What do westwide simulations suggest for climate changes in the 21st century?
* A: Simulated temperatures across the West by the end of the 21st century range from increases of 2 to 3 ºC at the low end of the uncertainty range, and as high as 5 to 6 ºC at the upper end of the uncertainty range (IPCC 2007). Precipitation changes in the West over the next century are more complex and uncertain, however, and differ within subregions. As both the Subtropical Jetstream and the Bermuda High intensify, the summer rains in the Southwest may intensify and shift to the north. Winter rains might decrease in the Southwest but increase in the northern half of the West (Salathé 2006). Interannual and interdecadal variability via El Niño-La Niña cycles may intensify (Timmermann et al. 1999), producing extreme winter events in both the Southwest and the Northwest.
