1. Report on 25-27 March Crystal City Workshop to Identify Grand Challenges in Climate Change Science By its cochair- Robert Dickinson For the 5 Sept. 2008 BERAC Meeting:

2. Process of report preparation Initial content agreed to by a drafting group meeting the afternoon following the workshop Initial content agreed to by a drafting group meeting the afternoon following the workshop Written by the co-chairs and iterated many times with a subset of the workshop participants. Written by the co-chairs and iterated many times with a subset of the workshop participants. Discussed at the May BERAC meeting. Discussed at the May BERAC meeting. Further editing based on inputs from closed interactive website used to distribute (twice) to all the workshop participants for comment and comments on comments. Further editing based on inputs from closed interactive website used to distribute (twice) to all the workshop participants for comment and comments on comments. Submitted to BERAC after further editing by cochairs and technical editing by DOE staff. Submitted to BERAC after further editing by cochairs and technical editing by DOE staff.

3. Background to the meeting Climate change from use of fossil fuel energy recognized by DOE as a major constraint on the Nations future development and use of energy. Climate change from use of fossil fuel energy recognized by DOE as a major constraint on the Nations future development and use of energy. IPCC 2007 reported that this climate change already highly visible and expected to continue unabated for at least the next several decades. IPCC 2007 reported that this climate change already highly visible and expected to continue unabated for at least the next several decades. Since that report, a number of further studies showing some changes happening even faster than anticipated. Since that report, a number of further studies showing some changes happening even faster than anticipated. A chorus of voices asking for more detailed local information on what has and will change for their planning horizons A chorus of voices asking for more detailed local information on what has and will change for their planning horizons NOAA planning on providing a “Climate Services” to meet this need with there yet being little of the research being done that such a “Services” would have to be built upon. NOAA planning on providing a “Climate Services” to meet this need with there yet being little of the research being done that such a “Services” would have to be built upon.

4. Grand Challenges Identified by the Workshop Improve the characterization of Earth’s climate, and its evolution through the last century to its present state. Improve the characterization of Earth’s climate, and its evolution through the last century to its present state. Predict Regional Climate Change for the Next Several Decades Predict Regional Climate Change for the Next Several Decades Simulate Earth System change over centuries Simulate Earth System change over centuries

5. Improve the characterization of Earth’s climate, and its evolution through the last century to its present state. Limited by both lack of understanding and data. Limited by both lack of understanding and data. Reanalyses to provide global system research data sets for many important system components. Test models and provide initial conditions for future projections. Reanalyses to provide global system research data sets for many important system components. Test models and provide initial conditions for future projections. Regional scale observational field programs Regional scale observational field programs

6. Predict Regional Climate Change for the Next Several Decades Much more climate detail can be provided by Much more climate detail can be provided by Use of latest high performance computational tools Use of latest high performance computational tools limiting time frame to decadal and processes to those that are important on that time frame. limiting time frame to decadal and processes to those that are important on that time frame. Additional information if initial state adequately constrained by observations – expected product from the first Challenge. Additional information if initial state adequately constrained by observations – expected product from the first Challenge. Decision support for adaptation at state and local level Decision support for adaptation at state and local level

7. Simulate Earth System change over centuries On century time scales many feedbacks affect climate system that are not yet modeled or adequately so (e.g., involving biogeochemical cycling, dynamic vegetation, and atmospheric chemistry). On century time scales many feedbacks affect climate system that are not yet modeled or adequately so (e.g., involving biogeochemical cycling, dynamic vegetation, and atmospheric chemistry). Carbon cycle feedbacks have large control on how much atmospheric CO2 over this time. Carbon cycle feedbacks have large control on how much atmospheric CO2 over this time. Decision support for mitigation policies Decision support for mitigation policies

8. Research needed to address Grand Challenges Characterize impacts of radiatively active constituents, especially aerosols and clouds on climate and air quality Characterize impacts of radiatively active constituents, especially aerosols and clouds on climate and air quality Interactions with clouds Interactions with clouds Precipitation Precipitation Moist convection Moist convection Atmospheric chemical processes Atmospheric chemical processes

9. Interactions between ecosystem processes and changes and the climate system. Interactions between ecosystem processes and changes and the climate system. Interactions between changing climate, hydrological systems – their management. Interactions between changing climate, hydrological systems – their management. Multiple generations of Earth System models Multiple generations of Earth System models Incorporate advances in process understanding to further model complexity and improve parameterizations Incorporate advances in process understanding to further model complexity and improve parameterizations Develop and improve initialization procedures validated through observational, experimental, and focused modeling activities. Develop and improve initialization procedures validated through observational, experimental, and focused modeling activities. Climate change Climate change Implications for energy systems Implications for energy systems Support strategies for mitigation that affect climate change and influence adaptation choices

10. Highlighted Directions Must include integration and communication Must include integration and communication Human dimension components Human dimension components Computational, observational, and experimental research initiatives Computational, observational, and experimental research initiatives Need enhanced computing capabilities Need enhanced computing capabilities Education of new scientists and public Education of new scientists and public

11. Decision Support Examples Grand ChallengePresent ClimateNext Several Decades Change Over Centuries Decision issueNeeded Decisions Options: green- house warming mitigation Technologies, incentives; consumption Mitigation consequences Corrections Optimum mitigation path; Adaptation Coastal flooding/infrastruct ure Insurance ratesSafety over design lifetimes Risk valuations Agricultural production Bio-fuel production impact food supply Land and new crops more droughts Ecosystem management Habitat loss; thresholds Biological reserves Protect livesAbrupt change

12. Implications for DOE’s Research Program Build from current strengths, e.g. Earth System modeling; field observations, clouds and aerosols, terrestrial systems, ice. Build from current strengths, e.g. Earth System modeling; field observations, clouds and aerosols, terrestrial systems, ice. Lead integration of whole system – requires partnerships with other agencies, etc. Lead integration of whole system – requires partnerships with other agencies, etc.