Melting of the Greenland ice sheet approaching a threshold

The Greenland ice sheet, which has melted at an increasing rate during the past 30 years, is an example of how the earth’s subsystems risk moving outside their stable Holocene state.

S. Zeff/Azote

S. Zeff/Azote

The Greenland ice sheet, which has melted at an increasing rate during the past 30 years, is an example of how the earth’s subsystems risk moving outside their stable Holocene state.  As the planet warms the ice melts, leaving more water and land exposed to the sun. Those surfaces in turn absorb more of the sun’s heat, leading to a self-enforced process with accelerated melting of snow and ice.  There are fears that melting of the entire sheet could raise sea levels globally by about 7 m.