Posted on 10/23/2007 8:07:09 PM PDT by NormsRevenge
PARIS (AFP) - Global warming could cut a swathe through the planet's species over the coming centuries, warns a study released Wednesday that shows a link between rising temperatures and mass extinctions reaching back half a billion years.
Each of five major eras of declining biodiversity -- including one in which 95 percent of the Earth's species disappeared -- correspond to cycles of severe warming over the 520-million-year period for which there are fossil records.
If emissions of greenhouse gas rise unchecked, the predicted increase in global temperature over the next several hundred years could fall within a similar range as these peaks, said the study, published in a British journal, Proceedings of The Royal Society B.
Previous studies have either looked for patterns in climate change or the causes of particular mass extinctions. But this is the first time the two been paired together to give a perspective over such a long time.
"If our results hold for current warming -- the magnitude of which is comparable with the long-term fluctuations in Earth climate -- they suggest that extinctions will increase," lead author Peter Mayhew said in a statement.
The UN's top panel of climate scientists, which won the Nobel Peace Prize earlier this month, forecasts an average increase by 2100 of between 1.1 C (1.98 F) and 6.4 C (11.52 F), compared to 1980-99 levels.
The trio of researchers, led by Timothy Benton at the University of Leeds in northern England, used sea surface temperatures -- extrapolated from fossilized records of the oxygen and acidity levels -- to determine the fluctuations over tens of millions of years between "greenhouse" and "icehouse" periods.
They then matched this data with changes in the number of plant and animal families inhabiting Earth, also based on fossil records.
The study did not dwell on the likely causes of these bouts of warming, whether natural cycles in the earth's climate or, most recently, to the burning of fossil fuels.
But whatever the causes, the result has been consistently the same: a more or less severe culling of life on Earth.
The death toll included 47 percent of all marine genera -- the classification above species -- and 18 percent of land vertebrate families.
At the end of the Permian period, some 250 million years ago, the planet's worst mass extinction wiped out 95 percent of all species, including 70 percent of land plants, insects and vertebrae.
"Our results provide the first clear evidence that global climate may explain substantial variation in the fossil record in a simple and consistent manner," the study states.
The same correlation held true for a flourishing of new species as well, with new flora and fauna multiplying during the interstices of "greenhouse" and "icehouse" cycles.
The researchers point out that the time-scale of their study does not help in making short-term predictions.
Does this mean we are all gonna die?
Yup, smoke ‘em if ya got ‘em. It was a heck of a ride. ;-)
What a fascinating way of dealing with the inconvenient truth that the Earth has regularly been more warm than it presently is== without human beings to blame.
The study did not dwell on the likely causes of these bouts of warming, whether natural cycles in the earth’s climate or, most recently, to the burning of fossil fuels.
Where did I put those deck chairs...
..or we could move to other planets or solar systems. that’s quite a ways down the road tho..
Sadly, many of us will not survive to see the end of this century.
That's a shame. What can the fossil record tell us about the burning of fossil fuels? Inquiring minds want to know.
This is all nice, but we really need more hysteria. Then, whallah! The solution! Agree to a 500% tax increase, payable to the UN, and all will be solved.
‘..or we could move to other planets or solar systems. that’s quite a ways down the road tho..’
Well, since it was only 66 years from Kitty Hawk to the moon, it may not be that far.
The UN’s top panel of climate scientists, which won the Nobel Peace Prize earlier this month...
Say no more...
At least three other planets have been found to be undergoing recent global warming!
“Each of five major eras of declining biodiversity — including one in which 95 percent of the Earth’s species disappeared — correspond to cycles of severe warming over the 520-million-year period for which there are fossil records.”
What were they driving back then?
yes but they are trying to say that any time there is global warming, we are doomed and if we’re responsible for new warming -oh my what are we gonna do!!
why do you think they tend to live in cold places like canada, sweden and norway?
No, no. PLEASE. Say no more!
I was unaware dinosaures drove SUVs. (?)
-Eddie01
And some of us are damn happy we lived to see this century.
There were very few carbon dioxide generators back then but the earth still warmed. Therefore, GW has nothing to do with man.
Doesn’t that seem so incredibly obvious to a logical human being?
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