Climate Change Extreme Events: Meeting the Information Needs of Water Resource Managers

Information about climate has long been used by water managers to develop short term and long term plans and strategies for regional and local water resources. Many water resource managers are now using output from downscaled global climate models (GCMs) to assist in planning for potential climate change. One aspect of climate that is important for such planning are estimates of future extreme storm (short term) and drought (long term) events. However, projections of extreme events are still very uncertain. At a recent workshop among climate scientists and water managers in the Southwest, it was concluded the science of climate change extreme events is at least a decade away from being robust enough to be useful in water resource management. . However, it was proposed that modern and paleo-climate records of past flooding and drought events be combined with projections from GCMs using a method similar to “planning” hydrology methods tested by the Bureau of Reclamation in 2009, to create future scenarios of extreme events. These scenarios may be useful to water resource managers until the science of extreme events is able to provide more detailed estimates. Based on the results of this workshop and other work being done by the Decision Center for a Desert City at Arizona State University and the Climate Assessment for the Southwest center at University of Arizona., this presentation will 1) report the results of the 2012 workshop on climate change and extreme events that provides a review of the extreme event data needs of water resource managers in the Southwest, the current state of extreme event climate science, 2) assess available information on past extreme events in the Southwest, and 3) present a method for combining information on past extremes with projected future climate to produce estimates of possible future extreme events useful to water resource managers.