Managing Water in a Changing Climate

Transcription

1 Managing Water in a Changing Climate Four in Forty Forum May 30, 2011 Adelaide, SA Brad Udall University of Colorado NOAA Visitor SA Department for Water bradley.udall@colorado.edu Global Climate Change Impacts in the United States 1

2 The Anthropocene is here! Climate Change is Primarily about the Water Cycle We must fundamentally re-think Water Management We Need 3 Rights The Right Priorities Environment, Critical Human Needs, Agriculture The Right Science Integrative, Multidisciplinary The Right Management Robust, Resilient, Adaptive (And the Right Math.) Key Points Global Climate Change Impacts in the United States 2

3 The Anthropocene is Here! We are stressing many aspects of the planet Freshwater Use Land use Changes Population Carbon Cycle Nitrogen Cycle Phosphorus Cycle Ocean Acidification Biodiversity Loss Plus Others While Climate Change is important, there are many other stressors Water A Common Linkage Global Climate Change Impacts in the United States 3

4 Climate Change is Primarily About Changes to the Water Cycle The water cycle is a primary mechanism by which the Earth moves heat from areas with too much to areas with too little. A warmer climate changes the physics of the atmosphere and differentially heats the planet causing both short term changes and long term water cycle changes Short Term Water Cycle Changes More Evap, More Precipitation More Floods, More Droughts Long Term Water Cycle Changes Sea Level Rise Changes are already well underway More Water Vapor Wet Areas Wetter, Dry Areas Drier More Intense Precipitation Many Others Global Climate Change Impacts in the United States 4

5 Need to Fundamentally Rethink 21 st Century Water Management Water Management Used to Be Easy Use Historical Data to Determine Planning Envelope Linear Increase in Demands over time Get More Supply when you run out However Historical Data less and less applicable Most Water Systems Over-allocated no more supply Of course we weren t lost. We were merely where we shouldn t have been, without knowing where that was. ~ T. Morris Longstreth Demand can t outpace supply and far more elastic than envisioned Now Changing Supplies Changing Demands Aging Water Systems Lots of Other Water-related Stresses Global Climate Change Impacts in the United States 5

6 The Right Priorities When Push Comes to Shove 1 = The Environment 2 = Critical Human Water Needs 3 = Agriculture Need to consider how we share within priorities Water markets critical Australia gets an A for getting this right! The Western U.S. gets an F. Global Climate Change Impacts in the United States 6

7 The Right Science Science is not just about models Basic Climate Theory Data and Monitoring Paleoclimate Social Science Important Economics, Psychology Beware of the Lure of False Certainty Models are critical, but very immature Model for insights not answers Plans are worthless, Planning is everything Must make useful Science Integrative, Multidisciplinary Synthesis Critical Science Takes Time Group Learning is mandatory Global Climate Change Impacts in the United States 7

8 The Right Management Robust, Resilient and Adaptive Linked Together Robust Solutions Solutions that consider needs of all 3 priorities Need to think in terms of Probability Distribution Functions Averages just part of the solution SDLS a Start, but Extremes Critical Robust may not be cheap Desal in Adelaide Resilient Solutions Management Flexibility Critical Manage for consequences of failure Black Swans" Adaptive Management Monitoring Key Tradeoffs with Certainty 21 st Century a Moving Target the entire century Global Climate Change Impacts in the United States 8

9 The Anthropocene is here! Climate Change is Primarily about the Water Cycle We must fundamentally re-think Water Management We Need 3 Rights The Right Priorities Environment, Critical Human Needs, Agriculture The Right Science Integrative, Multidisciplinary The Right Management Robust, Resilient, Adaptive (And we need to begin today ) Key Points Global Climate Change Impacts in the United States 9