Antarctica's brief rebound was caused by climate variability, not a 'new normal'

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Between 2021 and 2023, Antarctica appeared to be growing. Heavy snowfall fueled by wetter weather caused parts of the continent to gain mass, leading some to question whether climate change is really causing the ice to melt.

However, a new study shows that the precipitation increase was an anomaly related to extra-warm tropical ocean temperatures, not part of a long-term trend. Antarctica has been "shrinking" for decades as warm water melts ice from below and sends large chunks crashing into the ocean. Annual precipitation can't keep up with the rate of melt, causing a net mass loss.

However, the snow that fell on East Antarctica, a vast area that contains nearly 80% of Earth's land-bound ice, added mass faster than the ice was melting. Although mass loss continued in West Antarctica, the general trend seemed encouraging. "In the early 2020s, there was an exceptional amount of snowfall over parts of Antarctica.

Because Antarctica is so big, it doesn't take that much extra snow thickness to counter the loss of ice from the edges of the ice sheet, which led to the perception that the loss of ice is slowing down," said coauthor Eric Steig, a UW professor of Earth and space sciences. The question nagging researchers was whether this would continue into the future. To answer it, they needed to trace the origins of the precipitation.

Because warm air can hold more moisture than colder air, higher latitudes could eventually see wetter conditions due to global warming. Scientists recognize that the average amount of moisture in the air will increase as global temperatures rise. Some saw the heavier snowfall as evidence that this expected trend was materializing in Antarctica.

"Warmer conditions favor storms shifting toward the poles, which could offset ice loss through snowfall," said coauthor Qinghua Ding, a professor of atmospheric and climate science at UC Santa Barbara. But the data told a different story. Using a computational method that involves "tagging" water molecules, the researchers linked the extra precipitation in Antarctica to the tropical warm pool, a warm patch of ocean in the western Pacific and eastern Indian Ocean that makes an outsized contribution to extreme weather.