| Summary: | Twentieth-century weather records and temperature proxies (boreholes in the earth, ice cores in Montana glaciers) show temperature increases throughout western North America, northern precipitation increases, but decreases in the Southwest. Montane snowpacks are shrinking, flow patterns in western streams are changing. Climate models predict intensification of these trends, and optimum climate for wine-grape production shifting north out of California to Oregon, Washington, and British Columbia. Massive mountain pine beetle outbreaks are killing lodgepole pines in the Northwest, and in British Columbia where no outbreaks occurred historically. Shifting distributions and timing of plant and animal species are changing structures of natural communities. In Alaska, glaciers are receding, thermofrost is thawing, lakes are disappearing, forests are dying, natives’ coastal villages are no longer protected from erosion by sea ice and must be moved. Climate Warming in Western North America: Evidence and Environmental Effects documents these and other climate changes. https://digitalcommons.usu.edu/usufaculty_monographs/1014/thumbnail.jpg
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