Regional climate and hydrologic change in the Northern US Rockies and Pacific Northwest: Internally consistent projections of future climate for resource management

Planning for the effects of climate change on natural resources often requires detailed projections of future climate at scales consistent with the processes managers typically consider. While it is numerically possible to produce downscaled climate at very fine scales (<5km), both the absence of a sufficiently dense network of long term climate observations and the presence of local contingencies such as topography and land surface feedbacks from vegetation and snowpack make accurate estimation at these scales difficult and less tractable without very detailed local information. For such purposes as developing adaptation stratgies, vulnerability assessments, climate impacts assessments, and specific resource modeling at landscape scales, downscaled projections can be developed that maximize translation of climatic information from the coarser scales of global climate models (GCMs) to more local scales. This project was designed to provide climate information that meets those needs and creates a basis for more detailed work or for a more comprehensive approach to downscaling and regional climate modeling. The goal of this project was to (1) develop consistent historical and future downscaled climate and hydrologic data and projections using the same methodology for several major river basins in the western United States (Columbia, upper Missouri, upper Colorado, and Great Basins) and (2) summarize that information in forms consistent with the needs of the funding agencies. This report describes where to get the information developed as well as the methods, results obtained, uses of and uncertainties associated with the data and projections.