2024-01-31 13:24:01
Greenland absorbs more methane, a powerful greenhouse gas that accelerates global warming, than it emits, according to a study by the University of Copenhagen published in the journal Nature Communications Earth & Environment.
• Read also: Greenland has lost 20% more ice than expected over the past 40 years
• Read also: Arctic summer of 2023 was hottest on record
• Read also: In Greenland, polar bears forced to adapt because of global warming
“On average since 2000, the dry areas of ice-free Greenland have consumed more than 65,000 tonnes of methane per year from the atmosphere, while 9,000 tonnes of methane have been released each year from its wetlands ”, noted the university in a press release Wednesday.
These results are encouraging because methane, the second largest contributor to global warming after CO2, is particularly harmful to the environment. It is responsible for around 30% of the rise in temperatures since the industrial revolution, according to the United Nations.
For the researchers, the Greenland phenomenon “is partly explained by the extent of Greenland’s dry areas, where methane from the atmosphere is consumed in the upper layers of the soil, and partly by the fact that areas without ice of Greenland have only been so since the last ice age.
“This means that they have never stored much carbon, which could lead to significant methane emissions, as can be measured elsewhere in the Arctic,” explained geologist Bo Elberling, who led the study.
In Greenland, methane absorption is made possible by a unique group of microorganisms in the upper layer of Arctic soil, which ingest methane that enters the ground from the atmosphere and transform it into carbon dioxide, the effect is less harmful for the climate, it is specified.
Considered by the team as “good news for the climate”, this knowledge could be useful for the development of climate models.
It remains to be seen whether these results can be transposed to the rest of the Arctic, a region considered “a climatic time bomb”.
“The conclusion is not that Greenland will have an impact on the total amount of global atmospheric methane or that it will be decisive for methane budgets in the Arctic,” emphasize the researchers.
“Greenland’s methane uptake is simply too low compared to other known methane sources” such as Siberia, they add.
Methane lasts 12 years in the atmosphere, compared to centuries for carbon dioxide, but it has a greenhouse effect 25 times more powerful than CO2.
It is notably released into the atmosphere with the thawing of permafrost (or permafrost) in the Arctic, in turn fueling increased warming, and therefore continued thawing.
1706715703
#Greenland #methane #sink #emissions #source