Climate change could severely reduce the areas suitable for wild Arabica coffee before the end of the century.
That is the conclusion of work by a UK-Ethiopian team published in the academic journal Plos One.
It supports predictions that a changing climate could damage global production of coffee - the world's second most traded commodity after oil.
Wild Arabica is important for the sustainability of the coffee industry because of its genetic diversity.
Arabica coffee and Robusta coffee are the two main species used commercially, although the former provides about 70% of production.
The Arabica crops grown in the world's coffee plantations are from very limited genetic stock and are thought to lack the flexibility to cope with climate change and other threats such as pests and diseases.
The researchers from the Royal Botanic Gardens in Kew, UK, and the Environment and Coffee Forest Forum (ECFF) in Addis Ababa, Ethiopia, examined the future distribution of wild Arabica using climate modelling.
They looked at how wild Arabica might be affected under three different carbon emission scenarios and over three time intervals (2020, 2050 and 2080).
When the researchers looked at what would happen in the locations where Arabica was currently grown, the best-case outcome was a 65% reduction in suitable sites by 2080.
The worst-case outcome was a 99.7% reduction by 2080.
A different analytical approach yielded a 38% reduction as the most favourable outcome and a 90% reduction as the least favourable by 2080.
Cause for concern