Climate Change Threatens Legacy Coffee

Scientific American

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Rising seas and severe storms are the most talked-about threats of climate change. But here's another: no more coffee. Because rising temperatures may cripple wild populations of Arabica coffee—the most cultivated species in the world. So says a study in the journal PLoS ONE. Aaron P. Davis et al., The Impact of Climate Change on Indigenous Arabica Coffee (Coffea arabica): Predicting Future Trends and Identifying Priorities]

Researchers used climate models to forecast the effects of warming on Arabica coffee trees in Ethiopia, their native range. Under the best-case scenario—meaning fewer emissions and less warming—only a third of today's range would still be suitable for coffee by 2080. And the worst case? Wild arabica could be nearly wiped out in the region.

That's because coffee trees are sensitive to temperature, the researchers say, and they may not be able to colonize new areas fast enough to beat climate change. And that's assuming no direct human impact, like clearing land for grazing, which is already a problem there.

Of course the coffee in your cup doesn't come from wild trees. But wild coffee forests have a much bigger gene pool than cultivated crops, meaning more resistance to disease, pests and drought. Preserving that diversity might just be grounds to act on climate change.

—Christopher Intagliata

[The above text is a transcript of this podcast.]

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