Northern Greenland Ice Shelves Show Alarming Decline, Accelerating Sea Level Rise

New satellite data reveals Greenland has lost 35% of ice shelf volume since 1978, with only five large shelves remaining and three major shelves poised to drive significant future sea level rises.

Greenland's northern ice shelves, which act as floating dams, have lost 35% of their volume since 1978, roughly equivalent to a loss of 400 billion tons of ice that was previously preventing glaciers from flowing into the sea and escalating sea level rise.
Only five large ice shelves remain in northern Greenland, including the major ones — Petermann, Ryder and Nioghalvfjerdsbrae (also known as 79 North) — which could cause a 3.6 feet sea level rise if they completely melt, a process that could take several centuries.
Greenland's ice loss has contributed to about 17% of the observed sea level rise globally between 2006 and 2018. The collapse of Greenland's five remaining ice shelves could result in a significant acceleration of this rise.
Warm ocean waters are causing the ice shelves to retreat inland, exposing larger sections of ice to warmer conditions and leading to more melting, which could spark an unstoppable retreat due to the retrograde bedslope of the ground under the ice shelves.
Scientists have reported an increase in melt rates since the year 2000, reaching a peak in 2015, which correlates with a peak in ocean temperatures, indicating that the ice shelves are getting thinner and losing mass at a faster rate.