Antarctica, the planet’s largest ice sheet, lost 219 billion tons of ice annually from 2012 through 2017 — approximately triple the 73 billion ton melt rate of a decade ago, the scientists concluded. From 1992 through 1997, Antarctica lost 49 billion tons of ice annually.
The study is the product of a large group of Antarctic experts who collectively reviewed 24 recent measurements of Antarctic ice loss, reconciling their differences to produce the most definitive figures yet on changes in Antarctica. Their results — known formally as the “Ice Sheet Mass Balance Inter-comparison Exercise” (IMBIE) — were published Wednesday in the journal Nature.
The location of the ice melt is important for determining the future of coastal communities, according to climate scientists. And, due to West Antarctica melting, it turns out that the U.S. coastline will be hit extra hard, paying a sea level rise tax of about 25%.
The reason the location of the ice melt is important is due to peculiarities of the Earth’s climate system that have long been understood in academia, but not well-known by the public.
- The U.S. would see far more sea level rise from the melting of West Antarctica when compared to the shedding of ice from the Greenland Ice Sheet. For example, for every 1 centimeter of sea level rise from West Antarctica, Boston would see an increase in local sea level of about 1.25 centimeters.
The largest part of the continent, East Antarctica, has remained more stable and didn’t contribute much ice to the ocean during the period of study, the assessment says. However, in the last five years, it too has begun to lose ice, perhaps as much as 28 billion tons per year, although the uncertainty surrounding this number remains high.
What’s happening in East Antarctica is extremely important because it has by far the most ice to give, being capable of raising sea levels by well over 100 feet. A single East Antarctic glacier, Totten, has the potential to unleash as much total sea level rise as the entire West Antarctic ice sheet, or more.
If the acceleration continues, some of scientists’ worst fears about rising oceans could be realized, leaving low-lying cities and communities with less time to prepare than they’d hoped.
The result also reinforces that nations have a shorter window — perhaps no more than a decade — to cut greenhouse gas emissions if they hope to avert some of the worst consequences of climate change.