Rising global temperatures and subtle changes in seasonal conditions could make 99.7 percent of Arabica-growing areas unsuitable for the plant by 2080, according to a new study by researchers from Kew Gardens.
Although commercial growers could still grow their own crops by watering and artificially cooling them, the wild type has much greater genetic diversity which is essential to help plantations overcome threats like pests and disease.
Identifying new sites where Arabica could be grown away from its natural home in the mountains of Ethiopia and South Sudan could be the only way of preventing the demise of the species, researchers said.
Justin Moat, one of the report's authors, said: The "worst case scenario, as drawn from our analyses, is that wild Arabica could be extinct by 2080. This should alert decision makers to the fragility of the species."
Arabica the most popular bean
Arabica is one of only two species of bean used to make coffee and is by far the most popular, accounting for 70 percent of the global market including almost all fresh coffee sold in high street chains and supermarkets in the U.S. and most of Europe.
A different bean known as Robusta is used in freeze-dried coffee and is commonly drunk in Greece and Turkey, but its high caffeine content makes it much less pleasant to most palates.
The new study, published in the Public Library of Science ONE journal, used computer modeling to predict the survival prospects of Arabica coffee for the first time, based on three different climate change scenarios.
At the very least 65 percent of locations where Arabica is currently grown will become unsuitable by 2080, the study found, while the most extreme model predicted almost 100 percent.
In some areas, such as the Boma Plateau in South Sudan, the demise could come as early as 2020, based on the low flowering rate and poor health of current crops.
Aaron Davis, head of coffee research at the Royal Botanic Gardens, said: "Arabica can only exist in a very specific pace with a very specific number of other variables.
It is mainly temperature but also the relationship between temperature and seasonality – the average temperature during the wet season for example."
Climate change is happening so fast that caffeine farms would have to move their plantations 50m every decade to survive, he added.
The researchers said their estimates were "conservative" because they did not take into account the widespread deforestation taking place in the highland forests where the beans are grown, or other factors such as a drop in the number of birds which spread seeds.
Even if the beans do not disappear completely from the wild, climate change is highly likely to impact on yields and the taste of coffee beans in future decades, they added.
(Source: Daily Telegraph)
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