[Peakoil] Warming hits 'tipping point'

[roland mccall]

Warming hits 'tipping point'

Siberia feels the heat It's a frozen peat bog the size of France and Germany 
combined, contains billions of tonnes of greenhouse gas and, for the first 
time since the ice age, it is melting

Ian Sample, science correspondent
Thursday August 11, 2005
The Guardian

A vast expanse of western Sibera is undergoing an unprecedented thaw that 
could dramatically increase the rate of global warming, climate scientists 
warn today.
Researchers who have recently returned from the region found that an area of 
permafrost spanning a million square kilometres - the size of France and 
Germany combined - has started to melt for the first time since it formed 
11,000 years ago at the end of the last ice age.
The area, which covers the entire sub-Arctic region of western Siberia, is 
the world's largest frozen peat bog and scientists fear that as it thaws, it 
will release billions of tonnes of methane, a greenhouse gas 20 times more 
potent than carbon dioxide, into the atmosphere.
It is a scenario climate scientists have feared since first identifying 
"tipping points" - delicate thresholds where a slight rise in the Earth's 
temperature can cause a dramatic change in the environment that itself 
triggers a far greater increase in global temperatures.
The discovery was made by Sergei Kirpotin at Tomsk State University in 
western Siberia and Judith Marquand at Oxford University and is reported in 
New Scientist today.
The researchers found that what was until recently a barren expanse of 
frozen peat is turning into a broken landscape of mud and lakes, some more 
than a kilometre across.
Dr Kirpotin told the magazine the situation was an "ecological landslide 
that is probably irreversible and is undoubtedly connected to climatic 
warming". He added that the thaw had probably begun in the past three or 
four years.
Climate scientists yesterday reacted with alarm to the finding, and warned 
that predictions of future global temperatures would have to be revised 
upwards.
"When you start messing around with these natural systems, you can end up in 
situations where it's unstoppable. There are no brakes you can apply," said 
David Viner, a senior scientist at the Climatic Research Unit at the 
University of East Anglia.
"This is a big deal because you can't put the permafrost back once it's 
gone. The causal effect is human activity and it will ramp up temperatures 
even more than our emissions are doing."
In its last major report in 2001, the intergovernmental panel on climate 
change predicted a rise in global temperatures of 1.4C-5.8C between 1990 and 
2100, but the estimate only takes account of global warming driven by known 
greenhouse gas emissions.
"These positive feedbacks with landmasses weren't known about then. They had 
no idea how much they would add to global warming," said Dr Viner.
Western Siberia is heating up faster than anywhere else in the world, having 
experienced a rise of some 3C in the past 40 years. Scientists are 
particularly concerned about the permafrost, because as it thaws, it reveals 
bare ground which warms up more quickly than ice and snow, and so 
accelerates the rate at which the permafrost thaws.
Siberia's peat bogs have been producing methane since they formed at the end 
of the last ice age, but most of the gas had been trapped in the permafrost. 
According to Larry Smith, a hydrologist at the University of California, Los 
Angeles, the west Siberian peat bog could hold some 70bn tonnes of methane, 
a quarter of all of the methane stored in the ground around the world.
The permafrost is likely to take many decades at least to thaw, so the 
methane locked within it will not be released into the atmosphere in one 
burst, said Stephen Sitch, a climate scientist at the Met Office's Hadley 
Centre in Exeter.
But calculations by Dr Sitch and his colleagues show that even if methane 
seeped from the permafrost over the next 100 years, it would add around 700m 
tonnes of carbon into the atmosphere each year, roughly the same amount that 
is released annually from the world's wetlands and agriculture.
It would effectively double atmospheric levels of the gas, leading to a 10% 
to 25% increase in global warming, he said.
Tony Juniper, director of Friends of the Earth, said the finding was a stark 
message to politicians to take concerted action on climate change. "We knew 
at some point we'd get these feedbacks happening that exacerbate global 
warming, but this could lead to a massive injection of greenhouse gases.
"If we don't take action very soon, we could unleash runaway global warming 
that will be beyond our control and it will lead to social, economic and 
environmental devastation worldwide," he said. "There's still time to take 
action, but not much.
"The assumption has been that we wouldn't see these kinds of changes until 
the world is a little warmer, but this suggests we're running out of time."
In May this year, another group of researchers reported signs that global 
warming was damaging the permafrost. Katey Walter of the University of 
Alaska, Fairbanks, told a meeting of the Arctic Research Consortium of the 
US that her team had found methane hotspots in eastern Siberia. At the 
hotspots, methane was bubbling to the surface of the permafrost so quickly 
that it was preventing the surface from freezing over.
Last month, some of the world's worst air polluters, including the US and 
Australia, announced a partnership to cut greenhouse gas emissions through 
the use of new technologies.
The deal came after Tony Blair struggled at the G8 summit to get the US 
president, George Bush, to commit to any concerted action on climate change 
and has been heavily criticised for setting no targets for reductions in 
greenhouse gas emissions