How to save coffee from global warming

COFFEE IS A multi-billion dollar industry that supports the economies of several tropical countries. Roughly 100m farmers depend on it for their livelihoods. Unfortunately for them, and for the many other people around the world for whom coffee is a near-essential adjunct to life, coffee bushes grow best in a rather narrow range of temperatures, so their cultivation is threatened by a changing climate. But a chance discovery by Aaron Davis of the Royal Botanic Gardens, Kew, in Britain, published in Nature Plants, may offer a way out. Dr Davis and his colleagues report that they have tracked down a type of wild coffee which is both pleasant to taste and tolerant of higher temperatures.

The existing coffee market is dominated by Coffea arabica and Coffea canephora. Arabica hails from the highlands of Ethiopia and South Sudan. It prefers temperatures of 18-22°C. Coffea canephora, commonly called robusta, originated at lower elevations in west and central Africa. It was once thought capable of coping with temperatures of 30°C, but recent work suggests that it does not flourish above 24°C.