December 3, 2024
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The Arctic could become functionally ice-free in just a few years
Unless more is done to combat climate change, the Arctic is likely to be “ice-free” by mid-century, and could pass that grim milestone sooner.
A polar bear on an ice floe in Svalbard, Norway.
Shaffer & Hill/Getty Images
Climate wire | By the end of this decade, even at moderate levels of global warming, the Arctic Ocean could see its first ice-free day on record.
It’s an unlikely scenario, but it’s possible. And that’s becoming more and more likely as humans continue to pump greenhouse gases into the atmosphere.
Scientists sound the alarm in a study published Tuesday in a scientific journal. nature communications.
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The study relied on climate models that simulated trends in global temperatures and Arctic sea ice concentrations, and found that the only way to avoid ice-free days within the next few years is to meet the most ambitious goals of the Paris Agreement. It warns that the key is to reduce emissions fast enough to match the current content. The goal is to limit global warming to 1.5 degrees Celsius.
But experts agree that the world is almost certain to surpass that goal, with current global climate commitments putting global warming on track to exceed 2.6°C by the end of the century. I am doing it.
That means the first ice-free day in the Arctic is likely to occur within 20 years, a new study has found. But given the right conditions, it could happen within three to six years.
“This is definitely a very unlikely event,” said Céline Heuse, a scientist at the University of Gothenburg, and Alexandra Jahn, a climate scientist at the University of Colorado Boulder who co-authored the study. “We’re looking at the outer edges of what’s going to happen.”
The worst-case scenario would require a perfect storm of weather and weather conditions over the next few years, Jahn said.
Temperatures need to be extremely high, especially in fall, winter, and spring. This is more likely to happen when high pressure moves over the North Pole, trapping warm air in place. Rough weather can also help prepare the ocean for rapid melting, helping sea ice break up and melt into the ocean more quickly.
If all these conditions occur simultaneously and continue for several years, the Arctic Ocean could experience a catastrophic ice loss event by 2027.
Whether it happens that quickly is mostly up to chance. But unless humanity’s response to global warming changes dramatically, that day is drawing near.
Jahn said sea ice has been decreasing for decades due to climate change, and without it an ice-free Arctic Ocean would not be possible under any circumstances.
But the exact year in which it occurs depends on natural fluctuations in weather, so scientists’ uncertainty spans decades.
The study focused solely on the first ice-free day, the first time that Arctic sea ice extent was below 1 million square kilometers (386,102 square miles) above sea level, according to scientific definition. paying attention. This differs from other recent studies that have examined the timeline of the first ice-free month or summer in the Arctic.
Even if the first ice-free day occurs in the next few years, there will likely be several more after that. In these model simulations, ice-free periods last between 11 and 53 days. That means it could last less than two weeks or last until the first ice-free month, marking a new climate milestone.
Jahn cautioned that these are unlikely scenarios, with less than a 5% chance of occurring under current conditions. However, the most likely model scenarios still suggest that the first ice-free day will occur by mid-century, or even sooner. Studies predicting the first completely ice-free month suggest a similar timeline even if the world surpasses the 1.5-degree temperature threshold.
That doesn’t mean climate action isn’t important for the Arctic, Jahn warned, rather the opposite. Reducing greenhouse gas emissions as much as possible limits the total amount of sea ice that melts, reduces the frequency of ice-free summer events, and protects sea ice cover during the colder months of the year.
“Even if we don’t reach the target, it is possible to maintain a temperature of 1.6 degrees,” Jahn said. “It’s a remarkable achievement and will no doubt have a huge impact on what the Arctic will look like in the second half of the 21st century.”
Reprinted from E&E News Published with permission of POLITICO, LLC. Copyright 2024. E&E News provides news that matters to energy and environment professionals.
