Climate change will bring scorching summers, NASA scientists say

CBC.ca: NASA scientists predict average summer temperatures in the eastern United States will rise as much as five degrees Celsius by the 2080s as a result of global warming from rising amounts of greenhouse gases.

The study's climate model predicts temperatures in the region higher than those predicted by global models used by the Intergovernmental Panel on Climate Change, which said temperatures would rise between two and 3.5 degrees C in the same region by 2100.

This difference in predicted temperature is in large part because the NASA model takes into account the variation of rainfall in the region, said lead author Barry Lynn of NASA's Goddard Institute for Space Studies.…

The authors contend that previous future models of global climate also predict precipitation that falls too frequently and falls too early in the day. Both of these predictions would lead to increased daytime cloud cover, blocking sunlight that would otherwise cause surface temperatures to rise.

"Since the weather prediction model simulated the frequency and timing of summer precipitation more reliably than the global model, its daily high temperature predictions for the future are also believed to be more accurate," added co-author Leonard Druyan, of the NASA Goddard Institute for Space Studies and Columbia University.

The study is published in the April 2007 issue of the American Meteorological Society's Journal of Climate.