That’s because global warming has the potential to be a boon for profit seekers. The reason: a hotter climate could undermine crops, leading to smaller harvests and higher prices. By studying temperature and yield records from 1980 to 2008, the team of academics from Columbia University and Stanford University estimated that the global trend to warmer temperatures has led wheat yields to be 5.5 per cent lower than they would have been had the climate been stable, and corn yields to be 3.8 per cent lower.Some boon - higher food prices - more hunger. And, as a commenter on the Globe and Mail site said "The economic consequences of the instability created when other nations face declining crop yields and difficulty feeding all of their citizens is more likely than not to offset any benefits. One only has to look back to the the economic meltdown two years ago to see how bad things "over there" can cause havoc here."
The reduction spread out over the world was the equivalent to losing the annual corn harvest from Mexico and the wheat harvest of France. There was upside for Canadian farmers from the research. In their number crunching, the researchers noted no effect on yields in Canada and the U.S., because temperatures haven’t risen in those countries as they have elsewhere around the globe. “Pretty much every climate model says that [North American farmers] will get warming too,” but it has not yet been affected by the trend, Dr. Schlenker said.