The Arctic could be sea ice-free in summer as early as the 2030s, much sooner than previously estimated, and even under a low greenhouse gas emissions scenario, researchers say in a paper published on Tuesday. Scientists based in Korea, Canada and Germany used observation data from the years 1979-2019 to run new simulations. “The results indicate that the first sea-ice-free September will occur as early as the 2030s-2050s, regardless of emissions scenarios,” they conclude in the journal Nature Communications.
When experts talk about no ice, that means an area of ??less than 1 million square kilometres, because there may always be residual ice along the coasts. The Arctic Ocean covers an area of ??approximately 14 million square kilometers and is covered in ice for most of the year. September is the month in which the ice usually reaches its annual minimum.
“That’s about a decade earlier than recent projections from the IPCC,” the UN-mandated group of climate experts, points out Seung-Ki Min, of South Korea’s Pohang and Yonsei Universities, co-author of the article. The researchers also believe that the decline of this ice can be attributed mainly to greenhouse gas emissions, the other factors (aerosols, solar and volcanic activity, etc.) being much less important.
Sea ice, which forms the pack ice, is made of salt water on the surface of an ocean, which has frozen under the effect of the cold. Its melting does not directly cause a rise in the level of the oceans (contrary to that of the ice cap and glaciers), but nevertheless has harmful consequences. Indeed, this ice plays a very important role in summer, by returning the rays of the sun, which makes it possible to cool the Arctic. This mirror is now getting smaller and smaller, and the Arctic is therefore warming up much faster than other regions.
Disappearing ice will “accelerate arctic warming, which may increase mid-latitude extreme weather events, such as heat waves and wildfires,” notes Seung-Ki Min. “It may also accelerate global warming, by melting permafrost, as well as sea level rise by melting the Greenland Ice Sheet,” the researcher adds.
“This will be the first major component of our climate system that we lose through our greenhouse gas emissions,” said Dirk Notz of the University of Hamburg, another co-author of the study. “Scientists have been warning about this disappearance for decades and it’s sad to see that these warnings have largely gone unheeded,” he said.
Dirk Notz now hopes that policymakers will pay heed to the researchers’ findings “so that we can at least protect the other components of our climate system, limiting future warming as much as possible.”
