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Polar Warning: Even Antarctica’s Coldest Region Is Starting to Melt
Polar Warning: Even Antarctica’s Coldest Region Is Starting to Melt
East Antarctica is the coldest spot on earth, long thought to be untouched by warming. But now the glaciers and ice shelves in this frigid region are showing signs of melting, a development that portends dramatic rises in sea levels this century and beyond.
No place on Earth is colder than East Antarctica. Home to the South Pole and making up two-thirds of the southernmost continent, the vast ice sheets of East Antarctica — formed over tens of millions of years — are nearly three miles thick in places. The temperature commonly hovers around -67 degrees Fahrenheit (-55 degrees Celsius); in 2010, some spots on East Antarctica’s polar plateau plunged to a record-breaking -144 degrees F.
Now, however, parts of the East Antarctic are melting.
Research into what’s happening in East Antarctica is still in its early stages. It’s hard to decipher what exactly is taking place on a gigantic continent of ice with just a few decades of satellite data and limited actual measurements of things like snowfall and ocean temperatures. But according to one controversial paperreleased earlier this year, East Antarctica is now, in fact, shrinking, and is already responsible for 20 percent of the continent’s ice loss.
For decades, researchers considered this portion of the continent to be stable. While warming sea and air temperatures have caused ice shelves and glaciers in the lower-altitude, warmer western regions of the Antarctic to melt and collapse, the larger, colder East had seemed an untouchable behemoth. If anything, climate change was expected to bring more snow to its interior, making its ice sheets grow in size.
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World may hit 56m year carbon level by 2159
World may hit 56m year carbon level by 2159
Next stop the Pole? Crocodiles were once common in Arctic waters. Image: By Balaji Malliswamy on Unsplash
Long ago the polar ice vanished and tropical animals swam the Arctic. Greenhouse gases could reach that 56m year carbon level again in 140 years.
LONDON, 26 February, 2019 – Humankind could be about to open the throttle on greenhouse gas emissions and revert to a 56m year carbon level – to a world with a global temperature marked by ice-free poles and crocodiles in the waters of the Arctic.
And it could happen by the year 2159 – just five human generations or 140 years from now.
By then, if humans go on burning ever-greater quantities of fossil fuels to underwrite ever-accelerating destruction of forests, wetlands and savannahs, they will have pumped into the atmosphere about as much carbon as accumulated during a geological period called the Palaeocene-Eocene Thermal Maximum (PETM), a dramatic global warming event that reached its peak 56 million years ago.
The long-ago warming event occurred naturally, and the build-up of carbon dioxide in the atmosphere happened over a timespan of between 3,000 and 20,000 years.
The present sprint from a cool to an uncomfortably warm state will have happened in fewer than 300 years, because greenhouse gases from coal, oil and natural gas fumes are building up in the atmosphere nine or 10 times faster than in the PETM, according to a new study in the American Geophysical Union journal Paleoceanography and Paleoclimatology.
“You and I won’t be here in 2159, but that’s only about four generations away,” said Philip Gingerich, of the University of Michigan and author of the new study. “When you start to think about your children and your grandchildren, and your great-grandchildren, you’re about there.”
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Polar ice loss speeds up by leaps and bounds
Polar ice loss speeds up by leaps and bounds
More ice is melting in Antarctica, threatening much faster sea level rise. Image: By Danielle Barneson Unsplash
North and south, polar ice loss is happening faster than ever. Researchers now have a measure of the accelerating flow into the ocean.
LONDON, 22 January, 2019 – In the last few decades the speed of polar ice loss at both ends of the planet has begun to gallop away at rates which will have a marked effect on global sea levels.
Antarctica is now losing ice mass six times faster than it did 40 years ago. In the decade that began in 1979, the great white continent surrendered 40 billion tons of ice a year to raise global sea levels. By the decade 2009 to 2017, this mass loss had soared to 252 billion tons a year.
And in Greenland, the greatest concentration of terrestrial ice in the northern hemisphere has also accelerated its rate of ice loss fourfold in this century.
Satellite studies confirm that in 2003, around 102 billion tons of ice turned to flowing water or broke off into the ocean as floating bergs. By 2013, this figure had climbed to 393 billion tons a year.
“That’s just the tip of the iceberg, so to speak. As the Antarctic Ice Sheet continues to melt away, we expect multi-metre sea level rise from Antarctica in the coming centuries”
Scientists report in the Proceedings of the National Academy of Sciences that they studied high resolution aerial photographs, satellite radar readings and historic Landsat imagery to survey 18 south polar regions encompassing 176 basins and surrounding islands of Antarctica to take the most precise measurement of ice loss so far.
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