If mimicking a massive volcanic eruption by spraying sulfur dioxide into the air or flying thousands of mirrors into space to shade Earth to halt climate change doesn't cut it for you, how about this? A fleet of 1,500 automated ships, dubbed "albedo yachts," spewing saltwater into the sky to make denser clouds that reflect more sunlight—and cool the world.
Atmospheric physicist John Latham of the National Center for Atmospheric Research in Boulder, Colo., and a host of British colleagues propose that a such a battalion—total tab at least $2.6 billion—would ply the world's oceans thickening clouds as they went. The idea—minus the ships to accomplish it—was first proposed by Latham in 1990 and has popped up with new details every couple of years since.
The ships rely on so-called Flettner rotors, tall columns like enlarged smokestacks that jut up from the center of the ship and spin in the wind, driving the ship perpendicular to the air flow and also serving as the funnels from which the sea spray would emerge. Bonus: the ships are entirely unmanned and simply go with the flow of winds, cooling the sea surface.
The proposal appears in the journal Philosophical Transactions of the Royal Society A, which focuses on "Geoscale engineering to avert dangerous climate change." Other proposals include: fertilizing the ocean with iron to help plankton clean up our mess and the aforementioned manmade volcano.
Also highlighted: carbon neutral hydrocarbons, fossil fuels made directly from the carbon dioxide (CO2) in the air. The catch? These are also known as biofuels, i.e. plants that would otherwise potentially go to feed people (or grown on land that would otherwise grow food) going into gas tanks instead.
Research into such solutions appears to be warranted given the massive hole we are presently digging ourselves into as far as stabilizing atmospheric greenhouse gas levels. But the food versus fuel conundrum is emblematic of the problem with geoengineering: these are global scale experiments with unclear results and unintended consequences. For example, what would be the impact on rainfall from such sea-spray enhanced clouds?
Of course, we're already unwittingly running such a global scale experiment. It's known as climate change, wherein evolved apes burn enough fossil fuels to restore the greenhouse gas levels of previous geologic eras. And it might just be enough to bring the 10,000-year climate optimum that has allowed human civilization to flourish to come crashing to an end.
So what do you think? Is this a heroic unmanned fleet destined to save the world or an eerie and bad idea destined for maritime disaster?