Published in the December issue of the Annual Review of Ecology, Evolution, and Systematics, her review compiles 866 scientific studies on the ecological effects of human-induced climate change and shows that global warming has already caused extinctions in the most sensitive habitats.
"Polar species, such as polar bears in the Arctic and Adélie and emperor penguins in the Antarctic, are suffering massive population declines," Parmesan said.
A species that now occupies a mountaintop can't go any higher, which is why two-thirds of cloud forest frogs in Costa Rica have already gone extinct, Parmesan said.
Her analysis shows that global warming will continue to cause more extinctions over the next century.
Douglas Futuyma, professor of ecology and evolution at the State University of New York in Stony Brook, agrees.
"There is a grave concern about the prospects of a great number of species," he said. "They are likely to be harmed by temperature changes, by mismatch between their life cycles and the altered seasonal life cycles of species...on which they depend, and by invasion of competing species that are better adapted to warmer conditions."
