An unnatural disaster
The sheer scale of the disaster facing the planet shocked those involved in the research. They estimate that more than 1 million species will be lost by 2050.
The results are
described as "terrifying" by Chris Thomas, professor of
conservation biology at
Much of that loss - more than one in 10 of all plants and animals - is already irreversible because of the extra global warming gases already discharged into the atmosphere. But the scientists say that action to curb greenhouse gases now could save many more from the same fate.
It took two years for the largest global collaboration of experts to make the first major assessment of the effect of climate change on six biologically rich regions of the world taking in 20% of the land surface.
The research in
Those in flatter areas
Birds, which had the greatest chance of escape, could in theory move to a more suitable climate but the trees and other habitat they needed for survival could not keep pace and all would die.
Professor Thomas said: "When scientists set about research they hope to come up with definite results, but what we found we wish we had not. It was far, far worse than we thought, and what we have discovered may even be an underestimate."
Among the more startling findings of the scientists was that of 24 species of butterfly studied in Australia, all but three would disappear in much of their current range, and half would become extinct.
In the Cerrado region
In Europe, the continent least affected by climate change, survival rates were better, but even here under the higher estimates of climate change a quarter of the birds could become extinct, and between 11% and 17% of plant species.
One British example is
the Scottish crossbill which is found nowhere else. The future climate in
The crossbill would
need to move to
Commenting on the
findings in Nature, two other scientists, J Alan Pounds and Robert
Puschendorf, who has studied the extinction of frogs
in the mountains of
When other factors as well as increased temperatures were taken into account the extinctions would probably be greater.
"The risk of extinction increases as global warming interacts with other factors - such as landscape modification, species invasions and build-up of carbon dioxide - to disrupt communities and ecological interactions."
So many species are already destined for extinction because it takes at least 25 years for the greenhouse effect - or the trapping of the sun's rays by the carbon dioxide, methane and nitrous oxide already added to the air - to have its full effect on the planet. Deserts, grasslands and forests are already changing to make survival impossible.
discharging of more greenhouse gases, particularly by the
Prof Thomas said it was urgent to switch from fossil fuels to a non-carbon economy as quickly as possible. "It is possible to drastically reduce the output of greenhouse gases into the atmosphere and this research makes it imperative we do it as soon as possible. If we can stabilise the climate and even reverse the warming we could save these species, but we must start to act now."
If conservation groups wanted to save species they should devote at least half their energies to political campaigning to reduce global warming because that was the greatest single threat to survival of the species.
John Lanchbery, climate change campaigner for the Royal Society for the Protection of Birds, agreed: "This is a deeply depressing paper. President Bush risks having the biggest impact on wildlife since the meteorite that wiped out the dinosaurs.
"At best, in 50
years, a host of wildlife will be committed to extinction because of
human-induced climate change. At worst, the outcome does not bear thinking
about. Drastic action to cut emissions is clearly needed by everyone, but