Wednesday, 12 December 2018

Global Warming

The Arctic Is Not Doing Well (at All)

A new "report card" from the National Oceanographic and Atmospheric Administration (NOAA) Arctic Program paints a dire picture for the frozen North. According to the program's 2018 Arctic Report Card, Arctic surface air temperatures are warming twice as fast as in the rest of the globe, while populations of wild reindeer and caribou have tumbled by 50 percent over the last 20 years.

And the Arctic is setting alarming new records all the time. Air temperatures from 2014 to 2018 in the Arctic were warmer than in any prior year dating back to 1900, according to the report. The past 12 years have shown the lowest extents on record of Arctic sea ice. And the Greenland ice sheet is melting faster than it has in at least 350 years.

The annual report is the 13th issued by NOAA's Arctic Program. One of the most dramatic changes in today's Arctic, the report found, is the loss of the region's sea ice. The winter maximum sea ice of 2018, measured in March, was the second lowest in 39 years of record-keeping, behind only 2017. In 1985, the report authors wrote, ice that had survived multiple years of freezing and thawing made up 16 percent of the Arctic's sea ice. Today, that number is a mere 1 percent. The thinner, single-year ice that makes up 99 percent of the ice pack is more prone to melt and flow.

Warming temperatures, lost sea ice and long-term declines in snowpack on land have caused chaos for the Arctic's wildlife. While reindeer are mythologized in Christmas carols, real herds are suffering. Wild reindeer and their fellow foragers, tundra caribou, have been in decline since the 1990s, according to the report. Where there were once 4.7 million animals combined, there are now 2.1 million. Of 22 herds being monitored by researchers today, 20 are on the decline.

Climate is to blame for much of the decline, according to the report. Longer, warmer summers mean more parasites and heat stress for the winter-adapted grazing animals, along with a greater risk of grass-killing drought.

Meanwhile, toxic algal blooms driven by warming waters represent a new threat to marine life in the Arctic, the researchers wrote. Algal toxins have been found in ill or dead animals ranging from seabirds to seals to whales.

East Antarctica glacial stronghold melting as seas warm

A group of glaciers spanning an eighth of the East Antarctica coastline are being melted by the warming seas, scientists have discovered.

This Antarctic region stores a vast amount of ice, which, if lost, would in the long-term raise global sea level by tens of metres and drown coastal settlements around the world.

Freezing temperatures meant the East Antarctica region was until recently considered largely stable but the research indicates that the area is being affected by climate change.

The vast Totten glacier was known to be retreating but the new analysis shows that nearby glaciers in the East Antarctica area are also losing ice.

To the east of Totten, in Vincennes Bay, the height of the glaciers has fallen by about three metres in total since 2008, before which no loss had been recorded.

To the west of Totten, in Wilkes Land, the rate of height loss has doubled since 2009, with glaciers losing height by about two and a half metres to date.

The data comes from detailed maps of ice movement speed and height created by Nasa from satellite information.

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