Tag: Antarctica

What’s driving the collapse of Antarctic ice shelves?

New CSU study eyes regional climate cycle as one factor

Disintegration of ice shelves in East Antarctica could result in a spiraling increase in sea levels. PHOTO BY BOB BERWYN.
Disintegration of ice shelves in East Antarctica has been linked with a regional climate pattern and could result in a spiraling increase in sea levels. @bberwyn photo.

Staff Report

This year’s rapid loss of sea ice around Antarctica may make the floating ice shelves along the coast of the continent even more vulnerable to collapse, and a  Hemisphere climate cycle known as the Southern Annular Mode is probably a factor in the equation.

Just during the past 50 years, more than 28,000 square kilometers of ice shelves have crumbled along the Antarctic Peninsula, and one of the last remaining large ice shelves looks set to shed another piece about as large as Delaware. A new study led by Colorado State University scientists offers some new information on climate processes in the region. Continue reading “What’s driving the collapse of Antarctic ice shelves?”

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Sunday set: Meltdown

Global sea ice at record low

@bberwyn photos
It’s hard to really get your head around what it means that the Arctic ice cap is literally melting away, and perhaps even harder to imagine that massive tracts of Antarctic ice are also giving way to global warming. But the science is pretty clear: During other epochs of Earth’s geological history, at times when there were similar global temperatures and about the same amount of CO2 in the atmosphere, so much ice melted that sea level was at least 20 feet higher than today. Today’s Earth — our Earth — seems to be responding the same way. For all of December, the extent of global sea ice has set record lows every single day.  The Arctic meltdown is well documented by more than 100 years of data. Around the South Pole, more and more studies are showing warm layers of water melting large coastal slabs of ice that hold back the almost unimaginable masses of ice on the Antarctic continent. The images in this set are just snapshots, but what’s happening out there is very real. Take #climateaction now.

Climate roundup: The ill winds of global warming

Snow, ice, reindeers and forests …

Sunlit icebergs gleam on the horizon in the Antarctic Sound.
Sunlit icebergs gleam on the horizon in the Antarctic Sound. @bberwyn photo

By Bob Berwyn

2016 ended the way it began, with record warm temperatures and record-low sea ice in the Arctic. Federal scientists tracking the changes released a report detailing how the Arctic is unraveling. I covered it for InsideClimate News: The Arctic Is Unraveling,’ Scientists Conclude After Latest Climate Report.

Just before Christmas I wrote an enterprise piece on how the odds for a white Christmas have changed in different parts of the world. In many regions, the chances of seeing flakes on the holiday have decreased due to climate change, but a little counter-intuitively, they’ve also increased in other places: What Are Your Chances of a White Christmas? Probably Less Than They Used to Be.

In another Christmas-themed story, I reported on a Norwegian study that showed how widespread grazing by reindeer affects the reflectivity in northern tundra regions. It turns out that when the ungulates munch shrubs and brush, they make the world cooler: Save the Reindeer, Save the Arctic.

And with much of the West getting crushed by snowfall thanks to a subtropical weather connection, I explored a new study showing that such Pineapple Express storms are likely to become more frequent as the world warms: Global Warming Will Increase ‘Pineapple Express’ Storms in California.

Another sign that we may be near a climate tipping point is research from California showing that some severely burned forests just aren’t regenerating at all. The fires have become so big and so intense that all the seed stock trees are destroyed, leaving big cleared areas where there is no source for new growth — except for shrubs and brush that quickly grow to dominate the landscape and prevent new seedlings from taking root: California Forests Failing to Regrow After Intense Wildfires.

And some people think that they don’t have to worry about climate change because they heard global warming slowed down between 1998 and 2012. Not so, according to scientists who recalculated the rate of warming in the world’s oceans to show there was no hiatus: Already Debunked Global Warming ‘Hiatus’ Gets Another Dunking.

Climate: Sea ice at both poles way below average

Antarctic sea ice retreat could set stage for ice shelf collapses

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Melting Greenland glaciers in September 2015, photographed from a passenger jet. @bberwyn photo.

Staff ReportMonths of above-average temperatures in the Arctic slowed the growth of sea ice formation to a crawl during the second half of October, the National Snow and Ice Data Center reported in its latest monthly update.The ice scientists said that, starting Oct. 20, Arctic sea ice started setting daily record lows for extent.  After mid-October, ice growth returned to near-average rates, but extent remained at record low levels through late October. Both sea surface and air temperatures have remained unusually high, extending from the surface high up into the atmosphere. Continue reading “Climate: Sea ice at both poles way below average”

Antarctic sea ice peaks near record-low extent

Australian scientists document early start to melt season

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.
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Antarctic sea ice extent was near a record low in late September and early October. Via NSIDC.

Staff Report

Australian scientists say Antarctic sea ice started its annual spring retreat early this year and has set new daily record lows for extent during late September — during the Austral spring, when Antarctic sea ice is at a maximum.

In a press release, the Antarctic Climate & Ecosystems Cooperative Research Centre said the sea ice extent started its annual retreat early, just two years after  winter sea ice extent around Antarctica reached a new record high in September 2014, when it exceeded 20 million square kilometres for the first time since satellite measurements began in 1979.

This year, Antarctic sea ice began its annual spring retreat about four weeks earlier than average, after peaking at 18.5 million square kilometres on 28 August 2016, which was close to the lowest winter maximum on record.

Continue reading “Antarctic sea ice peaks near record-low extent”

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”