiing and hunting and fishing, and 

many, many other things. So it’s—there’s a lot at stake, which is 

why this gets so high. 

I’d like to ask that the—Dr. Christy’s third slide be put up just 

a for moment, and just point out that the average of the 102 climate models is 1 degree centigrade increase over those 36 years, 

and the observations are half a degree. So not wildly different, it’s 

half, but it’s still—looks like a straight line up from 1976 to 2015. 

And then replace it with Exhibit A from Dr. Mann, which is exactly 
121 

half a degree from 1979 to 2015. Those two data sets are very, very 

clear. 

And I ask Dr. Mann, so the 102 isn’t one degree over that 36- 

year period of time, it’s only half a degree centigrade or 1.8 Fahrenheit. And we also look—two other quick data sets. CO2 parts per 

billion in 1979 was 330. They were around 403 in 2016. So we have 

a 30 or 73 parts per billion increase, and it’s now increasing at 

three parts per billion per year and increasing, according to the 

EPA. What does Dr. Christy’s line look like in 2030, 2040, 2050? 

Dr. MANN. Yeah. Well as we see in that comparison, the various 

surface and lower atmosphere temperature data sets all agree pretty well on the warming over the past few decades, and so we can 

get into discussions about what’s happening in the mid and upper 

troposphere, but at the surface, there’s a pretty clear consistency 

among the records, and the records are consistent with the models. 

And that has been demonstrated in numerous publications, and the 

models allow us to project forward so we can feed the models with 

different possible scenarios for future fossil fuel burning. And it 

turns out that given sort of business as usual burning of fossil 

fuels, if we don’t do anything to stem our ongoing burning of fossil 

fuels and the increased elevation of greenhouse gases in the atmosphere, we will probably cross 2 degrees Celsius warming. That’s 

about 3–1/2 Fahrenheit warming of the planet relative to the preindustrial time in a matter of a couple of decades. It’s an important 

number because that amount of warming is what most scientists 

who’ve studies the impacts of climate change will tell you is when 

we truly get into dangerous and potentially irreversible changes in 

climate. 

So we’ll be there in a couple decades if we don’t do something 

about the problem. 

Mr. BEYER. I think that’s my larger point too is that Dr. Christy 

argues that we didn’t get close to the 102 average model, but it’s 

still significantly upward direction. And if—back to my India trip, 

they say when they bring the other 300 million people get electricity, that will be a 40 percent increase in what we expect the 

greenhouse gases to be. 

One more quick—and I only have a minute—but Dr. Mann, when 

you were at University of Virginia, the American Tradition Institute, used the FOIA stuff to try to get all of your emails. And Chris 

Horner and David Schnare were two ATI attorneys who sued UVA. 

David Schnare apparently was doing this on a pro bono basis while 

he was a full-time EPA employee and according to letters from the 

EPA, never did get permission. I’d like to submit those for the 

record, Mr. Chairman, the letters from the EPA. 

Chairman SMITH. Without objection. 

[The information appears in Appendix II] 

Mr. BEYER. One final thought. Dr. Curry, you just said, and I 

quote, ‘‘I’m not out there on the fringes.’’ Would you consider Dr. 

Christy and Dr. Pielke out there on the fringes? 

Dr. CURRY. Absolutely not. 

Mr. BEYER. Who is out there on the fringes, or is there a fringe? 

Dr. CURRY. There are some fringes. People who are questioning 

the fundamental thermodynamics of the, you know, of the greenhouse effect and things like that. There are some fringe things. You 
122 

do see a few papers published in fringe journals. There are some 

people out there on the fringe that I would call out there on the 

fringes. Who knows, you know. Occasionally I read the papers just 

to try to keep an open mind. They always send them to me. But 

I would regard that as out there on the fringes. I don’t regard myself, John Christy, or Roger Pielke as out there on the fringes. I 

think there’s a lot of scientists who share our perspective and who 

agree with us and who are not part of the politically active publically—you know, the Rankin file, the research geeks, who a lot of 

them out there agree with us. I hear from them all the time, especially from people working from—scientists working at government 

agencies who are afraid to speak out. I hear from a lot of them. 

Chairman SMITH. Gentleman’s time is expired. 

