What Climate Information Do Water Managers Need to Make Robust, Long-Term Plans? Robert Lempert Senior Scientist RAND US CLIVAR Mini-Symposium July 14, 2008

2 Climate Change Poses Significant Planning Challenge for Water Managers Climate change will likely have large but uncertain impacts on supply and demand for water “Stationarity is dead” –Most agencies already include climate (often implicitly) in many decisions –Amidst all the uncertainty one thing we do know for sure -- tomorrow’s climate will not be like the past’s Relaxing this assumption poses key challenges –How do you adjust plans based on uncertain climate projections? –How do you communicate these plans, especially when uncertain long-term benefits require near-term costs? Climate change will likely have large but uncertain impacts on supply and demand for water “Stationarity is dead” –Most agencies already include climate (often implicitly) in many decisions –Amidst all the uncertainty one thing we do know for sure -- tomorrow’s climate will not be like the past’s Relaxing this assumption poses key challenges –How do you adjust plans based on uncertain climate projections? –How do you communicate these plans, especially when uncertain long-term benefits require near-term costs?

3 Our Research Aims to Better Understand How to Characterize and Communicate Uncertain Information to Decision Makers RAND Hosts NSF-Funded Center on Managing Climate Change Uncertainty –Conducts fundamental research to improve the design and effective use of computer-based decision support tools that enhance climate-related and other decisions under deep uncertainty Research Focuses on Two Themes –Learn what characterizations of uncertainty are most effective for individuals and groups –Develop mathematical methods for scenario discovery and robust decisionmaking using Applied to Two Policy Areas –Abrupt climate change –California water resources management RAND Hosts NSF-Funded Center on Managing Climate Change Uncertainty –Conducts fundamental research to improve the design and effective use of computer-based decision support tools that enhance climate-related and other decisions under deep uncertainty Research Focuses on Two Themes –Learn what characterizations of uncertainty are most effective for individuals and groups –Develop mathematical methods for scenario discovery and robust decisionmaking using Applied to Two Policy Areas –Abrupt climate change –California water resources management

4 Outline Climate vulnerability and response option analysis for Inland Empire Utilities Agency (IEUA) –What impacts may climate change have on IEUA’s current plans? –What should IEUA do in response? Evaluating impacts of analysis on decision makers Observations on needs for climate information Climate vulnerability and response option analysis for Inland Empire Utilities Agency (IEUA) –What impacts may climate change have on IEUA’s current plans? –What should IEUA do in response? Evaluating impacts of analysis on decision makers Observations on needs for climate information

5 Conducted Vulnerability and Options Analysis for Inland Empire Utilities Agency (IEUA) –IEUA currently serves 800,000 people May add 300,000 by 2025 –Water presents a significant challenge –IEUA currently serves 800,000 people May add 300,000 by 2025 –Water presents a significant challenge

6 –Current water sources include: Groundwater 56% Imports32% Recycled1% Surface8% Desalter2% Conducted Vulnerability and Options Analysis for Inland Empire Utilities Agency (IEUA) –IEUA currently serves 800,000 people May add 300,000 by 2025 –Water presents a significant challenge –IEUA currently serves 800,000 people May add 300,000 by 2025 –Water presents a significant challenge

7 –Current water sources include: Groundwater 56% Imports32% Recycled1% Surface8% Desalter2% Focus of IEUA’s 20 year plan Conducted Vulnerability and Options Analysis for Inland Empire Utilities Agency (IEUA) –IEUA currently serves 800,000 people May add 300,000 by 2025 –Water presents a significant challenge –IEUA currently serves 800,000 people May add 300,000 by 2025 –Water presents a significant challenge

8 Model Performance of plans IEUA Plans System data & climate forecasts We Built a Model to Assess Performance of IEUA Plans in Different Future States of World –Model projects future water supply and demand for IEUA service area Consistent with IEUA management plans and assumptions Reflect plausible trends of climate change –Model projects future water supply and demand for IEUA service area Consistent with IEUA management plans and assumptions Reflect plausible trends of climate change Based on WEAP software tool

9 GCMs Project Plausible Temperature and Precipitation Ranges for Southern California –Derived from forecasts from 21 GCMs with A1B emissions scenario –Each forecast weighted by ability to reproduce past climate and level of agreement with other forecasts –Derived from forecasts from 21 GCMs with A1B emissions scenario –Each forecast weighted by ability to reproduce past climate and level of agreement with other forecasts % Change in Precipitation (2005 – 2030) (Tebaldi et al.) Temperature Precipitation

10 Generate Future Weather Sequences by Resampling Historic Local Climate Records KNN method produces hundreds of local weather sequences –Daily and monthly variability that matches historic Chino climate –Temperature and precipitation trends that match climate model forecasts KNN method produces hundreds of local weather sequences –Daily and monthly variability that matches historic Chino climate –Temperature and precipitation trends that match climate model forecasts (Yates et al.)

