By Robert Davis, USA TODAY
More than one-third of all species in several regions of the world are at risk of extinction by 2050 if global warming isn't controlled, says an international study out today.
"This study makes it clear that climate change is the most significant new threat for extinctions this century," said co-author Lee Hannah, climate change biologist for the Center for Applied Biodiversity Science at Conservation International, a non-profit, U.S.-based, international conservation organization. "We've got to start thinking about it."
An editorial in Nature agrees:
"The threat to life on Earth is not just a problem for the future. It is part of the here and now."
Air pollution has caused the climate to warm, meaning some plant and animal species must move to higher, cooler ground. At the same time, their natural migratory path has often been blocked by development, trapping them in an environment that no longer supports their life.
"Climate change is asking species to move when there is no place to move to," Hannah says.
Researchers looked 1,103 plant and animal species in six regions — including Australia, Brazil and South Africa — using widely accepted models that predict Earth's temperatures will increase by 2.5 degrees to 10.4 degrees Fahrenheit by 2100.
They found that between 15% and 37% of the studied species will be extinct or nearly extinct by 2050. Earth has about 14 million plant and animal species.
"If these projections are extrapolated globally and to other groups of land animals and plants, our analyses suggest that well over a million species could be threatened with extinction as a result of climate change," said study lead author Chris Thomas of the University of Leeds.
Alastair Fitter, a University of York ecologist who was not involved in the research, said climate change could hasten the effects of deforestation and the impact of invasive, non-native species.
"I think this is going to be third horseman in that particular apocalypse," said Fitter.
The fix, Hannah says, is twofold.
So-called greenhouse gasses, like car exhaust, must be cut fast to halt global warming; and conservation areas must be established "not only where the species is now, but where it will be in the future."