How Melting Permafrost Is Beginning to Transform the Arctic (Yale 360)
The frozen layer of soil that has underlain the Arctic tundra for millennia is now starting to thaw. This melting, which could release vast amounts of greenhouse gases, is already changing the Arctic landscape by causing landslides, draining lakes, and altering vegetation.
Yale Environment 360
Published at the Yale School of Forestry & Environmental Studies
BY ED STRUZIK • JANUARY 21, 2020
... What we do know is that if the Arctic continues to warm as quickly as climatologists are predicting, an estimated 2.5 million square miles of permafrost — 40 percent of the world’s total — could disappear by the end of the century, with enormous consequences. The most alarming is expected to be the release of huge stores of greenhouse gases, including methane, carbon dioxide, and nitrous oxide that have remained locked in the permafrost for ages. Pathogens will also be released.
But less well appreciated are the sweeping landscape changes that will alter tundra ecosystems, making it increasingly difficult for subsistence indigenous people, such as the Inuit, and Arctic animals to find food. The disintegration of subterranean ice that glues together the peat, clay, rocks, sand, and other inorganic minerals is now triggering landslides and slumping at alarming rates, resulting in stream flows changing, lakes suddenly draining, seashores collapsing, and water chemistry being altered in ways that could be deleterious to both humans and wildlife.
...The rapid thawing of permafrost has enormous implications for climate change. There are an estimated 1,400 gigatons of carbon frozen in permafrost, making the Arctic one of the largest carbon sinks in the world. That’s about four times more than humans have emitted since the Industrial Revolution, and nearly twice as much as is currently contained in the atmosphere. According to a recent report, a 3.6-degrees Fahrenheit ( 2 degrees Celsius) increase in temperature — expected by the end of the century — will result in a loss of about 40 percent of the world’s permafrost by 2100.
Greenhouse gases on the tundra are released in two ways. As permafrost thaws, once-dormant microorganisms break down organic matter, allowing methane and carbon to be released in the atmosphere. Thawing can also open pathways for methane to rise up from reservoirs deep in the earth.
More here from those Trump calls “prophets of doom” or, in other words, scientists doing science.
https://e360.yale.edu/features/how-melting-permafrost-is-beginning-to-transform-the-arctic
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