Mr. BEYER. Chair, I yield back. 

Chairman SMITH. Thank you, Mr. Beyer. 

The gentleman from Illinois, Mr. LaHood, is recognized. 

Mr. LAHOOD. Thank you, Mr. Chairman, and I want to thank the 

witnesses for your testimony here today. I appreciate it. 

Dr. Pielke, I wanted to start with you, and I was glad to hear 

your history of serving on this committee as a staffer and for 

George Brown. He was a Democrat, correct, that served here? 

Dr. PIELKE. That’s right. 

Mr. LAHOOD. I wanted to ask you, Dr. Pielke, have you ever felt 

attacked by a colleague because of your position on climate change 

science? 

Dr. PIELKE. Yes. It just happened. I mean, I was just called 

fringe or suggested to be fringe, and I’ve come here representing 

the science that’s in the IPCC report. It’s almost a bizarro sort of 

reaction to be called fringe when you’re representing mainstream 

science. 

Mr. LAHOOD. And let me ask you, has Dr. Mann ever directed 

negative comments to you in your work? 

Dr. PIELKE. Yeah, I don’t—I’m not interested in the food fight 

with Dr. Mann. I hope everyone takes a look at the YouTube of this 

testimony and sees Dr. Mann speaking and listens carefully, but 

he’s a respected scientist. He’s the leader of the climate change 

movement in the United States, and I think everyone deserves to 

see his behavior at this hearing. 

Mr. LAHOOD. And as I understand it in the past—and this is 

public record, Dr. Mann has referred to you as ‘‘a carnival barker’’ 

and also ‘‘a contrarian pundit.’’ Are you familiar with that? 

Dr. PIELKE. Yeah. I can’t keep up with all of Dr. Mann’s epithets. 

Mr. LAHOOD. And Dr. Curry, to you, have you ever felt attacked 

by a colleague because of your position on climate change science? 

Dr. CURRY. The only one who’s really attacked me publicly and 

vociferously is Michael Mann, and you heard, you know, some of 

that today, including being called a denier in his Congressional testimony. 

Most scientists are very respectful of my perspectives and want 

to engage me in debate. 

Mr. LAHOOD. And Dr. Christy, same question for you in terms 

of being attacked by a colleague because of your position on climate 

change science? 
123 

Dr. CHRISTY. You know, I try to forget all that, and so I’d rather 

not comment anymore. It’s just something that shouldn’t happen. 

I’m sorry it does. 

Mr. LAHOOD. Got you. Well thank you for that. 

And I guess as I’ve listened to the testimony here today, and I 

guess, Dr. Mann, I would ask you, as I understand it, you are involved currently with a defamation lawsuit about comments that 

were made about you that is currently pending in the DC. circuit, 

is that correct? 

Dr. MANN. I’m not going to speak about that here. It’s not appropriate to do so. 

Mr. LAHOOD. And I guess what I would question—I’ve read that 

defamation suit and I’m familiar with it, and I’m really perplexed 

in trying to figure out the rationale and the reasoning for engaging 

in those types of statements that relate to direct threats and bullying. And you mentioned in your opening statement about staying 

away from that. And yet, we have a suit that’s been filed based on 

those exact same things. And if the real goal is to get away from 

harassing and silencing critics, that does not seem to be the type 

of language you’d want to engage in, and there’s a real disconnect 

between a defamation suit that does the exact same thing, but 

you’re engaged in that in this public forum. Do you want to comment on that? 

Dr. MANN. So I’m not going to talk about the suit, but I do want 

to clarify that there are a number of statements that have been attributed to me that are not correct. I don’t believe I called anybody 

here a denier, and yet that’s been stated over and over again. So 

I’ve been misrepresented quite a bit today by several people—— 

Dr. CURRY. It’s in your written testimony. Go read it again. 

Dr. MANN. There—when I talked in the written statement, I described scientists who either deny the science or who reject its impacts, something to that effect. I did not call you a climate change 

denier, and so that’s just a misstatement. It’s been repeated here. 

But let me state that there’s a difference between disagreeing 

with people, which is not only appropriate but critical in science, 

to have honest and frank discussions of uncertainty to disagree, to 

call out those statements that you don’t believe to be supportable. 

