[ad_1]
Global warming is melting ice in Antarctica faster than ever – about six times more per year now than 40 years ago – leading to rising sea levels around the world, scientists warn.
The Antarctic melt has already raised global sea levels by 1.4 cm between 1979 and 2017, according to the report of the Proceedings of the National Academy of Sciences (PNAS), a peer-reviewed US magazine.
This 2016 photo provided by NASA shows Getz's ice shelf.
AP
And the rate of melting is expected to lead to a disastrous rise in sea levels in the next few years, according to lead author Eric Rignot, director of Earth system science at the University of California, Irvine.
"As the Antarctic ice sheet continues to melt, we expect Antarctica over the next few centuries to raise sea level rise at multiple levels," Rignot said.
An increase of 1.8 meters by 2100, as some scientists predict in the worst scenarios, would flood many coastal cities that house millions of people around the world, previous research has shown.
For the current study, researchers embarked on the longest ice mass assessment in Antarctica in 18 geographic regions.
The data came from high-resolution aerial photographs made by NASA airplanes, along with satellite radars from various space agencies.
Researchers have found that from 1979 to 1990, Antarctica lost an average of 40 billion tonnes of ice per year.
In the years 2009 to 2017, ice loss has increased more than sixfold to 252 billion tons per year.
Even more troubling, the researchers found that areas that were once considered "stable and immune to change" in Eastern Antarctica, are pouring quite a bit of ice, too, the study said.
Global warming is melting ice in Antarctica faster than ever.
AP
"The Wilkes Land sector in Eastern Antarctica in general has always been a major player in mass loss even in the 1980s, as our research has shown," Rignot said.
"This region is probably more climate-sensitive than traditionally assumed, and this is important to know because it contains even more ice than West Antarctica and the Antarctic Peninsula combined."
Ice Loss
The total amount of ice in Antarctica, if all melted, would be enough to raise sea level to 57 meters.
By far, most of the ice in Antarctica is concentrated in the east, where there is enough sea ice to reach 170 feet of sea level rise, compared to about 17 feet across the West Antarctic ice sheet.
The ice sheet of Eastern Antarctica is the largest in the world, containing about half of the Earth's fresh water.
So far, most polls have shown that most of the melting is happening in the West.
The huge Antarctic iceberg alarms scientists.
A landmark study published in Nature last June found that Antarctic ice melt has tripled since 1992 but did not show a significant melting in the east.
However, a later study published in Nature in September 2018 looked at layers of sediment from the ocean floor deposited the last time the Wilkes Subglacial Basin, part of Eastern Antarctica to southern Australia, melted about 125,000 years ago.
The study concluded that the huge basin would begin to melt again, with a sustained rise in temperature of just two degrees Celsius, which is needed within the climate of Paris to avoid uncontrolled global warming.
The latest research shows that the melting of Eastern Antarctica deserves "increased attention," according to the PNAS report.
Warming ocean water will only accelerate ice loss in the future, and experts say sea level will continue to rise for centuries, no matter what humans do now to contain climate change.
Recent research has shown that the oceans are heating up faster than previously thought, setting new heat records in recent years.
[ad_2]
Source link