Once we emit about 1000 gigatons of carbon, much of the massive ice sheet will melt irreversibly. We’ve emitted 500 gigatons so far. The Greenland Ice Sheet covers 1.7 million square kilometers (660,200 square miles) in the Arctic. If it melts entirely, global sea level would rise about 7 meters (23 feet), but scientists aren’t … Continue reading Meltdown Alert: Greenland Ice Sheet Nearing the Point of No Return