Climate: Not every ice age ends the same way

Meeting in Uruguay, an Antarctic science committe advocated for the 2012 establishment of marine reserves in the Southern Ocean and the Ross Sea. PHOTO BY BOB BERWYN.

How will the meltdown go this time?

Study finds link between Arctic and Antarctic ice sheet meltdowns

Staff Report

FRISCO — Climate shifts have played out in different ways in the past, scientists concluded in a new study, after finding that a dramatic ice sheet collapse at the end of the ice age before last caused widespread climate changes and led to a peak in the sea level well above its present height.

The team found the events 135,000 years ago caused the planet to warm in a different way to the end of the most recent ice age about 20,000 to 10,000 years ago. The findings will help scientists understand the processes that control Earth’s dramatic climate changes, said the leader of the study, Dr. Gianluca Marino of The Australian National University’s School of Earth Sciences. Continue reading

Are Mt. Everest’s glaciers doomed by global warming?

‘The signal of future glacier change in the region is clear: continued mass loss from glaciers is likely’

Researchers taking measurements in the Mera Glacier region of the Dudh Kosi basin. Photo courtesy Patrick Wagnon.

Researchers taking measurements in the Mera Glacier region of the Dudh Kosi basin. Photo courtesy Patrick Wagnon.

Scientists are trying to pinpoint the impacts of global warming on Himalayan glaciers and regional water supplies. Photo courtesy Nasa Earth Observatory.

Scientists are trying to pinpoint the impacts of global warming on Himalayan glaciers and regional water supplies. Photo courtesy Nasa Earth Observatory.

Staff Report

FRISCO —In the worst-case global warming scenario, glaciers in the Mt. Everest region — the roof of the world — could shrink between 70 percent and 99 percent by 2100, scientists said this week, waring of dire downstream consequences for millions of people who rely on water from those ice fields.

“The signal of future glacier change in the region is clear: continued and possibly accelerated mass loss from glaciers is likely given the projected increase in temperatures,” said Joseph Shea, a glacier hydrologist at the International Centre for Integrated Mountain Development, Kathmandu, Nepal, and leader of the study. Continue reading

Global warming meltdown projected for Canada’s glaciers

Ice loss will affect hydropower, freshwater ecosystems

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Staff Report

FRISCO — Global warming is likely to melt up to 70 percent of the glacial ice in western Canada by the end of the century. The meltdown will disrupt ecosystems and power supplies, and also affect water quality and wildlife habitat, according to scientists with the University of British Columbia. Continue reading

Climate: New book details global glacier losses

Most of the world’s ice rivers are shrinking into oblivion

The Dachstein Glacier in Austria has visibly and dramatically decreased in size in just a couple of decades. bberwyn photo.

The Dachstein Glacier in Austria has visibly and dramatically decreased in size in just a couple of decades. bberwyn photo.

By Summit Voice

FRISCO — For mountain dwellers around the world, shrinking glaciers are one of the most vivid symptoms of Earth’s rising fever. Those gleaming mantles of ice have already disappeared from iconic landscapes like Glacier National Park.

Globally, millions of people rely on glacier-regulated stream flows for water supplies, so communities need to prepare for disruptions in the hydrological cycle because it’s becoming increasingly apparent that the meltdown is not going to stop. Continue reading

Climate: Karakoram glaciers to keep growing

Study hints at complexity of forecasting climate change in the mountains

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A NASA Earth Observatory satellite image shows the heart of the Karakoram mountain range in Pakistan, along with the glaciers that supply water for millions of people below.

Staff Report

FRISCO — Teasing localized climate information from global models is tough at any level, and becomes even harder when you factor in the complexities of mountain topography and highly localized and seasonal weather patterns.

But new data has enabled scientists to better understand the long-vexing climate change puzzle of growing glaciers in the Karakoram mountains, a northern range of the greater Himalayas. Understanding the future of glaciers in that region, and around the world, has implications for millions of people who rely on the glaciers for water supplies.

Most glaciers in the Himalayas and around the world have been retreated for the past 150 years, and the melting has accelerated in the last few decades. But the Karakoram glaciers have been stable or growing. The new study says it’s because a unique and localized seasonal pattern keeps the mountain range relatively cold and dry during the summer. Continue reading

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

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

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