http://www.guardian.co.uk/climatechange/story/0,12374,980561,00.html
Global warming
could trigger mass extinction
Press Association
Thursday June 19, 2003
Rising global temperatures
over the next century could trigger
a catastrophe to rival the worst mass extinction in the history
of the planet, leading British scientists warned today.
Researchers
at Bristol University say their studies show that
six degrees of global warming was enough to wipe out up to
95% of the species which were alive on earth at the end of
the Permian period, 250 million years ago.
Up to six degrees
of warming is now predicted for the next
100 years by United Nations scientists from the Intergovernmental
Panel on Climate Change (IPCC), if nothing is done about emissions
of greenhouse gases, principally carbon dioxide, the chief cause
of global warming.
This compares with
a 0.6C rise over the last century,
according to the IPCC.
The Permian mass extinction
is 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
species 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, Professor Michael Benton.
When Life Nearly Died chronicles the geological efforts
leading up to the discovery and its potential implications.
Prof Benton, who was
scientific advisor to the blockbuster
BBC series Walking With Dinosaurs, said: "The end-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 concerned 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 current impacts 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."
