SAN FRANCISCO (AA) – A 30-year study on Alaskan permafrost found vast stores of carbon are likely escaping into the planet’s atmosphere, the National Oceanic and Atmospheric Administration (NOAA) said Wednesday.
The study observed how much methane gas was released from permafrost -- a thick level of frozen soil that encircles the globe near the Arctic Circle.
During a span of three decades, the Alaskan climate warmed considerably but the amount of methane emissions exiting the permafrost appeared stable.
The NOAA, NASA and University of Colorado Boulder scientists saw positive and negative aspects to the findings.
Methane, a carbon gas, has 28 times the global warming ability of carbon dioxide -- gas emitted during various human activities that is linked to climate change.
Scientists claim that arctic permafrost contains 1 trillion tons of carbon, or about 2.5 times as much carbon that has been emitted by humans since the dawn of the Industrial Revolution in the 1700s.
This carbon is still escaping into the atmosphere as the permafrost slowly thaws, scientists note, even if it isn’t being emitted as methane gas.
The study was published Wednesday in the journal Geophysical Research Letters.
“There has been a huge increase in Arctic warming, and while we do see spikes in methane due to short-term temperature changes, we’re not seeing a long-term change in methane levels,” lead author Colm Sweeney of NOAA said in a statement.
By monitoring how the Alaskan permafrost melted, researchers concluded that the massive trove of carbon is being emitted as carbon dioxide.
“It’s happening,” Sweeney said. “It just isn’t showing up as methane.”
Even though the amount of methane emitted hasn’t significantly increased, scientists believe that could change if global warming continues.
“This finding is critical to science’s understanding of how the Arctic is responding to the unprecedented disruption of its climate and the degradation of permafrost,” NOAA said.
- Barry Eitel
- Culture & Science