The List

Hacking the Climate

7 far-out geoengineering ideas that could save the planet -- or destroy it trying.

With rising sea levels threatening to swallow coastal cities and bizarre weather patterns disrupting the global food supply, geoengineering -- or deliberate, large-scale intervention to reverse the effects of global warming -- looks like a much-needed lifeboat for humanity. But tinkering with the climate also comes with risks -- and a glance at the dubious history of climate hacking isn't all that reassuring. From the early cloud-seeding experiments of the Cold War to America's rainmaking exploits in Vietnam to China's weather manipulation efforts at the Beijing Olympics, our efforts to master Mother Earth have left much to be desired. And today's geoengineering schemes promise much steeper downsides. Herewith, then, are seven far-out geoengineering ideas that could save the planet -- or destroy it trying.


Plans for reducing the amount of sunlight that reaches the planet -- a technique known as solar radiation management (SRM) -- range from injecting reflective aerosols into the atmosphere to whitening the tops of buildings in order to bounce solar radiation back into space. But perhaps the most ambitious SRM proposal, presented by physicist and former Pentagon weapons designer Lowell Wood at a roundtable convened by the White House in 2001, is to launch a giant mirror into orbit between the sun and the Earth. The mirror (or a few smaller ones), would be composed of tiny aluminum threads and span roughly 600,000 square miles -- enough to deflect approximately 1 percent of incoming solar radiation. "If they had broadcast that meeting live to people in Europe, there would have been riots," recalled one participant in the roundtable where Wood presented his idea. "Here were the bomb guys from Livermore talking about stuff that strikes most greens as being completely wrong and off-the-wall."



One idea that didn't come up at the White House roundtable, but which doesn't require a huge intellectual leap from Wood's proposal, is mining moon dust to create a different kind of space-based solar shade. Enter Curtis Struck, a professor of astronomy at Iowa State University who proposed doing exactly that in a 2007 paper in the Journal of the British Interplanetary Society. In addition to discussing the possibility of deflecting sunlight with "captured comets," Struck suggests that it might be possible to use laser vaporization to turn lunar boulders into clouds of dust that would pass in front of the sun once per month and block radiation for approximately 20 hours at a time. Lunar dust might have been the "No. 1 environmental problem on the moon" for the Apollo astronauts who had to deal with its corrosive effect on their equipment, but who knew it might prove to be the solution to the No. 1 environmental problem on Earth?


If moon dust and giant orbital space mirrors sound like impractical solutions to global warming, what about artificially beefing up cloud cover, which already reflects about a quarter of the sun's rays back into space? That's exactly what climatologist Jonathan Latham had in mind when in 1991 he proposed pumping ultrafine saltwater from the ocean into the air in order to create thicker and longer-lasting clouds. Scientists have proposed numerous so-called "marine cloud brightening" schemes since then, the most creative of which involve fleets of cloud-generating ships -- or albedo yachts -- that troll around the ocean puffing out vapor. Stephen Salter, an engineering professor at the University of Edinburgh who proposed creating a fleet of 1,500 albedo yachts, even designed a wind-powered prototype that generates enough power with underwater turbines to sustain the entire cloud-making operation.

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J. MacNeill/The Royal Society  


So far, we've only talked about schemes for reflecting sunlight back into space, thereby reducing the greenhouse effect that's caused by carbon dioxide emissions. But what about removing the carbon dioxide directly? One of the most creative proposals for doing that, laid out by Ernest Agee in a 2013 article in the Journal of Applied Meteorology and Climatology, involves building giant, football field-sized freezers in the Antarctic. That's right. Agee argues that cooling the air inside these jumbo freezers to -140 degrees Celsius will cause the carbon dioxide to turn into "CO2 snow," which can then be stored deep underground. Using the energy from 16 wind farms -- "There's a lot of wind energy in the Antarctic," Agee told the New Scientist -- the Purdue University professor calculates that it would be possible to remove roughly 1 billion tons of carbon dioxide from the atmosphere every year. That's roughly 1/35th of the planet's total annual CO2 emissions -- though not everybody agrees with Agee's math.


Not all plans for sucking CO2 out of the atmosphere involve massive infrastructure investment. In fact, one of the most hotly debated options requires only a fishing boat and a bucket of iron slurry. So-called iron fertilization, first proposed by John Gribbon in 1988, involves adding iron compounds to sea water in order to stimulate massive algae blooms. These blooms, in turn, remove CO2 from the atmosphere and bury it on the ocean floor. It sounds terrific in theory, but in practice, scientists fear that it could cause toxic tides and massive oceanic dead zones. Nonetheless, iron fertilization moved out of the realm of the hypothetical in 2012, when American entrepreneur Russ George took it upon himself to empty 100 tons of iron sulfate into the Pacific Ocean roughly 200 nautical miles west of the Haida Gwaii islands. The stunt earned him the distinction of being the world's first geo-vigilante, but it also put him on the wrong side of a handful of international laws and U.N. resolutions. George later told the Scientific American he would do it again, given the chance: "A reasonable, intelligent, earnest and honest scientist would not plan to do it only once. That's not good science."

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F. Lamiot/Wikimedia Commons


Assuming George doesn't unilaterally counteract the greenhouse effect, there's also rising sea levels to contend with. Melting Arctic sea ice, which functions as a sort of planetary air conditioner, promises to flood coastal cities around the world -- and it's disappearing fast. Just last month, the National Oceanic and Atmospheric Administration confirmed that snow cover in the Arctic was a whopping 18 percent lower in 2012 than in any other year in the satellite era. Ideas for reversing this trend run the gamut from firing reflective aerosols into the Arctic stratosphere to pumping river water onto polar ice caps in order to make them thicker. One particularly ambitious proposal involves wrapping much of Greenland in giant, reflective blankets to slow the thaw. Jason Box, the Ohio State University professor who dreamed up this scheme, has already tested it with 10,000 square meters of specially designed polypropylene blankets. "It's going to be expensive, but when you consider the cost of reengineering our coastlines -- this may actually be cheaper," Box told the Telegraph. The man's got a point.


Wrapping Greenland in polypropylene is no slouch, but the award for the most drastic proposal goes to Dutch science writer Rolf Schuttenhelm, who in 2008 suggested building a 200 mile-long dam across the Bering Strait. The so-called St. Lawrence Dam, connecting Siberia and Alaska via St. Lawrence Island, would halt the northward flow of warmer and saltier water from the Pacific Ocean and thereby keep the Arctic frozen. Interestingly, Schuttenhelm's plan is the exact inverse of a Soviet scheme, laid out by an engineer named Petr Michailovich Borisov in 1960, to melt the polar ice caps and improve the Arctic's climate. Don't expect either plan to go forward anytime soon.

NASA Goddard/Flickr 

Sara Francis/U.S. Coast Guard via Getty Images


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