VOA科学技术2023--Study: Part of Antarctica to Experience ‘Unavoidable’ Melt（在线收听）

Study: Part of Antarctica to Experience ‘Unavoidable’ Melt

A new study says that no matter how much the world cuts back on carbon emissions, a large and important part of Antarctica is expected to disappear.

Researchers used computer models to predict the future melting of protective ice around Antarctica's Amundsen Sea in western Antarctica. They said the "unavoidable" melting will take hundreds of years. It will slowly add nearly 1.8 meters to sea levels. And it will be enough to reshape where and how people live in the future.

The study was published recently in Nature Climate Change. It found that even if future warming was limited to just a few tenths of a degree more, it would have "limited power to prevent ocean warming that could lead to the collapse of the West Antarctic Ice Sheet."

Many scientists say the goal of just a few tenths of a degree of warming is unlikely to be met.

"Our main question here was: How much control do we still have over ice shelf melting? How much melting can still be prevented by reducing emissions?" said study lead writer Kaitlin Naughten. She is an expert on oceans at the British Antarctic Survey.

She said their research suggests that Earth is set on the path to a quick increase in the rate of ocean warming and ice shelf melting over the rest of the century.

While past studies have talked about how serious the situation is, Naughten was the first to use computer modeling to study how warm water from below will melt the ice.

The study looked at four different cases in how much carbon emissions the world produces. In each case, ocean warming was just too much for this area of the ice to survive, the study found.

Naughten looked at melting, floating areas of ice that hold back glaciers. Once these areas of ice melt, there is nothing to stop the glaciers behind them from flowing into the sea.

The study also looked at what would happen if future warming was limited to 1.5 degrees Celsius over mid-19th century levels: the international goal. They found the runaway melting process in this case as well.

The world has already warmed about 1.2 degrees Celsius since pre-industrial times and much of this summer went past the 1.5 degrees mark.

Naughten's study looked at the part of the West Antarctic Ice Sheet that is most at risk from melting from below, near the Amundsen Sea. It includes the very large Thwaites ice shelf that is melting so fast it is called "the Doomsday Glacier."

That part of Antarctica "is doomed," said University of California Irvine ice scientist ice scientist Eric Rignot. He was not part of the study. He added, "The damage has already been done."

Naughten does not like to use the word "doomed," because she said 100 years from now, the world might not just stop but drive back carbon levels in the air and climate change. But she said what is happening now on the ground is a slow collapse that cannot be stopped, at least not in this century.

Words in This Story

emission – n. the act of producing or sending out something (such as energy or gas) from a source

shelf – n. a flat area of rock, sand, or ice, especially underwater

glacier – n. a very large area of ice that moves slowly down a slope or valley or over a wide area of land

runaway – adj. operating, running, or increasing in a fast and dangerous way that cannot be controlled

doom – n. very bad events or situations that cannot be avoided