|Northwest passages are open all over the place!|
When sea ice melts it does not raise sea levels. (Just like your Coke doesn't overflow when the ice cubes melt.) This is a huge relief for those of us mile-highers not interested in making room for climate refugees from the lower elevations. Unfortunately, sea ice's next door neighboor, the Greenland ice sheet, is also melting, and has been since the 90's. This summer, NASA reported this:
On average in the summer, about half of the surface of Greenland's ice sheet naturally melts. At high elevations, most of that melt water quickly refreezes in place. Near the coast, some of the melt water is retained by the ice sheet and the rest is lost to the ocean. But this year the extent of ice melting at or near the surface jumped dramatically. According to satellite data, an estimated 97 percent of the ice sheet surface thawed at some point in mid-July.Note that they're reporting surface melt. Greenland is thick and they are referring to just the top layer here. Because Greenland's ice is on land, not floating, it most definitely can contribute to sea level rise. Only time will tell just how much. The ice sheet, which is 3000 meters (10,000 feet) thick in some places, holds the potential to raise sea levels by 7.3 meters. Of course this will be a slow process, but one that I would argue is inevitable considering our current path towards unlimited and unregulated carbon dioxide emissions.
If you're interested in learning more about this, come chat with me or take my MTR 1600 course on Global Climate Change.