Another Warming Trend

The bad news on the climate seems to be accelerating. Monday's Washington Post reported on new information in Nature Geoscience stating that ice sheets in Antarctica have begun to show signs of melting. Although the Arctic has long been the focus of melting, Antarctica was long presumed to be relatively safe from warming temperatures. In fact, the reality that the southern hemisphere didn't seem to be experiencing the same obvious symptoms of global warming as the northern hemisphere has been used by skeptics of global warming to prove that no part of the planet is warming. For better or worse, those days appear to be over. Here's what the Post wrote:

Climatic changes appear to be destabilizing vast ice sheets of western Antarctica that had previously seemed relatively protected from global warming, researchers reported yesterday, raising the prospect of faster sea-level rise than current estimates.

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[Eric] Rignot[, senior scientist with NASA's Jet Propulsion Laboratory and lead author of the Nature Geophysics material] said the tonnage of yearly ice loss in Antarctica is approaching that of Greenland, where ice sheets are known to be melting rapidly in some parts and where ancient glaciers have been in retreat. He said the change in Antarctica could become considerably more dramatic because the continent's western shelf, an expanse of ice and snow roughly the size of Texas, is largely below sea level and has broad and flat expanses of ice that could move quickly. Much of Greenland's ice flows through relatively narrow valleys in mountainous terrain, which slows its motion.

Some of the most alarming prognostications in the article concern a continuation of the Arctic melting with simultaneous Antarctic melting.

"Both Greenland and the West Antarctic ice sheet are huge bodies of ice and snow, which are sitting on land," said Rajendra Pachauri, chief of the IPCC [(Intergovernmental Panel on Climate Change)], the United Nations' scientific advisory group. "If, through a process of melting, they collapse and are submerged in the sea, then we really are talking about sea-level rises of several meters." (A meter is about a yard.) Last year, the IPCC tentatively estimated that sea levels would rise by eight inches to two feet by the end of the century, assuming no melting in West Antarctica.

That's right, a rise of the ocean "eight inches to two feet" is the best-case scenario. Better start putting the sweaters away.