December 3, 2024
3 read me
The Arctic could be ice-free in a few years
The Arctic is likely to be “ice-free” by mid-century, and may pass that grim milestone much sooner, unless much more is done to combat climate change.
Polar bear on ice in Svalbard, Norway.
Schafer & Hill/Getty Images
KLIMAWIRE | By the end of the decade, the Arctic Ocean could see its first ice-free day, despite modest levels of global warming.
It is a difficult scenario, but it is possible. And it’s becoming more and more plausible as humans continue to pour greenhouse gases into the atmosphere.
Scientists raised the alarm in one study published Tuesday in the scientific journal Nature Communications.
About supporting science journalism
If you like this article, please consider supporting our award-winning journalism subscribe. By purchasing a subscription, you’re helping to ensure a future of impactful stories about the discoveries and ideas that shape our world.
The study — which is based on climate models simulating trends in global temperature and Arctic ice concentration — warns that the only way to avoid an ice-free day in the coming years is to reduce emissions fast enough to keep up with the ambitious goals of the Paris Agreement. The goal is to reduce global warming to 1.5 degrees Celsius.
However, experts agree that the world is certain blow off that targetcurrent global climate commitments putting the planet on track to warm more than 2.6 C by the end of the century.
That means the first ice-free day in the Arctic will happen in two decades, new research says. But if the right conditions are met, it could happen in three to six years.
“It’s definitely a very difficult event,” said Alexandra Jahn, a climate scientist at the University of Colorado at Boulder, who co-authored the study with Céline Heuzé, a scientist at the University of Gothenburg. “We’re looking at the outside of what might happen.”
The worst-case scenario would require a perfect storm of weather and climate conditions in the coming years, Jahn said.
Temperatures should be unusually warm, especially in autumn, winter and spring. This is most likely to happen when high pressure weather systems move over the Arctic, trapping warm air in place. Stormy weather can also contribute to rapid ocean melting by breaking up sea ice and helping it dissolve faster in the ocean.
If all of these conditions occur together—and persist for several years—the Arctic Ocean could experience a catastrophic ice loss event by 2027.
Whether it happens quickly or not is largely a matter of luck. But that day is on the horizon, barring a dramatic shift in humanity’s response to global warming.
Climate change has caused sea ice to decrease over the decades, without which an ice-free Arctic Ocean would be impossible in any case, Jahn said.
But the exact year it occurs will depend on natural weather fluctuations, giving scientists decades of uncertainty.
The study is careful to focus on the first ice-free day: by scientific definitions, this is the first time the Arctic sea ice cover has decreased below 1 million square kilometers of ocean surface. Therefore, it differs from other recent studies that have investigated timelines for the first ice-free month or summer in the Arctic.
If the first ice-free day happens in the next few years, there will likely be many more to come. In these model simulations, the ice-free period lasts between 11 and 53 days. That means it could end in less than two weeks or extend into the first ice-free month, another climate milestone.
Jahn cautions that these are improbable events, with less than a 5 percent chance of happening under current circumstances. But the most likely model scenarios still suggest that the first ice-free day will occur by half a century or perhaps sooner. Studies predicting the first full ice-free month have suggested similar timelines if the world exceeds the 1.5C threshold.
This is not to say that climate action is not important for the Arctic, Jahn notes, but quite the opposite. Minimizing greenhouse gas emissions will limit the amount of sea ice that melts, reduce ice-free summer events and protect the sea ice cover during the colder parts of the year.
“Even if we miss the target, we can stick to 1.6 degrees,” Jahn said. “Then it will be a huge achievement and will certainly have a big impact on how the Arctic will play out in the second half of the 21st century.”
Reprinted E&E News Courtesy of POLITICO, LLC. Copyright 2024. E&E News provides essential news for energy and environmental professionals.