That is completely appropriate. That’s very different, for example, 

from an accusation of misconduct or fraud. Those are two completely different things, and it’s unfortunate that in your question 

you are conflating those two groups of things. 

Mr. LAHOOD. Well, that’s your opinion, Dr. Mann, but are you 

denying that as it relates to Dr. Pielke’s work on client—climate 

change science that you didn’t call him a carnival barker or a 

contrarian pundit? 

Dr. MANN. You would have t provide me the context. I don’t remember everything I’ve ever said or done. But what I can tell you 

is that Dr. Pielke has made the following statement. This is a 

quote. 

Mr. LAHOOD. Well let me—— 

Dr. MANN. In the Wall Street Journal, he said ‘‘There is scamp 

evidence to indicate that hurricanes, floods, tornadoes, or drought 

have become more frequent or intense in the U.S. or globally.’’ That 

is simply not true. The best available science is now attributing in-
124 

dividual droughts and floods at a fairly high level of confidence to 

climate change. So do I challenge him publicly when he says things 

like that? Of course I do. Is that appropriate? Of course it is. 

Mr. LAHOOD. So are—again, are you denying—let me ask you 

this. Is it fair to say you could have said that and you don’t remember that here today? 

Dr. MANN. I don’t remember everything that I’ve ever said, and 

you would have to provide me the context. I’m not sure that your 

characterization is correct. You would have to show me the context. 

You haven’t done that. 

Mr. LAHOOD. I would be happy to show you that. 

I guess my point is you seem overly sensitive to criticism as it 

relates to the defamation suit that engages in the same activity 

that you’re engaged here today with these three witnesses, and I 

think there’s some hypocrisy in that. 

Thank you. 

Chairman SMITH. Thank you, Mr. LaHood, and without objection, 

I now put into the record, if it’s not already a part of the record, 

page 6 of Dr. Mann’s written testimony today where, Dr. Curry, he 

says ‘‘Climate science denier Judith Curry.’’ 

[The information appears in Appendix II] 

Chairman SMITH. I assume that is you he is wrongfully referring 

to. 

Dr. MANN. Climate science. It wasn’t climate change. That’s different, but—— 

Chairman SMITH. Climate science denier. 

Dr. CURRY. Climate science denier Judith Curry. 

Chairman SMITH. I think that—— 

Dr. MANN. And I’ve described the science that she’s denying. 

Chairman SMITH. That clearly contradicts what Dr. Mann so 

well—— 

Dr. MANN. I’ve described the science that she’s denying. 

Chairman SMITH. The gentleman from Illinois, Mr. Foster, is recognized. 

Mr. FOSTER. Well thank you. As a Ph.D. physicist, I would just— 

very interested in how this is sort of—a very strange mixture of 

science and not. 

And so maybe I’d like to try to understand what the range of 

agreement is here. Is there anyone on the panel here that believes, 

for example, on the policy side that the cutbacks in climate science, 

space-based measurements of things like temperature ice sheet 

thickness and so on at NOAA, NASA, EPA and the other places of 

the magnitude contemplated in the skinny budget of the Trump 

Administration are, in fact, a good idea? Is there anyone who believes that those cutbacks are a good idea? 

Dr. CHRISTY. Well, you know, as a scientist, we live on observations and data, and that’s how we learn and discover things that 

will help us. So I’m all for—— 

Mr. FOSTER. So there—— 

Dr. CHRISTY. —the observing systems being made—— 

Mr. FOSTER. Well-funded and so there is a consensus actually 

that that’s not a good idea. 

Let’s see. Under the physics point of view, if we go to the other 

end, Dr. Curry, you indicate that your criteria for what represented 
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fringe were just rejection of fundamental thermodynamics and so 

on. Does everyone on this panel agree, for example, that you know, 

the temperature of the Earth is set in general terms by radiative 

balance, and that the infrared absorption spectra of carbon dioxide 

is a very relevant driving term, and that the uncertainty really is 

in the other positive and negative feedback terms that may or may 

not be present, changes in the convection, things—many of which 

simply redistribute where the excess heat goes when you put carbon dioxide in the atmosphere. The other ones, you know, potentially increase or decrease the albido of the Earth, things like that, 

where there is—you know, you can imagine mechanisms that either make things better or worse. For example, you know, if we 

melt the methane release that could come from Siberia, if we melt 

all of the swamps in Siberia, basically. There are very possibly a 

very strong positive as well as negative feedback loops. Is that sort 

of the range of disagreement that we’re seeing here? Anyone feel 

themselves outside of that? 

