# Presentation: 907676

## Status of CCSP Synthesis and Assessment Product 3.1

**Anjuli Bamzai**
**Program Manager**
**Climate Change Prediction Program**
**U.S. Department of Energy**
**Nov 14-16 CCSP Workshop **
**     *****Climate Science in Support of  Decision Making***
***     ******Session 2: Climate Variability and Change***

## CCSP S&A  Product 3.1

**Title:**** *****Climate models and their uses and limitations, including climate sensitivity, feedbacks, and uncertainty analysis***
**Participating Agencies:***** ******DOE, NASA, NOAA, NSF***

**Notes:**
Computer simulation models of the coupled atmosphere–land surface–ocean–sea ice system are essential scientific tools for understanding and predicting natural and human-caused changes in the Earth’s climate. Coupled climate system models (called “climate models” herein) provide scientists a way to integrate their knowledge about elements of the climate system in a mathematical framework so that they can conduct computer simulations of the system. 
The topics addressed by this CCSP product are the strengths and limitations of climate models at different spatial and temporal scales. Its purpose is to provide this information on the strengths and limitations of the results from climate models, in ways that will allow the potential user of the information to evaluate how best it may be applied or not applied (CCSP Strategic Plan, page 19). This CCSP product will focus on natural and human-caused factors influencing climate variability and change during the period 1870-2000, and will seek to characterize all sources of uncertainties in climate models and their implications on the uses and limitations of climate model results for future climate change. Discussion of specific future projections of climate will be limited in this product, because Synthesis and Assessment Product 3.2 will deal with climate projections. This product will focus on the models and their sensitivity, feedbacks, strengths and limitations, rather than future projections using these climate models.

## Timeline of Climate Model Development

## Contents of S&A 3.1 Draft Prospectus

**      ****1.**** Overview: Description of topic, audience, intended use, questions to be**
**          ****addressed  ****2.**** ****Contact info for responsible individuals at lead and supporting agencies**** ****3.**** ****Lead authors*  **
**4.**** ****Proposed Plans for Drafting, Reviewing, Producing and Disseminating **
**          ****the Product ****5.**** Proposed Approach for Evaluation and Communication of Uncertainty **
**          ****and Confidence Levels of Climate Model Output. E.g. of volcanic forcing.****6.**** Relation to Other National and International Assessment Processes ****7.**** ****Timeline****	***** Qualifications in Appendix A**

**Notes:**
The intended audiences of this CCSP product are decision makers and researchers who use climate model output as input to studies or analyses in their respective, non-climatic disciplines (e.g., ecosystem science, hydrology and water resources, economics, human health, and agriculture/forestry). In order to facilitate application and decision making using information generated by climate models, an evaluation and assessment of limitations of state-of-the-science climate models is essential. This product is directed towards this goal. Users often need climate information at regional scales and Question 5 (see below) addresses issues related to dynamical downscaling of climate projections. 
The intended use of this CCSP product is to provide information to those who use climate model outputs about the strengths and limitations associated with using models to project the potential effects of human activities on climate and sea-level rise. A discussion of appropriate and inappropriate uses of model output will be included. The product will address scientific issues on a comprehensive, objective, open, and transparent basis. While based on the peer-reviewed scientific literature, it will be written to be accessible and useful to the well-informed general reader and decision maker. 

## Contents of S&A  3.1Draft Prospectus (contd.)

**Overview:**** ****Description of topic, audience, intended use, questions to be addressed. **
**           **
**	****Focus is on natural and human-caused factors influencing climate variability and change, ~1870 to 2000;  characterize sources of uncertainties in comprehensive coupled climate models. Discussion on future projections of climate will be limited.**
** **
**       ****Audience is primarily climate model researchers, modelers from impacts community including those who use climate model output as input to studies/analyses in their disciplines.**
**          **

