Antarctica — Earth’s coldest, Southern-most continent — is melting faster than scientists anticipated, according to a new report.
A study published on Wednesday by more than 80 co-authors from around the world in Nature found that Antarctica’s melt rate has tripled in the last decade. And it’s likely due to human emission of greenhouse gasses.
“We are able to say that the increased ice loss is mainly due to ocean-driven melting in West Antarctica,” lead author Andrew Shepherd, researcher from the University of Leeds, told USA Today. “The ocean is about 1 degree (F) too warm for the ice, and it is melting and retreating as a result.”
The study looked at the “mass balance of the Antarctica Ice Sheet between 1992 and 2017,” and found that during that time the continent lost three trillion tons of ice and raised sea levels three-tenths of an inch, according to the New York Times. And 40% of that loss happened in the last five years.
Around 219 billion tons of ice were lost annually between 2012 and 2017, according to the Washington Post. Two decades ago, between 1992 and 1997, the continent lost 49 billion tons of ice annually.
Antarctica, which is technically classified as a desert, due to the small amount of precipitation it receives in the form of snow, is home to most of Earth’s fresh water (between 60 and 90%). The continent is split into two regions by the Transantarctic Mountains: West Antarctica, which is smaller, is mainly composed of frozen Islands, while East Antarctica makes up two-thirds of the continent and is colder and more remote.
Ice on the Eastern side, which is roughly the size of Australia, is known for being more stable than the Western side. However, “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,” the Post explains.
Most of Antarctica’s ice loss measured in this study came from the West Antarctica and the Antarctic Peninsula — which scientists have known were melting. However, growth of East Antarctica, which usually gains mass due to snowfall, was not enough to offset losses from West Antarctica and the Antarctic Peninsula, according to the Times.
The Post also points out that East Antarctica lost around 28 billion tons of ice annually during the last five years.
“We cannot count on East Antarctica to be the quiet player, and we start to observe change there in some sectors that have potential, and they’re vulnerable,” co-author Isabella Velicogna, a researcher from University of California, told told the Post.
So what does this mean in terms of sea level rise? According to the study, the Antarctic melt is causing a sea level rise of half a millimeter per year.
At the rate that Antarctica is melting, the sea level could rise by 15 centimeters or six inches by 2100 — enough to flood Brooklyn 20 times per year, according to Shepherd. Scientists are unsure if the continent will continue to melt at this rate; a lot is dependent on greenhouse gas emissions.
“We should be worried,” Velicogna told the USA Today. “Things are happening. They are happening faster than we expected.”