From: "Rich Gauszka" 


"Mark"  wrote in message
news:433ca1f4$1{at}w3.nls.net...
>
> "Geo"  wrote in message
news:433ca015$1{at}w3.nls.net...
>> "Adam"  wrote in message
>> news:43393e3f$1{at}w3.nls.net...
>>
>>> > so what is 30 years on a cosmic timescale? When they
start saying "its
>> the
>>> > strongest storm in 30,000 years" then I'll take
notice and that's
>>> > still
>>> > pretty recent to be making a judgment call like this.
>>
>>> Blimey we'll have evolved to include webbed feet by then.
>>
>> Yeah, forced by climate change no doubt..
>
> That's actually the ultimate solution to all the hand wringing, adapt,
> just as we have since the beginning, just as we will going forward with
> ever more sophisticated technolgy, webbed or not <"hey, did you see the
> webs on that chick?"> 
>
>

Oh goodie - I'm looking forward to being a CO2 breather .

The good news is it looks like the Earth itself can combat global warming -
the bad is that it may take about 150,000 years

http://news.bbc.co.uk/1/hi/sci/tech/3451787.stm

About 180 million years ago, temperatures on Earth rapidly shot up by about
5 Celsius.
The cause is thought to have been a sudden release of huge amounts of
methane from the sea bed. Methane is itself a greenhouse gas but it is
short-lived.

However, it is easily oxidised to carbon dioxide (CO2) which lingers in the
atmosphere for long periods of time.

Mass extinction

Plants and animals were affected by the sudden rise in atmospheric CO2.
Scientists have found evidence of a marine mass extinction during this
period that killed off 84% of bivalve shellfish.

Over a period of about 150,000 years, the Earth returned to normal and life
continued flourishing. How this happened was a mystery, but now scientists
from the Open University in Milton Keynes claim to have a possible answer.

"Our new evidence has shown that this warming caused the weathering of
rocks on the Earth's surface to rapidly increase by at least 400%,"
said Dr Anthony Cohen, who led the research.

"This intense rock-weathering effectively put a brake on global
warming through chemical reactions that consumed the atmosphere's extra
carbon dioxide."

They discovered that intense rock weathering coincided with warm conditions
and high atmospheric CO2.

'Methane burp'

Weathering occurs through the action of rain. Although the researchers did
not uncover direct evidence for increased precipitation, they believe there
were no limitations on water during the period.

The warm conditions caused by the "methane burp" would have sped
up the rate at which weathering occurred. This led to minerals such as
calcium and magnesium eroding from rocks and pouring into the sea.

Calcium combined with CO2, for instance, would have caused the
precipitation of calcium carbonate. This process of CO2 consumption would
have lowered levels of the greenhouse gas on a global scale.

As CO2 levels fell, so did global temperatures.

"Global warming is affecting the climate today, but it's very
difficult to predict what's going to happen," Dr Cohen told BBC News
Online.

"The reason for doing these studies is that you get the whole history.
If you learn what happened then, that can inform how you deal with [the
same problem] in future."

Dr Cohen added that there are still vast reserves of carbon - possibly as
much as 14,000 gigatons - locked up as methane ice in ocean sediments.

If global temperatures reach a critical point, it is possible they might
suddenly be released into the atmosphere causing a similar event to the one
that occurred during the Jurassic.

"What we have learned from these rocks is how the Earth can, over a
long time, combat global warming. What we need to discover now is why and
at what point it goes into combat mode, and precisely how long the conflict
takes to resolve," he explained.

--- BBBS/NT v4.01 Flag-5