Polar Meltdown
Is the heat wave on the Antarctic Peninsula a harbinger of global climate change?
On ice. The bulk of the continent has only warmed a degree or so in the same time. Even this is enough to make some climate scientists worry that a significant part of its ice cap could someday melt, raising sea levels precariously. But there is no sign of that yet, and the South Pole itself, atop a 2-mile-thick layer of ice where temperatures stay well below zero, may actually have cooled a bit. Such inconsistency is among reasons skeptics assert that global warming is too uncertain to merit costly programs to contain it.
But here warming is no mere hypothesis. And one senses how high the stakes are if the skeptics are wrong. The local warm-up is already in the same ballpark as that which the Intergovernmental Panel on Climate Change--set up in 1988 by the United Nations and the World Meteorological Organization to advise politicians--expects for the rest of the world during the next century.
The changes aren't subtle. One hundred miles to the east, on the other side of the Antarctic Peninsula, the immense and supposedly permanent Larsen Ice Shelf began to disintegrate in 1995. Nearly 1,000 square miles of shelf have collapsed just in the past two years, with thousands of square miles more appearing ready to go. "Climate change showed up on the radar screen 30 years ago or so, but most people back then never thought we'd really have to worry about it," says Bill Fraser, a tall, rangy ecologist and penguin specialist from Montana State University. He is the station's chief scientist and has been coming down here for two decades. "Now, right here, we're basically confirming what the models back then said would happen if climate changed. The species most vulnerable, those at the edges of their natural ranges, would be affected first. And that is what is happening."
In recent years, hints of wildlife migrations and local extinctions have been picked up around the world--butterflies moving to new ranges, for instance, or plants moving to higher altitudes on mountains. But the picture here is simpler and starker. Not only is warming greater but, except for the occasional scientist or carefully monitored tourist, direct human impact is scant. So one cannot blame wildlife changes on factors like toxic pollution, agriculture, or urbanization.
And wildlife shifts are unmistakable. Around Palmer and elsewhere on the western side of the peninsula there is not only less ice but a new set of residents. Southern elephant seals--the males are massive, sluglike beasts that can reach 8,800 pounds--usually raise their young farther north in more temperate climes like the Falkland Islands. But one day this summer 254 elephant seals, including many pups, were seen on just two islands near Palmer, with uncounted others presumably living up and down the coast. More hospitable weather is the only explanation scientists have for this sudden migration southward.
New colonies. Fur seals, too, were not reported here before midcentury. But five years ago, a research vessel counted 2,000 of them on just one island farther south. Similarly, gentoo penguins and chinstrap penguins, species common closer to South America but virtually absent in fossil deposits around Palmer, are establishing new colonies on the peninsula. And while nobody expects forests to appear on these icy plains, low grass, tiny shrubs, and mosses are thickening rapidly in many areas of the peninsula.
advertisement
