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Friday, 8 September, 2000, 18:39 GMT 19:39 UK
Bacteria 'hasten climate change'
svalbard sunset
The pristine Arctic is a valuable observatory
By environment correspondent Alex Kirby in Ny-Alesund, Svalbard

A Swedish scientist working in the Arctic circle says he believes he has found a way in which nature is speeding up the rate of global warming.

He says more carbon dioxide (CO2) is being released by bacteria in the soil to add to that resulting from human activity.

Dr Kim Holmen has also found levels of another greenhouse gas, methane, are increasing fast.

He believes his discoveries probably mean some disturbing news ahead.

Dr Holmen is associate professor of global change studies and greenhouse gases in the department of meteorology at Stockholm University.

He chairs the greenhouse gas monitoring programme of the World Meteorological Organisation, is working at the Mount Zeppelin air monitoring station at Ny-Alesund, the world's most northerly settlement.

Sensitive

It has a population of about 60 scientists, and is on the west coast of Spitsbergen, the largest island in the Svalbard group, about 600 miles from the North Pole.

svalbard fjord
Industrial pollution is blown north to Svalbard
The Mount Zeppelin station has instruments sensitive enough to detect cigarette smoke two kilometres away. Dr Holmen has been using them to monitor the increase in the atmosphere of several greenhouse gases.

Using as a baseline the amount of CO2 in 1860 (the earliest reliable date, he says) as 290 parts per million (ppm), he has found that it has now reached an annual average of 375 ppm. The figure fluctuates a little according to the season.

Molecule for molecule, methane is 30 times as potent a greenhouse gas as CO2. Dr Holmen has used analysis of Greenland ice cores to establish a baseline for atmospheric methane in 1800 of 700 parts per billion.

In August 2000, he measured it on Mount Zeppelin at 1,850 ppb.

Speaking from Mount Zeppelin, Dr Holmen said: "The increase in the amount of CO2 and methane in the atmosphere is very rapid.

Feeding on itself

"It's quite extraordinary, and we must expect surprises, probably nasty surprises."

Dr Holmen believes he has also found what scientists call a positive feedback - a way in which global warming triggers processes which intensify its effects.

Ten years ago, he says, we knew that pollution was helping to warm the atmosphere. Then, in 1993, the Phillipines volcano Mount Pinatubo erupted, spewing out aerosols which cooled the atmosphere during the two following years.

mount pinatubo smoking
Pinatubo's eruption was instructive
Human influences continued unabated, but were not enough to outweigh Pinatubo's cooling effect. So Dr Holmen concluded that there must be another factor at work as well.

In 1996 the cooling gave way to renewed warming. But Dr Holmen says only part of that is attributable to pollution. The rest, he believes, shows nature taking a hand.

He says: "An outstanding feature of the global carbon cycle has been discovered because of the climatic fluctuation caused by the Mount Pinatubo eruption.

"We've a positive feedback mechanism. We think it releases more CO2 because of the respiration rates of bacteria in the soil. The natural system accelerates global warming."

Uncertainty

He is also concerned at the effect on the atmosphere of aircraft, which can cause high, thin clouds to form.

These trap the Sun's heat and also enhance the greenhouse effect. "The greatest uncertainty is clouds", he says.

"An error of one or two per cent by a computer looking at clouds can make the difference between a warming and a cooling world."

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See also:

06 Sep 00 | Sci/Tech
Global warming 'a reality'
01 Sep 00 | Sci/Tech
Radar probes pollution damage
17 Aug 00 | Sci/Tech
Carbon at 20 million year high
14 Aug 00 | Sci/Tech
Arctic warming gathers pace
21 Jul 00 | Sci/Tech
Greenland's coastal ice thins fast
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