NSIDC Augsut 2019 Record Greenland melting summer of 2019
An Arctic emergency would bring to the mind of many people
the vast Greeland ice sheet, melting and raising world sea levels,
There are several big concerns about the Greenland ice sheet
under global warming. The Arctic is in an abrupt warming state,
warming in some Arctic regions at up to 3 X the rate of other world regions.
1. Increased summer melting ponds reduce the albedo
cooling of the ice sheet taking more heat into the Arctic
2. The melting from above and below connecteed by ice
stream and rivers will at some point render the ice sheet
in a state of irrreversible slowly sliding into the sea rising world sea slevels,
3. The vast volumes of freahwater added to the Arctic saltwater is slowing
the Arctic Deep Ocean Conveyer current (also called the Thermohaline
and Meridial Overtruning Circulation (MOC). This is most often cited of the
potential abrupt climate changes. If the current stops the warming
Gulf Stream stops and W.Europe would exposed to a year round freezing influence.
Greenland is the second largest ice body in the world, after the Antarctic Ice Sheet.
An ice sheet or ice sheets covering significant parts of Greenland for the last 18 million years
The Greenland Ice Sheet extends about 1.7 million square kilometers (656,000 square miles), covering most of the island of Greenland, three times the size of Texas.
Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth.
The thickness is generally more than 2 km (1.2 mi) and over 3 km (1.9 mi) at its thickest point.
It is not the only ice mass of Greenland – isolated glaciers and small ice caps cover between 76,000 and 100,000 square kilometres (29,000 and 39,000 sq mi) around the periphery.
The current ice sheet is as old as 110,000 years
If the entire 2,850,000 cubic kilometres (684,000 cu mi) of ice were to melt, it would lead to a global sea level rise of 7.2 m (24 ft).
At some point enough ice will have melted from the ice sheet below that its sheer weight will put it an irreversible state of loss to the sea.
But the ice melt is far from the greatest Arctic emergency scenario, which is Artic methane and CO2 feedback hothouse Earth and runaway.
The rapid warming in the Arctic is known as Arctic Amplification and is due to feedbacks involving many parts of the Arctic environment: loss of sea ice and snow cover, changes in land ice and vegetation cover, and atmospheric water vapor.
22 Sept 2015 VIDEO NASA
The hidden meltdown of Greenland
The Sun Aug 2019 report of record Greenland melt with VIDEO