Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Thawing permafrost increases greenhouse gas emission from subarctic mires

25.02.2004


The permafrost in the mires of subarctic Sweden is undergoing dramatic changes. The part of the soils that thaws in the summer, the so-called active layer, has become deeper since 1970 and the permafrost has disappeared altogether in some locations. This has lead to significant changes in the vegetation composition and subsequent increase in emissions of the powerful greenhouse gas methane. Methane is 25 times more potent compared to carbon dioxide as greenhouse gas.



Behind these new findings is an international research team lead from the GeoBiosphere Science Centre at Lund University, Sweden. The results have just been published in the prestigious American scientific journal Geophysical Research Letters. The results are unique as there are very few places in the circumpolar North where a multi-decadal comparison of observations is possible. The Abisko region in subarctic Sweden is unique in the circumpolar North with respect to long-term records of climate, permafrost and other environmental variables. There are likewise many historical investigations that recent observations may be compared with. The Abisko area is recognised as part of the international network of Man and the Biosphere Reserves (under the auspices of UNESCO).

In the present study airborne infrared images are used to compare the vegetation distribution in 1970 with that of 2000. Dramatic changes are observed and these are related to the climate warming and decreasing permafrost extent that has been observed over the same period. Also the land-atmosphere exchanges of carbon dioxide and methane has been studied for a long time in Abisko. The exchange of carbon dioxide with ecosystems can either be an atmospheric source or sink while in the case of methane it is predominantly a source. Methane is released from the breakdown of plant material under wet soil conditions.


Permafrost disappearance and subsequent wetter soil conditions have lead to increases in methane emissions.

"At a particular mire, Stordalen, we have been able to estimate an increase in methane emissions of at least 20% but maybe as much as 60% from 1970 to 2000” says one of the researchers Torben R. Christensen at the GeoBiosphere Science Centre at Lund University.

"Despite methane being such an important greenhouse gas it is often forgotten in the discussions around the greenhouse effect. Methane is released from rice agriculture and meat production but the largest single source of methane is the natural wetlands. If what is seen in subarctic Sweden is a representative picture for the circumpolar North this could mean an acceleration in the rate of predicted climate warming.

"The annual mean temperature in Abisko is –0.7ºC but during recent years it has often been above zero. One might imagine the cold subarctic ecosystems as very static but in areas where the mean annual temperature is around zero the ecosystems may be extremely sensitive. The ecosystems are dynamic and their response to climate change is very rapid. This we have seen clearly here in Abisko” says Torben R. Christensen.

Göran Frankel | alfa
Further information:
http://www.lu.se/info/pm/670_pressm.html

More articles from Earth Sciences:

nachricht Lightning, with a chance of antimatter
24.11.2017 | Kyoto University

nachricht A huge hydrogen generator at the Earth's core-mantle boundary
24.11.2017 | Science China Press

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Lightning, with a chance of antimatter

24.11.2017 | Earth Sciences

A huge hydrogen generator at the Earth's core-mantle boundary

24.11.2017 | Earth Sciences

Scientists find why CP El Niño is harder to predict than EP El Niño

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>