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Climate study shows how melting ice is raising sea level around Antarctica

‘The interaction between air, sea and ice in these seas is central to the stability of the Antarctic Ice Sheet and global sea levels’

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A new study tracks global warming impacts around Antarctica. bberwyn photo.

By Summit Voice

FRISCO — Global warming is upsetting the delicate balance between Antarctic ice, air and sea, University of Southampton scientists said this week, releasing results of a study showing a rapid rise in sea level around the frozen continent.

Based on an analysis of 19 years worth of satellite data, the researcher said sea level around the coast of Antarctica has climbed 2 centimeters more than the global average, driven almost entirely by an increase in freshwater, which is less dense than saltwater. That can cause localized increases in sea level, said Craig Rye, lead author of the paper published in the journal Nature Geoscience. Continue reading

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Antarctica: Life beneath the ice

Antarctic peak.

Science mission finds microbial life beneath Antarctic ice sheets. bberwyn photo.

Simple organisms process basic elements to survive

Staff Report

FRISCO —Tiny organisms living beneath the vast Antarctic ice fields can convert ammonium and methane into the energy required for growth, surviving in one of the most unlikely environments on Earth, according to scientists who studied a subsurface lake that hasn’t seen sunlight for millions of years.

“We were able to prove unequivocally to the world that Antarctica is not a dead continent,” said Montana State University professor John Priscu, the chief scientist of the U.S. project called WISSARD that sampled the sub-ice environment. Continue reading

Climate: Melting Antarctic ice sheets likely to become big factor in sea level rise sooner than thought

‘Official’ IPCC sea level estimates may be too low

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Antarctica ice is becoming a bigger factor in global sea level rise. bberwyn photo.

By Bob Berwyn

FRISCO — Although Antarctica’s vast ice sheets are only a small factor in global sea level rise right now, that’s likely to change in coming decades, scientists said after a new analysis of ocean temperatures around the frozen continent.

“If greenhouse gases continue to rise as before, ice discharge from Antarctica could raise the global ocean by an additional 1 to 37 centimeters in this century already,” says lead author Anders Levermann, with the Potsdam Institute for Climate Impact Research. “Now this is a big range – which is exactly why we call it a risk: Science needs to be clear about the uncertainty, so that decision makers at the coast and in coastal megacities like Shanghai or New York can consider the potential implications in their planning processes,” says Levermann.

The scientists analyzed how rising global mean temperatures resulted in a warming of the ocean around Antarctica, thus influencing the melting of the Antarctic ice shelves. The marine ice sheets in West Antarctica alone have the potential to elevate sea level by several meters – over several centuries. Continue reading

Climate change drives Antarctic fur seal decline

Fur seals on Half Moon Island, in the South Shetland chain, off the Antarctic Peninsula. PHOTO BY BOB BERWYN.

Fur seals on Half Moon Island, in the South Shetland chain, off the Antarctic Peninsula. bberwyn photo.

Survival of the fittest?

By Summit Voice

FRISCO — After studying fur seals around Antarctica for decades, researchers with the British Antarctic Survey say they’re seeing distinct genetic changes related to a changing climate and food availability. But despite a shift  towards individuals more suited to changing environmental conditions, this fitness is not passing down through generations, leaving the fur seal population on South Georgia Island in decline. Continue reading

Climate: Are emperor penguins doomed?

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Emperor penguins in Antarctica. Photo courtesy BAS.

New study projects 50 percent decline by century’s end as sea ice habitat dwindles

Staff Report

FRISCO — Antarctica’s emperor penguins may be colonizing new territory right now, but the long-term outlook for the birds is grim, according to new research showing that changes in sea ice concentration will likely cause most colonies to decline by 50 percent by the end of the century.

Even the most remote reaches of Antarctica won’t be immune to the changes, the study leaders said, describing the results of their findings in a new article in the journal Nature Climate Change.

The study concludes that emperor penguins are fully deserving of an endangered species listing based on global warming threats. The research will help inform federal bio-crats as they ponder a listing under the Endangered Species Act. Continue reading

Environment: Are Antarctica’s emperor penguins going mobile in response to global warming?

Emporer penguins and chicks near the British Antarctic Survey’s Halley Research Station on the Brunt Ice Shelf, Antarctica.

Emporer penguins and chicks near the British Antarctic Survey’s Halley Research Station on the Brunt Ice Shelf, Antarctica. Photo courtesy BAS.

Penguin populations in flux

By Summit Voice

FRISCO — Just six months after scientists documented breeding emperor penguins moving from sea ice to ice-shelf habitat, a new study reinforces the idea that Antarctica’s iconic birds may be more mobile than thought. It’s too early to say for sure, but that could be good news in terms in terms of global warming, which is likely to change the face of the frozen continent in the decades ahead.

The fundamental questions hinge on how dependent the birds are on their icy habitat. Some studies have shown that emperor penguins may suffer as sea ice shrinks, while other researchers recently doubled their estimate for total population numbers. Overall, penguin populations around Antarctica are in a state of flux. Read all our emperor penguin stories here. Continue reading

Climate: Genetic study takes nuanced look at historic penguin response to global warming

Gradual warmup after ice age was beneficial to many species, but rapid rate of current warming may be too much for the flightless birds

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Populations of chinstrap penguins are declining fast as sea ice melts around the Antarctic Peninsula. bberwyn photo.

By Summit Voice

* More Summit Voice stories and photos on penguins here.

FRISCO — A new genetic analysis of historic penguin populations in Antarctica offers a nuanced view of how the flightless birds responded to climate change during the past 30 years. The findings suggests that, between the last ice age and up to around 1,000 years ago, penguin populations expanded as ice retreated and global temperatures warmed.

But warming has accelerated the past few decades; now many species may be declining because ice is retreating too far and too fast, according to the researchers from the Universities of Southampton and Oxford, who looked at genetic diversity to recreate past population sizes. A report of the research is published in the journal Scientific Reports. Continue reading

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