Some will say this study is  just a wild assumption – that you can’t untangle ‘normal’ droughts from impacts of climate change. First  remember climate change is a force multiplier: it makes droughts and floods far worse than normal. And secondly it is pretty obvious that if temps climb much higher in most parts of Mexico there will be major crop failures and then what are people supposed to do? Lay down and die? They are going to move — wouldn’t you?  — Stephen

From Sci Am magazine:

A reduction in crop yields could spur even more migration from south to north, a new analysis finds

By David Biello

Climate change’s impacts on crop yields may force as many as seven million Mexicans to emigrate to the U.S. over the next 70 years, according to research published July 26 in the Proceedings of the National Academy of Sciences. The study is among the first to attempt to put hard numbers on questions about “environmental refugees” that may be caused by climate change.

“There is a significant response of emigration from Mexico to past climate variations,” says atmospheric scientist Michael Oppenheimer of Princeton University, an author of the study. “Climate changes predicted by the global circulation models would cause several percent of the Mexican population to move north [if] all other factors are held constant.”

via Climate Change May Mean More Mexican Immigration: Scientific American.