Robert Larter
Twaites Glacier in West Antarctica in 2019. New research shows that global warming is
CNN
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of Antarctic ice sheet Glaciers are melting in new and alarming ways that scientific models used to predict future sea-level rise do not take into account, according to a new study, suggesting that current projections may be significantly underestimating the problem.
Scientists from the British Antarctic Survey found that warm ocean water could be seeping below the ice sheet’s “frost line” – the point where ice rises from the ocean floor and begins to float – triggering rapid melting that could lead to a tipping point, they said in a report published Tuesday in the journal Nature Geoscience.
A tipping point is the threshold at which a series of small changes accumulate to cause a system to cross the point of no return.
Here’s how ice melts: Warmer ocean water opens cavities in the ice, allowing more water to seep in, melting the ice even more and creating bigger cavities.
Research has shown that even small increases in ocean temperatures can have a huge impact on how much ice melts, and warmer oceans caused by climate change will accelerate this process.
“You get this runaway feedback,” Alex Bradley, an ice dynamics researcher at BAS and lead author of the paper, told CNN that this is something of a tipping point, “which could lead to a very rapid change in the amount of melting that’s happening in these places.”
This tipping point would come about through accelerating ice flow into the ocean, a process not currently included in models of future sea-level rise, Bradley said, adding that “our projections of sea-level rise are likely significantly underestimated.”
The impacts will not be felt immediately, but sea level rise will accumulate over decades to centuries, threatening coastal communities around the world, according to the study.
The study didn’t provide a timeframe for when a tipping point might be reached, nor did it provide figures for how much sea level rise is expected to occur, but this region is crucial: The Antarctic ice sheet already loses an average of 150 billion tons of ice each year, and collectively the ice sheet contains enough water to raise global sea levels by 10 million metric tons. Approximately 190 feet (about 58 meters).
This is not the first study to point out Antarctica’s vulnerability to the climate crisis. West Antarctica’s vulnerability In particular, the Thwaites Glacier As the Doomsday Glacier This could have a devastating effect on sea level rise.
But what surprised Bradley in the study, which used climate models to understand how this melting mechanism would affect the entire ice sheet, was that some of the most vulnerable glaciers were in East Antarctica.
Sebnem Coskun/Anadolu/Getty Images
An iceberg in Antarctica, February 8, 2024. Numerous studies have looked at how vulnerable this vast continent is to the effects of the climate crisis.
Eric Rignot, a professor of Earth system science at the University of California, Irvine, who was not involved in the study, told CNN that the research “opens the door to looking more closely at the physical processes that are happening in the grounding zone.”
“But this region is highly complex and poorly observed, and much more research and field observations are needed,” he cautioned, including clarifying the processes that control seawater intrusion under the ice and how exactly that affects ice melt.
A recent study in West Antarctica has shown that melting at the base of glaciers is actually Lower than expectedThat’s because it was being held back by a layer of cooler, fresher water, but scientists still found it to be retreating quickly.
Ted Scambos, a glaciologist at the University of Colorado Boulder, said the new model developed by the BAS scientists is “potentially very important” but needs to be considered in conjunction with more recent research on the mechanisms behind ice melt and the effect of tides pumping water under the ice.
Bradley hopes the study will spur further research into which areas are most at risk, and provide further impetus for policies to tackle the climate crisis. “Any little bit of warming in the ocean, any little bit of climate change, gets us closer to these tipping points,” he said.