29 April 2015

Global warming to have devastating effect on supply and quality of Arabica coffee

The cup may be half empty when it comes to the future of coffee. Global warming is having a negative effect on global production, affecting the supply, quality and price of your favourite cuppa.


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 neighbouring 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.

Read: What is global warming?

Farmers stand to lose half their production

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.

“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.

In Tanzania, Arabica coffee is cultivated in the southern and northern highlands along the slopes of Mount Kilimanjaro and in the Mbeya region, where the majority of small producers are based.

Alessandro Craparo, the study’s author, told the Thomson Reuters Foundation that if temperature increases follow the trend of the past few decades, coffee yields in Tanzania’s highlands will likely to drop to around 200 kg per hectare by the year 2030.

“Coffee yields have declined to their lowest point in years, with many farmers in Tanzania giving up on coffee completely,” Craparo said.

Temperature changes are unlikely to affect other coffee species such as Robusta, which is grown at lower altitude and is more climate-resilient than Arabica, he said.

Read: World economy harmed by global warming

Tanzania is the tip of the iceberg

According to the study, although governments in coffee-producing countries have invested heavily in the coffee sector, most have not put in place strategies to adapt to climate change, putting at risk the lucrative industry and the jobs of millions of small-scale farmers who depend on coffee.

Coffee is a lucrative industry. In 2009/2010 global coffee exports generated 15.4 billion U.S dollars. The industry employs an estimated 26 million people spread across 52 coffee-producing countries.

Arabica coffee is the most popular type of coffee globally. The International Coffee Organisation states that it currently makes up 60% of the global supply of coffee.

All variants of Arabica coffee can be traced back to Ethiopia. Because of this narrow gene pool, Arabica coffee is particularly susceptible to climate change, National Geographic reports.

Currently, Brazil, Colombia and Ethiopia, the world's three largest producers of Arabica coffee are also under threat from rising temperatures.

The results of a 2012 study published in  Plos One suggests that by 2080, 65% of areas containing wild Arabica coffee will no have the correct climatic conditions for the plants to grow.

Naturally-occurring coffee supplies contribute significantly to production. 25% of Ethiopia's coffee output grows in the wild without the use of irrigation and other sophisticated farming methods.

Based on the current rate of global warming, the future of coffee seems bleak. Without urgent intervention and the implementation of climate control measures, countries such as Tanzania, Ethiopia and Brazil could take a potentially-devastating knock to their economy.

James Teri, the head of TACRI, said Tanzania’s government has taken some measure to deal with the changing conditions, including advising farmer to relocate to higher altitudes in order to sustain coffee quality and quantity.

“We have also introduced new climate-tolerant coffee varieties which have been introduced to farmers in various coffee growing areas,” he said.

Read more:

Coffee drinkers may live longer

Coffee has mysterious benefits for your heart

Why coffee and tea are amazing for you

Image: Black roasted arabica coffee beans and cup full of coffee from Shutterstock

Additional reporting by Health24


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