11 Model Performance of plans IEUA Plans System data & climate forecasts Model Assess Performance of IEUA Plans in Many Different Scenarios Temp: +1.6 o C Precip: -10% Scenario B Plan suffers shortages in adverse future climate Year Annual supply (taf) Recycled Groundwater Local Supplies Imports Dry-year yield Surplus Shortage Temp: +0.7 o C Precip: +3% Scenario A Plan generates surpluses in benign future climate Year Annual supply (taf) Recycled Groundwater Imports Surplus Local Supplies

12 First Developed “Standard” Scenarios Based on Estimates of Key Driving Forces –Qualitatively choose the most important driving forces –Constructed “scenario matrix” based on these driving forces Slightly warmer & wetter climate Hotter & drier climate Meet goals Don’t meet goals Scenario A Slightly warmer & wetter Meet all goals Scenario C Slightly warmer & wetter Miss goals Scenario B Hotter & drier Meet all goals Scenario D Hotter & drier Miss goals

13 These “Standard” Scenarios Suggest That Climate Change Could Significantly Affect IEUA Meeting goals of 2005 UWMP could help manage risks Slightly warmer & wetter climate Hotter & drier climate Meet goals Don’t meet goals Scenario A Slightly warmer & wetter Meet all goals (0% of years) Scenario C Slightly warmer & wetter Miss goals (0% of years) Scenario B Hotter & drier Meet all goals (19% of years) Scenario D Hotter & drier Miss goals (42% of years)

14 Many Uncertain Factors Could Impact the Performance of Current IEUA Plan Natural Processes Future temperatures Future precipitation Changes in groundwater processes Performance of Management Strategies Development of aggressive waste-water recycling program Implementation of groundwater replenishment Costs of Future Supplies and Management Activities Imported supplies Water use efficiency

15 Planners in S. California, for Instance, Face a Range of Possible Future Climate Conditions Summer-time temperature change ( ) +.1C +2.1C 0 Likely range Results based on statistical summary of 21 of the world’s best Global Climate Models Winter-time precipitation change ( ) +8% -19% 0 Likely range No changeHotter WetterMuch drier

16 Many Uncertain Factors Could Impact the Performance of Current IEUA Plan Natural Processes Future temperatures Future precipitation Changes in groundwater processes Performance of Management Strategies Development of aggressive waste-water recycling program Implementation of groundwater replenishment Costs of Future Supplies and Management Activities Imported supplies Water use efficiency

17 Conducted Elicitations Among IEUA’s Planners and Community to Estimate Likelihood of Achieving Goals RecyclingReplenishment Goal Miss goal Miss goal Probability of meeting UWMP goals Meet Goals Miss Goals

18 Many Uncertain Factors Could Impact the Performance of Current IEUA Plan Natural Processes Future temperatures Future precipitation Changes in groundwater processes Performance of Management Strategies Development of aggressive waste-water recycling program Implementation of groundwater replenishment Costs of Future Supplies and Management Activities Imported supplies Water use efficiency

19 Robust Decision Making (RDM) Enables Good Decisions Under Deep Uncertainty Deep uncertainty obtains when –Decision makers don’t know or agree on the system model or the probability distributions for the inputs to the model RDM is a quantitative decision analytic approach that –Identifies robust strategies, ones that work reasonably well compared to the alternatives across a wide range of plausible scenarios Deep uncertainty obtains when –Decision makers don’t know or agree on the system model or the probability distributions for the inputs to the model RDM is a quantitative decision analytic approach that –Identifies robust strategies, ones that work reasonably well compared to the alternatives across a wide range of plausible scenarios Candidate strategy Identify vulnerabilities Assess alternatives for ameliorating vulnerabilities RDM combines key advantages of scenario planning and quantitative decision analysis in ways that –Decision makers find credible –Contribute usefully to contentious debates RDM combines key advantages of scenario planning and quantitative decision analysis in ways that –Decision makers find credible –Contribute usefully to contentious debates

PV shortage cost ($ billions) PV supply cost ($ billions) Scenario A Scenario B Adverse climate $3.4 billion in supply cost $1.9 billion in shortage cost Current IEUA 2005 Urban Water Management Plan Benign climate $3.3 billion in supply cost $0 in shortage cost “Scenario Maps” Help Decision Makers Visualize How Plans Evolve Over Many Futures

