Why global warming threatens east African coffee

JEREMIAH LETTING learned about coffee from his father. As a child in the late 1980s, he worked on his family’s one-acre (0.4 hectare) coffee farm in the hills of Nandi county, western Kenya. The cycle ran like clockwork: cultivate, plant, ripen, harvest and sell. “Every year was the same,” he says. “It was timely.”No longer. As the chairman of a co-operative, he now represents 303 smallholder coffee farmers who are suffering from droughts, unpredictable rains and rising temperatures that bring pests and disease. Warming weather in east Africa, the birthplace of coffee, is already beginning to harm one of the region’s most important export crops, which is worth some $2bn a year (see chart). Overheating coffee shrubs also foreshadow the harm that may befall other vital crops such as tea, Kenya’s biggest export. And if coffee becomes more expensive or less tasty, it is not just farmers who will suffer, but the big chunk of humanity who together glug down some 3bn cups of the stuff a day, at a cost of about $200bn a year.