Climate change may drive wild coffee plants to extinction by 2080, according to research from the Royal Botanic Gardens at Kew in southwest London. Computer modelling has predicted arabica coffee will no longer be able to be grown in up to 99.7 per cent of its original range in Ethiopia and South Sudan if temperatures continue to increase in line with predictions.
The beans, the lifeblood of coffee farmers and baristas alike, are picked from just two cultivated species—Coffea arabica and robusta—with the sweeter arabica making up 70 per cent of the world’s commercial production. The wild populations are regarded as important to the industry because they are a storehouse of genetic diversity that will be a resource for coffee cultivators looking for plants tolerant of pests, drought and diseases such as leaf rust, to which many xvarieties are already susceptible.
The hotter the season, the faster the coffee fruit develops and the lower the quality of the product. Higher temperatures stress the plants and decrease the yield. Changes in the coffee plantations of the Boma Plateau in South Sudan have been observed over the past 70 years—the arabica coffee there has become more sparse, fewer seedlings grow and flower-bud development is down.
As wild coffee plants in Ethiopia are affected by increasing temperatures, so will be those in commercial plantations, worldwide. The Kew Gardens report predicts that as coffee cultivation becomes more difficult, production will fall and farm management (such as irrigation) will intensify. However, the authors urged that more detailed modelling on local and regional scales be undertaken to allow farmers and decision-makers to future-proof their crop.
The results of the Kew study have already caused a good deal of alarm in the West and may prove as motivating for consumers as dire predictions of sea-level rise, ocean acidification or supercharged storms.