Tag: Antarctica

Antarctic krill could take a big global warming hit

A feeding penguin near the Antarctic Peninsula. @bberwyn photo.

Study projects major loss in habitat

Staff Report

Changes in ocean temperatures and sea ice formation around Antarctica could imperil the region’s krill — tiny crustaceans that are at the base of the food chain. Scientists say they’ve already documented a big drop in krill populations since the 1970s. Losing more krill would reduce the amount of food available for whales, penguins, seals, squid, fish and other marine life.

A new study published online in Geophysical Research Letters says up to 80 percent of suitable krill habitat could disappear by 2100. The research examines the effects of a warmer ocean and a decline in sea ice on these small crustaceans, said Andrea Piñones, a marine scientist at Center for Advance Studies in Arid Zones (Centro de Estudios Avanzados en Zonas Aridas) in Coquimbo, Chile, and lead author of the study. Continue reading “Antarctic krill could take a big global warming hit”

Antarctic sea ice meltdown likely in a warming world

New study offers climate clues from most recent interglacial warm period

Antarctic sea ice
Antarctic sea ice is likely to decline dramatically in coming decades, which could lead to amplification of global warming in the southern hemisphere. @bberwyn photo.

By Bob Berwyn

The last time the Earth was as warm as today was about 128,000 years ago — and Antarctic sea ice extent was 65 percent smaller than it is now, according to British scientists who tracked past climate change in the region by studying ice core samples from that era.

That means Antarctic sea ice is on course to shrink dramatically in the decades and centuries ahead, said British Antarctic Survey scientist Max Holloway, who with a team of researchers analyzed oxygen isotopes in ice and air bubbles trapped for 128,000 years in the East Antarctic Ice Sheet. Continue reading “Antarctic sea ice meltdown likely in a warming world”

What’s the tipping point for Antarctica’s ice sheets?

New study suggests rapid meltdown during post-ice age warming

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How long will it take for Antarctica’s ice sheets to melt? @bberwyn photo.

Staff Report

After taking a close look at rocks from West Antarctica’s dramatic Ellsworth Mountains, climate researchers say there’s a chance that ice sheets in the region could melt quickly as the planet warms, potentially causing sea level to rise by  six to eight feet.

The new study, published in Nature Communications, took a close look at Antarctic climate change about 21,000 years ago during a period of warming after the coldest point of the most recent Ice Age. They found that  the West Antarctic Ice Sheet reached a tipping point, after which it thinned relatively quickly, losing 400m of thickness in 3,000 years. Continue reading “What’s the tipping point for Antarctica’s ice sheets?”

Warming oceans seen as main cause of glacier meltdown on the Antarctic Peninsula

Disintegration of ice shelves in East Antarctica could result in a spiraling increase in sea levels. PHOTO BY BOB BERWYN.
Warming ocean water is creeping up the continental shelf around the Antarctic Peninsula and melting glaciers in some parts of the region. @bberwyn photo.

Staff Report

British researchers say regional patterns of melting of glaciers on the Antarctic Peninsula are linked with warming oceans in the region. The Antarctic Peninsula is one of the biggest contributors to sea level rise, so the new finding will help pinpoint how fast and how high seas will rise in the decades ahead.

The southernmost glaciers flowing to the coast on the western side of the Peninsula are retreating rapidly, but those in the north show little change, the scientists said in a new study published last week in the journal Science. Since accurate measurements started in the 1940s, 94 percent of the 674 glaciers in the region have retreated. Continue reading “Warming oceans seen as main cause of glacier meltdown on the Antarctic Peninsula”

Eruption poses threat to huge penguin colony

chinstrap penguin
A chinstrap penguin on Deception Island. @bberwyn photo.

British Antarctic Survey scientists to monitor impacts of ash deposits

Staff Report

A volcanic eruption in the remote South Sandwich archipelago, near the tip of the Antarctic Peninsula, may threaten the largest known colony of chinstrap penguins, according to scientists with the British Antarctic Survey who have been monitoring the eruption.

The Mt. Curry volcano on Zavodovski Island has been erupting since March, sending ash toward the penguin enclave. The uninhabited island is part of the British Overseas Territory of South Georgia and the South Sandwich Islands. After reports of a 7.2 magnitude earthquake last month, researchers confirmed from satellite imagery that not one, but two volcanoes are erupting in the South Sandwich Islands — Mt. Curry on Zavodovski Island to the north of the archipelago and Mt. Sourabaya on Bristol Island to the south. Continue reading “Eruption poses threat to huge penguin colony”

Connecting the climate change dots

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Global warming is going to push the snow line uphill by as much as 1,400 feet in many western mountains. @bberwyn photo.

Pole to pole and across the world’s oceans and mountains, climate change impacts are adding up

By Bob Berwyn

For any Summit Voice readers not following my Twitter or Facebook feeds, here’s a list of links to my recent stories for InsideClimate News.

Of greatest interest here in the West is a new University of Utah study that projects a dramatic upward shift of the snowline in the Rockies and coastal ranges in California, Oregon and Washington. Less spring snowpack at lower elevations has huge effects on we manage our water, and could also result in more early season wildfires: Unabated Global Warming Threatens West’s Snowpack, Water Supply.

In mid-May I wrote about the latest update to NOAA’s annual greenhouse gas index, which showed that atmospheric CO2 concentration showed its biggest annual increase on record in the past year. The index also showed a surge in Methane, an etremely potent heat-trapping pollutant: Far From Turning a Corner, Global CO2 Emissions Still Accelerating. Continue reading “Connecting the climate change dots”

Warming oceans to aid spread of invasive species in Antarctica

Kelp rafts seen pathways for non-native worms, snails

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For now, humans are the main invasive species in Antarctica, but that could change as the surrounding ocean warms. @bberwyn photo.

Staff Report

Parts of Antarctica could soon face an invasion by exotic species floating southward on kelp rafts, Australian researchers found in a new study published in the journal Ecography.

While the Antarctic circumpolar current has long formed a barrier to invasive species, the research found that the kelp rafts often cross that Antarctic Polar Front, carrying with them crustaceans, worms, snails and other seaweeds across hundreds of kilometres of open ocean. Continue reading “Warming oceans to aid spread of invasive species in Antarctica”