Scientists Suggest End of Arctic Sea Ice in 2060, after Possible Brief Expansion

Includes corrections

Arctic sea ice could disappear completely by 2060 in the summer months due to accelerated warming from both a buildup of human-caused greenhouse gases and the planet's natural greenhouse effect, a group of scientists from the National Center for Atmospheric Research concluded in a new study.

However, the researchers said they still can't predict with certainty whether sea ice will retreat or expand during the next decade.

That finding keeps alive a scientific puzzle that has persisted for years, with implications that reach beyond academic circles.

Getting the question resolved is of mounting interest for businesses and countries, who are eager to tap economic opportunities of the melting Arctic as it opens the region to commercial shipping and oil exploration. By contrast, some climate skeptics opposing greenhouse gas regulation policies in Congress and other governments have an interest in bolstering the scientific uncertainty. 

In an interview with SolveClimate News, Jen Kay, NCAR climate scientist and lead author of the research, said the study shows that predicting what will happen to Arctic sea ice from now until 2020 is tricky, because of the unpredictable effects that winds, clouds and temperature changes have on patterns of atmospheric circulation. These natural fluctuations are too volatile to be trusted when incorporated into climate models, she said.

However, "according to our research greenhouse gases are definitely affecting the ice," Kay said, cognizant of how the study's ambiguity on the politically charged issue may be interpreted.

"If you look at a 20-year period and asked me, 'What's the trend going to be?' I would say large and negative. But if you ask about the trend over a 10-year period, I'd have to say, 'I don't know,'" she said.

According to the research, which was published in last week's Geophysical Research Letters, Arctic ice has a 50-50 chance of experiencing a brief revival before it completely disappears during the summer by 2060.

Kay said that wind and the other atmospheric variants will cause the vacillation in sea ice, which may expand several times before vanishing.

This may seem inconsistent with the dramatic findings announced last week by the National Snow and Ice Data Center that sea ice extent in the Arctic hit a record low this July. The Arctic region has lost ice equivalent to roughly three times the size of Texas since 2000, according to NSIDC.

However, even during the predicted periods of expansion, sea ice could easily swing the other way from a mix of human-driven climate changes, due mainly from the burning of fossil fuels and cutting down of tropical forests, and erratic natural causes, the NCAR study suggests.

Overall, the short-term natural variables are so inconstant that any predictions made today on sea ice would be too unreliable to be conclusive, Kay warned.

Bruno Tremblay, a climate scientist at McGill University in Montreal who was not involved in the research, agreed.

"There is a bit of a battle over people wanting — and making — short-term climate predictions. Even scientists participate in it," he told SolveClimate News.

 "Sometimes you go to conferences and someone will say, 'In seven years, there will be no more summer sea ice.' But as this paper shows, you can't make these statements. There's just too much variability. And people in business are going to have to wait and see just like everyone else."

Human-made vs. Natural Warming

Using the Community Climate System Model 4.0 (CCSM4), which was developed at NCAR with several organizations and funding from the National Science Foundation and the Department of Energy, Kay and her colleagues sought to answer another difficult question: what percentage of climate change is due to anthropogenic, or human-made, causes versus natural variables?