**Notes:**
The intended audiences of this CCSP product are decision makers and researchers who use climate model output as input to studies or analyses in their respective, non-climatic disciplines (e.g., ecosystem science, hydrology and water resources, economics, human health, and agriculture and forestry). In order to facilitate application and decision-making using climate model information, an evaluation and assessment of the state of science of climate models is essential. This product is directed towards this goal. Users often need climate information at regional scales and Question 5 of the prospectus addresses issues related to dynamical downscaling of climate projections.  The intended use of this CCSP product is to provide information to those who use climate model outputs about the current strengths and limitations associated with using models to project the potential effects of human activities on climate and sea-level rise. The product will address scientific issues on a comprehensive, objective, open, and transparent basis. While based on the peer-reviewed literature, it will be written to be accessible and useful to the well-informed general reader and decision maker. 
In preparing this draft prospectus, careful consideration has been given to the feedback received from stakeholders at the December 2002 Climate Change Science Program Planning Workshop for Scientists and Stakeholders. In addition, other recent developments have been reflected. For example, results from a workshop focusing on tropical biases that degrade projections have also guided the selection of topics to be covered in the product. The authors also intend to further shape the product with the input provided by scientists, decision makers, and general readers during the prospectus public comment period.
5.	Drafting Process (Including Materials to be Used in Preparing the Product)
The lead authors—organized by the coordinating lead author—will meet in person, through e-mail exchanges, and via teleconferences (as they see fit) to draft answers to the six key questions addressed in the product. They will also prepare an introductory section to describe the topic, the audience, and the intended use of this product. The coordinating lead author may assign primary responsibility for drafting the text associated with each question to a specific author. The lead authors will incorporate material from any contributing authors in the draft product as they see fit.
After the product is drafted, the lead authors (or coordinating lead author and the authors responsible for each of the six questions) will write a non-technical summary.
Lead and contributing authors will base all their writing on published, peer-reviewed scientific literature. Lead authors will consider the full range of relevant peer-reviewed information. The product and its non-technical summary will identify disparate views, where appropriate 

## Contents of S&A  3.1 Draft Prospectus (contd.)

***Specific questions to be addressed:***
***Q1: What are the major components and processes of the climate system that are included in present state-of-the-science climate models, and how do climate models represent these aspects of the climate system? ***
***Q2: How are changes in the Earth’s energy balance incorporated into climate ******	******models? How sensitive is the Earth’s  (modeled) climate to changes in the factors that affect the energy balance?***

**Notes:**
Specific questions to be addressed by this CCSP product are:
1)	What are the major components and processes of the climate system that are included in present state-of-the-science climate models, and how do climate models represent these aspects of the climate system? This section will include descriptions of crucial processes such as tropical convection and major feedbacks in the climate system (e.g., clouds, atmospheric water vapor, surface albedo, and soil moisture). This section will evaluate the ability of current generation of models to simulate key processes, and identify gaps in understanding.  It will also include brief discussion of crucial processes that are likely to play an important role in climate that not yet incorporated in the models. 
2)	How are changes in the Earth’s energy balance incorporated into climate models? How sensitive is the Earth’s (modeled) climate to changes in the factors that affect the energy balance? This section will explain current approaches for incorporating changes in radiative forcing from both natural and human factors since the pre-industrial era. These include changes resulting from greenhouse gas and trace constituent emissions into the atmosphere, volcanic eruptions, and variations in the sun’s intensity. This section will present a brief overview of the response of the global climate system, as derived from climate model results, for the various forcings (e.g., solar, volcanic, aerosols, anthropogenically derived greenhouse gases). The relative contributions of natural variability and human-caused factors for the period under consideration will be examined. (Note: Synthesis and Assessment Product 2.3 will focus on aerosols and their relationships to climate change, so aerosols will be treated only briefly in this product.)
3)	How uncertain are climate model results? In what ways has uncertainty in model-based simulation and prediction both increased and decreased over time with increased knowledge about the climate system? This section will provide a discussion of the major sources of uncertainty in climate model results , as estimated through structured intercomparisons to observations, including the identification of the major sources of uncertainty in model assumptions and the characterization of radiative forcing. A description (or acknowledgement) of how increased knowledge can lead to greater uncertainty by increasing the number and complexity of processes included in climate models will be included.
4)	How well do climate models simulate natural variability and how does variability change over time? The ability of climate models to simulate the climatology and interannual variability is crucial for their use by the impacts and applications community. This section will describe efforts to evaluate these aspects of model performance. This section will also discuss the ability of climate models to simulate known patterns of natural variability, such as the Madden-Julian Oscillation, the El Niño Southern Oscillation, the North Atlantic Oscillation, and the Pacific Decadal Oscillation. We will include a section on how these modes of variability have changed over time.
5)	How well do climate models simulate regional climate variability and change? This section will discuss how changes in certain regions (e.g., the North Atlantic or Tropical Pacific) can influence global climate change. It will also discuss limitations of “downscaling” methodologies, including regional climate modeling, used to obtain regional information from global simulations.
6)	What are the tradeoffs to be made in further climate model development (e.g., between increasing spatial/temporal resolution and representing additional physical/biological processes)? This section will consider the opportunities and constraints on future model development (e.g., additional computational cycles and lack of process knowledge). It will outline prospects for improvements potentially important to policymaking and decision-making. 
Answers to each of these questions will include descriptions of the spatial and temporal aspects of climate models as they relate to each of the questions—for example, how uncertainty at the mean annual global scale (e.g., mean annual global surface temperature) is related to uncertainty at a continental or sub-continental scale. Three variables—surface temperature, precipitation, and sea level—will be emphasized in this CCSP product because they are often considered by decision makers and non-climate scientists concerned with climate variability and change.
This CCSP product will be an “interpreted product” as that term is used in the information quality guidelines issued by the Department of Commerce and NOAA. Namely, an interpreted product is one that has “... been developed through interpretation of original data and synthesized products. In many cases, this information incorporates additional contextual and/or normative data, standards, or information that puts original data and synthesized products into larger spatial, temporal, or issue contexts. This information is subject to scientific interpretation, evaluation, and judgment. Examples of interpreted products include journal articles, scientific papers, technical reports, and production of and contributions to integrated assessments.”

