Tadesse Gole, currently at the University of Bonn, Germany, claims only an international emergency programme can save the surviving remnants of the wild arabica coffee plants growing in the highland rainforests of south-west Ethiopia.
Over 90% of the coffee drunk in the world comes from a few commercial varieties of arabica bean. But the ability to develop new varieties that can overcome disease depends on the survival of the many wild varieties in Ethiopia.
And these highland forests have lost more than half their trees in the last 30 years.
Cash crop
"We gave the world coffee. Now we hope the international community will collaborate with us to save its genetic base," said Tadesse Gole, in the magazine New Scientist.
He said Ethiopian government plans to protect three forest fragments have foundered for lack of cash.
Arabica beans are so widely used they are the most valuable international commodity after oil.
Most of the coffee is grown on plantations outside Ethiopia from a handful of cultivated varieties created from a few individual bushes.
But these plantations are at risk from disease, such as the coffee rust that hit Brazil in the 1970s. And when disaster strikes, plant breeders turn to Ethiopia for genetic help.
Gene bank
It is home to the largest coffee gene bank, at Jimma, and the even greater genetic reserves scattered through the forests, where arabica bushes make up much of the undergrowth.
But these forests now cover less than 2,000 square kilometres, according to Dr Tadesse.
They are being exploited for timber, and razed to make way for tea plantations and to allow for the mass resettlement of people displaced by the drought in the 1980s.
Dr Tadesse said that, despite the seed banks and plantations, "we know very little about the biology of the wild coffee".
Local farmers who cultivate about 100 traditional varieties in their own gardens may know more about wild coffee than anyone else, he said.
Global problem
Gene banks for coffee outside Ethiopia, in Kenya, Brazil, Colombia, Costa Rica and elsewhere, are also in danger, said Charles Adwanda of Kenya's Coffee Research Foundation.
Coffee genes can only be saved by planting bushes in fields, because the seeds do not survive in cold stores.
"Civil unrest, illegal clearing for narcotics cultivation, and the sale of research land to private developers" are wrecking many of these fields, said Mr Adwanda.
This leaves Ethiopia's threatened forests as the last line of defence against the genetic devastation of the world's favourite drink.