Even the modest temperature rise agreed in the International Climate Change Restriction Plan may have shown that ice caps in this century melted so their loss would be "irreversible", experts warned Monday.
The 2015 Paris Agreement limits the nation to a temperature that is "significantly below" two degrees Celsius (3.6 degrees Celsius) above pre-industrial levels and to less than 1.5C if at all possible.
This balm to get 1.5-2C warmer up to 2100 is the best case of a scientist based on our consumption of natural resources and combustion of fossil fuels and will require radical, global changes in lifestyle.
For comparison, the approach of man's usual approach – if we continue to emit greenhouse effect gases at the current level – we will see the Earth heat by as much as 4C.
Scientists have known for decades that the icebergs of Greenland and Antarctica are decreasing, but it is assumed to survive temperatures of 1.5-2C relatively undamaged.
However, according to a new analysis published in the journal Nature Climate Change, even modest global warming can cause irreparable damage to polar ice, contributing to the catastrophic rise in sea levels.
"We say 1.5-2C is close to the boundary for which more dramatic effects from ice sheets can be expected," Frank Fattin, Head of Geographical Sciences, Free University in Brussels and lead author of the study, told AFP.
His team collapsed data on annual temperature rise, ice plate coverage and known melt levels and found that the Greenland and Antarctic ice sheets would reach the "point" at about 2C.
"The existence of a turning point implies that changes to the ice sheets are potentially irreversible – returning to the pre-industrial climate may not stabilize the ice sheet after the spillage has been interrupted," Pattin said.
"Counting this century"
The ice in Greenland and Antarctica contains enough frozen waters to raise the global sea level several meters.
Only the Greenland ice sheet contributed every year since the mid-nineties to grow 0.7 millimeter to the global sea level.
And poles heat up faster than anything else on Earth, and only Greenland is 5C warmer in winter and 2C in the summer since then.
Although scientists predict that hundreds of years will continue to melt even at enormous global temperatures, Monday's study provides further reasons for concern with the only realistic plan of humanity that prevents warming.
Many models of the 1.5-2C scenario allow the threshold to interrupt the short-term, potential heating of the planet for several degrees more, before using carbon and other technologies to bring temperatures up to 2100.
The study warned against this approach, however, saying that the return loop that followed the higher temperatures "would lead to self-indenting melting of the entire ice sheet," even if these lifting would be offset later.
For Greenland, the team said with a 95 percent confidence that a large drop in ice would appear at a warming of 1.8 degrees.
"For Greenland and Antarctica, it is known that the brake points existed for levels of heating that could have been reached by the end of this century," Pattin said.