Socioeconomic impacts of climate change on US water supplies

A greenhouse warning would have major effects on water supplies and demands . A framework for examining the socioeconomic impacts associated with chang es in the long-term availability of water is developed and applied to the h ydrologic implications of the Canadian and British Hadley2 general circulat ion models (GCMs) for the 18 water resource regions in the conterminous Uni ted States. The climate projections of these two GCMs have very different i mplications for future water supplies and costs. The Canadian model suggest s most of the nation would be much drier in the year 2030. Under the least- cost management scenario the drier climate could add nearly $105 billion to the estimated costs of balancing supplies and demands relative to the cost s without climate change. Measures to protect instream flows and irrigation could result in significantly higher costs. In contrast, projections based on the Hadley model suggest water supplies would increase throughout much of the nation, reducing the costs of balancing water supplies with demands relative to the no-climate change case.