PV shortage cost ($ billions) PV supply cost ($ billions) Current IEUA Plan (200 Scenarios) “Scenario Maps” Help Decision Makers Visualize How Plans Evolve Over Many Futures

PV shortage cost ($ billions) PV supply cost ($ billions) Current IEUA Plan $3.75 billion cost threshold Current plan generates high costs in 120 of 200 Scenarios “Scenario Maps” Help Decision Makers Visualize How Plans Evolve Over Many Futures

PV shortage cost ($ billions) PV supply cost ($ billions) Current IEUA Plan Statistical Analysis Suggests Key Factors That Create Vulnerabilities for Existing Plan Natural Processes Future temperatures Future precipitation Changes in groundwater processes Performance of Management Strategies Development of aggressive waste-water recycling program Implementation of groundwater replenishment Costs of Future Supplies and Management Activities Imported supplies Water use efficiency These three factors explain 70% of vulnerabilities of IEUA’s current plans

24 Response Options May Help IEUA Address These Vulnerabilities

25 Can Quantify Some, But Not All, Of These Costs Costs increase over time

26 Should IEUA Act Now or Later to Reduce Potential Climate Vulnerabilities? Act now to augment 2005 Plan? NO Monitor, and take additional action if supplies drop too low In 2015, 2020, 2025, …. YES Implement additional efficiency, recycling, and replenishment In 2015, 2020, 2025, …. Monitor, and take additional action if supplies drop too low

27 Compare Nine Strategies Over 200 Scenarios Reflecting Key Uncertainties Static options Update options Number of Scenarios (PV Costs > $3.75 billion) Current Plan forever Current Plan + DYY and recycling Current Plan + replenishment Current Plan with updates Current Plan + replenishment with updates Current Plan + efficiency Current Plan + efficiency with updates Current Plan + DYY and recycling with updates Current Plan + all enhancements

28 Just Allowing IEUA’s Current Plan to Update Reduces Vulnerability Substantially Static options Update options From 120 Down to 30 Number of Scenarios (PV Costs > $3.75 billion) Current Plan forever Current Plan + DYY and recycling Current Plan + replenishment Current Plan with updates Current Plan + replenishment with updates Current Plan + efficiency Current Plan + efficiency with updates Current Plan + DYY and recycling with updates Current Plan + all enhancements

29 Acting Now Reduces Future Vulnerabilities Even More Current Plan with updates Current Plan + replenishment with updates Current Plan + efficiency Current Plan + efficiency with updates Current Plan + DYY and recycling with updates Current Plan + all enhancements Static options Update options Number of Scenarios (PV Costs > $3.75 billion)

30 Acting Now Reduces Future Vulnerabilities Even More Current Plan with updates Current Plan + replenishment with updates Current Plan + efficiency Current Plan + efficiency with updates Current Plan + DYY and recycling with updates Current Plan + all enhancements Static options Update options Number of Scenarios (PV Costs > $3.75 billion) Implementation becomes more challenging This analysis helped IEUA decide to make more near-term efficiency investments, and to monitor performance and adapt as needed down the road

31 Outline Climate vulnerability and response option analysis for Inland Empire Utilities Agency (IEUA) Evaluating impacts of analysis on decision makers Observations on needs for climate information Climate vulnerability and response option analysis for Inland Empire Utilities Agency (IEUA) Evaluating impacts of analysis on decision makers Observations on needs for climate information

32 We Also Evaluated How This Analysis Affected Policy-Makers’ Views Four IEUA workshops presented modeling results to participants including: –Agency professional managers and technical staff –Local elected officials –Community stakeholders “Real-time” surveys measured participants’ –Understanding of concepts –Willingness to adjust policy choices based on information presented –Views on RDM Four IEUA workshops presented modeling results to participants including: –Agency professional managers and technical staff –Local elected officials –Community stakeholders “Real-time” surveys measured participants’ –Understanding of concepts –Willingness to adjust policy choices based on information presented –Views on RDM