## Contents of S&A 3.1Draft Prospectus (contd.) 

***Q3: How uncertain are climate model results? In what ways has uncertainty in model-based simulation and prediction both increased and decreased over time with increased knowledge about the climate system?  (an example of aerosol-climate to follow)***
***Q4: How well do climate models simulate global climate variability over the historical period? ***
***Q5: How well do climate models simulate regional climate variability and change?****** ***
***Q6: What are the tradeoffs to be made in further climate model development (e.g., between increasing spatial/temporal resolution and representing additional physical/biological processes)? ***

## Agency Contact Info:
DOE Anjuli Bamzai Anjuli.Bamzai@science.doe.gov 
NASA  Don Anderson Donald.Anderson-1@nasa.gov 
NOAA Ants Leetmaa Ants.Leetmaa@noaa.gov
NSF Jay Fein  jfein@nsf.gov

3. Lead author Info: 
  Dr. David Bader/PCMDI LLNL (coordinating lead author)
  Dr. Curtis Covey/PCMDI LLNL
  Dr. Bill Gutowski/Iowa State
  Dr. Isaac Held/NOAA GFDL
  Dr. Jeffrey Kiehl/NCAR
  Dr. Ken Kunkel/Ill Water Survey, UIUC
  Dr. David Rind/NASA GISS

**DOE Anjuli Bamzai **_[Anjuli.Bamzai@science.doe.gov](mailto:Anjuli.Bamzai@science.doe.gov)__ _
**NASA  Don Anderson **_[Donald.Anderson-1@nasa.gov](mailto:Donald.Anderson-1@nasa.gov)__ _
**NOAA Ants Leetmaa **_[Ants.Leetmaa@noaa.gov](mailto:Ants.Leetmaa@noaa.gov)_
**NSF Jay Fein  **_[jfein@nsf.gov](mailto:jfein@nsf.gov)_
**3. Lead author Info:**** **
**  ****Dr. David Bader/PCMDI LLNL (coordinating lead author)**
**  ****Dr. Curtis Covey/PCMDI LLNL**
**  ****Dr. Bill Gutowski/Iowa State**
**  ****Dr. Isaac Held/NOAA GFDL**
**  ****Dr. Jeffrey Kiehl/NCAR**
**  ****Dr. Ken Kunkel/Ill Water Survey, UIUC**
**  ****Dr. David Rind/NASA GISS**

**Contents of S&A  3.1 *****Draft *****Prospectus (*****contd*****.)**

## 4. Review Plan
 Currently the draft prospectus is awaiting concurrence from the CCSP Principals
    Public review of draft prospectus complete
 Conforming to the Data Quality Act of Jan 2005, the Peer Review Plan is up at http://www.science.doe.gov/informationtechnologymgmt/html/hisa.htm   
 FACA Charter pending approval at DOE
 FACA committee pending approval at
     DOE

