Study projects glacier retreat to peak before mid-century under 1.5 degrees Celsius global warming

New Delhi, Dec 15 (PTI) Glacier loss around the world could peak in 2041 with about 2,000 disappearing every year under a global warming of 1.5 degrees Celsius, a study has projected.

After 2041, as smaller glaciers would have already disappeared, yearly loss would see a decline, researchers led by those at ETH Zurich and other institutes in Switzerland and Belgium explained.

Under a global warming of 4 degrees Celsius, the peak occurs in 2055, but around 4,000 glaciers might be lost every year, the authors projected in the study published in the journal Nature Climate Change, adding that in warmer conditions, small as well as large glaciers would vanish completely.

Regions with small glaciers at lower elevations or near the equator were found to be particularly vulnerable -- including the Alps, the Caucasus (between Europe and Asia), the Rocky Mountains (North America), and parts of the Andes (South America) and African mountain ranges that lie in low latitudes.

"In these regions, more than half of all glaciers are expected to vanish within the next ten to twenty years," lead author Lander Van Tricht, a researcher at ETH Zurich's chair of glaciology, said.

"For the first time, we've put years on when every single glacier on Earth will disappear," Van Tricht said.

Co-author Daniel Farinotti, professor of glaciology at ETH Zurich, said, "The results underline how urgently ambitious climate action is needed." The High-Mountain Asia range, which includes the Himalayas and Karakoram, hosts more than a third of the world's glaciers, making it a key contributor to the global glacier distribution, the authors said.

Due to a predominance of glaciers with intermediate sizes, the region could see a peak in glacier extinction around mid-century, strongly reflecting the global pattern, they said.

"Here, using three global glacier models, we project a sharp rise in the number of glaciers disappearing worldwide, peaking between 2041 and 2055 with up to (nearly) 4,000 glaciers vanishing annually," the authors wrote.

The study found that overall, only 18,000 glaciers would remain by 2100 under a global temperature rise of 4 degrees Celsius, whereas at 1.5 degrees Celsius of global warming, around 100,000 would remain.

For the Alps -- Europe's highest, most extensive mountain range -- for a global warming of 1.5 degrees Celsius, 12 per cent of the glaciers would remain, while one per cent would remain at a global temperature rise of 4 degrees Celsius.

Around 4,400 glaciers in North America's Rocky Mountains would endure at 1.5 degrees Celsius of global warming -- a fourth of today's 18,000 glaciers, the researchers found.

Central Asia, which hosts the largest glacier population, currently loses 200-300 glaciers per year -- the rate is projected to peak at about 500 per year under a global warming of 1.5 degrees Celsius, increasing to around 1,100 per year under 4 degrees Celsius of global warming.

Further, there is no region left in the world where glacier numbers are not declining, the researchers said. PTI KRS KRS AMJ AMJ