Global sea level rise has been accelerating recently, rather than increasing steadily, according to a new study based on 25 years of NASA and European satellite data.
This acceleration is mainly caused by increased melting in Greenland and Antarctica, which may double the total sea level rise by 2100.
If ocean rise continues to change at this pace, sea level will rise 26 inches (65 centimeters) by 2100, with the risk to cause significant problems for coastal cities, according to the new assessment by lead author Steve Nerem and cNASA’s Goddard Space Flight Center in Greenbelt, Maryland; CU Boulder; the University of South Florida in Tampa; and Old Dominion University in Norfolk, Virginia.
Increasing GHG in Earth’s atmosphere increase the temperature of air and water, causing sea level to rise in two ways. First, warmer water expands, and this “thermal expansion” of the ocean has contributed about half of the 2.8 inches (7 centimeters) of global mean sea level rise we’ve seen over the last 25 years. Second, melting land ice flows into the ocean, also increasing sea level across the globe.
In 2018, NASA will launch two new satellite missions to improv future sea level projections: the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission, a partnership with GeoForschungsZentrum (GFZ) in Germany, will measure the mass of the Greenland and Antarctic ice sheets; while the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) will make accurate observations of the elevation of ice sheets and glaciers.
