Scientists have long thought that the Greenland ice sheet was reliably stable. Even during periods of weather that were warmer than normal and the slow but steady rise of sea temperatures, these vast swaths of ice seemed to be holding their own. However, recent research has indicated that this is not the case, and that the planet could be facing the loss of the Greenland ice sheet.
The second largest body of ice on the planet, the mile-thick Greenland ice sheet covers roughly 660,000 square miles, or about 80 percent of the total landmass of Greenland. Scientists use the ice as a tool to measure past geological activity, as historical data is often a good way to predict future events.
Until recently, scientists had believed that this immense ice field had survived the last geological period intact, but a new study shows the sheet has completely melted in the past. During the period known as the Pleistocene epoch, an era stretching from 2.6 million to 11,700 years ago, Greenland was nearly deglaciated entirely. The massive Greenland ice sheet had shrunk to a mere 10 percent of its current size, and stayed that way for nearly 30,000 years.
While this prehistoric event may seem irrelevant now, it indicates that the ice sheet is not as stable as previously thought. A complete loss of the Greenland ice sheet would cause a rise in sea levels of up to 20 feet, which would have a catastrophic effect on coastlines the world over. Paleoclimatologist at Columbia University and study co-author Joerg Schaeferexplains, “This makes the Greenland ice sheet look highly unstable. We have to be prepared that this ice sheet might go again, and it might go again soon.”
In geological terms, “soon” can be a very long time. But with a 2012 study showing that the Greenland ice sheet is melting at a rate five times faster than 25 years ago, big changes could be looming on the horizon.
Featured Image from Ivan Bandura/Unsplash
