International scientists are warning that the world’s largest ice sheet in Antarctica is losing ice much faster than previously thought.
A recent study by Australian researchers and others outlined what could happen if targets to limit global temperature rise are not met.
Nerilie Abram is a professor in the Research School of Earth Sciences at the Australian National University. She co-authored a study that recently appeared in the journal Nature. He warned that the melting of the East Antarctic ice sheet could be disastrous.
Abram said: “By 2500, East Antarctica could contribute up to 5 meters of sea level. [rises] on top of the sea level rise we will have already had from Greenland and West Antarctica.”
The East Antarctic Ice Sheet contains most of the world’s glacial ice. It was thought to be less affected by global warming compared to the West Antarctic or Greenland ice sheets.
The study by Abram and other researchers says that if temperature rise is limited to 2 degrees Celsius, the East Antarctic ice sheet should remain stable. In other words, it should stay generally the same size. But researchers warn that warmer temperatures could cause more melting and raise sea levels around the world by many metres.
Abram said: “It gives us even more reason to make sure we’re doing everything we can to stay below that 2 degree warming level.”
The Paris Agreement, signed in 2015, aims to limit global warming to less than 2 degrees Celsius.
The 200-foot (60-meter-high) face of the Getz Ice Shelf in Antarctica is marked with cracks where icebergs are likely to break off or break off in this 2016 photo. (Credit: NASA/GSFC /OIB)
NASA study
Another study of Antarctica published in Nature it was drawn from research by scientists at NASA’s Jet Propulsion Laboratory (JPL) in California. Scientists discovered that the edge of the East Antarctic Ice Sheet has been losing ice faster than natural processes can replace it.
The edges of an ice sheet are known as ice shelves. They extend from the ice sheet to the water. They are permanent floating sheets of frozen fresh water.
Ice shelves take thousands of years to form. They hold back glaciers that would otherwise easily fall into the ocean and cause sea levels to rise.
For the JPL study, researchers examined more than 50,000 kilometers of the Antarctic coastline. They found that the loss of ice from pieces of coastal glaciers breaking off into the ocean was almost the same as the loss of ice due to the thinning of large continental ice shelves. The thinning of the ice is the result of the warming of the ocean water below.
Together, the two processes have reduced the mass of the Antarctic ice shelves by 12 trillion metric tons since 1997. That’s double the previous estimate of 6 trillion metric tons.
“Antarctica is collapsing at its edges,” said JPL scientist Chad Greene, lead author of the study.
Eric Wolff is a professor at the University of Cambridge in Great Britain. He said of the JPL study, “If we keep to the 2 degrees of global warming promised by the Paris Agreement, sea level rise due to the East Antarctic ice sheet should be modest “.
But, he said, failure to limit global warming and reduce greenhouse gas emissions would risk “many meters of sea level rise over the next few centuries”.
I’m Ashley Thompson.
Hai Do wrote this story to learn English with materials from VOA News and NASA JPL.
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Words in this story
contribute – v. help make something happen
stable – adj. in good condition that is not likely to change
glacier – n. very large area of ice that moves slowly through an area
crumble – v. break into small pieces
modest – adj. not very large in size or quantity