An eye-opening study released in October and spotted last week by 350.org shows the effects that full development of Canada's tar sands would have on global food production, and the forecast isn't good particularly for regions already vulnerable to climate change, such as Africa.
David Wheeler at the Center for Global Development put together an analysis assuming that the entire deposit will be mined and the extracted crude oil burned by 2100, which he calculated would release 209 gigatons of carbon into the atmosphere—and, in turn, raising the atmospheric CO2 concentration by 99 parts per million. (Remember why 350.org exists: because 350 ppm is the safe upper limit for CO2 in our atmosphere, according to scientists. And, uh, 99 is a pretty significant percentage of 350.)
Using those calculations to project losses in agricultural productivity by 2080 around the world, Wheeler arrives at the crux of the study [PDF]:
Agricultural productivity losses affect the livelihoods of over 3 billion people in the developing world. The median projected loss is 5.6 percent, with 25 percent of countries experiencing losses of 7.1 percent or greater. Africa suffers disproportionately, with a median loss of 7 percent and impacts extending to a 12.8 percent loss in the worst case. India, with a rural population of 804 million, suffers a 7.9 percent productivity loss.
There is striking asymmetry in regional impacts. Full exploitation of the oil sands deposit by Canada, a high-income country, would have the most severe impacts on regions where the poorest countries are concentrated. Substantially smaller losses are projected for high-income, higher-latitude countries in Europe, North America, and Oceania.