June 14, 2018•Update: June 14, 2018
By Safvan Allahverdi
WASHINGTON
Melting ice in Antarctica has raised sea levels by 7.6 millimeters or nearly one third of an inch with about 3 trillion tons of ice disappearing since 1992, according to new studies.
"In a major collaborative effort, scientists from around the world have used information from satellites to reveal that ice melting in Antarctica has not only raised sea levels by 7.6 mm since 1992, but, critically, almost half of this rise has occurred in the last five years," the European Space Agency (ESA) said in a report Wednesday.
The journal Nature, a UK-based multidisciplinary scientific magazine, also said that prior to 2012, when the last such study was carried out, Antarctica was losing 76 billion tons of ice a year, causing sea levels to rise at a rate of 0.2 mm a year.
"Since then, however, Antarctica has been losing ice three times as fast," it noted, adding that between 2012 and 2017, it lost 219 billion tons of ice annually, raising sea levels by 0.6 mm a year.
A separate study also warned that the melting ice could contribute more than 25 centimeters to a total global sea level rise of more than a meter by 2070 and could lead eventually to the collapse of the entire west Antarctic ice sheet and around 3.5m of sea-level rise unless urgent action is taken.
West Antarctica has already lost 159 billion tons of ice a year from 2012 through 2017 compared with 65 billion tons from 2002 through 2007, according to the study.
Andrew Shepherd, a lead author of the study on accelerating ice loss, emphasized that if the acceleration continues, it could have catastrophic consequences for low-lying cities around the world.
“This has to be a concern for the governments we trust to protect our coastal cities and communities,” Shepherd added, saying they have been tracking the ice losses and global sea level contribution with confidence thanks to the satellites their space agencies have launched.
Eric Rignot, professor of Earth system science at the University of California, Irvine and a senior research scientist at NASA's Jet Propulsion Laboratory, additionally stated that measurements collected by radar satellites over the years have documented glacier changes around Antarctica at "an amazing level of precision".
"So that we have now a very detailed and thorough understanding of the rapid changes in ice flow taking place in Antarctica and how they raise sea levels worldwide.”
