Climate Number: 200 Gigatons
Average global sea level is rising by about three millimeters per year. There are three main contributors to this rise, each of which separately account for about one millimeter each: the thermal expansion of water, or the fact that warmer waters occupies more space than cooler water; the melting of mountain glaciers and ice caps; and the melting of the Greenland and Antarctic Ice Sheets, which are ancient ice masses that sit on bedrock masses near the poles. In Greenland, high rates of surface melt were experienced between 2000 to 2010, with record melt extents happening in 2010 when temperatures were as high as 4.3 degrees Fahrenheit above the 1970-2000 climate normal. During the last decade, Greenland has contributed about 200 gigatons of ice, or around 48 cubic miles of ice into the ocean each year, accounting for about one-sixth of global sea level rise during this period.
For comparison: 200 gigatons is equivalent in volume to 550,000 Empire State Buildings, 38 Lake Okeechobees and 11 Great Salt Lakes.
Seasons: Winter, Spring, Summer, Fall
Source: Mernild, SH et al. “Increasing mass loss from Greenland’s Mittivakkat Gletscher.” The Cryosphere 5 (2011): 341-348.
