Want climate news in your inbox? Sign up here for Climate Fwd:, our email newsletter

Aaron Davis, a British botanist, has spent 30 years trekking across forests and farms to chronicle the fate of one plant: coffee.

He has recorded how a warming planet is making it harder to grow coffee in traditional coffee-producing regions, including Ethiopia, the birthplace of the world’s most popular bean, arabica. He has mapped where farmers can grow coffee next: basically upcountry, where it’s cooler. He has gone searching for rare varieties in the wild.

Now, in what is perhaps his most disheartening research, Dr. Davis has found that wild coffee, the dozens of varieties that once occurred under forest canopies on at least three continents, is at risk of vanishing forever. Among the world’s 124 coffee species, he and a team of scientists have concluded, 60 percent are at risk of extinction in the wild. Climate change and deforestation are to blame.

It matters because those wild varieties could be crucial for coffee’s survival in the era of global warming. In those plants could lie the genes that scientists need to develop new varieties that can grow on a hotter, drier planet.