Even the toughest coffee trees may be no match for climate change. A new study of the plant that produces robusta coffee suggests its heat tolerance has been consistently overestimated. Worse yet, when temperatures just slightly cross this point, yields plummet. The findings suggest the multibillion-dollar coffee industry could be facing a much tougher future on even a slightly warmer planet.
The study, published in Global Change Biology, was built on 10 years of yield observations on almost 800 farms across Southeast Asia. The analysis suggests that the optimal temperature range for robusta is 20.5 degrees C, which is markedly lower than the temperatures currently considered optimal. For every 1-degree increase over this new optimal range, yields decrease by 14 percent.