-  **Currently the draft prospectus is awaiting concurrence from the CCSP Principals**
**    ****Public review of draft prospectus complete**
** ****Conforming to the Data Quality Act of Jan 2005, the Peer Review Plan is up at **_[http://www.science.doe.gov/informationtechnologymgmt/html/hisa.htm](http://www.science.doe.gov/informationtechnologymgmt/html/hisa.htm)__   _
** ****FACA Charter pending approval at DOE**
** ****FACA committee pending approval at**
**     ****DOE**

**Contents of S&A  3.1 *****Draft *****Prospectus (*****contd*****.)**

## 5.    Proposed Approach for Evaluation and Communication of Uncertainty and Confidence Levels of Climate Model Output
           The central theme of this CCSP Product is uncertainty and confidence levels of climate model output with respect to climate change caused by natural forcing and human activities during the period 1870-2000 

           Sources of Key Uncertainties in Climate Change Assessments
 Future emissions  
 Climate sensitivity*
 Heat flux into the ocean
 Radiative forcing due to aerosols and clouds  E.g. to follow.
 Carbon Cycle/climate feedbacks
 Changes in ocean circulation

         * The climate sensitivity determines how much the climate will change for a given change in atmospheric composition. It is usually expressed as the eventual  global-mean warming for a doubling of the CO2 concentration, and lies in the range of 1.5-4.5o C with 90% confidence

**           ****The central theme of this CCSP Product is uncertainty and confidence levels of climate model output with respect to climate change caused by natural forcing and human activities during the period 1870-2000 **
**           ****Sources of Key Uncertainties in Climate Change Assessments**
** ****Future emissions  **
** ****Climate sensitivity***
** ****Heat flux into the ocean**
** ****Radiative forcing due to aerosols and clouds  E.g. to follow.**
** ****Carbon Cycle/climate feedbacks**
** ****Changes in ocean circulation**
**         ***** ****The climate sensitivity determines how much the climate will change for a given change in atmospheric composition. It is usually expressed as the eventual  global-mean warming for a doubling of the CO2 concentration, and lies in the range of 1.5-4.5o C with 90% confidence**

**Current Contents of ****3.1 *****Draft***** Prospectus (contd.)**

**Notes:**
5. The intended audiences of this CCSP product are decision makers and researchers who use climate model output as input to studies or analyses in their respective, non-climatic disciplines (e.g., ecosystem science, hydrology and water resources, economics, human health, and agriculture and forestry). In order to facilitate application and decision-making using climate model information, an evaluation and assessment of the state of science of climate models is essential. This product is directed towards this goal. Users often need climate information at regional scales and Question 5 of the prospectus addresses issues related to dynamical downscaling of climate projections.  The intended use of this CCSP product is to provide information to those who use climate model outputs about the current strengths and limitations associated with using models to project the potential effects of human activities on climate and sea-level rise. The product will address scientific issues on a comprehensive, objective, open, and transparent basis. While based on the peer-reviewed literature, it will be written to be accessible and useful to the well-informed general reader and decision maker. 
In preparing this draft prospectus, careful consideration has been given to the feedback received from stakeholders at the December 2002 Climate Change Science Program Planning Workshop for Scientists and Stakeholders. In addition, other recent developments have been reflected. For example, results from a workshop focusing on tropical biases that degrade projections have also guided the selection of topics to be covered in the product. The authors also intend to further shape the product with the input provided by scientists, decision makers, and general readers during the prospectus public comment period.
5.	Drafting Process (Including Materials to be Used in Preparing the Product)
The lead authors—organized by the coordinating lead author—will meet in person, through e-mail exchanges, and via teleconferences (as they see fit) to draft answers to the six key questions addressed in the product. They will also prepare an introductory section to describe the topic, the audience, and the intended use of this product. The coordinating lead author may assign primary responsibility for drafting the text associated with each question to a specific author. The lead authors will incorporate material from any contributing authors in the draft product as they see fit.
After the product is drafted, the lead authors (or coordinating lead author and the authors responsible for each of the six questions) will write a non-technical summary.
Lead and contributing authors will base all their writing on published, peer-reviewed scientific literature. Lead authors will consider the full range of relevant peer-reviewed information. The product and its non-technical summary will identify disparate views, where appropriate 

##  Proposed Approach for S&A 3.1: E.g. inclusion of understanding on aerosol-climate interactions in climate modeling runs to simulate effect of past volcanoes**  

**** First IPCC:  Climate change considered to be driven by anthropogenic GHG.  Inadequate understanding of aerosol climate interactions. Subsequent IPCC reports documented studies on aerosol-climate interactions.  Recent studies have confounded the previously orderly world of IPCC of the 1990s**

## Title slide

- Mt Pinatubo eruption in the Philippines, June 15, 1991.  Gases and solids injected 20 km into the stratosphere.

