Thursday , November 26 2020

Modest warming risks "irreversible" sheet ice sheet, warns study »Manila News Bulletin



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By AFP

Even modestly rising temperatures agreed according to an international plan to limit climate and the climate could see ice caps melt enough this century for their loss to be "irreversible", warned Monday experts.

The Paris Agreement 2015 limits countries to temperatures "below 2 ° C (3.6 ° F) above the pre-industrial level and less than 1.5 ° C, if any.

The ice contained in Greenland and Antarctica contains water and is frozen enough to raise the global sea surface a few meters (GETTY PHOTOS NORTH AMERICA / AFP / File / MARIO TAMA / MANILA BULLININ)

The ice contained in Greenland and Antarctica contains water and is frozen enough to raise the global sea surface a few meters (GETTY PHOTOS NORTH AMERICA / AFP / File / MARIO TAMA / MANILA BULLININ)

This ballpark of getting a 1.5-2C hotter by 2100 is the best case of scientists in case of our consumption of natural resources burning fossil fuels, and will require radical changes, a global lifestyle to achieve.

For the sake of comparison, the business-as-usual approach to humans – if we continue to emit greenhouse gases at the current rate – you will see Earth's temperature at 4C.

Scientists have known for decades that the ice sheets of Greenland and Antarctica are shrinking, but the assumption was that they would maintain a 1.5-2C rise in relative temperature.

However, according to a new analysis published in the journal Nature Climate Change, even modest global warming could irreversibly damage the polar pole, contributing to rising sea levels.

"We say that 1.5-2C is close to the limit for which we can expect more dramatic effects on the ice sheets," said Frank Patten, head of the Department of Geological Sciences, the Free University of Brussels and lead research research.

His team hit data on annual temperature rise, ice sheet coverage, and melting levels, and found that Greenland and Antarctic ice sheets would also reach the "turning point" around 2C.

"The existence of the turning point implies that changes in the ice sheets are irreversible – the return to pre-industrial climate may not stabilize the ice sheet as soon as the turning point passes," Patten said.

"Turning Point This Century"

The ice contained in Greenland and Antarctica contains enough frozen water to lift the global sea surface a few feet away.

Greenland's ice sheet alone has contributed 0.7 millimeters to sea level rise every year since the mid-1990s.

And the poles are heating faster than anywhere else on Earth, with Greenland alone 5C warm in the winter and 2C in the summer since.

Although scientists estimate it will take hundreds of years for them to melt away even with huge global temperature increases, Monday's research provides another reason to worry about humanity's only realistic plan to prevent warming.

Many models of the 1.5-2C scenario allow the threshold to be compromised in the short term, potentially heating the Earth a few degrees higher, before using carbon carbon and other technologies to return temperatures back to the 2100 line.

The study warned against this approach, however, saying that the feedback loop determined by higher temperatures would "lead to self-melting of each ice sheet" even if those later rose offset.

For Greenland, the team said with 95 percent certainty that a large ice sheet decline would occur at a value of 1.8C of warming.

"Both Greenland and Antarctica are known for the turning points at warming levels that can be reached before the end of this century," Patten said.


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