We should stop driving SUVs, recycle whenever possible and solar-power our houses. By now, most of us know all of this. But if all else fails, and global warming runs amok, maybe we could just refreeze those dwindling Arctic ice caps ourselves. At least that’s what Peter Flynn, a mechanical engineer at the University of Alberta, suggests.
In a study published recently in the journal Climatic Change, Flynn lays out a plan to freeze sea ice in the Arctic using a fleet of over 8,000 ice-producing barges. Reconstructing the ice will strengthen the ice cap, maintain the strength of down-welling Arctic sea currents and stabilize temperatures in Europe.
Flynn&emdash;who originally set out to investigate whether Arctic currents could be used to sequester dissolved carbon&emdash;became interested in the weakening of down-welling currents caused by the melting of freshwater ice. The down-welling saline currents flow south, creating a vacuum that gets filled by the up-welling tropical waters that flow north and maintain Europe’s moderate weather. However, with new freshwater ice diluting the down-welling ocean currents and weakening the vacuum that pulls warmer waters north, Europe is actually at risk of cooling off.
“When you put a layer of freshwater on the top of the ocean you interfere with the circulation pattern,” Flynn said. “So, the irony is that first you get global warming, and then you get plunged into a deep freeze by interfering with this current.”
Flynn and his co-author, graduate student Songjian Zhou, speculated that, in a global warming crisis an artificial means of cooling the currents might be Europe’s only recourse. They came up with seven potential methods for artificially cooling the ice caps, including cooling pools, cooling towers similar to those used by nuclear power plants and boats decked out with coils to act as giant refrigerators. The most reasonably priced option were the ice barges. At a cost of a mere $50 billion, it was orders of magnitude cheaper than the other schemes.
In their paper, Flynn and Zhou describe unmanned barges that could spray water in the air to help speed the initial creation of the ice sheet, and then pump seawater across the ice sheet which would freeze over the sheet and thicken it. The vast amount of saline ice produced would eventually melt, strengthening the down-welling cold current with dense salt water.
“The way I get my head wrapped around it is to say, conservatively, 100 million people would be at risk [of experiencing cooler temperatures], and it’s probably more like 400 million,” Flynn said, rationalizing the expense of the project. “So if a glacier’s at your back door and your way of life is disappearing, $500 per capita is pretty reasonable.”
Christopher Field, director of global ecology at the Carnegie Institute, called Flynn’s scheme interesting and useful but said the immediate focus should be on finding ways to prevent climate change, or at least to adapt to it.
“We should think of that as the back up to the back up,” said Field.
Flynn maintains, however, that his plan is meant only as a last recourse —calling it “a contingency, looking around the bend, ‘what if,’ kind of work.”
“The right thing to do with global warming is to deal with the causes, not the symptoms,” he said. “But we’re not doing very good as a species dealing with the causes. So, I think of this study as identifying a possible emergency response if we fail to deal with the causes of global warming.”
Originally published February 14, 2006
