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Greenland’s largest glacier likely to melt faster than you think: study



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Over the past 20 years, the world ice sheet atop Greenland and Antarctica has become the single largest source of sea level.

In the past 20 years, the world ice sheets above Greenland and Antarctica have been the biggest contributors to sea level rise.

Greenland’s three largest glaciers (which hold enough frozen water to a height of about 1.3 meters above world sea level) could melt faster than their worst warming predictions, according to a study published Tuesday.


By 2000, the main cause of sea level rise was seawater expansion as glaciers melt and warm.

However, over the past 20 years, the global ice sheets in Greenland and Antarctica have been the biggest contributors to sea level rise.

A team of researchers based in Denmark and the UK used historical images and other data to estimate how much ice was lost in Jakobshavn Isbrae, Kangerlussuaq Glacier, and Helheim Glaciers in Greenland in the 20th century.

They found that Jakobshavn Isbrae lost more than 1.5 trillion tons of ice between 1880 and 2012, while Kangerlussuaq and Helheim lost 1.4 trillion tons and 31 billion tons, respectively, between 1900 and 2012.

The melting of glaciers has already contributed more than 8 millimeters to the world’s sea level, researchers say.

Shfaqat Abbas Khan, a researcher at the Danish Institute of Technology, said the use of photographs taken before the satellite era is another tool that can help recreate the ice loss of the last century.

“Historical measurements of the 19th and 20th centuries can hide important information that could greatly improve our future prospects,” he told AFP.

IPCC, the UN’s climate science advisory panel, predicted sea level rise in all sources between 30-110 cm by 2100, depending on emissions.

Under the IPCC’s high emission pathway known as RCP8.5, no action has been taken to contain carbon pollution during the 21st century, leading to a climate that is 3C hotter than pre-industrial levels.

The model for the three glaciers featured in Tuesday’s study was run according to RCP8.5, predicting a 9.1-14.9mm rise in sea level by 2100.

But the thesis Nature CommunicationPointed out that the temperature rise of the high-emission path was more than four times greater than during the 20th century, when three glaciers already added 8 mm to the sea.

“The worst-case scenario is an underestimated one,” Khan said. “The ice loss could be three to four times greater than previous expectations for the glacier considered in this study,” Khan said.

Retreat and thinning of Jakobshavn Isbræ from 1875 to 2012. Source: Shfaqat Abbas Khan, DTU Space Denmark.

nature A study published in September found that if greenhouse gas emissions continued without decline, Greenland’s ice sheet would shed about 36 trillion tonnes this century, which would be enough to lift the world’s waterways by about 10 cm.


Experts warn that the release could raise sea level by 40 cm by 2100.


Additional information:
Centennial reaction to Greenland’s three largest exit glaciers, Nature Communication (2020). DOI: 10.1038 / s41467-020-19580-5, www.nature.com/articles/s41467-020-19580-5

© 2020 AFP

Summons: Greenland’s Largest Glacier Potential to Melt Faster Than Feared: A Study Retrieved From https://phys.org/news/2020-11-greenland-largest-glaciers-faster.html, November 17, 2020 (2020) November 17-

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