Biologist quoted by Associated Press

Whenever the world's tropical seas warm several degrees, Earth has experienced mass extinctions over millions of years, according to a first-of-its-kind statistical study of fossil records. And scientists fear it may be about to happen again but in a matter of several decades, not tens of millions of years. Four of the five major extinctions over 520 million years of Earth history have been linked to warmer tropical seas, something that indicates a warmer world overall, according to the new study published Oct. 24. "We found that over the fossil record as a whole, the higher the temperatures have been, the higher the extinctions have been," said University of York ecologist Peter Mayhew, the co-author of the peer-reviewed research published in the Proceedings of the Royal Society B, a British journal. In the British study, Mayhew and his colleagues looked at temperatures in 10 million-year chunks because fossil records aren't that precise in time measurements. They then compared those to the number of species, the number of species families, and overall biodiversity. They found more biodiversity with lower temperatures and more species dying with higher temperatures. University of Texas biologist Camille Parmesan, who studies how existing species are changing with global warming but wasn't part of either team, said she was "blown away" by the Mayhew study and called it "very convincing."

The Associated Press
Extinctions Linked to Hotter Temperatures
(Oct. 24)