Aaron Davis, head of coffee research at Kew, who co-led the work, said that among coffee species threatened with extinction are some that could be used to breed and develop the coffees ofthe future, including some that have resistance to disease and that can withstand worsening climatic conditions.
Global coffee trade relies on two species - Arabica (Coffea arabica) and Robusta (Coffea canephora).
"There is potential to use previously unutilised or under-utilised wild coffee species to produce new coffee crop cultivars or hybrids, via breeding, that are able to grow in climates that arabica and robusta coffee can not tolerate", Dr Davis said. "The more I study coffee and other crop plants, what I really sincerely believe is that an understanding of the wild ancestors can really tell you a lot about the crop plants themselves", he said in a 2018 interview with the National Post.
Savor that cup of coffee while you can. Some of the threatened species also live within protected lands, increasing their chances of survival-as well as the survival of the animals the coffee depends on to spread its seed. As climate change and disease risks escalate, wild coffee species offer a crucial resource for maintaining the world's coffee supply.
Wild coffee species - and wild varieties of the commercial species - are nearly all in decline due to competition for land use and overharvesting of the coffee plant for timber or firewood.
It's also possible that experimenting with different types of wild coffee could yield tasty new brews.
"There's a market for low-caffeine coffee and, in fact, some of these [wild species] could be a way we produce naturally decaffeinated coffee", Professor Henry said.
According to scientists, the key threat to most wild species of coffee remains the reduction of its habitat due to deforestation, agriculture and livestock.
The researchers called for a major commitment from countries that grow coffee, particularly African countries such as Ethiopia and South Sudan, to "develop and conserve their wild coffee resources [supported] by the worldwide development and conservation communities".
Genetic interbreeding may be the best way to save commercial coffee species.
In the study, researchers used criteria the risk of extinction that have been set by the red book of the International Union for conservation of nature, to all 124 species of coffee.
It had not been seen in the wild since 1954, and has all but vanished from coffee plantations and botanic gardens.
"Certainly some of the wild relatives might offer us options for breeding some of those in the future". A report published previous year by Crop Trust found relatively few coffee plants maintained in gene banks around the world.
Coffee trees, like many tropical plants, have seeds that do not survive the freeze-drying process used in conventional seed banks - 45% of coffee species have not been "backed up" outside the wild.
This is because seed bank storage freezers, even at -20 degrees Celsius, don't cut it when it comes to preserving coffee beans.
The most popular kind of coffee for commercial production, arabica, is already on the endangered species list.