Global warming has caused over 3 trillion tons of ice to melt from Antarctica in the past quarter-century and tripled ice loss there in the past decade, a new study finds.
The total is equivalent to over 2 quadrillion gallons of water added to the world's oceans, making Antarctica's melting ice sheets one of the largest contributors to rising sea levels. That amount of water is enough to fill over a billion swimming pools and cover Texas to a depth of nearly 13 feet.
“Even though Antarctica is far from most human civilization, its ice sheet is losing mass to the ocean, and is an increasing contribution to sea-level rise," said study co-author Helen Amanda Fricker, a glaciologist at Scripps Institution of Oceanography. This "will have large impacts on coastlines all around all the world.”
“The future we choose could determine when we need to rebuild airports, cities and infrastructure so that we can become resilient to such changes," she said.
The study is the most complete analysis yet to measure Antarctica's ice sheet changes.
Overall, scientists say the melting ice in Antarctica is responsible for about one-third of all sea-level rise around the world. "The global sea level trend is about 3.4 millimeters per year, so prior to 2012, Antarctica was responsible for about one-tenth of the trend," said Andrew Shepherd of the University of Leeds in the U.K. Since then, it has been responsible for three times as much, he said.
The threefold jump in ice loss from the continent as a whole is a combination of increased melting of ice from West Antarctica and the Antarctic Peninsula, with a small signal from the ice sheet in East Antarctica.
The cause is clearly due to the warming world, with temperatures boosted by the increased amount of carbon dioxide humanity emits from the burning of fossil fuels such as gas, oil and coal.
"We are able to say that the increased ice loss is mainly due to ocean-driven melting in West Antarctica," Shepherd said. "The ocean is about 1 degree (F) too warm for the ice, and it is melting and retreating as a result." He said this matches the temperature changes our planet has experienced, on average, during the industrial era.
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, NASA said. The continent stores enough frozen water to raise global sea levels by 190 feet, if it were to melt entirely, which is not predicted to occur.
“We should be worried,” said University of California Irvine’s Isabella Velicogna, one of 88 co-authors. “Things are happening. They are happening faster than we expected.”
Part of West Antarctica, where most of the melting occurred, “is in a state of collapse,” said co-author Ian Joughin of the University of Washington.
Wednesday's assessment of conditions in Antarctica is based on combined data from 24 satellite surveys. Results from the project were published Wednesday in the peer-reviewed British journal Nature.
Contributing: The Associated Press