Meltdown

The news, politics, the internet, even in theaters—wherever you turn there’s no way to escape the issue of climate change. In recent years climate change, and more specifically global warming, has become a hot issue in our society. It seems like just about everyone has an opinion to voice on climate change, be it the skeptical nay-saying of senator James Inhofe (R-OK) who calls global warming “the second-largest hoax ever played on the American people”, the environmental activism of Al Gore and his academy award winning documentary film 'An Inconvenient Truth', or Hollywood’s light-on-science-but-heavy-on-action movies like 'The Day After Tomorrow'. This month climate change was once again thrust to the forefront of our cultural awareness (and the front page of our newspapers) with the collapse of the Wilkins Ice Shelf in Antarctica. What importance does this ice shelf have, and what can it tell us about the state of the global climate? Let’s take a closer look.

The Wilkins Ice Shelf is located on the Antarctic Peninsula—the northernmost extent of Antarctica, at a mere 70 degrees south latitude. This still places it well within the polar region, with the moderating influence of the nearby ocean. Geographically, the ice shelf covers about 14,000 square kilometers; a region approximately the size of Connecticut. The area that has recently collapsed was around 450 square kilometers—about the size of Norman. The recent collapse left only a thin beam of ice, just 15 km or so thick, supporting the remainder of the ice shelf, as pictured above on the right, the loss of which could lead to complete disintegration.

What contributed to the disintegration of the ice shelf? To answer that we must first take a foray into the details of global warming. Though the name “global warming” implies a worldwide, uniform warming, this is not the case. Climate change is regional, and when it comes to global warming, evidence shows that some areas of the globe are warming considerably more (and much faster) than others. Polar regions are experiencing greater warming than equatorial areas, and in particular the Antarctic Peninsula is among the fastest-warming areas, with an observed temperature increase of 0.5 C per decade over the last 50 years. Though 0.5 C may seem small, even a minor change in the average temperature can result in a large difference in the regional climate.

The scope of the warming in the Antarctic Peninsula is underscored by the fact that the collapse of the Wilkins Ice Shelf is hardly unprecedented—Wilkins is just the latest in a series of ice shelves to collapse along the Antarctic Peninsula. In recent years the Prince Gustav Channel, Larsen Inlet, Larsen B, Wordie, Muller, and Jones ice shelves have all collapsed and disappeared completely. It remains to be seen whether what remains of the Wilkins ice shelf will meet the same fate.

Unlike polar ice caps such as those in Greenland and on the main Antarctic continent, the collapse of ice shelves like Wilkins will not contribute to sea level rise since the ice shelf is already floating on the ocean surface. However, many climate scientists feel that this recent collapse should be heeded as a possible indicator of events to come. Take, for example, the words of the British Antarctic Survey’s David Vaughan: “The importance of [the Wilkins Ice Shelf] is that it’s farther south than any ice shelf we’ve seen retreating before, it’s bigger than any ice shelf we’ve seen retreating before, and in the long term it could be a taste of other things to come. It is another indication of the impact that climate change is having on the region.”





Story is © Nate Snook, 2008