Is Antarctica’s Fate Sealed?

Southern elephant seal pup

The following is a guest post from Dr. Geoff Lipsett-Moore, the Conservancy’s northern Australia program director. Dr. Moore has previously dabbled in cooler climates, including overwintering on Heard Island and an expedition to summit unclimbed peaks on the peninsula. Read more about his adventures.

While on a hike in southwest Tasmania recently, my wife and I stumbled across a young southern elephant seal bull hauled out on a beach. He was a long way north (roughly 1500 km, or 900 miles) of Macquarie Island, his usual haunt. The rich smells and happy farting sounds from the young sleeping bull instantly whisked me back in time and space to the Subantarctic islands and beyond.

When most people think of Antarctica, they think of cold. They conjure up a sheet of ice — a forbidding, impenetrable, icy wasteland where only penguins, seals and a hearty few scientists and explorers and adventurers dare tread.

As someone who’s spent some time in the Subantarctic and Antarctica, however, I can tell you that the western coast of the Antarctic peninsula is considered to be the fastest-warming place on Earth.

Things are changing for Antarctica. On the continent where, in 1989, scientists recorded the coldest temperature ever — -89° Celsius, or -128° Fahrenheit — things are heating up. That’s worrying news — for science, for wildlife and for people.

There’s proof on the peninsula. Over the past sixty years, mid-winter temperatures here have increased at a rate of roughly one degree Celsius per decade. In some places, temperatures have increased at a rate that’s 10 times greater than the average rate of global warming. Rainfall, which used to be a rarity on the peninsula, is becoming an increasingly frequent phenomenon.

That’s bad news for many penguin populations. Adélie penguins, for example, have largely fled the peninsula: the population there has decreased by more than 80 percent. Meanwhile, gentoo penguins have taken over. Because this species can survive without ice, they’re thriving in areas they would have previously considered to be inhospitable.

Heard Island coastline

In perhaps the most distressing indication of change, a colony of emperor penguins that had been studied since 1948 was locally extirpated. Scientists found that the colony, once located off the peninsula in the Dion islands, disappeared due to a lack of sea ice and predicted that other colonies may meet similar fates.

Warming isn’t unique to western Antarctica. The eastern portion of the continent has also seen major glacial retreat. Over the past decade, the area has lost more than 10 gigatons of ice each year.

The Arctic and Antarctic ice sheets are like the bulb of a thermometer, and the extent of the winter sea ice in both regions is a bit like mercury in the stem of that same thermometer. It allows us to measure global well-being in the same way we measure our own health against a steady core temperature of 37.5° Celsius. The rapid decline in winter sea ice extent and the rapid break-out in summer is symptomatic of the general decline in the health of the planet brought about by our own consumptive activities.

Seeing a young seal bull up on the Tasmanian beach, I’m reminded that the world is rapidly changing. As a Subantarctic beast, the bull seemed perfectly comfortable lying on a the Tasmanian beach. From my past meanderings across glaciers, whether on Subantarctic Heard Island or the Antarctic Peninsula, I suspect many of the crossings which previously required ice axe and crampons now require either a pair of flippers and a dry suit or gum boots.

The positive in this is that the world and climate has always changed and life on earth has always adapted to match it. However, can life as we know it respond to the current rate of change? I guess we’ll see.

[Images courtesy of Geoff Lipsett-Moore/TNC]

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