Researchers sound alarm over "unprecedented ice-free" threat to Arctic
Why it matters: The peer-reviewed findings on the effects of human-caused climate change in the region, published in Nature Communications, suggest the first ice-free summer could be in the 2030s. That's a decade sooner than previously projected.
Thought bubble: Many studies have projected when the Arctic sea ice would be seasonally ice-free, and all could be proven wrong given the nonlinearities and variability inherent in the Arctic climate system.
- One thing is for sure though, there are going to be surprises, many of them in a warmer, less ice-covered direction. Using different techniques to examine these questions is valuable, since the region is already heating up so quickly. That applies to the climate and geopolitics.
What they did: Researchers examined satellite data and climate models from 1979-2019 to see how Arctic sea ice has changed.
- They used this information to model future melting.
What they found: The researchers discovered the models underestimated the pace of melting compared with observations of ice in the Arctic over the period they examined, according to the study.
- "By scaling models' sea ice response to greenhouse gases to best match the observed trend in an approach validated in an imperfect model test, we project an ice-free Arctic in September under all scenarios considered," wrote the researchers in the study, led by Seung-Ki Min of Pohang University.
- "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."
Threat level: "[W]e may experience an unprecedented ice-free Arctic climate in the next decade or two, irrespective of emission scenarios," per the study.
- This would affect human society and the ecosystem both within and outside the Arctic, through changing Arctic marine activities as well as further accelerating the Arctic warming,” the researchers wrote.
By the numbers: The research indicates that 90% of the melting in the region is due to human-caused global heating and natural factors account for the remainder.
What they're saying: Julienne Stroeve, a senior scientist at the NSIDC who was not involved in the study, said in an emailed statement Tuesday it's impossible to give an exact date to when an ice-free summer will emerge.
- "This is because we cannot predict atmospheric conditions and the ice is quite sensitive to the the year-to-year weather variability and we also do not have long-enough or trustworthy records of ice thickness to know if the ice is so thin it would suddenly melt out," Stroeve said.
- "With others I have looked at using today's ice thickness estimates from satellite together with the weather conditions of summer 2007 and 2012 and we didn't find we had a more massive loss of ice that we had during those two summers.
- "This implies that the ice cover is still somewhat resilient to completely disappearing in today’s climate state."