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Arctic permafrost may unleash carbon within decades: NASA

Plants remove carbon dioxide from the air during photosynthesis, so increased plant growth means less carbon in the atmosphere

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  • Permafrost in Northern Arctic can potentially become a permanent source of Carbon
  • It was previously thought to be safe from the effects of Global Warming
  • Rising temperature in the Arctic can cause severe carbon emissions

Permafrost in the coldest northern Arctic — formerly thought to be at least temporarily shielded from global warming by its extreme environment — could thaw enough to become a permanent source of carbon to the atmosphere in a few decades, warns a NASA-led study. This will happen in this century, with the peak transition occurring in 40 to 60 years, said the study.

Permafrost in Northern Arctic can become a permanent source of carbon in this century itself, according to NASA. Wikimedia Commons
Permafrost in Northern Arctic can become a permanent source of carbon in this century itself, according to NASA. Wikimedia Commons

Permafrost is soil that has remained frozen for years or centuries under topsoil. It contains carbon-rich organic material, such as leaves, that froze without decaying, NASA said in a statement on Tuesday.

As rising Arctic air temperatures cause permafrost to thaw, the organic material decomposes and releases its carbon to the atmosphere in the form of the greenhouse gases carbon dioxide and methane.

The researchers calculated that as thawing continues, by the year 2300, total carbon emissions from the coldest northern Arctic will be 10 times as much as all human-produced fossil fuel emissions in 2016.

Warmer, more southerly permafrost regions will not become a carbon source until the end of the 22nd century, even though they are thawing now, said the study led by scientist Nicholas Parazoo of NASA’s Jet Propulsion Laboratory in Pasadena, California.

That is because other changing Arctic processes will counter the effect of thawing soil in these regions.

The finding that the colder region would transition sooner than the warmer one came as a surprise, according to Parazoo. The researchers used data on soil temperatures in Alaska and Siberia and a numerical model that calculates changes in carbon emissions as plants grow and permafrost thaws in response to climate change.

They assessed when the Arctic will transition to a carbon source instead of the carbon-neutral area it is today — with some processes removing about as much carbon from the atmosphere as other processes emit.

World is under threat due to Global Warming. Wikimedia Commons

They divided the Arctic into two regions of equal size, a colder northern region and a warmer, more southerly belt encircling the northern region. There is far more permafrost in the northern region than in the southern one.

Over the course of the model simulations, northern permafrost lost about five times more carbon per century than southern permafrost.

The southern region transitioned more slowly in the model simulations, Parazoo said, because plant growth increased much faster than expected in the south.

Also Read: Global warming portends ill for India’s flourishing Dairy sector: Experts

Plants remove carbon dioxide from the air during photosynthesis, so increased plant growth means less carbon in the atmosphere.

According to the model, as the southern Arctic grows warmer, increased photosynthesis will balance increased permafrost emissions until the late 2100s. IANS

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Greenland’s Ice Melting Faster Than Expected: Study

Researchers say the accelerated ice loss is caused by a combination of global warming, as well as the North Atlantic oscillation.

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Greenland
The Greenland ice sheet is seen in southeastern Greenland, Aug. 3, 2017. VOA

Ice in Greenland is melting faster than previously thought, according to a new study published in the Proceedings of the National Academy of Sciences.

The study found that most of Greenland’s rapid ice depletion is from a surprising source — land that is largely devoid of glaciers.

The land in question is from Greenland’s ice sheet itself, which is 10,000 feet thick in places.

Scientists previously focused most of their studies on Greenland’s glaciers, in the southeast and northwest regions of the country, and found that the glaciers have increasingly been dislodging chucks into the ocean.

However, scientists in the newly published study say they realize there is another major source of ice melt, in the country’s southwest region, which is mostly devoid of large glaciers.

Greenland
FILE – An iceberg is seen melting off the coast of Ammasalik, Greenland, July 19, 2007. VOA

They say this suggests that the surface ice is simply melting as global temperatures rise.

“We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers,” said Michael Bevis, lead author of the paper and a professor of geodynamics at Ohio State University. “But now we recognize a second serious problem — increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea.”

Researchers say the ice rate loss across Greenland has increased four-fold since 2003, which they say will lead to a greater sea level rise.

In the 20th century, Greenland has lost around 9,000 billion tons of ice in total, causing about 25 millimeters (1 inch) of sea level rise, according to National Geographic.

Scientists say if all of Greenland’s vast ice sheet were to melt, global sea levels would rise by 7 meters (23 feet) , flooding most coastal developments around the world.

Personnel stand aboard the Finnish icebreaker MSV Nordica as it arrives into Nuuk, Greenland, after traversing the Northwest Passage through the Canadian Arctic Archipelago, July 29, 2017.
Personnel stand aboard the Finnish icebreaker MSV Nordica as it arrives into Nuuk, Greenland, after traversing the Northwest Passage through the Canadian Arctic Archipelago, July 29, 2017. VOA

The latest study used data from NASA satellites, as well as GPS stations across Greenland, to analyze changes in ice mass.

Also Read: New Technology That Can Clean Water Twice As of Now

Researchers say the accelerated ice loss is caused by a combination of global warming, as well as the North Atlantic oscillation, a periodic weather phenomenon that brings warmer air to western Greenland.

Greenland’s much larger neighbor, the Antarctic ice sheet, is also losing ice faster than previously thought, according to a recent study in the Proceedings of the National Academy of Sciences. That study, published earlier this month, found that Antarctic melting has raised global sea levels 1.4 centimeters between 1979 and 2017. (VOA)