Warmer weather means that Tanzania is producing less coffee as higher temperatures affect yields, hurting both the nation’s producers and coffee drinkers who may pay more per cup, a South African university has found.

 

According to a study conducted by the University of Witwatersrand, researchers have established that higher night-time temperatures are the main factor behind a significant decline in Tanzania’s Arabica coffee yields.

 

Coffee is Tanzania’s largest export crop; on average the country produces around 50,000 metric tons each year of which approximately 70 percent is Arabica. Sales generate over $100 million per year, according to data from Tanzania’s Coffee Board.

 

The East African nation produces less than 1 percent of the world’s Arabic coffee, but the industry employs about 2.4 million people in Tanzania and several millions in neighboring countries.

 

Since 1966, however, coffee production has dropped by 46 percent in Tanzania – a trend research predicts is likely to continue. Over that period, Tanzania’s night-time average temperature has risen by 1.4 degrees Celsius.

 

According to the study, published in the journal Agricultural and Forests Meteorology, for each 1-degree Celsius rise in mean minimum (night-time) temperature, farmers in Tanzania are likely to see a loss of approximately 137 kilograms of coffee per hectare. That is almost half the average small producer’s production, which is currently 225 kilograms per hectare.

 

Negotiators at U.N. climate talks are working toward a global agreement to limit global warming to 2 degrees Celsius – but the world is currently on a path toward at least 4 degrees Celsius of warming by the turn of the century, scientists say.

 

“Our forecast indicates that if the trend continues as has been observed during recent decades, then Arabica coffee production in Tanzania will drop to 145 kg per hectare by the year 2060," the University of Witwatersrand study said.

 

Researchers say the threat to Tanzania’s coffee production should spur the country’s authorities to design climate-smart practices that might help cushion farmers from worsening losses.