Tag: Antarctica

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

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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”

Climate: Increased Antarctica snowfall no buffer to sea level rise

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What happens in Antarctica the next few decades will affect the whole world. @bberwyn photo.

New research suggests that Antarctica’s contribution to sea level rise over the next few decades has been underestimated

By Bob Berwyn

When it comes to the question of how much sea levels will rise in the global warming era, Antarctica is the big, frozen, enchilada.

Just a partial meltdown of the ice shelves along the western fringe of the continent could raise sea level two to three feet in a few hundred years, and more extensive melting of inland ice sheets would send seas surging upward higher and faster than most coastal communities could adapt for.

Until recently, Antarctica’s inland ice fields were deemed as relatively stable, and recent NASA research even suggested that global warming will increase snowfall over Antarctica and build more ice mass—a process that could slow melting and offset sea level rise.

But after taking a close look at new ice core samples that indicate temperatures and snowfall rates going back several thousand years, researchers with the University of Washington said they’re not sure of the linkage between a warming climate and precipitation. Continue reading “Climate: Increased Antarctica snowfall no buffer to sea level rise”

Climate: Antarctic ice shelf retreat may be irreversible

Yes, there is still lots of ice in Antarctica, but it's melting faster than ever. bberwyn photo.
Yes, there is still lots of ice in Antarctica, but it’s melting faster than ever. @bberwyn photo.

ESA satellites offer clues about climate change consequences

Staff Report

An analysis of data from European Space Agency satellites shows that Antarctic ice shelves may be losing their buttressing role as they get thinner and retreat inland.

The findings, announced in February, used ice velocity data to show that there is a critical tipping point at which the shelves act like a restraining band, holding back the the ice that flows toward the sea. In a dramatic press release, the ESA said that, if the ice is lost, it could be “point of no return” for Antarctica’s ice.

The ice shelves are huge and losing them would have serious implications for global climate, speeding the rise of sea level. The Ross Ice Shelf, for example, is the size of Spain and towers hundreds of meters above sea level. Continue reading “Climate: Antarctic ice shelf retreat may be irreversible”