WASHINGTON — The Arctic could be free of sea ice roughly a decade earlier than projected, scientists warn – another clear sign the climate crisis is happening faster than expected as the world continues to pump out planet-heating pollution.
A new study published Tuesday in the journal Nature Communications found Arctic sea ice could disappear completely during the month of September as early as the 2030s. Even if the world makes significant cuts to planet-heating pollution today, the Arctic could still see summers free of sea ice by the 2050s, scientists reported.
The researchers analyzed changes from 1979 to 2019, comparing different satellite data and climate models to assess how Arctic sea ice was changing.
They found that declining sea ice was largely the result of human-caused, planet-heating pollution, and previous models had underestimated Arctic sea ice melting trends.
“We were surprised to find that an ice-free Arctic will be there in summer irrespective of our effort at reducing emissions, which was not expected,” Seung-Ki Min, lead author of the study and professor at Pohang University of Science and Technology in South Korea, told CNN.
Arctic ice builds up during the winter and then melts in the summer, typically reaching its lowest levels in September, before the cycle begins again.
Once Arctic summers become ice-free, the buildup of sea ice in the colder seasons will be much slower, Min said. The warmer it gets, the more likely the Arctic is to stay free of sea ice further into the colder season.
Under a “higher emissions pathway” – in which the world continues to burn fossil fuels and levels of planet-warming pollution continue to rise – the study projects the Arctic will see a complete loss of sea ice from August until as late as October before the 2080s, Min said.
The study’s findings contrast with the UN Intergovernmental Panel on Climate Change’s 2021 state-of-the-science report, which found the Arctic would be “be practically ice-free near mid-century under intermediate and high greenhouse gas emissions scenarios.”
This new study shows it could happen 10 years earlier, regardless of emission scenarios, Min said.
Over the past several decades, the Arctic has warmed four times faster than the rest of the world, a 2022 study showed. There has already been a rapid loss of sea ice in the region, with September sea ice shrinking at a rate of 12.6% per decade, according to NASA.
An Arctic with no summer sea ice would send dire ripple effects around the world. The bright white ice reflects solar energy away from the Earth. When this ice melts, it exposes the darker ocean, which absorbs more heat causing additional warming – a feedback process called “Arctic amplification.”
The decline of sea ice can also have an effect on global weather stretching well beyond the Arctic.
“We need to prepare ourselves for a world with warmer Arctic very soon,” Min said. “Since Arctic warming is suggested to bring weather extremes like heatwaves, wildfires, and floods on Northern mid- and high latitudes, the earlier onset of an ice-free Arctic also implies that we will be experiencing extreme events faster than predicted.”
A sea ice-free Arctic could also lead to an increase in commercial shipping as new routes open up, which would have a knock-on effect. According to last year’s annual Arctic report card by the National Oceanic and Atmospheric Administration, a surge in shipping traffic would lead to more emissions and pollution in the region.
Mika Rantanen, researcher with the Finnish Meteorological Institute and lead author of the 2022 study, told CNN the study published Tuesday benefited from “novel and state-of-the-art methodology” to predict when the Arctic will be ice-free.
“The methodology is very careful and brings a high degree of certainty in the attribution,” said Rantanen, who was not involved in the study. “The most striking result is not that the sea ice loss is attributed to greenhouse gas increases, which was already largely known, but that they project ice-free Arctic earlier than previously thought by about decade.”
Min said the findings show that the Arctic is on the verge of becoming “seriously ill,” and that the region has reached a “tipping point.”
“We can regard the Arctic sea ice as the immune system of our body which protects our body from harmful things,” Min said. “Without the protector, the Arctic’s condition will go from bad to worse quickly.”
