Global warming over the next century could trigger a catastrophe
to rival the worst mass extinction in the history of the planet, scientists
have warned.
Researchers at Bristol University have discovered that a mere 6 degrees
of global warming was enough to wipe out up to 95 per cent of the species
which were alive on earth at the end of the Permian period, 250 million
years ago.
United Nations scientists from the Intergovernmental Panel on Climate Change
predict up to 6 degrees of warming for the next 100 years if nothing is
done about emissions of greenhouse gases, principally carbon dioxide, the
chief cause of global warming.
The Permian mass extinction is now thought to have been caused by gigantic
volcanic eruptions that triggered a runaway greenhouse effect and nearly
put an end to life on Earth.
Conditions in what geologists have termed this "post apocalyptic greenhouse"
were so severe that only one large land animal was left alive and it took
100 million years for species diversity to return to former levels.
This dramatic new finding is revealed in a book by Bristol
University's head of earth sciences, Michael Benton, which chronicles the
geological efforts leading up to the discovery and its potential implications.
Professor Benton said: "The Permian crisis nearly marked the end of
life. It's estimated that fewer than one in 10 species survived.
"Geologists are only now coming to appreciate the severity of this
global catastrophe and to understand how and why so many species died out
so quickly."
Other climate experts say they are appalled that a disaster of such magnitude
could be repeated within this century because of human activities.
Global warming author Mark Lynas, who recently travelled around the world
witnessing the impact of climate change, said the findings must be a wake
up call for politicians and citizens alike.
He said: "This is a global emergency.
"We are heading for disaster and yet the world is on fossil fuel autopilot.
"There needs to be an immediate phase-out of coal, oil and gas and
a phase in of clean energy sources. People can no longer ignore this looming
catastrophe."
Copyright © 2003. The Sydney Morning Herald
http://www.smh.com.au/articles/2003/06/19/1055828440526.html
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