Tuesday, February 27, 2024
Tuesday, February 27, 2024
HomeScienceAntarctic tipping point that occurred 8,000 years ago 'could happen again'

Antarctic tipping point that occurred 8,000 years ago ‘could happen again’

As EU scientists confirmed that a worrying trend of historically high temperatures continued last month, UK researchers released A study released Thursday warns how fossil fuel-driven global warming could lead to rapid and catastrophic ice loss in Antarctica not seen in thousands of years.

The study, published by researchers from the British Antarctic Survey (BAS) and the University of Cambridge in
Nature GeoscienceIt is based on an ice core from the West Antarctic Ice Sheet that is more than 2,100 feet long.

“We now have direct evidence that this ice sheet suffered rapid ice loss in the past,”
saying Lead author and Cambridge Earth sciences professor Eric Wolff said in a statement. “This scenario is not something that exists only in our model predictions and could happen again if parts of this ice sheet become unstable.”

“The same processes we are now seeing beginning, in areas like the Thwaites Glacier, have played out before in similar areas of Antarctica and, in fact, the rate of ice loss was equal to our worst fears about uncontrolled ice loss.” “.

Isobel Rowell, co-author of the study and a BAS researcher, explained that “we wanted to know what happened to the West Antarctic ice sheet at the end of the last Ice Age, when temperatures on Earth were rising, albeit at a faster rate. slower than current anthropogenic warming.”

“Using ice cores we can go back to that time and estimate the thickness and extent of the ice sheet,” he continued. The team measured stable water isotopes and the pressure of air bubbles in the core, and found that the ice sheet “shrinked suddenly and dramatically” about 8,000 years ago.

“We already knew from the models that the ice was thinning at that time, but the date was uncertain,” Rowell said, referring to estimates from 5,000 to 12,000 years ago. “We now have a very precisely dated observation of that retreat that can be incorporated into improved models.”

Previous models also did not indicate how quickly the recall occurred. However, the team’s measurements showed that “once the ice thinned, it contracted very quickly,” Wolff said.

“This was clearly a turning point, a runaway process,” he added. “It is now crucial to find out whether additional heat could destabilize the ice and cause it to start retreating again.”

Ted Scambos, a glaciologist at the University of Colorado at Boulder, was not involved in the study, but called it “excellent detective work” and
saidcnn that its message is that “the amount of ice stored in Antarctica can change very quickly, at a rate that would be difficult for many coastal cities to cope with.”

cnn He noted that the study contributes to scientists’ warnings about conditions in Antarctica:

For example, the Thwaites Glacier, also in West Antarctica,
is melting quickly. A 2022 study said the Thwaites, nicknamed the Doomsday Glacier for the catastrophic impact its collapse would have on sea level rise, was hanging “by the nails” as the planet warms.

This new study adds to these concerns, Scambos said. “(This) shows that the same processes we are now seeing beginning, in areas like the Thwaites Glacier, have played out before in similar areas of Antarctica and, in fact, the rate of ice loss was equal to our worst fears about an uncontrolled ice. loss.”

As common dreamsreported in October, a study published in Nature Climate Change found that the West Antarctic Ice Sheet, which contains enough ice to raise global mean sea level by more than 17 feet, faces an “inevitable” increase in melting over the rest of this century.

“If we wanted to preserve it in its historic state, we would have needed action on climate change decades ago,” lead author and BAS researcher Kaitlin Naughten said at the time, while emphasizing that “we must not stop working to reduce our dependence “. on fossil fuels.

The publication of that study preceded the 28th United Nations Climate Change Conference in Dubai. After COP28 ended in December with a final agreement that did not explicitly support a global phase-out of fossil fuels, scientists called it a “tragedy for the planet.”

Despite the pressure it received in the United Arab Emirates for having a fossil fuel chief executive leading the last summit, Azerbaijan, host of COP29, plans to have an oil executive leading the next one, scheduled for November. Azerbaijan also plans to increase its gas production by a third over the next decade.

The host of COP29 is far from alone. Global Witness revealed last month that oil and gas companies that signed a decarbonisation pact at last year’s conference plan to burn around 62% of the world’s carbon budget by 2050, prompting new demands for governments to stop give in to the polluters and implement more ambitious measures. climate policies.

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