Melting permafrost is no laughing matter
In addition to large quantities of dissolved organic carbon, the water
locked up in the permafrost also contains a high concentration of
ammonium. Under certain conditions, microorganisms in the soil can
convert ammonium to nitrous oxide (N2O), also known as laughing gas. In the upper atmosphere, N2O contributes significantly to the destruction of ozone, while in lower parts of the atmosphere,
it’s 300 more effective at storing heat than carbon dioxide. The gas is
currently ranked third behind CO2 and methane as a contributor to global warming.
Scientists have assumed that only small amounts of N2O were released when the permafrost thawed, but according to research carried out by a team led by Professor Bo Elberling of the University of Copenhagen, that assumption could prove to be erroneous.
Elberling’s team analysed core samples taken from the permafrost in a number of locations across the Arctic.
They found that thawing and draining the soils had little impact on N2O production. But when the drained soil was resaturated with meltwater from the frozen soils, as would happen following thawing, the production of N2O jumped by a factor of more than 20. Almost a third of this gas then escaped into the atmosphere.
‘This study shows that the natural production of laughing gas in the soil of Arctic regions can potentially reach levels that have hitherto only been observed in tropical areas,’ Elberling said.
June 2010
Scientists have assumed that only small amounts of N2O were released when the permafrost thawed, but according to research carried out by a team led by Professor Bo Elberling of the University of Copenhagen, that assumption could prove to be erroneous.
Elberling’s team analysed core samples taken from the permafrost in a number of locations across the Arctic.
They found that thawing and draining the soils had little impact on N2O production. But when the drained soil was resaturated with meltwater from the frozen soils, as would happen following thawing, the production of N2O jumped by a factor of more than 20. Almost a third of this gas then escaped into the atmosphere.
‘This study shows that the natural production of laughing gas in the soil of Arctic regions can potentially reach levels that have hitherto only been observed in tropical areas,’ Elberling said.
June 2010
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