1. DRC 2006.Presenters Name.March 7-9.p 1 Californias enormous computing resources allow climate simulations at unprecedented resolution capturing Californias regional climate phenomena 50Km resolution 9 Km resolution Target Resolutions Global: 15 Km Regional: 1 Km Duffy and Taylor

2. DRC 2006.Presenters Name.March 7-9.p 2 Californias complex terrain drives the need for high resolution climate models Wintertime precipitation rate Duffy

3. DRC 2006.Presenters Name.March 7-9.p 3 Local forcings (such as irrigation) are critical to understanding local climate change Observed trends Natural variability and trends in California temperature records Degree C natural internal variability (from model simulations) WinterSpringSummerFall Data for 2000 Developed by Food and Agriculture Organization and David Lobell Annual irrigation data

4. DRC 2006.Presenters Name.March 7-9.p 4 Federal, State, and academic partnerships are key to making progress in regional climate Federal –DOE – energy use impacts on regional climate DOE Program on climate simulation diagnosis and analysis Large compute resources –NOAA – climate prediction mission Existing regional climate assessment centers via RISA program –NASA – Earth science R&D and satellite observations Modeling analysis and data assimilation; large compute resources State –CEC – Energy and climate research in CA Funding climate change research (regional climate, impacts, adaptation, inventory methods, emission reductions, …) since 2003 ($6M/year) Leadership in CA Biennial Assessment –CARB – implementation of AB32 Universities Innovative models and modeling approaches (e.g., parameterizations) Ground based observation stations and modeling analysis Educating next generation of researchers

5. DRC 2006.Presenters Name.March 7-9.p 5 Aerosols transported across the Pacific are dramatically impacting Californias air quality standards 1950 - 1990 l N. America: SO 2 decreased from 41% to 17%. l Asia: SO 2 increased from 7% to 37%. Regional percentage of fossil fuel SO 2 emissions (Dignon) Currently 25% of PM2.5 limits in CA are caused by aerosol transported from across the Pacific China is building 1 GW of fossil fuel power plants per week CameronSmith

6. DRC 2006.Presenters Name.March 7-9.p 6 Diminished mountain snowpak will reduce water supplies Impacts residential, commercial, agriculture, and energy production

7. DRC 2006.Presenters Name.March 7-9.p 7 Climate change could prove disastrous for our nations levees Rising sea levels combined with wetter storms will likely cause levee failures Mauer

8. DRC 2006.Presenters Name.March 7-9.p 8 Increases in California temperatures will cause decreases in crop productivity

9. DRC 2006.Presenters Name.March 7-9.p 9 Regional Climate Summary Climate modeling at the global and regional scale is critical to understanding Californias climate change impacts and forming strategies in adaptation and mitigation –Resolving the important processes driving climate change is important –New science understanding is important Climate models (as always) depend on quality observations –Evaluate, diagnosis, analyze, and improve Climate change will strongly impact Californias future in air quality, water resources, and agriculture (also human health, and others) A partnership across Federal, State, and Academic institutions is required to make progress in understanding and addressing climate change at the regional and local scale As Charlie Kennel said – Its global, its regional, and its local

10. DRC 2006.Presenters Name.March 7-9.p 10 Backup

11. DRC 2006.Presenters Name.March 7-9.p 11 Climate simulation/analysis focuses more and more on regional issues Why? Because humans and natural ecosystems experience regional, not global, climate; Because improvements in climate models make meaningful regional projections possible Regional climate changes will determine societal impacts and drive climate-related policy decisions Water availability Recreation Extreme events Air quality Human health Agriculture

12. DRC 2006.Presenters Name.March 7-9.p 12 Regional models can represent major characteristics of Californias precipitation patterns

13. DRC 2006.Presenters Name.March 7-9.p 13 Irrigation database over California is a sub- county resolution % irrigation 100 0 Data for 2000 Developed by Food and Agriculture Organization and David Lobell

14. DRC 2006.Presenters Name.March 7-9.p 14 River flow measurements show changes in runoff timings during the 20 th century – is this climate change? Rivers depending on snowmelt show earlier flow patterns Rivers dependent on precipitation show later flow patterns Cayan et al., Bull. AMS. 2001; Stewart et al., J Clim., 2005 Spring pulse Center time Trends in SP (1948-2000 )