And so that—and is there anyone that feels that that range of 

uncertainty makes it likely that this is never going to be a problem 

if we continue business as usual? So you all think—would agree 

that it’s more likely than not that this will be a big problem? 

Dr. CURRY. I would say that we don’t know. 

Mr. FOSTER. No, do you think it is more likely than not that this 

would be a big problem? 

Dr. CURRY. I would say as likely as not. 

Mr. FOSTER. All right. Dr. Mann, do you—— 

Dr. MANN. I just want to say that’s what I’m talking about. I 

didn’t call Judith Curry a climate change denier here today. There 

is a statement in the written statement that she’s a science—climate science denier, and this is precisely what I’m talking about. 

She has argued that we might be responsible for less than 50 percent of the warming that we have seen. The IPCC has assessed 

that. They’ve actually estimated the likelihood that that could be 

true. It is one in 10,000. One in 10,000 is the likelihood of something that she claims to be true. That is a rejection of basic accepted science. 

Mr. FOSTER. Based on climate—— 

Dr. MANN. That is a rejection of science. 

Dr. CURRY. Based on climate models—— 

Dr. MANN. That’s a rejection of science. 

Dr. CURRY. —I have argued that the climate models are not fit 

for that purpose. 

Dr. MANN. It’s a rejection of accepted science. 

Dr. CURRY. No, it’s a rejection of a manufactured consensus. 

That’s what I rejected. 

Dr. MANN. Well just one last statement. 

Mr. FOSTER. If we could separate from temperatures. The question of ocean acidification, is there an agreement that as you raise 

CO2 levels in the atmosphere that this will lead to ocean acidification, or is that also sort of thought of as a fringe point of view? So 

that one, there is agreement on, because that has very severe environmental consequences, obviously, that are not—it’s interesting 

that they’re not really under debate. 
126 

Dr. CURRY. The environmental consequences—our understanding 

of the ecological impacts of ocean acidification is in its infancy, and 

how this relates to ecosystems. I mean, we don’t know very much 

about how slow rates, highly variable ocean acidification impacts 

ecosystems. It’s something under investigation. 

Mr. FOSTER. It could be either better or worse than our current 

best estimate? 

Dr. CURRY. Yes. 

Mr. FOSTER. Okay. The other sort of general question is what is 

the proper response to fringe? How do you set what is defined as 

a fringe opinion? You know, in physics conferences, there’s always 

a poster session where you have people that say Einstein was 

wrong, you know, and they are very sweet people with a variety 

of science credentials. And it’s always a delicate thing trying to understand. You know, I’ve often gone and had conversation with people, listen to their very interesting theories, and yet they’re not 

given plenary talks at this thing. And so how do you—what is the 

right way to handle that? How many standard deviations do you 

have to be out of the mainstream before it is acceptable to do that? 

Yeah, Dr. Curry, how would you—— 

Dr. CURRY. Well, the point is is you ignore these things if you 

don’t find them interesting or convincing. Okay, you ignore it. And 

most of these things don’t have any particular consequence to our 

engineering, our technologies, or to the most consequential, you 

know, science issues of the day. So you just ignore it. There’s no 

reason to squash it, okay? You just—if somebody catches somebody’s attention and you look at it and you consider it, maybe it 

tweaked something in your brain about oh, you know, there is 

some sort of line suggested by this that maybe we should explore, 

or you ignore it. There’s no reason to squash it or even particularly 

define it. 

Chairman SMITH. The gentleman’s time—— 

Dr. CURRY. Just don’t pay attention to it. 

Chairman SMITH. The gentleman’s time has expired. Thank you, 

Mr. Foster. 

The gentleman from Georgia, Mr. Loudermilk, is recognized. 

Mr. LOUDERMILK. Thank you, Mr. Chairman, and thank all the 

witnesses for being here. This is—there for a while, I thought you 

guys were in the Republican conference debating Obamacare repeal. 

