Wired's Brandon Keim questioned The New York Times' Nick Kristof on the premise of an article in the Atlantic called "The Real Roots of Darfur," i.e., that the crisis there is directly tied to climate change and the drying of the Sahel (the semi-desert band between the Sahara and the rest of Africa). Here's Keim's take on Kristof's response;

He knows as much about Darfur as anyone -- and in his words, "the cause-and-effect is overstated." Other countries are experiencing drought, and they're not responding by annihilating entire populations.

Of course, the argument isn't "desertification --> genocide." It's more, like Stephan Faris says in that Atlantic piece, quoting Alex de Waal:

[Environmental degradation] creates very dry tinder. So if anyone wants to put a match to it, they can light it up.