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Antarctica’s Ice Melting Six Times Faster Due To Global Warming: Study

Warming ocean water will only speed up ice loss in the future.

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Antarctica, Ice
The Collins glacier on King George Island has retreated in the last 10 years and shows signs of fragility, in the Antarctic, Feb. 2, 2018. VOA

Global warming is melting ice in Antarctica faster than ever before — about six times more per year now than 40 years ago — leading to increasingly high sea levels worldwide, scientists warned on Monday.

Already, Antarctic melting has raised global sea levels more than half an inch (1.4 centimeters) between 1979 and 2017, said the report in the Proceedings of the National Academy of Sciences (PNAS), a peer-reviewed US journal.

And the pace of melting is expected to lead to disastrous sea level rise in the years to come, according to lead author Eric Rignot, chair of Earth system science at the University of California, Irvine.

“As the Antarctic ice sheet continues to melt away, we expect multi-meter sea level rise from Antarctica in the coming centuries,” Rignot said.

Iceberg, Antarctica
Iceberg, Antarctica, Pixabay

A rise of 1.8 meters (six feet) by 2100, as some scientists forecast in worst-case scenarios would flood many coastal cities that are home to millions of people around the world, previous research has shown.

For the current study, researchers embarked on the longest-ever assessment of ice mass in the Antarctic, across 18 geographic regions.

Data came from high-resolution aerial photographs taken by NASA planes, along with satellite radar from multiple space agencies.

Researchers discovered that from 1979 to 1990, Antarctica shed an average of 40 billion tons of ice mass annually.

By the years 2009 to 2017, the ice loss had increased more than sixfold, to 252 billion tons per year.

A glacier is shown in a photo taken in Half Moon Bay, Antarctica, Feb. 18, 2018.
A glacier is shown in a photo taken in Half Moon Bay, Antarctica, Feb. 18, 2018. VOA

Even more worrying, researchers found that areas that were once considered “stable and immune to change” in East Antarctica, are shedding quite a lot of ice, too, said the study.

“The Wilkes Land sector of East Antarctica has, overall, always been an important participant in the mass loss, even as far back as the 1980s, as our research has shown,” Rignot said.

Also Read: Emission of CO2 Levels Higher In Antarctica Than Believed

“This region is probably more sensitive to climate than has traditionally been assumed, and that’s important to know, because it holds even more ice than West Antarctica and the Antarctic Peninsula together.”

Warming ocean water will only speed up ice loss in the future, Rignot said.

Recent research has shown that oceans are heating up faster than previously thought, setting new heat records in the last few years. (VOA)

Next Story

Himalayas’ Killer Lakes Expanding as Global Warming Accelerates Melting

Obliterating everything in its path, a burst is predictable only in its destructiveness

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Himalaya, Lakes, Global Warming
A view of the Imja glacial lake controlled exit channel in the Everest region of the Solukhumbu district, 140 km northeast of Kathmandu, Nov. 22, 2018. Nepal's Imja glacial lake would be a miracle to behold, were it not a portent of catastrophic floods. VOA

When a “Himalayan tsunami” roars down from the rooftop of the world, water from an overflowing glacial lake obeys gravity. Obliterating everything in its path, a burst is predictable only in its destructiveness.

“There was no meaning in it,” one person who withstood the waters in India’s Himalayas told a Public Radio International reporter. “It didn’t give anyone a chance to survive.”

Christian Huggel, a professor at the University of Zurich in Switzerland who specializes in glaciology and geomorphodynamics (the study of changing forms of geologic surfaces), said thousands of cubic meters of water moving down a mountain “is really quite destructive and it can happen suddenly.”

That water comes from glacial lake outburst floods, or GLOFs, which are increasing in frequency as climate change increases the rate of glacial melting. This catastrophic lake drainage occurs wherever there are glaciers in places such as Peru and Alaska.

