The Arctic could see its first ice-free day by as early as 2027, a team of scientists has warned in a new report published in Nature Communications.
Arctic sea ice cover is known to be shrinking due to global warming caused by greenhouse gas emissions. Estimates put the loss of ice at 12% per decade and climatologists have noted the “visible transition from a white Arctic Ocean to a predominantly blue Arctic Ocean during the summer”. For the climate community, if the amount of sea ice were to fall below a million square kilometres, the region would be considered “ice-free”.
To calculate how bad things could get and how quickly, the team analysed multiple different scenarios using the latest climate models to predict changes to the Arctic environment. They found that the projected first ice-free day could occur in three years’ time or not happen until 2100. But 11 of the models said the Arctic would be ice-free by 2027, another two said it would happen within four years from now, and another six said it would take just five to six years. 34 of the analyses said the Arctic would reach the first ice-free day within a decade.
Why does Arctic sea ice matter?
The loss of sea ice has “cascading effects on the rest of the climate system” the scientists say, such as “warming of the upper ocean, accelerating sea ice loss year round and therefore further accelerating climate change,” leading to “more extreme events at mid-latitudes.”
Humans are not the only ones who will feel these consequences. “A further reduction of the summer sea ice cover will also negatively impact the already-stressed Arctic ecosystem, from the emblematic polar bear to the crucial zooplankton,” the report notes.
Sea ice being weakened over time
The point of the study is to “raise awareness for the potential of a rapid loss of sea ice in the near future, and to provide insights into what may lead to such rare but high-impact events”. In the worst case scenarios, the ice would disappear as a result of being “pre-conditioned” by warmer atmospheric conditions than usual in the preceding years, particularly in autumn, with warm spells lasting through December, the study showed.
In all the early ice loss stories, a “series of events in the last winter, spring, and summer finish weakening the ice both dynamically and thermodynamically, leading to that first ice-free day,” the authors said. Those events include warmer conditions than normal over the Barents Sea, warm air throughout the winter, an early spring with warm air blocked over the Arctic by atmospheric pressure, and a “warm to very warm summer.” Storm activity also served to weaken the sea ice in some scenarios.
Some of those conditions are already being met, with record-breaking global temperatures recorded in 2023 and the ten hottest years since records began in 1850 all occurring in the last decade. Still, the researchers expressed some optimism that “A drastic cut in emissions could delay the timeline for an ice-free Arctic and reduce the time the ocean stays ice-free.”