*Courtesy W. Washington/NCAR*

## Proposed Approach for S&A 3.1:

**Proposed Approach for S&A 3.1:**
***E.g.***** Including aerosol-climate interactions due to volcanoes**

***Courtesy W. Washington/NCAR***

## Proposed Approach for S&A 3.1: 

***Agreement with observations in  simulations that include both natural and greenhouse gas forcing ***

**Proposed Approach for S&A 3.1: **
**Evaluation of Climate model simulations **
**for historical period 1870-2000**

*Courtesy W. Washington/NCAR*

***Courtesy W. Washington/NCAR***

**Notes:**
Simulations using the improved model for the historical period (20th century runs) show agreement with observations when both natural variability and greenhouse gas forcing is incorporated. 
Simulations using the improved model for the historical period (20th century runs) show agreement with observations when both natural variability and greenhouse gas forcing is incorporated. 
Natural forcings do not fully explain observed late 20thcentury warming(uncertainty in climate model response is reduced by demonstrating that 20thcentury temperatures are directly related to the relevant forcings)•Climate models with only “natural” forcings (volcanic and solar) do not reproduce observed late 20thcentury warming•When increases in anthropogenic greenhouse gases and sulfate aerosols are included, models are able reproduce observed late 20thcentury warmingMeehl, G.A., W.M. Washington, C. Ammann, J.M. Arblaster, T.M.L. Wigley, and C. Tebaldi, 2004: Combinations of natural and anthropogenic forcings and 20th century climate. J. Climate, 17, 3721-3727.

## Relationship to Other National/International Assessments 
     Crucial input to S&A 3.1 likely to be 
      (i) AR4 Chap 8 (Climate Models and Their Evaluation), Chap 9 (Understanding and Attributing Change); 
      (ii) relevant NRC reports on climate models e.g. 2005 NRC Radiative Forcing of Climate; 
      (iii) Results of U.S. CLIVAR Climate Model Evaluation Project(CMEP) 
       (iv) Review process

**     ****Crucial input to S&A 3.1 likely to be **
**      ****(i) AR4 Chap 8 (Climate Models and Their Evaluation), Chap 9 (Understanding and Attributing Change); **
**      ****(ii) relevant NRC reports on climate models *****e.g.***** 2005 NRC Radiative Forcing of Climate; **
**      ****(iii) Results of U.S. CLIVAR Climate Model Evaluation Project(CMEP) **
**       ****(iv) Review process**

**Current Contents of ****3.1 *****Draft***** Prospectus (contd.)**

##      Timeline for S&A 3.1

_**  **__**2005**_
-  **Feb****	**** Approved prospectus posted on CCSP web site,**
**                         ****and lead and contributing authors selected by  **
**                         ****lead agency**
**Nov****	****             CCSP Principals approve draft prospectus **
**Nov – Dec****	**** Draft product written by lead authors, with **
**                         ****input from potential contributing authors**

##    Timeline for S&A 3.1 (contd.)

_**  **__**2006**_
**Jan-Apr ****       Draft product written by lead authors, with input       **
**                           ****from contributors (contd.)**
**Apr****	****               Peer reviewers selected by lead and supporting **
**                           ****agencies **
**May-July****      Draft product peer-reviewed**
**July-Aug****       Lead authors revise draft product based on public**
**                           ****comment**
**Sep-Oct****	****   Draft product made available for public comment **
**                          ****(45 days)**
**Nov****               Draft product revised based on public comments **
**                          ****FACA Advisory Committee Meeting**
**Dec ****              CCSP Principals review product**

##    Timeline for S&A 3.1 (contd.)

_**2007**_
**Jan-Feb****	****NSTC clearance **
**Mar           ****Lead agency produces final product**
**                       ****according to format provided by CCSPO**
**Apr****           Online version of report released, lead  **
**                      ****agency coordinates with CCSPO**
**Jul**** ****	****          Hardcopy version of report released, lead **
**                      ****agency coordinates with CCSPO**