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Arctic carbon crisis, thawing permafrost pushes earth toward dangerous climate thresholds.
The tunnel is located north of Fairbanks, Alaska, was hand dug in the 1960’s and is operated by the U.S. Army Cold Regions Research and Engineering Laboratory. This is the place where many scientific investigations of permafrost – the ground that remains frozen throughout several years, are conducted.(Image Credit: NASA/Kate Ramsayer)
New Delhi: New NASA-supported research shows how the warming of the Arctic permafrost will release greenhouse gases that will fuel climate change in the coming decades. For centuries, it has preserved twice the amount of carbon currently in the atmosphere, stretching from Alaska to Siberia. But as the Arctic continues to warm at a rate between two and four times the global average, the permafrost is changing from a sink to a source of greenhouse gases.
Permafrost consists of ground and peat that has remained frozen for thousands of years. But, when these soils melt, microorganisms break down the organic matter, and the release of carbon dioxide (CO₂) and methane (CH₄) occurs. Methane is of particular concern: while it remains in the atmosphere for about 10 years, it warms the planet 28 times stronger than CO₂ during the course of 100 years. This burst of methane suggests that warming from thawing permafrost could actually intensify warming in the short term.
Monitoring emissions in the Arctic region
The study was in the framework of the RECCAP-2 project of the Global Carbon Project and aimed at tracking the emissions of greenhouse gases over the Arctic permafrost that covers 7 million square miles and during the period of 2000-2020. It was a net emitter during this period due in large part to lakes and wetlands where water saturation slows the decomposition of organic matter and prompts methane-producing bacteria. Although some of the CO₂ released into the atmosphere can be absorbed by the existing forests, the level of greenhouse gases in the region augmented global warming.
This comprehensive greenhouse gas budget was assessed using both bottom-up and top-down approaches by scientists. Field observations, ecosystem models, and information from other satellites, including NASA’s Orbiting Carbon Observatory-2 (OCO-2) offered additional information, but the bottom-up approach suggested a more warming effect. The results highlight the difficulties of measuring emissions from a territory so vast and environmentally diverse.
At the same time, the study shows that the Arctic permafrost is increasing near-term warming; long-term trends remain unknown. It means that events like wildfires or heat waves can lead to a strong shift in the emissions-carbon uptake balance. The report is an important starting point for future climate forecasts; the study underscores the importance of tracking permafrost as the Arctic continues to warm.
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