Himalaya, Lakes, Global Warming
The retreating ice of the Pastoruri glacier is seen in the Huascaran National Park in Huaraz, Peru, Aug. 12, 2016. The melting of glaciers has put cities like Huaraz at risk of what scientists call a “glof,” or glacial lake outburst flood. VOA

The most devastating GLOFs occur in the Himalayan regions of India, Pakistan, Afghanistan, Bangladesh, Bhutan, India, Myanmar, Nepal and the Tibetan Plateau. When combined, the area has the third-largest accumulation of snow and ice after Antarctica and the Arctic.

Melting glaciers

In the Himalayas, climate change melted glaciers by a vertical foot and half of ice each year from 2000 to 2016, according to a study released in June’s Science Advances by Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y.

That is twice the rate of melting from 1975 to 2000.

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Local people have noticed the change. In a 2016 interview from the Everest basecamp, Dr. Nima Namgyal Sherpa told VOA that in the past, the glacial streams in the mid-Everest region started flowing in May, but the Sherpas now see the flow beginning in April.

That melted snowpack seeps down to fill mountainside indentations to form glacial lakes. As global warming accelerates the melting, the lakes are expanding, as is their number and threat, monitored in some areas with automated sensors and manual early warning systems by army and police personnel with communication gear.

“Bigger lakes may increase the risk of catastrophic dam failure,” Joseph Shea, a glacier hydrologist at the University of Saskatchewan in Saskatoon, Canada, told the magazine Science.

Today, there are more than a thousand glacial lakes on the Tibetan Plateau, with more than 130 larger than 0.1 square kilometer in Nepal alone. The lakes threaten the livelihoods and lives of tens of thousands of people who live in some of the world’s most remote areas.

Himalaya, Lakes, Global Warming
When a “Himalayan tsunami” roars down from the rooftop of the world, water from an overflowing glacial lake obeys gravity. Pixabay

On June 12, 2016, a GLOF near Mount Everest sent 2 million cubic meters of water toward the Nepalese village of Chukhung, which lost just one outhouse to the torrents, in part because scientists warned residents in the area about the approaching danger.

Weeks later, on July 5, a GLOF near the village of Chaku registered on seismometers, which had been installed after an earthquake the year before, as a “huge pulse of energy,” Kristen Cook, a geologist at the GFZ German Research Center for Geosciences, told EOS, an online site that covers earth and space science news.

Examining satellite images, Cook and her colleagues found the GLOF moved boulders as large as 6 meters in diameter.

Early warning systems 

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This year, on July 7, a GLOF early warning system of weather monitoring stations and river discharge sensors saved lives in Pakistan’s Golain Valley, which has more than 50 glaciers and nine glacial lakes.

The event destroyed villages, roads and bridges, but there were no reported deaths. A shepherd located upstream from the valley called authorities to report the burst, which gave communities downstream as much as an hour to evacuate.

“Our standing crops [and] apple and apricot orchards have been completely destroyed,” Safdar Ali, whose shop was heavily damaged as the water swept away livestock, stored grain, irrigation channels and micro hydropower plants, told Reuters.

“I see no loss of human life this time as a positive,” Amanullah Khan, assistant country director for the U.N. Development Program (UNDP) told Reuters. “It shows our training has been a success.”

The UNDP program, which helped establish flood protection systems in the area starting in 2011, has installed small-scale drainage systems and mini-dams, and taught people in the remote region survival skills, such as simple first aid, because the arrival of skilled emergency help can be delayed by the rugged topography.

The International Center for Integrated Mountain Development (ICIMOD) and other international groups are setting up early warning systems for glacial lakes in Nepal.

Local governments are taking preventive measures, such as removing loose rocks and debris that make the bursts of water even more destructive. Authorities are also draining glacial lakes to reduce the amount of water released by a breach, and they are discouraging settlement in GLOF hazard zones.

“If the lakes burst above the villages up in the Everest area, up between 12,000 to 13,000 feet, there are villages all the way downstream and they will wipe [away] some of these villages,” said Norbu Tenzin Norgyal, whose father, Sherpa Tenzin Norgyal, summited Mount Everest with Sir Edmund Hillary in 1953. “The danger is real.” (VOA)