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Climate: Heat-trapping greenhouse gases the biggest driver of global glacier meltdown

‘In our data we find unambiguous evidence of anthropogenic contribution to glacier mass loss’

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Shrinking glaciers on the Dachstein Mountains in Austria will affect water supplies far downstream in local areas and in distant rivers. bberwyn photo.

Staff Report

FRISCO — Some of the world’s glaciers were shrinking before the onset of unchecked heat-trapping pollution, but the human factor in the glacial equation has grown exponentially in the past few decades.

A new modeling study led by scientists at the University of Innsbruck (Austria) shows that only about 25 percent of the global glacier mass loss during the period of 1851 to 2010 is attributable to anthropogenic causes. However, between 1991 and 2010 the fraction increased to about two-thirds.

“In the 19th and first half of 20th century we observed that glacier mass loss attributable to human activity is hardly noticeable but since then has steadily increased,” said researcher Ben Marzeion, explaining that scaled-down regional models can detect an anthropogenic influence in America and the Alps, where glacier changes are particularly well documented. Continue reading

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Glacier inventory to help with sea level projections

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The world’s glaciers are dwindling.

CU Boulder scientists help lead mapping effort

Staff Report

FRISCO — Lots of quibbling over the exact rate and pace of glacier melt has at least partly obscured the grim reality that many of the world’s glaciated regions will see profound changes in the next few decades as global temperatures continue to rise.

That meltdown will raise sea level, but so far, nobody has been able to quantify the amount precisely. But new data gathered in a study led by University of Colorado, Boulder scientists should help. The team, including researchers from Trent University in Ontario, Canada recently completed the first mapping of virtually all of the world’s glaciers. That enables calculations of their volumes and ongoing contributions to global sea rise as the world warms. Continue reading

South America glacier decline linked with global warming

Temps, not snowfall, drive shrinkage of Peru’s Quelccaya Ice Cap

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The Quelccaya Ice Capis likely shrinking as global temperatures increase. Photo via Edubucher and a Creative Commons share-alike license.

By Summit Voice

FRISCO — Geologists are getting better at unraveling the mysteries of historic glacial episodes, as technology helps understand how the ice sheets respond to climate change.

One recent research project led by scientists from Dartmouth University suggests that temperature is the driving factor in shaping the size of Peru’s Quelccaya Ice Cap. The 17-square mile glacier in the Andes has been shrinking dramatically in the past few decades, making it a global warming symbol.

The findings support the idea that tropical glaciers are rapidly shrinking because of a warming climate — not because of a lack of snowfall. The study results will  help scientists to better understand the natural variability of past and modern climate and to refine models that predict tropical glaciers’ response to future climate change. Continue reading

Climate: Are Greenland’s glaciers speeding up?

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New data shows at least one glacier moving at a record pace of 50 feet per day

By Summit Voice

FRISCO — Arctic ice researchers say detailed measurements show that one Greenland’s glaciers has been moving at a record speed the past few years.

The scientists with the University of Washington and the German Space Agency measured the movement of the Jakobshavn Isbræ (Jakobshavn Glacier) in 2012 and 2013, concluding that the glacier is moving four times as fast as during the 1990s.

“We are now seeing summer speeds more than 4 times what they were in the 1990s on a glacier which at that time was believed to be one of the fastest, if not the fastest, glacier in Greenland,” said Ian Joughin, a researcher at the Polar Science Center, University of Washington and lead-author of the study. Continue reading

Climate: Melting Himalayan glaciers threaten farms

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A NASA Earth Observatory image shows the high peaks of the snow-capped Himalaya Mountains.

New study documents pace of ice loss in world’s tallest mountain

By Summit Voice

FRISCO — Melting Himalyan glaciers may not be causing a direct rise in sea level, but in some cases, the water is causing lakes overflow, flooding valuable agricultural land.

Glaciers are important indicators of climate change. Global warming causes mountain glaciers to melt, which, apart from the shrinking of the Greenlandic and Antarctic ice sheets, is regarded as one of the main causes of the present global sea-level rise.

Tibet’s glaciers have been losing mass at the rate of about 16 gigatons per year for the past decade. That loss is spread across about 80 percent of Tibet’s glaciers, according to Tobias Bolch, a glaciologist from the University of Zurich. That’s more than four times the volume of water in Lake Zurich and around six percent of the total loss in mass of all the glaciers on Earth. Continue reading

Study confirms rapid warming in European Alps

Does industrial soot play a role in the meltdown of Alpine glaciers?

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How long will the European Alps remain snow-clad? Photo courtesy NASA Earth Observatory.

By Summit Voice

FRISCO — With temperatures in the European Alps rising twice as fast as the global average, there’s little hope of saving some of the world’s most famous glaciers without immediate and significant cuts in greenhouse gas emissions.

And there’s little doubt that the warming is caused by those emissions. Findings from a new study presented this week at the American Geophysical Union conference show the sudden onset of warming about 30 years ago. The study, led by researchers with the Byrd Polar Research Center at Ohio State, offers new and compelling evidence that the Italian Alps are warming at an unprecedented rate. Continue reading

Climate: Study eyes speed of Antarctic glaciers

Findings may help fine-tune sea level rise projections

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Melting Antarctic glaciers are contributing to sea level rise. bberwyn photo.

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A NASA map shows Antarctica’s major glaciers.

By Summit Voice

FRISCO — Calculating the speed of glaciers in Antarctica is a key piece of information for climate scientists trying to project sea level rise, but until recently, they haven’t been able to include information about what’s happening beneath the ice, where the glaciers meet the ground.

It turns out there are narrow strips of dirt and rock creating friction zones that slow the flow, according to scientists with Princeton University and the British Antarctic Survey, who used mathematical models, ground-penetrating radar and other instruments to try and determine the lay of the land. Continue reading

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