droughtHere is yet another carbon-cycle amplifying feedback not in most climate models.

On the one hand, the United Nations’ top climate official, Yvo de Boer, announced that:

Climate change has become the prime cause of an accelerating spread of deserts which threatens the world’s drylands.

On the other hand, he pointed out that desertification would, in turn, accelerate climate change:

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You’ll see a sort of feedback mechanism … quite a lot of carbon is captured in soil, so with more desertification (exposing the soil), you also get more CO2 emissions. They are two halves of the same coin.

Well, two sides of the same coin, anyway. But we get his point. He was interviewed at a U.N. desertification conference in Madrid. What’s coming?

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Major deserts like the Sahara, Gobi and Kalahari are all expanding and desertification has begun to threaten countries like Spain and Kazakhstan, where swathes of cropland have had to be abandoned in the last three decades.

The U.N. estimates that more than 250 million people are directly affected by desertification and approximately one billion in over 100 countries are at risk.

But not to worry. Bjørn Lomborg says it’s going to get wetter elsewhere on the planet, so overall we’ll be in better shape. More flooding, you say? Well then, just build better levees …

This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.