Will Climate Change Really Spur Mass Migrations of Mexicans to the U.S.?

Every time governmentsfail to take serious steps on climate change, it seems the parlor game of predicting what our warmer world will look like heats up. And the newest of those predictions, appearing this week in the Proceedings of the National Academy of Sciences, pokes at what is presently one of the country's most sensitive spots: immigration. Michael Oppenheimer of Princeton published a study that estimates that between 1.4 and 6.7 million people could become climate refugees emigrating from rural Mexico to the United States between now and 2080. That's 2 to 10 percent of the present Mexican population, and it doesn't include people who would make the move for other reasons. Is it a major concern? Yes. How much stock should you put in those statistics? Not much. Oppenheimer and colleagues used projections of decreased agricultural output driven by rising temperatures to get these figures.