The Arctic Ocean is warming much faster than predicted by climate models used by United Nations experts, thus accelerating the melting of sea ice, two Swedish studies released on Tuesday warned.
Relatively warm currents in the deep Arctic are actually warmer and closer to the surface than experts previously thought, according to the studies from the University of Gothenburg, published by the Journal of Climate. These warm currents are coming into direct contact with sea ice and accelerating its melting in winter, they say.
The researchers compared their observations with calculations from 14 models considered by the Intergovernmental Panel on Climate Change (IPCC), the panel of experts responsible for the UN’s major climate reports.
The role of deep water flowing under the Arctic from the Atlantic is underestimated by these models, they conclude.
“We are sure that what happens in the Arctic in real life does not happen as in the models,” said Céline Heuzé, a climate scientist at the University of Gothenburg and leader of one of the studies. “The forecasts shared by the IPCC are a little too optimistic. It’s going to be even worse and faster than predicted.”
Already last year, a study found that the Arctic atmosphere had warmed four times faster than elsewhere over the past 40 years, twice as fast as the modelling used by the IPCC.
The disappearance of sea ice is accelerating warming because of a phenomenon known as “Arctic amplification”.
This occurs when sea ice, which naturally reflects the sun’s heat, melts and reverts to dark seawater, which absorbs more solar radiation and warms.