33 Surveys Suggest Workshop Changed Views Participants reported: –RDM helped support comparison of climate-related risks and choice among plans –Preference for scatter plot over histogram scenario displays After the workshop: –35% said consequences of bad climate change now appeared “more serious” than before –40% thought the likelihood of of bad climate change outcomes for the IEUA was “greater” than before –75% though the ability of IEUA planner to plan for and manage effects was “greater” than before Overall, analysis increased: –Perceived likelihood of serious climate impacts –Confidence that IEUA could take effective actions to reduce its vulnerability to climate change –Support for near-term efficiency enhancements to current IEUA plan Participants reported: –RDM helped support comparison of climate-related risks and choice among plans –Preference for scatter plot over histogram scenario displays After the workshop: –35% said consequences of bad climate change now appeared “more serious” than before –40% thought the likelihood of of bad climate change outcomes for the IEUA was “greater” than before –75% though the ability of IEUA planner to plan for and manage effects was “greater” than before Overall, analysis increased: –Perceived likelihood of serious climate impacts –Confidence that IEUA could take effective actions to reduce its vulnerability to climate change –Support for near-term efficiency enhancements to current IEUA plan

34 Climate Information Re-Enforced IEUA’s Commitment to Implement 2005 Plan Current climate projections adequate to: –Emphasize importance of UWMP long-range goals –Increase emphasis on conservation –Suggest importance of increased storm intensity Climate change only one of several key uncertainties affecting performance of long-range plans For many participants, willingness to accept seriousness of climate challenge contingent on confidence in effective response options Current climate projections adequate to: –Emphasize importance of UWMP long-range goals –Increase emphasis on conservation –Suggest importance of increased storm intensity Climate change only one of several key uncertainties affecting performance of long-range plans For many participants, willingness to accept seriousness of climate challenge contingent on confidence in effective response options

35 Other Water Agencies May Have Additional Information Needs While IEUA’s favorable response options make it a special case, –Many water agencies likely to have sufficient information to their long-range plans more robust to climate change Information needs often depend on vulnerabilities and available response options, but key needs include –Improved generation of future weather sequences –Length and frequency of future droughts –Characterization of potential extreme events While IEUA’s favorable response options make it a special case, –Many water agencies likely to have sufficient information to their long-range plans more robust to climate change Information needs often depend on vulnerabilities and available response options, but key needs include –Improved generation of future weather sequences –Length and frequency of future droughts –Characterization of potential extreme events

36 More Information David G. Groves, Robert J. Lempert, Debra Knopman, Sandra H. Berry: Preparing for an Uncertain Climate Future: Identifying Robust Water Management Strategies, RAND DB-550-NSF, David G. Groves, Debra Knopman, Robert J. Lempert, Sandra H. Berry, and Lynne Wainfan, Presenting Uncertainty About Climate Change to Water Resource Managers, RAND TR-505-NSF, David G Groves, David Yates, Claudia Tebaldi, “Developing and Applying Uncertain Global Climate Change Projections for Regional Water Management Planning,” submitted Robert J. Lempert, David G. Groves, Steven W. Popper, Steve C. Bankes: "A General, Analytic Method for Generating Robust Strategies and Narrative Scenarios,” Management Science, vol 52, no 4, April 2006 Steven W. Popper, Robert J. Lempert, and Steven C. Bankes: "Shaping the Future," Scientific American, vol 292, no. 4 pp , April David G. Groves, Robert J. Lempert, Debra Knopman, Sandra H. Berry: Preparing for an Uncertain Climate Future: Identifying Robust Water Management Strategies, RAND DB-550-NSF, David G. Groves, Debra Knopman, Robert J. Lempert, Sandra H. Berry, and Lynne Wainfan, Presenting Uncertainty About Climate Change to Water Resource Managers, RAND TR-505-NSF, David G Groves, David Yates, Claudia Tebaldi, “Developing and Applying Uncertain Global Climate Change Projections for Regional Water Management Planning,” submitted Robert J. Lempert, David G. Groves, Steven W. Popper, Steve C. Bankes: "A General, Analytic Method for Generating Robust Strategies and Narrative Scenarios,” Management Science, vol 52, no 4, April 2006 Steven W. Popper, Robert J. Lempert, and Steven C. Bankes: "Shaping the Future," Scientific American, vol 292, no. 4 pp , April

37 Thank you!

38 Statistical Analysis Suggests Key Driving Forces Generating High Cost Outcomes Conducted statistical, cluster-finding analysis over all the model runs to identify the factors most strongly associated with shortages in UWMP Meet recycling goal Meet replenishment goal Future climate New conservation Reduced groundwater infiltration Climate on imports MissExceedMeet MissExceedMeet DrierWetter -5%+20% -20%0% WeakStrong Explains 70% of high cost cases

39 IEUA’s 2005 UWMP Calls for Significant Increase Conjunctive Use and Recycling (TAF)2005 Use2010 Goal2025 Goal Urban Chino Basin Ground Water Use (+ 40%) 165 (+ 75%) Recycled Water Supply (direct use) (+ 275%) 69 (+ 630%)