By Janet Raloff
Some 9 percent of mammal species throughout the Western Hemisphere could, within roughly a century, become climate refugees with no suitable homes, a new study finds. In some areas conditions will be far worse, with 39 to 50 percent of mammals unable to emigrate fast enough to find suitable ecosystems.
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“If species can’t migrate spontaneously, they’re going to go extinct. That’s the bottom line,” says Nina Hewitt of York University in Toronto, a biogeographer who was not involved in the new analyses.
The work is not the first study to gauge whether species will keep pace with climate-induced changes to their environments, including a warming or drying. But earlier efforts merely looked at an ideal climate for some species and then evaluated whether and where these conditions might exist decades down the line. Such studies “assumed if a suitable climate existed, the species would move there,” explains Carrie Schloss of the University of Washington in Seattle. Schloss led the new study, which appeared online the week of May 14 in the Proceedings of the National Academy of Sciences.