http://www.cbc.ca/story/science/national/2005/01/21/extinction-050121.html
SEATTLE – Global warming – not a cataclysmic collision with an asteroid – may have nearly snuffed out life on Earth 250 million years ago, two recent reports suggest.
The biggest mass extinction in the planet’s history, known as the “Great Dying,” eliminated 90 per cent of marine life and nearly three-quarters of all plants and animals on land.
Recently uncovered evidence led many scientists to speculate that a giant meteor crashed to earth and triggered the catastrophe, just like the one believed to have wiped out the dinosaurs millions of years later.
But two studies reported in Thursday’s online edition of the journal Science point to a much slower-acting culprit – global warming.