Global Warming to Cause Mass Extinctions?

Global warming over the coming century could mean a return of temperatures last seen in the age of the dinosaur and lead to the extinction of up to half of all species, a scientist said on Thursday.

Not only will carbon dioxide levels be at the highest levels for 24 million years, but global average temperatures will be higher than for up to 10 million years, said Chris Thomas of the University of York.

Between 10 and 99 percent of species will be faced with atmospheric conditions that last existed before they evolved, and as a result from 10-50 percent of them could disappear.