Rising night time temperatures are affecting Tanzania’s coffee farmers

The warm weather that Tanzania is currently experiencing could negatively affect the nation’s coffee harvest later this year, a South African university has determined.

Despite stating the obvious in their conclusion, the methodology that the research team from the University of Witwatersrand, Johannesburg, used was actually quite interesting.

The study determined that overnight temperatures were having a detrimental effect upon Tanzania’s coffee crops and is the main reason for a stark drop in harvests in recent decades.

Published in the journal Agricultural and Forest Meteorology, the report indicated that for every one degree Celsius rise in night-time temperatures farmers are likely to lose 137kg of coffee per hectare.

This is very serious for Tanzania’s coffee growers because the average yield per hectare for a small holder coffee farmer is 225kg.

Pouring through the available data the research team noted that coffee production has fallen by an alarming forty-six percent since 1966, during which nocturnal temperatures have risen by 1.4 degrees.

“Coffee yields have declined to their lowest point in years,” said Alessandro Craparo, the study’s lead author.

“Many farmers in Tanzania [are] giving up on coffee completely.

“Our forecast indicates that if the trend continues, as [it] has been observed during recent decades, then Arabica coffee production in Tanzania will drop to 145kg per hectare by the year 2060.”

Worryingly, these findings will not only affect jobs and the prosperity of the coffee industry in Tanzania, but in other, major, coffee producing countries as well. Warm weather isn’t solely confined to the African continent.

The report also suggested that Tanzania’s reliance on aging coffee trees was also a contributing factor to the ever diminishing harvests, something which Godsteven Maro of the Tanzanian Coffee Research Institute (TACRI) believes to be have been understated by the Witwatersrand academics.

“To attribute [this] trend solely to the change [in] temperature carries some subjectivity,” he said.