At the start of a new millennium, the Greenland ice sheet reached a state of continuous mass loss, which is active today and will remain so for the foreseeable future.
The discovery was made by a team of researchers who surveyed satellite data captured over more than 40 years. As the second-largest ice sheet in the word, the Greenland Ice Sheet covers almost 80 percent of the island. Should it melt entirely, the global sea level would rise by approximately 24 feet, a trait which makes it the largest single contributor to rising sea levels.
An unexpected change
According to the study, the accelerated glacial retreat forced the ice shelter to enter an imbalanced state. Due to this state, it is unlikely that the ice sheet would gain more ice than it looses even if the oceans and atmosphere would maintain a stable temperature.
During the decades before the start of the 21st century, the ice sheet enjoyed a state of equilibrium as the ice lost during summer would return with the help of snowfall during winter. During the first months of 2000 ice loss outpaced snowfall recovers, marking the tipping point.
The tipping point found by the researchers suggests a radical change, which can be compared to shifting into a faster gear. As accelerated drainage takes place near the edges of the ice sheet mass loss will become a stable trend.
It is theorized that the cause of the change is tied to the thinning of glaciers during the early 2000s. As the glaciers became thinner, more ice could escape, boosting the discharge rate from 420 gigatons to 480 gigatons of ice per year.
A return to the balanced state is conditioned by reduced melting or a substantial snowfall increase. However, such a change is unlikely according to all the available climate change scenarios that have been consulted.
The study was published in a scientific journal.