Now researchers at Arizona State University are floating a plan to save the thinning Arctic ice cap with help from a vast armada of wind-powered water pumps positioned across Earth's northernmost reaches.
The pumps — each connected to a hose and a windmill, with the whole apparatus fixed to a buoy to stay afloat — would suck up frigid seawater and spread it on the ice during the long Arctic winter. The scientists say that would help protect existing sea ice and speed the formation of new ice.
Pumping 1.4 meters of seawater onto a given area of the frigid surface would yield an additional 1 meter of ice in a single winter, the scientists say in a paper published recently in the journal Earth's Future. To build a sufficient quantity of ice over roughly 10 percent of the Arctic (the minimum area required to yield a significant benefit), 10 million of the pumps would be needed.
Building, deploying, and running them all would cost an estimated $50 billion per year.
That's an awful lot of pumps — and money. But the scientists behind the plan say it makes sense even while acknowledging that it sounds a bit wacky.
"Maybe trying to make more ice in the Arctic using windmills and pumps and hoses is a crazy idea," Dr. Steven Desch, an astrophysicist in ASU's School of Earth and Space Exploration and the paper's first author, said in a written statement. "But what's really crazy is doing nothing while the Arctic melts."
Whether or not the plan is feasible, the loss of Arctic sea ice is a serious matter. Ice reflects about 80 percent of sunlight, whereas the ocean absorbs 90 percent. Less sea ice means the planet's reflectivity (what scientists call albedo) declines and our planet absorbs more heat from the sun. And as the Arctic thaws, the permafrost melts. As it does, it releases the greenhouse gas methane, which traps more heat in the atmosphere.
Sea ice thickness in the central Arctic Ocean declined by 65 percent between 1975 and 2012 and continues on a downward trend, according to a new report from the Arctic Monitoring and Assessment Program. As the ice cap thins, it's also shrinking in area. NASA says the Arctic's sea ice maximum extent has decreased by an average of 2.8 percent per decade since 1979.
To protect the polar ice and rein in climate change, scientists and politicians have stressed the importance of reducing carbon emissions. But Desch told NBC News MACH in an email that it's "too late to save the Arctic sea ice without direct intervention" like he and his colleagues envision.
What do others make of the plan? Desch said he received positive feedback from members of the public but also skepticism from some experts.
One climate scientist with doubts is Dr. Mark Serreze, a professor of geography at the University of Colorado, Boulder, and director of the National Snow & Ice Data Center.
In an email to MACH, he called the new research "a serious effort" but added that "the issue, of course, is whether society has the will to do this in the massive scale that would be required — the Arctic Ocean is a pretty big place. My own view, however, is that unless we deal with the root cause of Arctic sea ice loss — namely, global warming — this just amounts to a Band-Aid fix."
Desch isn't calling for the plan to be implemented right away. But he said the research would continue. The next steps will be to build and test a prototype and to initiate a public dialog to address some key questions about setting up all those floating pumps. These include whether it would be ethical to intervene in the Arctic on such an enormous scale — and whether it would be ethical not to intervene.
No matter what, Desch told The Guardian, "We cannot keep on just telling people, 'Stop driving your car, or it's the end of the world.' We have to give them alternative options."