Greenland’s largest glaciers could lose more ice than previously predicted if emissions continued as usual

The Arctic island is the largest contributor of terrestrial ice to sea level rise.

Greenland is known as the biggest contributor to sea level rise, but a new study explores how the island’s glaciers could lose more ice than previously predicted.

The three largest glaciers, Jakobshavn Isbræ, Kangerlussuaq, and Helheim, are responsible for about 12% of the entire ice sheet and contain enough ice to raise sea level by about 1.3 meters, or about 4.3 feet, according to the study published Tuesday in Nature.

Together, the three glaciers already contributed about 8.1 millimeters or 0.32 inches to global sea level between 1880 and 2012, the study authors say. They used historical photographs to calculate the amount of ice lost during that time period.

Unless drastic efforts are made to reduce global greenhouse gas emissions, climate change models predict that Earth’s temperature will rise 3.7 degrees Celsius from pre-industrial temperatures by the end of the century.

The world’s surface temperature has risen by just over 1 degree Celsius since 1880, according to NASA. The goal of the Paris Agreement is to keep that increase below 2 degrees Celsius, but scientists have determined that the combination of commitments from each participating nation is still not enough to mitigate the temperature increase.

The rate of ice loss in Greenland has increased over the past decade, and models predict further acceleration in the coming decades, according to the study. The Jakobshavn Isbræ and Kangerlussuaq glaciers have gone through “periods of dynamic instability” and are sensitive to small fluctuations in the atmosphere or warming of the oceans, the study says. Scientists expect them to continue to shrink and lose mass.

Globally, sea levels increased by an average of 17 centimeters or about 6.7 inches in the 20th century due to the loss of land mass of ice, thermal expansion of the oceans and changes in terrestrial water storage. according to the study. That number could increase to 2 meters or 6.56 feet by 2100.

The Greenland ice sheet is a major contributor to sea level rise. The melting could eventually expose up to 400 million people to flooding by the end of the century, according to a study commissioned by NASA and the European Space Agency and published in Nature last year.

Warming events are becoming much more frequent, climate scientists told ABC News last year after unusual warming patterns caused the Greenland ice sheet to melt at near record speeds. In September, a portion of the Greenland ice sheet measuring 42.3 square miles in the far northeastern Arctic was cut off, which provided further evidence to scientists of the rapid rate at which Earth’s temperature is rising.

The ice shelf has lost about 62 square miles, or twice the size of Manhattan, since 1999, according to the Associated Press.