Ice losses from Antarctica have tripled since 2012, increasing global sea levels by 0.12 inch, according to a major new international climate assessment funded by NASA and European Space Agency (ESA).
According to the study, ice losses from Antarctica are causing sea levels to rise faster today than at any time in the past 25 years. Results of the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) were published last week in the journal Nature.
This latest IMBIE is the most complete assessment of Antarctic ice mass changes to date, combining 24 satellite surveys of Antarctica and involving 80 scientists from 42 international organizations.
The team looked at the mass balance of the Antarctic ice sheet from 1992 to 2017 and found ice losses from Antarctica raised global sea levels by 0.3 inches, with a sharp uptick in ice loss in recent years. They attribute the threefold increase in ice loss from the continent since 2012 to a combination of increased rates of ice melt in West Antarctica and the Antarctic Peninsula, and reduced growth of the East Antarctic ice sheet.
Prior to 2012, ice was lost at a steady rate of about 83.8 billion tons per year, contributing about 0.008 inches a year to sea level rise. Since 2012, the amount of ice loss per year has tripled to 241.4 billion tons – equivalent to about 0.02 inches per year of sea level rise.
West Antarctica experienced the greatest recent change, with ice loss rising from 58.4 billion tons per year in the 1990s, to 175.3 billion tons a year since 2012.
At the northern tip of the continent, ice-shelf collapse at the Antarctic Peninsula has driven an increase of 27.6 billion tons in ice loss per year since the early 2000s. Meanwhile, the team found the East Antarctic ice sheet has remained relatively balanced during the past 25 years, gaining an average of 5.5 billion tons of ice per year.
Antarctica’s potential contribution to global sea level rise from its land-held ice is almost 7.5 times greater than all other sources of land-held ice in the world combined. The continent stores enough frozen water to raise global sea levels by 190 feet, if it were to melt entirely.
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