2023-09-08 09:18:28
Antarctica is likely warming nearly twice as fast as the rest of the world and faster than climate change models predict, with potentially far-reaching consequences for global sea level rise, according to a scientific study.
According to The Guardian, scientists analyzed 78 cores (a core is a sample of material, a cylindrical column taken during drilling for the purpose of further study) of Antarctic ice to recreate temperatures 1,000 years ago, and found that warming across the continent goes beyond that , which could be expected from natural fluctuations.
In West Antarctica, a region considered particularly vulnerable to warming due to an ice sheet that, if destroyed, could raise global sea levels by several metres, the study found that warming is occurring twice as fast as climate models suggest.
Climate scientists have long expected the polar regions to warm faster than the rest of the planet – a phenomenon known as polar amplification – and this has been seen in the Arctic.
Dr Mathieu Casado, from the Laboratory of Climate and Environmental Sciences in France and lead author of the study, said the researchers found “direct evidence” that Antarctica is also currently experiencing increased melting of Antarctic ice.
“It is extremely alarming to see such significant warming in Antarctica, beyond the range of natural variability,” Dr Casado said.
Antarctica is the size of the continental United States and Mexico combined, but has only 23 permanent weather stations, and only three of them are off the coast, writes The Guardian.
Mathieu Casado and his colleagues examined 78 Antarctic ice cores that contain temperature data, then compared those temperatures to climate models and observations.
The study, published in the journal Nature Climate Change, found that Antarctica is warming at a rate of 0.22°C to 0.32°C per decade, compared with 0.18°C per decade predicted by climate models.
Some of the warming in Antarctica is likely being masked by changes in wind patterns, which are also believed to be linked to global warming and the loss of the ozone layer over the continent, which has led to lower temperatures.
Dr Sarah Jackson, an ice core expert at the Australian National University who was not involved in the study, admits the results were “deeply disturbing”.
“All of our projections for future sea level rise are based on these low rates of warming. Our models may be underestimating the ice loss we could experience,” she said.
Dr Danielle Udy, a climate scientist and ice core expert at the University of Tasmania who was not involved in the work, said the research was timely “given the extreme events we are seeing in Antarctica”.
Scientists are struggling to understand why sea ice levels in Antarctica have been at record lows over the past two years, and some suggest global warming may now be affecting the region.
Thousands of emperor penguin chicks likely died in late 2022 after the usually stable sea ice that supports colonies in West Antarctica melted.
Dr. Kyle Klem, a scientist at Victoria University of Wellington in New Zealand, studied recent record high temperatures at one weather station at the South Pole.
Clem says Antarctica’s climate is subject to large natural variations, but Dr. Casado’s team’s study showed “a marked change in the Antarctic climate and the emergence of man-made polarity intensification.”
The scientist believes the results will be critical to understanding the future of the continent, “as greenhouse gas emissions continue to increase.”
“The results of this study have particular implications for considering future changes in Antarctic sea ice, terrestrial and marine ecosystems, and perhaps even sea level rise,” Klem said. “If Antarctica is already experiencing anthropogenic polarity amplification beyond what is simulated by climate models, then future warming is likely to be greater than currently predicted by climate models.”
Warming in Antarctica, he said, is also likely to lead to further loss of sea ice, which will have implications for “ocean warming, global ocean circulation and marine ecosystems.”
“In terms of sea level rise, ocean warming is already melting protective ice shelves in West Antarctica and causing the West Antarctic Ice Sheet to retreat.”
More warming could also lead to more melting of the coastal ice shelves that protect the glaciers.
“This has already been observed on the Antarctic Peninsula in recent decades, and it may become more common around Antarctica sooner than expected as the Antarctic climate warms more,” he said.
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