The retreat of Arctic sea ice has been so dramatic over the last few years that atlases are being changed. Now it turns out Greenland's ice sheets are also melting faster than we thought -- not on the visible surface, but due to currents deep below the ocean.
While the loss of polar sea ice is troubling, the hidden sublimation of Greenland's ice is of greater concern. That's because these continental ice sheets and glaciers hold up to 90 per cent of our fresh water on Earth. NASA put together a video today to highlight how their researchers discovered the meltdown.
As Greenland's ice warms in the summer, it pushes its way down through fjords and towards the ocean, where some of it breaks off into the sea. This is, of course, happening at an accelerated rate, too -- an iceberg the size of Manhattan calved off of Greenland last week. When the ice hits the ocean at sea level, it doesn't melt that quickly -- the water is literally ice-cold. But as NASA glaciologists looked deeper beneath the water, they saw that the thicker ice sheets were being carved away faster and more dramatically than they expected by warm currents pushing up from the tropics.
Yesterday we learned that the Earth's sea levels are locked into an inevitable 0.91m rise even without any intervention. Losing all of Greenland's ice would automatically raise the sea level another 7m. Oceans Melting Greenland (yep, OMG) s a new NASA initiative that will study the way that climate change is affecting Greenland's ice -- and how we can stop its devastation.