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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

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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

Study tracks historic Antarctica meltdowns

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Reading the history of Antarctica’s ice sheets is helping climate scientists project the future.

Transition from glacial periods punctuated by sudden surges of ice melt and sea level rise

Staff Report

FRISCO — Even without the addition of heat-trapping greenhouse gases from fossil fuel combustion, the Antarctica ice sheets may be vulnerable to sudden collapse and melting. One such episode, about 14,600 years ago, is thought to have caused sea level to rise by more than 12 feet in just 100 years.

Scientists are racing to understand the dynamics of the Antarctic ice sheets because of the potentially significant consequences of rapid changes, and in one of the newest studies, they’ve traced some of the big iceberg calving events between about 19,000 and 9,000 years ago by analyzing deep sea sediment cores extracted from the region between the Falkland Islands and the Antarctic Peninsula. Continue reading

Study shows precedent for fast Antarctica meltdown

The water in the Antarctic Sound can be smooth as glass, and sometimes look thick and oily, probably because it's so cold. Click on the photo to learn about some of the environmental issues in Antarctica.

The water in the Antarctic Sound can be smooth as glass, and sometimes look thick and oily, probably because it’s so cold. Click on the photo to learn about some of the environmental issues in Antarctica.

“During that time, the sea level on a global basis rose about 50 feet in just 350 years…”

FRISCO — There’s precedent for  rapid meltdown of the Antarctic ice sheets, scientists said this week announcing findings from a new study that tracked the history of the ice sheets back to the last ice age.

The scientists said the Antarctic Ice Sheet began melting about 5,000 years earlier than previously thought coming out of the last ice age — and that shrinkage of the vast ice sheet accelerated during eight distinct episodes, causing rapid sea level rise.

Results of this latest study are being published this week in the journal Nature. It was conducted by researchers at University of Cologne, Oregon State University, the Alfred-Wegener-Institute, University of Hawaii at Manoa, University of Lapland, University of New South Wales, and University of Bonn. Continue reading

Antarctica’s Thwaites Glacier starting to collapse

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Thwaites Glacier, Photo courtesy NASA.

New data means sea level may rise more — and sooner — than expected

Staff Report

FRISCO — Antarctica’s massive, fast-moving Thwaites Glacier is probably going to be history in a couple of centuries, leading to a two-foot rise in global sea level, according to a new study funded by the National Science Foundation.

The glacier is a key piece in the global sea level puzzle, acting as an ice dam, stabilizing and regulating movement toward the sea of the massive West Antarctic Ice Sheet. The ice sheet contains enough ice to cause another 3 to 4 meters (10 to 13 feet) of global sea level rise. Continue reading

Moss springs back to life after 1,500 years in deep freeze

New study offers snapshot of changing world

It may look like grass, but it's not — it's moss.

It may look like grass, but it’s not — it’s moss. bberwyn photo.

Staff Report

FRISCO — Some hardy species of moss may be able to regenerate after surviving for thousands of years buried deep beneath polar ice. Researchers from the British Antarctic Survey and Reading University said their study for the first time shows that some plants have the ability to survive century to millennial scale ice ages.

The research may help scientists better project how polar regions will change in coming decades as ice sheets retreat. The study is the first to show that mosses can survive century to millennial scale ice ages. Continue reading

Report: Ecosystem disruptions expected in Ross Sea

‘Portions of the food web that depend on ice in their life cycles will be negatively impacted, leading to severe ecological disruptions’

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How will changes in the Antarctic food chain affect aquatic mammals? bberwyn photo.

Staff Report

FRISCO — Climate change will fundamentally change The Ross Sea, one of Antarctica’s productive biological regions, but exactly how those changes will play out is hard to predict, scientists said after running computer models combining sea-ice, ocean, atmosphere and ice-shelf interactions.

The region is likely to experience ‘severe ecological disruptions,” a group of scientists wrote in their new study, explaining that rising temperatures and changing wind patterns will create longer periods of ice-free open water, affecting the life cycles of both predators and prey. Continue reading

Climate: Freshwater cap around Antarctica inhibiting natural upwelling of warmer water

Findings may help explain recent expansion of Antarctic sea ice

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Study shows impacts of increased precipitation over Southern Ocean. bberwyn photo.

Staff Report

FRISCO — Enhanced rainfall over the Southern Ocean may be blocking the release of relatively warm waters from the depths, researchers said this week in a study published in Nature Climate Change.

The research shows that salinity at the surface of the Southern Ocean has steadily decreased since the 1950s. This lid of fresh water on top of the ocean prevents mixing with the warm waters underneath. As a result, the deep ocean heat has been unable to get out and melt back the wintertime Antarctic ice pack. Continue reading

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