Cultivation of the arabica coffee plant, staple of daily caffeine fixes and economic lifeline for millions of small farmers, is under threat from climate change as the rising temperatures and new rainfall patterns limit the areas where it can be grown, researchers have warned.
Arabica, which has long been prized for its delicate and aromatic flavour, accounts for 70 per cent of the global coffee market share. But it is particularly sensitive to temperature increases, which reduce its growth, flowering and fruiting and make it more susceptible to coffee pests.
With global temperatures forecast to increase by 2-2.5 Celsius over the next few decades, a report predicts some of the major coffee-producing countries will suffer serious losses, reducing supplies and driving up prices.
The joint study, published by the International Centre for Tropical Agriculture (CIAT) under the CGIAR Research Programme on Climate Change, Agriculture and Food Security (CCAFS), models the global suitability of arabica cultivation to see how production will be affected in 2050.
It predicts that Brazil, Vietnam , Indonesia and Colombia - which between them produce 65 per cent of the global market share of arabica - will find themselves experiencing severe losses unless steps are taken to change the genetics of the crops as well as the manner and areas in which it is grown.
Dr Peter Läderach, a CCAFS climate change specialist and co-author of the report, said although some countries would be able to mitigate the "massive impact" of climate change by simply moving their coffee to higher, cooler areas, it was not an option for everyone.
"If you look at the countries that will lose out most, they're countries like El Salvador, Nicaragua and Honduras, which have steep hills and volcanoes," Läderach, said. "As you move up, there's less and less area. But if you look at some South American or east African countries, you have plateaus and a lot of areas at higher altitudes, so they will lose much less."
Without new strategies, says the study, Brazil alone can expect its current arabica production to drop by 25 per cent by 2050.
"In Brazil, they produce coffee on the plains and don't have any mountains so they can't move up," said Läderach.
"What they would have to do is look for adaptation strategies. This study shows that we urgently need to start breeding new varieties and adapting growing practices, like putting in shade to decrease temperatures. But the problem in Brazil is it's very mechanised, and if you put trees there, they won't be able to bring the machines in."
Coffee, the second-most traded commodity after oil, is grown by an estimated 25 million farmers in more than 60 tropical countries, making it a key source of revenue for many developing nations. Läderach said that failure to find new and better ways to grow arabica would have serious consequences for both humans and the environment.
"If you look at Burundi or Uganda or Nicaragua, they depend very heavily on coffee, so they'd miss all that income for the development of their countries," he said. "Environmentally … it brings a lot of benefits like biodiversity and soil and water conservation, and erosion control."
Although developing hardier coffee strains, planting more shade and encouraging farmers to grow other crops would help compensate for the losses wrought by climate change, said Läderach, there were no quick or easy solutions.
There is, however another possibility: With Brazil and Central America forecast to suffer most keenly, arabica production could be shifted not upwards but further eastwards, to Africa, Asia and the Pacific.
But while such a move could revolutionise the coffee industry, it is far from risk-free.
Dr Tim Schilling, executive director of World Coffee Research, which is funded by the global coffee industry, has his doubts. "There's competition for land among other cash crops in Indonesia and the Pacific, and it is unknown whether Africa could build the necessary capacity in terms of politics, business climate, supporting institutions and infrastructure," he said.