Dr. Curry, being from Georgia, I appreciate you being here again. 

If I recall last year when you were here, in part of your testimony 

you—let me just ask you the question this way. Do you believe that 

the climate is changing? 

Dr. CURRY. Absolutely. Climate is always changing. 

Mr. LOUDERMILK. Do you believe that human activity could be a 

cause? 

Dr. CURRY. Oh, it is a cause. It does contribute. 

Mr. LOUDERMILK. Okay. So you actually do believe that it 

does—— 

Dr. CURRY. Oh yeah, sure. The question is whether it’s the dominant cause. 

Mr. LOUDERMILK. Right. 
127 

Dr. CURRY. Okay, and even the IPCC says more than half, okay? 

And that’s from 51 percent to 99 percent. That’s a big—— 

Mr. LOUDERMILK. So you don’t deny that human activity is—— 

Dr. CURRY. No, absolutely not. 

Mr. LOUDERMILK. Okay. 

Dr. CURRY. I just don’t know how much is human versus how 

much is natural, and I think there’s a great deal of uncertainty, 

and it’s very difficult to entangle it. 

Mr. LOUDERMILK. Is that uncertainty possibly because we don’t 

really fully understand what causes this climate machine? 

Dr. CURRY. Absolutely. Our understanding of climate dynamics 

on decades to century to millennial time scale is far from complete. 

Mr. LOUDERMILK. Okay. Dr. Christy, same question. Do you believe that there’s change in the climate? 

Dr. CHRISTY. Yes. 

Mr. LOUDERMILK. Okay, that—do you believe that it’s possible 

that human activity could contribute to it? 

Dr. CHRISTY. I actually have a couple papers showing how humans have affected the temperature, mainly through the surface 

thermometers, urbanization—— 

Mr. LOUDERMILK. It doesn’t sound like either one of you are 

deniers of—— 

Dr. CHRISTY. And that carbon dioxide is a greenhouse gas. It 

can’t not absorb infrared energy. 

Mr. LOUDERMILK. Okay. Dr. Mann, obviously you think, you 

know, climate is changing. Do you think that it’s possible that 

human activity is not the dominant factor? 

Dr. MANN. So I already spoke to that. Judith Curry is on record, 

and we just heard it—— 

Mr. LOUDERMILK. No, I’m asking you. What do you think? 

Dr. MANN. Well saying less than 50 percent. It might be less 

than 50 percent. The IPCC actually has a very nice—— 

Mr. LOUDERMILK. I’m asking what do you think? 

Dr. MANN. I believe what the IPCC has said about this, that 

the—less than—the proposition that we are responsible for less 

than 50 percent of the warming can be dismissed as a 1 in 10,000 

proposition—— 

Mr. LOUDERMILK. Okay. Well what do you think, or are you 

just—— 

Dr. MANN. I accept the consensus. 

Mr. LOUDERMILK. I don’t want you to parrot what IPCC says. 

Dr. MANN. I accept the world’s scientists opinion. I accept the 

consensus. 

Mr. LOUDERMILK. So in your opinion, there could not be no 

chance that human activity does not—is not the major contributor? 

Dr. MANN. Well it’s a double negative, but there is a possibility 

we’ll wake up tomorrow and gravity no longer exists. Those are 

possibilities, but extremely unlikely. 

Mr. LOUDERMILK. Okay. It doesn’t sound like anybody or any 

amount of data could convince you otherwise at this point. 

Dr. MANN. I go with the physics. 

Mr. LOUDERMILK. Okay, so—— 

Dr. MANN. You can go with opinions if you want. I go with physics. 
128 

Mr. LOUDERMILK. We could say you’re a denier of natural 

change. 

Dr. MANN. No, I actually—my career in large part was built on 

my studies of natural variability. The Atlantic multi-decadal oscillation that Judith Curry loves to talk about, that was coined by me. 

My early studies—— 

Mr. LOUDERMILK. Let me ask you this question. 

Dr. MANN. —established the importance of internal oscillations 

in the climate. 

Mr. LOUDERMILK. I’m not trying to be—— 

Dr. MANN. I just want to inform—— 

Mr. LOUDERMILK. —confrontative—— 

Dr. MANN. No, I just want to make sure you know that. 

