Climate change is threatening to put wild arabica coffee at risk of near extinction by 2080, a new study shows.

The "moderate" predictions from researchers at Britain's Royal Botanic Gardens at Kew with scientists in Ethiopia show that indigenous arabica plants, a bank of genetic diversity for the cultivated crop, face a "profoundly negative influence" from a warming planet.

"The extinction of arabica coffee is a startling and worrying prospect," said study co-author author Aaron Davis, head of coffee research at the Royal Botanic Gardens.

The researchers looked at three possible emission scenarios over three time intervals -- 2020, 2050 and 2080 --  in 349 localities across south-western Ethiopia, south-eastern South Sudan  and northern Kenya:

"Our modelling shows a profoundly negative trend for the future distribution of indigenous Arabica coffee under the influence of accelerated global climate change," according to the study.

The Guardian adds:

The researchers conducted two types of analysis. In the locality analysis, they found that the best outcome was for a 65% fall in the number of pre-existing bioclimatically suitable localities and the worst was for a 99.7% drop by 2080.

In the area analysis, the best outcome was a 38% reduction in suitable growing regions and the worst case was a 90% reduction by 2080.

Davis said the predictions were conservative, since the modelling did not factor in large-scale deforestation now taking place in Ethiopia and South Sudan, another Arabica coffee region.

"The models assume intact natural vegetation, whereas the highland forests of Ethiopia and South Sudan are highly fragmented due to deforestation," the researchers wrote.

"Other factors, such as pests and diseases, changes in flowering times, and perhaps a reduction in the number of birds (which disperse the coffee seeds), are not included, and these are likely to have a compounding negative influence."