Frogs, salamanders and other amphibians may eventually have no haven left on the globe because of three growing problems, a study predicts.
Scientists have long known that amphibians are under attack from a killer fungus, climate change and shrinking habitat.
But in the study to appear online on Wednesday in the journal Nature, computer models project that in about 70 years those threats will spread, leaving no part of the world immune from at least one of them.
Frogs seem to have the most worrisome outlook, said Dr Christian Hof of the Biodiversity and Climate Research Centre in Frankfurt, the lead author of the study.
Meanwhile, federal scientists in the US are meeting in Missouri this week to monitor the situation and try to figure out solutions.
Several important US species - boreal toads in the Rocky Mountains and the mountain yellow-legged frog in the Sierra Nevada mountains - are shrinking in numbers, said zoologist Steve Corn, who is part of the US Geological Survey's Amphibian Research and Monitoring Initiative.
The western part of the US has the problems worse than does the East.
About a third of the world's amphibian species are threatened with extinction, and 159 species already have disappeared, a 2008 international study found.
Dr Hof's study was the first to look at projections of the three threats by geography and see if they overlap.
While they overlap to some extent, it is not nearly as much as expected. But the wide distribution of threats leaves no refuge for amphibians. The strongest threats seem to be where the most species of amphibians live, concentrating the potential loss of diversity, said Dr Hof and Prof Ross Alford, an amphibian expert at James Cook University in Australia, who was not part of the research.
The biggest threats are seen - mostly from climate change - to frogs and other amphibians in tropical Africa, northern South America and the Andes Mountains, Dr Hof said.
In the northern Andes, which have the largest number of frog species in the world, more than 160 frog species are at risk, he said.
Prof Alford and other outside scientists said they thought Dr Hof's work might be overly pessimistic.
But they said studying the geographic distribution of amphibian threats in the future is important.