In a new paper researchers take an interest in the immediate future of Arctic sea ice - the masses of frozen water that drift out to sea. In recent decades, these seas have seen a rapid decline in such ice, with the Arctic spending an increasing proportion of the year without it.
According to the sixth Intergovernmental Panel on Climate Change (IPCC) report, the Arctic may be ice-free in September by the middle of the 21st century. Such projections are based on scenarios corresponding to high and medium carbon dioxide emissions.
"These results emphasize the profound impacts 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," wrote scientists.
The authors of the new study believe that IPCC models underestimate the impact of greenhouse gases on total sea ice extent. They suggest that by 2080-2100, the Arctic seas will have lost their summer ice cover one way or another, even if a 'optimistic' low-emission scenario is realized.
The researchers believe the earlier approach of dividing the Arctic into 15% ice-covered cells leads to errors. Instead, they are simply looking at the total ice-covered area of the ocean, which can be estimated directly from satellite imagery.
The scientists used observations from 1979 to 2019 to adjust their models and make sure they were accurate. In doing so, they confirmed that the rate of decline in sea ice has been particularly rapid since the 1990s.
The authors found that the impact of human activity on sea ice loss is year-round, not a single month. The most dramatic changes, however, are expected in the Arctic September, the month when sea ice is at its thinnest.
The study was published in Nature Communications journal.