The Arctic Ocean could become free of sea ice during the months of September from 2030-2050 under all emissions scenarios, according to a model-based study, a decade earlier than previously predicted.
Research published in Nature Communications, led by Pohang University of Science and Technology (South Korea), indicates that this possibility can occur even in a scenario of low greenhouse gas emissions.
The sixth assessment report of the International Panel on Climate Change (IPCC), published last March, predicts that the Arctic will be virtually ice-free on average in September, close to mid-century under scenarios of intermediate and high emissions, although not low emissions.
However, the new study published Tuesday projects that the Arctic could become free of sea ice in September from 2030-2050 under all emissions scenarios.
An image from the NASa shows the Arctic Ocean at its minimum ice point. In 10 years it could thaw completely every September. Photo: Reuters
These results highlight "the profound impact of greenhouse gas emissions on the Arctic and demonstrate the importance of planning for and adapting to a seasonally ice-free Arctic in the near future," the authors write.
In recent decades, Arctic sea ice has declined rapidly in all seasons, with an increasing decline since 2000.
An Arctic without sea ice would affect human societies and natural ecosystems, both inside and outside that region, for example by changing marine activity, further accelerating the warming of the area and altering the carbon cycle.
The team led by Seung-Ki Min used observational data between 1979 and 2019 to constrain climate model simulations. The results suggest that the human impact on declining sea ice in the Arctic can be observed year-round and can be largely attributed to increased greenhouse gas emissions.
The habitat of polar bears will be significantly affected. Photo: AFP
However, the contribution of aerosols and natural factors (such as solar and volcanic activity) turned out to be much smaller.
As for the contribution of aerosols and other ozone-depleting substances (ODS) to the disappearance of sea ice during the Arctic summer, the journal PNAS published last May a study on how the Montreal Protocol, which limits its use, helps delay this scenario.
The model-based research noted that the implementation of this protocol, which came into force in 1999, is delaying the onset of the first ice-free Arctic summer by up to 15 years.
If this international treaty had not been enacted, the global average surface temperature would be about half a degree warmer and the Arctic ice cap almost one degree warmer by 2050, the study said.
The Montreal Protocol aims to reduce atmospheric concentrations of ODS, commonly used in products such as refrigerators, air conditioners, fire extinguishers and aerosols.