By Agence France-Presse
Even the moderate temperature increases agreed upon under an international plan to limit climate catastrophe could see ice caps melting enough so that their loss is "irreversible", experts said Monday.
The 2015 Paris Agreement limits the nations so that the temperature rises "well below" at two degrees Celsius (3.6 degrees Celsius) above pre-industrial levels and less than 1.5 c if possible.
This 1.5-2C fastest stage for the year 2100 is the best scenario for scientists based on our consumption of natural resources and combustion of fossil fuels and will require radical and global lifestyle changes.
For comparison, the business approach of men as usual (if they continue to emit greenhouse gases at the current speed) they will see the Earth's heat up to 4C.
Scientists have known for decades that the ice sheets of Greenland and Antarctica are declining, but they were supposed to survive a 1.5 to 2C relatively intact temperature rise.
However, according to a new analysis published in the journal Nature Climate Change, modest global warming may cause irreversible damage to polar ice, contributing to catastrophic elevations.
"We say that 1.5-2C is close to the limit for what can be expected more dramatic effects from the ice sheets," said Frank Frank Pattyn, head of the geosciences department of the Free University of Brussels and author of the main study.
Its equipment dampened data on annual temperature increases, ice sheet coverage and known melting levels and found that ice sheets in Greenland and Antarctica would reach a "tilt point" around 2C.
"The existence of a turning point means that changes in the ice layer are potentially irreversible: returning to a pre-industrial climate may not stabilize the ice layer once the tilt point has crossed," Pattyn said.
"Turning point in this century"
The ice contained in Greenland and Antarctica contains enough frozen water to raise global sea levels to several meters.
The ice sheet of Greenland contributed only 0.7 millimeters to global sea level each year since the mid-1990s.
And the poles warm up faster than anywhere else on the Earth, with Greenland only 5C warmer in winter and 2C in summer since then.
Although scientists would predict that it would take hundreds of years to melt even with huge global temperature increases, Monday's study is causing more concern for the only realistic plan of humanity to prevent fugitive heating.
Many models of the 1.5-2C scenario allow to reduce the threshold in the short term, potentially heating the planet several higher degrees before using carbon capture and other technologies so that temperatures return to the line by 2100.
However, the study warned of this approach, stating that a feedback circuit caused by higher temperatures "would lead to the self-sustaining fusion of the entire ice layer," although the increases were subsequently offset.
For Greenland, the team said 95 percent of the certainty that the largest decline in the ice sheet would occur at 1.8 kilograms.
"By Greenland and Antarctica, the turning points are known for the heating levels that could be reached before the end of this century," said Pattyn.