Al Jazeera America had an interesting article about recent trends in the yields of coffee production in Tanzania. Farmers there have noticed a 50 percent decrease in yield over the last sixty years. Originally the yield loss was attributed to changes in rainfall, but a recent study by scientists at the International Institute of Tropical Agriculture have indicated that a more likely culprit is a rise of 1.43 degrees Centigrade (about 3 degrees F) in the minimum temperatures over the last 50 years. The rise in nighttime temperatures affects the growth pattern of the coffee plants and also increases the range of pests and diseases which affect the coffee plantations.
You can read the article at https://america.aljazeera.com/articles/2015/8/16/for-tanzanias-coffee-farmers-climate-change-is-a-buzz-kill1.html. The original research article is available at ScienceDirect here.
Farmers receive a tremendous return from coffee. As the climate warms, they are likely to be forced to change to growing bananas and other less lucrative crops, which may impact the economies of the major coffee-producing regions. Consumers are likely to pay higher and higher prices if the yield continues to decline as expected under future warming.
