[Several more articles below]
A huge expanse of western Siberia is going through an unprecedented thaw that could speed the rate of global warming dramatically, AP reported Thursday quoting the Guardian.
Scientists recently back from the Russian region say the world’s largest frozen peat bog is melting into shallow lakes. It is thawing for the first time since it formed 11,000 years ago.
The area, a million square kilometers, is equivalent to the size of France and Germany and could release billions of tones of methane, a greenhouse gas, into the atmosphere, the New Scientist said on its website.
The discovery was made by Judith Marquand from Britain’s University of Oxford and botanist Sergei Kirpotin from Russia’s Tomsk State University.
Kirpotin described the situation as an “ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming”.
The whole western Siberian sub-Arctic region has started to thaw, he added, and this “has all happened in the last three or four years”.
Climate scientists were worried by the discovery and warned future global temperature predictions may have to be revised.
“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,” David Viner, a senior scientist at the Climatic Research Unit at Britain’s University of East Anglia, told The Guardian newspaper.
“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,” he told the British daily’s Thursday edition.
The intergovernmental panel on climate change thought in its last major report in 2001 that global temperatures would rise between 1.4 degrees Celsius and 5.8 degrees Celsius between 1990 and 2100.
However, that only considered global warming sparked 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,” Viner said.
source: http://www.mosnews.com/news/2005/08/11/siberianthaw.shtml 14aug2005
THE world's largest frozen peat bog is melting. An area stretching for a million square kilometres across the permafrost of western Siberia is turning into a mass of shallow lakes as the ground melts, according to Russian researchers just back from the region.
The sudden melting of a bog the size of France and Germany combined could unleash billions of tonnes of methane, a potent greenhouse gas, into the atmosphere.
The news of the dramatic transformation of one of the world's least visited landscapes comes from Sergei Kirpotin, a botanist at Tomsk State University, Russia, and Judith Marquand at the University of Oxford.
Kirpotin describes an "ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming". He says that the entire western Siberian sub-Arctic region has begun to melt, and this "has all happened in the last three or four years".
What was until recently a featureless expanse of frozen peat is turning into a watery landscape of lakes, some more than a kilometre across. Kirpotin suspects that some unknown critical threshold has been crossed, triggering the melting.
Western Siberia has warmed faster than almost anywhere else on the planet, with an increase in average temperatures of some 3 °C in the last 40 years. The warming is believed to be a combination of man-made climate change, a cyclical change in atmospheric circulation known as the Arctic oscillation, plus feedbacks caused by melting ice, which exposes bare ground and ocean. These absorb more solar heat than white ice and snow.
Similar warming has also been taking place in Alaska: earlier this summer Jon Pelletier of the University of Arizona in Tucson reported a major expansion of lakes on the North Slope fringing the Arctic Ocean.
The findings from western Siberia follow a report two months ago that thousands of lakes in eastern Siberia have disappeared in the last 30 years, also because of climate change (New Scientist, 11 June, p 16). This apparent contradiction arises because the two events represent opposite end of the same process, known as thermokarsk.
In this process, rising air temperatures first create "frost-heave", which turns the flat permafrost into a series of hollows and hummocks known as salsas. Then as the permafrost begins to melt, water collects on the surface, forming ponds that are prevented from draining away by the frozen bog beneath. The ponds coalesce into ever larger lakes until, finally, the last permafrost melts and the lakes drain away underground.
Siberia's peat bogs formed around 11,000 years ago at the end of the last ice age. Since then they have been generating methane, most of which has been trapped within the permafrost, and sometimes deeper in ice-like structures known as clathrates. Larry Smith of the University of California, Los Angeles, estimates that the west Siberian bog alone contains some 70 billion tonnes of methane, a quarter of all the methane stored on the land surface worldwide.
His colleague Karen Frey says if the bogs dry out as they warm, the methane will oxidise and escape into the air as carbon dioxide. But if the bogs remain wet, as is the case in western Siberia today, then the methane will be released straight into the atmosphere. Methane is 20 times as potent a greenhouse gas as carbon dioxide.