Mr. LOUDERMILK. Okay. Do you believe that we truly understand 

what creates the weather? What is—do we understand the climate 

machine? 

Dr. MANN. So the weather is caused by what we call baroclinic 

instability. I’d be happy to talk to you for hours offline about—— 

Mr. LOUDERMILK. But I mean, do you disagree with Dr. Curry 

that—you sound like we have grasps on science that we know what 

creates this weather patterns and we know what creates—— 

Dr. MANN. I’m not sure how to—— 

Mr. LOUDERMILK. —the weather machine? 

Dr. MANN. —parse that question. We understand at a great level 

of detail the workings of the atmosphere, the workings of the ocean 

and the ice sheets and the way they interact. Thousands of scientists have been studying these things for decades. We understand—— 

Mr. LOUDERMILK. Let me ask you this. 

Dr. MANN. —the science of climate as well as the science of just 

about any other field. 

Mr. LOUDERMILK. I don’t want to filibuster. I’m running out of 

time here. 

So why do we ban—— 

Dr. CHRISTY. I would just like to add that when we understand 

other fields of science, we can predict the behavior. 

Mr. LOUDERMILK. Right. 

Dr. CHRISTY. I have demonstrated we cannot predict—— 

Mr. LOUDERMILK. Okay. The National Academy of Science agrees 

with you, at least they did in the 1970s, when they said we do not 

have a good quantitative understanding of our climate machine 

and what determines its course. Without the fundamental understanding, it does not seem possible to predict the climate. 

Why did we have a ban on sulfuric dioxide in the 1970s, Dr. 

Mann? 

Dr. MANN. Yeah, so you’re right that, you know, more than 40 

years ago we didn’t have nearly the understanding we have today. 

In 1975, the National Academy of Science actually said they didn’t 

know what was going to win out. They didn’t say that global warming isn’t caused by increase in greenhouse gases. What they were 

saying in that report was that we don’t know what’s going to win 

out, the warming effect of increasing greenhouse gases, or the cooling effect of these particulates that we are producing. 
129 

Mr. LOUDERMILK. So there were differences among the scientific 

community because as was mentioned earlier, there was a cooling 

trend? 

Dr. MANN. Yeah, we understand very well where that came from. 

The state—— 

Mr. LOUDERMILK. The policy result was the reaction of lawmakers and banning sulfuric dioxide in response to the cooling 

trend that a group of scientists said was definitely causing the cooling of the Earth. And I just refer back to Dr. Curry. 

Dr. MANN. Can I answer? 

Mr. LOUDERMILK. Dr. Curry, does this show evidence of—that we 

really don’t have a full grasp of what causes the climate change? 

Dr. CURRY. There are—— 

Mr. LOUDERMILK. And I think what your thing is, we may overreact in public policy that could actually have a diminishing factor 

in—— 

Chairman SMITH. The gentleman’s time has expired. Do you 

want to answer very quickly, Dr. Curry? 

Dr. CURRY. That’s okay. 

Chairman SMITH. Okay. I’m sorry. The gentleman from Florida, 

Mr. Webster, has a unanimous consent request. 

Mr. WEBSTER. Yes, Mr. Chair. I have a report here entitled 

‘‘What Triggers Ice Ages’’ and I would like to have that entered 

into the record. 

Chairman SMITH. Without objection. 

[The information appears in Appendix II] 

Chairman SMITH. And the gentlewoman from Texas has a unanimous consent request, and she is recognized for that purpose. 

Ms. JOHNSON. Thank you, Mr. Chairman. I’d like to enter into 

the record an article published in Scientific American that debunks 

the claim that there was a pause in global warming, and I’d also 

like to enter into the record a blog post by the Union of Concerned 

Scientists that breaks down Dr. Lindzen’s letter to President 

Trump. 

Chairman SMITH. Okay, without objection. 

[The information appears in Appendix II] 

Chairman SMITH. And the gentlewoman from Connecticut, Ms. 

Esty, is recognized for her questions. 

Ms. ESTY. Thank you, Mr. Chairman. 

