Animal and plant species have begun dying off or changing sooner than predicted because of global warming, a review of hundreds of research studies contends.
These fast-moving adaptations come as a surprise even to biologists and ecologists because they are occurring so rapidly.
At least 70 species of frogs, mostly mountain dwellers that had nowhere to go to escape the creeping heat, havebecome extinct because of climate change, the analysis says. It also reports that between 100 and 200 other cold-dependent animal species, such as penguins and polar bears are in deep trouble.
"We are finally seeing species going extinct," said University of Texas biologist Camille Parmesan, author of the study. "Now we've got the evidence. It's here. It's real. This is not just biologists' intuition. It's what's happening."
Her review of 866 scientific studies is summed up in the journal Annual Review of Ecology, Evolution and Systematics.
Parmesan reports seeing trends of animal populations moving northward if they can, of species adapting slightly because of climate change, of plants blooming earlier, and of an increase in pests and parasites.
Parmesan and others have been predicting such changes for years, but even she was surprised to find evidence that it's already happening; she figured it would be another decade away.
Just five years ago, biologists, though not complacent, figured the harmful biological effects of global warming were much farther down the road, said Douglas Futuyma, professor of ecology and evolution at the State University of New York in Stony Brook.
"I feel as though we are staring crisis in the face," Futuyma said. "It's not just down the road somewhere. It is just hurtling toward us. Anyone who is 10 years old right now is going to be facing a very different and frightening world by the time that they are 50 or 60."
While over the past several years studies have shown problems with certain species, animal populations or geographic areas, Parmesan's is the first comprehensive analysis showing the big picture of global-warming induced changes, said Chris Thomas, a professor of conservation biology at the University of York in England.
While it's impossible to prove conclusively that the changes are the result of global warming, the evidence is so strong and other supportable explanations are lacking, Thomas said, so it is "statistically virtually impossible that these are just chance observations."
The most noticeable changes in plants and animals have to do with earlier springs, Parmesan said. The best example can be seen in earlier cherry blossoms and grape harvests and in 65 British bird species that in general are laying their first eggs nearly nine days earlier than 35 years ago.
Parmesan said she worries most about the cold-adapted species, such as emperor penguins that have dropped from 300 breeding pairs to just nine in the western Antarctic Peninsula, or polar bears, which are dropping in numbers and weight in the Arctic.
The cold-dependent species on mountaintops have nowhere to go, which is why two-thirds of a certain grouping of frog species have already gone extinct, Parmesan said.
Populations of animals that adapt better to warmth or can move and live farther north are adapting better than other populations in the same species, Parmesan said.
"We are seeing a lot of evolution now," Parmesan said. However, no new gene mutations have shown themselves, not surprising because that could take millions of years, she said.