In May this year, Katey Walter of the University of Alaska Fairbanks told a meeting in Washington of the Arctic Research Consortium of the US that she had found methane hotspots in eastern Siberia, where the gas was bubbling from thawing permafrost so fast it was preventing the surface from freezing, even in the midst of winter.
An international research partnership known as the Global Carbon Project earlier this year identified melting permafrost as a major source of feedbacks that could accelerate climate change by releasing greenhouse gases into the atmosphere. "Several hundred billion tonnes of carbon could be released," said the project's chief scientist, Pep Canadell of the CSIRO Division of Marine and Atmospheric Research in Canberra, Australia.
source: http://www.physorg.com/news5769.html 14aug2005
The largest frozen peat bog in the world, lying in western Siberia, is melting, according to Russian scientists. The million square kilometre area*, previously permafrost, is becoming a series of increasingly soggy shallow lakes, some already more than a kilometre across.
The melting raises the spectre of vast quantities of methane suddenly being released into the atmosphere. Methane is one of the most potent greenhouse gases, with a warming effect 20 times greater than that of carbon dioxide.
The bogs are thought to contain some 70 billion tonnes of methane, a quarter of all the land-stored methane on the planet.
The researchers, Sergei Kirpotin, a botanist at Tomsk State University, Russia, and Judith Marquand at the University of Oxford, told New Scientist that the whole western Siberian sub-arctic region has begun to melt, and that this has only happened in the last four years. Kirpotin said he had witnessed an "ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming".
The frozen peat bogs formed at the end of the last ice age, around 11,000 years ago. One thing peat bogs do is produce methane, a byproduct of rotting organic material. However, since Siberia has been frozen, most of the methane generated over the last 11,000 years has been trapped in the permafrost.
Now that it is melting, and provided the region stays wet, all that methane will be released into the atmosphere. If the bogs dry out, the methane will have a chance to oxidise to form carbon dioxide before it escapes the bogs, which would lessen the impact.
Siberia is particularly vulnerable to climate change, it seem, and the region has warmed faster than anywhere else on the planet. A positive feedback cycle is created when ice melts, exposing more ground which absorbs more solar energy than ice or snow. This, in combination with regional weather shifts, such as the Arctic oscillation, is thought to be behind the region's three degree increase in average temperatures over the last 40 years. ®
Note: *Almost 50 times the size of Wales, for those who like to keep track of these things
source: http://www.theregister.co.uk/2005/08/11/melting_siberia_threat/ 14aug2005
A vast expanse of western Siberia is undergoing an unprecedented thaw that could dramatically increase the rate of global warming, climate scientists warned yesterday.
Researchers who have recently returned from the region found that an area of permafrost spanning 1 million km2 — 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 hike in global temperatures.
The discovery was made by Sergei Kirpotin at Tomsk State University in western Siberia and Judith Marquand at Oxford University and was reported in New Scientist yesterday.
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 1km across.
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 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."
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.
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 scientist at the Met Office's Hadley Centre in Exeter.
But calculations by Sitch and his colleagues show that even if methane seeped from the permafrost over the next 100 years, it would add around 700 million 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 percent to 25 percent increase in global warming, he said.
source: http://www.taipeitimes.com/News/world/archives/2005/08/12/2003267406 14aug2005
The scientists warned the melting permafrost could unleash billions of tons of greenhouse gases into the atmosphere, the Daily Telegraph reported Thursday.
The 360,000 square miles of western Siberia may turn into a watery landscape of shallow lakes and it could release huge quantities of methane trapped in the frozen peat, according to researchers Sergei Kirpotin, a botanist from Tomsk State University in Russia, and Judith Marquand from Oxford University.
Kirpotin told New Scientist the western Siberian sub-Arctic region had begun to melt in the last three or four years in an "ecological landslide that is probably irreversible and undoubtedly connected to climatic warming."
source: http://www.physorg.com/news5769.html 14aug2005