Category: Antarctica

How will Antarctica respond to global warming?

Long-term studies show potential impacts of climate change

Antarctic biodiversity is at risk from climate change. Photo by Bob Berwyn.
Antarctic ecosystems are at risk from climate change. @bberwyn photo.

Staff Report

A new set of scientific reports highlights the value of long-term observations in relatively undisturbed ecosystems and also offers a preview of how global warming may change Antarctica in coming decades.

The research shows that a period of unusual warmth in 2001 and 2002, caused by a confluence two natural climate cycles,  accelerated the microbial food chain and shook up the distribution of penguin populations and thinned glaciers according to October issue of the journal BioScience .

The research came out of two long-term ecological research stations, including Palmer Station, on the West Antarctic Peninsula, where scientists study how “changing sea ice extent influences marine ecology and the multilayered food webs of the coastal, nearshore, and continental slope ecosystems.” Other studies were done at the  McMurdo Dry Valleys LTER, in an ice-free polar desert where glacial meltwater plays a huge role in ecosystems. Continue reading “How will Antarctica respond to global warming?”

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

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?”

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”

Warming oceans to aid spread of invasive species in Antarctica

Kelp rafts seen pathways for non-native worms, snails

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”

Crumbling Antarctic ice sheets could speed sea level rise

Fifty feet in 500 years?

Mountains of the Antarctic Sound.
New climate modeling suggests more significant melting of the Antarctic ice sheets and ice shelves driven by atmospheric warming. @bberwyn photo.

Staff Report

The edges of Antarctic ice sheets may crumble and collapse much faster than most existing climate models suggest, potentially raising global sea level by as much as 50 feet in the next 500 years, according to researchers from Penn State and University of Massachusetts, Amherst.

The scientists added new, previously underestimated processes to their projection after studying the role of Antarctic ice melting during the warm Pliocene era, about 3 million years ago when sea level rose by as much as 30 to 60 feet. Continue reading “Crumbling Antarctic ice sheets could speed sea level rise”