As the Earth’s average surface temperature rises, another degree Celsius will rise 2.5 meters above sea level from Antarctica alone, and a three-degree increase in the frozen continent will see an increase of 6.5 meters, scientists warned on Wednesday.
This catastrophic increase in the global waterline – enough to develop the coastal cities from Mumbai to Miami and displace millions of people – will unfold in hundreds to thousands of years.
But man-made greenhouse gas emissions that can guarantee such an outcome are bound to happen on a time scale measured in decades. Nature.
The most alarming findings of the study are that sea level rise is caused by the disintegration of the Antarctic ice-sheet – in which the oceans have enough frozen water to rise meters to meters – it becomes dramatically larger with each additional degree of warming.
For example, sea level rise would average 1.3 meters (four feet) every first two degrees above pre-industrial levels.
The average surface temperature of the Earth has already risen by one degree since the end of the 19th century, which is enough to increase the intensity of fatal heatwaves, droughts and tropical cyclones.
But above that benchmark from 2C to 6C, the sea level rise will be 2.4 meters per degree of doubling and warming.
At the top of the range, scientists say, climate change will destroy cultures and recreate the world’s coastal maps.
In addition, the result of each added degree will be 10 more meters, pushing the entire ice sheet beyond any compensation point and delivering the oceans to levels not seen for millions of years.
“Ultimately, it is the burning of our coal and oil that determines when and where the extreme temperature threshold in Antarctica can be exceeded,” said Anders Liverman, a climate scientist and co-author of the Potsdam Institute for Climate Impact Research.
“And even if the loss of ice occurs on the scales for a long time, the respective carbon dioxide levels could be reached in the near future.”
A ‘survival threat’
The ice sheet over the top of West Antarctica would be the first, not so low as the hot air, but the warm ocean water would melt beneath the glaciers’ underground and erase their sea-facing edges known as ice sheets.
“These glaciers make up the size of a Florida slide in the ocean,” said Torsten Albrecht, a registered co-author and researcher at the Potsdam Institute.
Once the global warming crosses the 6C threshold, the dynamics change.
“Huge mountains of ice” – up to five kilometers thick – “where the air is warmer, it slowly sinks to lower heights, this melts more on the surface of the ice,” Albrecht added.
The process has already produced rivers of molten water on a sheet of Greenland ice, with a massive loss of more than half a trillion tons last year alone.
This very important and timely study highlights the urgent need to stabilize the increase in surface temperature with the Paris Reason explanation goals, so that the total sea level rise can be limited to a few meters, said Matt Palmer, of the UK’s Met Office Fis sea level rise. The scientist who did not participate in the research.
The 2015 treaty called global warming “well below” at 2C and, if possible, 1.5C.
Commenting on the study, Jonathan Bember, a professor of glaciology at the University of Bristol, told the Science Media Center that the 2C world also poses an existential threat to states across the nation.
“We’re thinking of cutting nations off the map – nothing more serious than that.”
ન્સી Agency France-Press
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