Monday, April 17, 2017

Climate change taking big bite out of alpine glaciers

Across the Alps, glaciers have lost half their volume since 1900. And there is no letting up: Melting has accelerated since 1980. Most Alpine glaciers will be gone by the end of this century, scientists say.

"It's almost time to say farewell to our glaciers," Austrian mountain farmer Siggi Ellmauer said, looking at the craggy summits across the Pyhrn valley. After a tour of the nature camp he's building for school kids, Ellmauer talks about how climate change is reshaping his world.

"As a child, I never would have thought they could vanish. Even 20 years ago there were still patches of ice up there on those north-facing slopes. I've watched, we've all watched the glaciers shrink here and across the country," he said.

"When will they all be completely gone?"

Most glaciers in Austria and across the Alps are going to disappear by 2100, scientists say. There is already enough heat-trapping pollution in the air to melt nearly all the ice, even if greenhouse gas emissions are cut to zero immediately, said climate physicist Carl-Friedrich Schleussner, who works as a scientific advisor for the NGO Climate Analytics.

Some future climate impacts could be mitigated by limiting global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) - but not the demise of alpine glaciers, he added.

A few shards of ice will linger in high shady crags, but the powerful rivers of ice that carved the valleys as recently as 150 years ago will be gone. The climate will probably be too warm for new glaciers to form for centuries to come, Schleussner added.


Glacier ice is the largest reservoir of freshwater on Earth, holding more water than all lakes, rivers, soils and plants combined.


Austria's glaciers are not only losing in length - that is, how far they extend down the valley - they are also becoming thinner, said Anton Neureiter, a glaciologist with Austria's central Institute for Meteorology and Geodynamics (ZAMG) who monitors ice mass on 12 glaciers both north and south of the main crest of the Alps.


A recent update from World Glacier Monitoring Service says the Austrian decline is in line with recent global averages.

Readings from 130 glaciers around the world showed an average thinning of 1.1 meters (3.6 feet) in 2015. Since 1980, the world's glaciers have thinned on average by almost 20 meters (65.6 feet).

The world's glaciers outside the polar regions contain enough water to raise global sea level by 0.3 to 0.6 meters (1 to 2 feet), which would swamp some low-lying islands and worsen coastal flooding during storm surges and hurricanes. About 670 million people would be affected.

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