(Yes, We Should Blast Moon Dust into Outer Space to Cool the Earth)
Recently I was enjoying a long-distance phone chat with an old friend of mine, and the conversation turned, as it inevitably does, to the weather. She lives in Ohio, I live in Florida, and yet our answers to our respective inquiries about “How’s the weather where you are” were identical: Hot AF.
Fortunately, scientists like David Keith have been telling us for years that we are not helpless in the battle against climate change. If worse comes to worst, for a few billion dollars we could deploy specialized aircraft to release particles of sulfur (or some more exotic material) into the upper atmosphere, thus reflecting enough sunlight back into space to cool the planet very quickly. Of course, as professor David warns, we have a poor grasp of what possible, global side-effects such a radical course of action might have (although one one wonders if these side-effects could be any worse than a Canada-sized wildfire or a continent-wide heat-wave in India). It is precisely because of these unknown side-effects, he explains, that we need to start thinking about the problem now, with a clear head.
Along these lines, one of the strangest—and yet most encouraging—options to the “solar dimming” set of possible mitigation strategies is the idea that we might blast moondust into outer space. Yeah. For real. This dust, if aimed properly, would linger in one of the Lagrange points between the earth and the sun and, for a time, reduce solar radiation falling on the earth’s surface. The effect would be short-lived due to solar wind blowing the dust away into interplanetary space, but this is a good thing in that the technique would thus be throttleable. We could blast as much as or little dust as needed to cool the planet without plunging it inadvertently into a new ice age. (Have you seen that movie SnowPiercer?) Also, unlike the sulfur-in-the-sky option, the lunar dust wouldn’t contribute to air pollution or acid rain here on earth.
Obviously, the notion that we might somehow shoot lunar dust into space on a routine, industrial scale seems like science fiction. But is it? The space agencies of many nations such as the U.S., China, and Japan have planned future missions to the moon. One can imagine a gradual infrastructure of settlements, supplies, and equipment gathering on the moon over time, much as one formed in the American West in the 19th Century. One could presumably build some kind of mass-driver or rail-gun that could shoot the dust into space, and power it with solar energy. (Extra power could be stored during the two-week long lunar “day” to keep the gun shooting during the “night”).
How much would such a setup cost? Billions? Trillions? On the other hand, how much would it cost to rescue two-hundred million people from Europe if the Atlantic thermohaline circulation is disrupted, as some scientists predict it will? Or to build sea-walls around New York and Miami and San Diego and every other major coastal city? Or to feed South America if the crops there dry up during the next heat wave?
It’s time to think outside-the-box, people.
If worse comes to worst, we shouldn’t rule out going back to the moon. And building a huge cannon there. Or anything else we have to do to cool off the planet.
Here is the original article on SingularityHub where I learned about this idea:
Ash Clifton, Writer 