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A less pessimistic Arctic sea ice view New research points to a gradual, reversible ice shrinkage under global warming, rather than a sudden rapid loss of ice cover Alan Bailey Petroleum News
The multiyear shrinkage of the extent of the Arctic sea ice cover has become one of the most prominent lines of evidence demonstrating the continuing warming of the Earth’s climate. And scientists have argued that there will likely be a future tipping point, a point at which the self-reinforcing nature of the ice melt will cause a sudden acceleration in ice loss, leading to an ice-free polar region. Pass that tipping point and the loss of ice will be irreversible, some scientists have said.
But two scientists in the Scripps Institution of Oceanography have conducted research which points to a less catastrophic future, according to an April 22 news release from the institution. New climate and ice modeling that the scientists have conducted, while not contradicting the general thesis that the Earth is becoming warmer and that the sea ice is melting, have indicated that there will be no tipping point in the melt. And the loss of ice will simply reverse, if the climate cools, modeling has found.
Combined model While the more cataclysmic view of the ice melt has come from mathematical modeling of the ice-melt process itself, the new perspective comes from combining this “process model” with global climate models. This more complex, and potentially more realistic, view of the situation erases the tipping point from the ice-melt scenario. Then, with no tipping point, the ice melt becomes reversible.
“We found that two key physical processes, which were often overlooked in previous process models, were actually essential for accurately describing whether sea ice loss is reversible,” said Ian Eisenman, a professor of climate dynamics at Scripps and one of the scientists conducting the research. “One relates to how heat moves from the tropics to the poles and the other is associated with the seasonal cycle. None of the relevant previous process modeling studies had included both of these factors, which led them to spuriously identify a tipping point that did not correspond to the real world.”
“So if global warming does soon melt all the Arctic sea ice, at least we can expect to get it back if we somehow manage to cool the plant back down again,” said Till Wagner, the other Scripps scientist involved in the research.
The Office of Naval Research and the National Science Foundation funded the Scripps research, with the Navy funding coming as part of a strategy to better understand future changes in the Arctic Ocean and to clarify how the challenges that those changes may bring for future naval operations.
“The Navy has broad interest in the evolution of the Arctic,” said Frank Herr from the Office of Naval Research. “Sea ice dynamics are a critical component of the changing environmental picture. Our physical models lack important details on the processes controlling ice formation and melting, thus ONR is conducting a series of experimental efforts on sea ice, open water processes, acoustics, and circulation.”
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