Did Global Warming Cause Earth’s Mass Extinction 250 Million Years Ago?

Fasten your seat belts for tons of controversy and discussion over some scientists’ startling conclusion: Earth’s mass extinction 250 years ago was caused by global warming:

New Delhi, Jan 21 : The biggest mass extinction in the history of earth some 250 million years ago was caused by global warming and not by the impact of asteroid or comet as earlier believed, new evidence has indicated.

In a paper published by Science Express, the online version of the journal Science, yesterday researchers headed by University of Washington scientist Peter Ward said they have found no evidence for an impact at the time of "the Great Dying" 250 million years ago.

Instead, their research indicates the culprit might have been atmospheric warming because of greenhouse gases triggered by erupting volcanoes.

The extinction occurred at the boundary between the Permian and Triassic periods at a time when all land was concentrated in a supercontinent called Pangea.

The Great Dying is considered the biggest catastrophe in the history of life on Earth, with 90 per cent of all marine life and nearly three-quarters of land-based plant and animal life going extinct.

"The marine extinction and the land extinction appear to be simultaneous, based on the geochemical evidence we found," their paper said.

"Animals and plants both on land and in the sea were dying at the same time, and apparently from the same causes too much heat and too little oxygen."