Lemaire Channel, Antarctica

Global Warming in Antarctica: How Climate Change is Impacting "The Great White Desert"

Guest Contributor|March 27, 2017|Blog Post

Although it’s typically thought of as one of the planet’s coldest places, global warming in Antarctica is raising temperatures at an alarming rate. In late February 2017, the temperature in one area of Antarctica was the same as in Cairo, Egypt. Around the same time, the World Meteorological Organization (WMO) announced a new record high—63.5º F had been recorded at an Argentine Research Base on the Antarctic Peninsula.

That’s stunning, especially when you consider that the average yearly temperature for Antarctica ranges from around 14ºF on the coasts to around -70ºF deep in the interior. But the sad fact is that the global warming in Antarctica seems to be impacting the peninsula at an even greater rate than the rest of the world.

There’s also been an increase of warm, dry, “Foehn”-type winds that has helped drive these record temperatures even higher. As a result, the sea ice in the region is at a record low. And then there’s Larsen C—a Delaware-sized ice sheet that may be about to bust free. Clearly, Antarctica is undergoing some major shifts brought on by climate change, and that’s a big deal we don’t hear nearly enough about.

After all, the southernmost continent’s ice sheet holds about 90% of the world’s freshwater; it is fairly unlikely that it would all melt off. But if it did, the WMO estimates that sea levels all around the world would rise by about 200 feet. It would be difficult to overemphasize the dramatic impacts this would have on the planet’s coastal regions. We’d say goodbye to Florida, Amsterdam, and London. But, if left unchecked, global warming in Antarctica will have significant local impacts, too…

 

How Global Warming Affects Antarctic Ice

Talking about global warming in Antarctica as a whole is tricky, because the climate varies widely over the continent. Climate change therefore has a wide variety of impacts. Overall, temperatures in the Antarctic Peninsula have warmed by about three degrees Fahrenheit; this warming has caused ice sheets that have been stable for millennia to weaken and retreat.

The Larsen B ice sheet broke free from the continent back in 2002. These processes are historically natural, but they’re happening much faster now, which could lead to profound impacts on the rest of the continent. A massive chunk of ice broke free from the Pine Island Glacier early this year, and another stunning iceberg came off in 2015. The region is extremely sensitive to small rises in annual average temperatures, but the reason for that is unclear.

Regardless, the result has been that the West Antarctic Ice Sheet is thinning dramatically. About 90% of the glaciers in the area have retreated over the past 50 years, and a number of these are retreating at increasingly accelerated rates. In May 2014 it was announced that the West Antarctica Ice Sheet is actually collapsing. Climate scientists say this could take several hundred years to happen, but it appears to be irreversible at this point.

What we do know is that all this melting ice will eventually have an impact on sea levels around the world. In fact, satellite measurements of the sea level over the past 30 years indicate a rise of about 3mm a year—around a foot over the last 100 years. These rising seas also have a more immediate impact on marine life and wildlife on the continent.

 

How Global Warming Affects Antarctica’s Marine Life

Krill are tiny crustaceans that look like miniature shrimp. These little beasties, which are about the size of a paper clip, are vitally important for marine life. As an essential food source, they power the planet’s marine food chain.

Krill feed on the algae that grow at the base of sea ice. Less sea ice means less food for the krill, which means fewer krill. In 2004, the British Antarctic Survey noted a striking decline in krill numbers in Antarctica.

Some estimates suggest that krill numbers may have dropped by as much as 80% since the 1970s; this is very bad. Hundreds of different species—from fish to penguins (and other birds), seals, and whales—depend on krill for their survival. As the krill disappears, the animals that depend on them as a food source will also disappear. For the priceless Southern Ocean fisheries, this could spell disaster.

On land, Antarctica’s only two flowering plants (Antarctic hair grass and Antarctic pearlwort) are already spreading their range rapidly. Part of the reason for this shift is that it has started raining in the summer. It used to snow—even in summer—but now it rains; this gives the plants more available water and new land, free from snow and ice, for them to colonize.

 

How Global Warming Affects Antarctica’s Wildlife

Despite the fact that Antarctica is among the most inhospitable regions on the planet, the continent is a hot spot for biodiversity. But climate change is having an impact on Antarctic animals.

For example, the reduction in sea ice is hammering local penguin populations; at the Palmer Research Station, the number of Adélie penguins has dropped some 65% since 1990. Adélies need that sea ice, and feed almost exclusively on the declining krill. Emperor penguins are feeling it too; a 2014 study suggested they be considered for IUCN Endangered Species status due to the impacts of global warming.

While some penguin species are in rapid decline, others seem to be adjusting to climate change. Overall, the Adélies, emperor, and chinstrap penguins seem to be losing the struggle to adapt. Frequently, these species are being replaced by Gentoo penguins. 

Like penguins, many species of seals and whales are dependent on the ice sheets and floes for food and/or reproduction. Some species prefer ice-free conditions, and their numbers appear steady. But for those that require the ice, the effects of global warming are stark; the minke whale and the orca need the ice. A 2012 paper pointed out that whale and seal’s dependence on krill-fueled food chains suggests that they may also be in decline.

 

Where is Antarctica Headed?

So, is the entire whole of Antarctica warming? Nope. While the Antarctic Peninsula region is warming very rapidly, the rest of the continent remains locked in a deep freeze. But that does not mean we don’t have a problem.

Antarctic ice shelves are melting dramatically. These temperature rises on the coast are eating away at the ice sheets, and the ice sheets actually hold back the glaciers. Once you remove the sheets, a massive amount of ice from the interior glaciers will start flowing out to the ocean, where they will melt rapidly.

As these glaciers spill into the ocean, temperatures inland will begin to rise. At that point, the whole of the continent will begin to change more rapidly. In other words, it’s high time we get more proactive in combating climate change in Antarctica, and all around the world.

 

Jim O’Donnell is a freelance environmental journalist and conservation photographer. He is the author of “Notes for the Aurora Society: 1500 Miles on Foot Across Finland.” In addition to his blog, Around the World in Eighty Years, his writing and photography have appeared in National Geographic Maps, New Mexico Magazine, Perceptive Travel, and more.

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