Community Modeling and Long-term Predictions of the Integrated Water Cycle

1. Community Modeling and Long-term Predictions of the Integrated Water Cycle Topic 6 Report Out Washington DC September 24-26, 2012

2. Topic 6: Use-inspired water cycle research to meet the most pressing energy andenvironmental challenges • Kristen Averyt • Jared Bales • Kate Calvin • Dan Cayan • Paul Faeth • Jay Famiglietti • Auroop Ganguly • Pierre Gentine • Mohammad Hejazi • Kathy Hibbard • Paul Houser • Kathy Jacobs • Tony Janetos • Brian O’Neill • Adam Schlosser • Soroosh Sorooshian • Ken Strzepek • Claudia Tebaldi • Vince Tidwell • John Weyant • Craig Zamuda

3. Water is critical to every aspect of the North American economy, public health, energy, and food production Population, climate and environmental change are quickly modifying the water supply-demand balance We need to establish the scientific basis, observation, prediction and decision approaches to manage water security and sustainability • Ensuring America's water security

4. WATER EVALUATION AND PLANNING (WEAP) SYSTEM Utah Project Northern California Upr Co Front Range Powell and Mead Four Corners Chama Rio Grande Southern California Arizona and Lwr Colorado

5. U.S. Fuel mix, w/o & w/ water constraint Wind Nuclear If water is constrained, the fuel mix will change to favor options that use less water. We assume a 20% cap on wind. Gas Coal < 2010-2040 Wind Nuclear Gas Source: Faeth, unpublished. Coal

6. D (P – E): 2030’s vs. Current Darker brown: Dryer Darker Blue: Wetter CMIP3 MMEs Median Nine CMIP3 models CMIP5 MMEs Median Seven CMIP5 models

7. Water Availability

8. Topic 6: Use-inspired water cycle research` Priority Research Directions (3 to 5) 6.1 Careful attention needs to be given to the hierarchy of models 6.2 How does water availability influence energy sector development and vice-versa 6.3 How does water availability influence food sector development and vice-versa 6.4 How does water availability influence tradeoffs in food/energy sector development 6.5 Designing infrastructure for intensifying extreme events

9. Topic 6: Use-inspired water cycle research` Careful attention needs to be given to the hierarchy of models Scientific Needs/Opportunities CLM and related models are unlikely to incorporate detailed representation of water use dynamics in the foreseeable future. Set of policy relevant questions require global perspective Additional set of questions require a regional/local view Uncertainty associated with modeling both physical and social dynamics

10. Topic 6: Use-inspired water cycle research` Careful attention needs to be given to the hierarchy of models Research Approaches • Develop hierarchy of models • Limit use modeling in CLM to that which drives changes in atmospheric or ocean circulation dynamics • Global model at large watershed scale to address global policy issues (emissions, food security, energy security, etc.) • Detailed regional scale models • Work to standardize” information passed between models (downscaled climate data, changes in land cover) • Multiple vs. single community model paradigm? • Risk based analysis • Encourage stakeholder engagement in analysis design

12. Topic 6: Use-inspired water cycle research` Careful attention needs to be given to the hierarchy of models Scientific/User Impacts Improved model interoperability Broader engagement by stakeholders and decision makers Improved policy relevance of analysis

13. Topic 6: Use-inspired water cycle research` Water-Energy-Food Nexus Scientific Needs/Opportunities • Water supply requirements • Total runoff and variability (high vs. lows) • Timing of runoff relative to storage capacity • Frequency between high and low flows • Duration of low flows (severity, return period, duration of droughts) • Groundwater • Recharge • surface water discharge • Volume available • Brackish water availability/ Water Reuse opportunity (cost, technology) • Water quality issues • Pollution • Effluent temperature • Non-point sediment/nutrient • Quality sensitive to use patterns

14. Topic 6: Use-inspired water cycle research` Water-Energy-Food Nexus Scientific Needs/Opportunities • Demand Side requirements • Data requirements • Improved estimates of food/energy/public health/hazards management. Engaging stakeholders in process (example, Food and Agriculture 2030 estimates). • Current baseline data (withdrawal/consumption, source, sector) • Processes • Technology evolution and adoption. How big of impact can a particular technology have at given cost levels • Relations of demands to economics (changing diet, greater energy use, improved water conservation). • Geospatial economic and demographic drivers • Tight linkage to evaporation and transpiration demands • Link between precipitation (timing/amount) and irrigation/industrial/municipal practices • Clearly articulate energy technology pathways and the related impacts on water demand

15. Topic 6: Use-inspired water cycle research` Water-Energy-Food Nexus Scientific Needs/Opportunities • Institutional requirements • Modeling water markets • Reservoir operations • Treaties/Compacts • Environmental flows

16. Topic 6: Use-inspired water cycle research` Water-Energy-Food Nexus Research Approaches • Models largely exist; however, implementation issues exist: • Computational burden • Scaling processes/parameters from regional scale (where models largely exist) to large river basin scale • Data availability, proprietary data (international and industrial) • Biggest challenge is to integrate the linkage with water explicitly (food/energy already represented in IAMs) • Expand engagement with social sciences

17. Topic 6: Use-inspired water cycle research` Water-Energy-Food Nexus Scientific/User Impacts Address broader suite of policy questions Water conveys climate effects to other sectors

18. Topic 6: Use-inspired water cycle research` Designing infrastructure for intensifying extreme events Scientific Needs/Opportunities