I’d like to return again to the question a little bit about—the 

topic here is on scientific process. Do we have agreement that scientific process is about proposing hypotheses, testing them, revising, and continuing to do that in the ultimate goal of trying to arrive at some sort of truth? That that’s the objective, never attained 

in its entirety, but that’s the objective? If that—if there’s agreement? I’m getting nods that that is, in layperson’s terms, the understanding of scientific process. 

What do people think we should be funding research to do in the 

area of climate, recognizing that there are bands within which humans will not survive on the Earth if it goes outside those bands? 

Does anybody think that cutting climate funding for research 

should happen now, given the robust disagreement on this panel? 

Because there are proposals on the table that—right now to cut 

planetary science funding, to stop NOAA from looking at it, to stop 
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NASA from looking at this, because of a disagreement about how 

to interpret and prioritize those results. Do I—Dr. Curry, do you 

believe we should be funding more science or less scientific research in this field? 

Dr. CURRY. Different science. 

Ms. ESTY. Okay, but the—let’s be clear that proposals in the socalled skinny budget from the President would be for cutting that 

research? 

Dr. CURRY. Yeah. It’s a matter of priority. Spending more money 

on climate model taxonomy isn’t going to get us anywhere. Spending more money on observing systems will. 

Ms. ESTY. Which would be NASA, for example. 

Dr. CURRY. Yeah, and spending more money on fundamental understanding, theory regarding climate dynamics on a range of time 

scales, that would pay dividends. 

Ms. ESTY. And those are some—precisely the ones that are being 

cut in the proposals on the table right now, so I’m glad to see 

there’s agreement, that I think you agree with those of us on this 

panel that would like to see that funding continue to try to determine this. 

Our job will be to take the science and to try to make public policy decisions. Clearly, there is not total certainty here. However, if 

the risk is sufficiently great, we take steps even without certainty. 

I’m part of a resiliency caucus that is looking at things we can do 

to design safer buildings so we survive storms better, whether 

they’re tornadoes or hurricanes. We take steps—most of us carry 

insurance on our homes, even though we’ve probably never lived in 

a home that’s burned to the ground. 

So in addition to whatever you discover and whatever the disputes may be about science, there’s significant research showing 

that humans have some impact, right, and we’re not talking trivial 

either. I don’t think anyone at this table has talked trivial impact. 

So I believe we should be continuing to fund research, but make 

no mistake, even if it’s—whether it’s 20 percent, 30 percent, 50 percent, the consequences to human beings now and in the future are 

significant. 

I want to note that I was at a conference 15 years ago, RAND 

Corporation conference, talking about how the next wars would be 

over water. This is a national security issue. So even if, for example, overall water patterns, the amount of rainfall is the same, 

where it flows, when it flows, how fast it comes down has major 

implications for crops, major implications for the stability of other 

countries. So I think these are the kinds of issues that we should 

be funding, because it’s not simply a question of who gets the research dollars. The consequences for this country are very grave for 

our citizens. 

So I would ask you as much as possible to join us in funding robust research and then let those of us in elected positions make decisions in that band of uncertainty. Because I can tell you right 

now that constituents in my district in Connecticut are deeply concerned at what they see as an over-politicization of science right 

now, and I’m afraid we saw that in this room today, which I deeply 

regret and I hope we can get agreement to fund robust, open-source 

research that allows decision making by this body in light of that 
131 

uncertainty. So I will side, however, with Dr. Mann that at some 

point, we have to go with consensus for the time being as we continue research. And I would say that is the prudent course is to go 

with consensus, while continuing research. That doesn’t mean stopping research. That means continuing research, and yet we cannot 

wait for final ultimate truth to make decisions. 

And with that, I yield back my 12 seconds. 

Chairman SMITH. Thank you, Ms. Esty. 

Thank you all for your testimony today. This has obviously been 

enlightening, sometimes a little contentious, but nevertheless, informative to all of us who are up here. I appreciate your attendance 

and we stand adjourned. 

[Whereupon, at 12:29 p.m., the Committee was adjourned.] 

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Appendix I 

ANSWERS TO POST-HEARING QUESTIONS
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ANSWERS TO POST-HEARING QUESTIONS

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Appendix II 

ADDITIONAL MATERIAL FOR THE RECORD
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DOCUMENTS SUBMITTED BY RANKING MEMBER

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