April 3, 2013

Rising temperature difference between hemispheres could dramatically shift rainfall patterns in tropics




One often ignored consequence of global climate change is that the Northern Hemisphere is becoming warmer than the Southern Hemisphere, which could significantly alter tropical precipitation patterns, according to a new study by climatologists from the University of California, Berkeley, and the University of Washington, Seattle.

Such a shift could increase or decrease seasonal rainfall in areas such as the Amazon, sub-Saharan Africa or East Asia, leaving some areas wetter and some drier than today.

“A key finding is a tendency to shift tropical rainfall northward, which could mean increases in monsoon weather systems in Asia or shifts of the wet season from south to north in Africa and South America,” said UC Berkeley graduate student Andrew R. Friedman, who led the analysis.