We’ve seen many strange geoengineering proposals over the years, but this has to rank as one of the most bizarre – in the Nov. 12 issue of the journal Advances in Space Research, a team from the University of Strathclyde proposed blowing up asteroids in order to create a large dust clouds that would act as a sunshade for the planet. This ‘dust sunshield’ would reflect sun light to stop it from heating the planet and melting the icecaps. However there are many that feel that a geoengineering project on this scale would do more harm than good.
The Scottish team believe that the dust cloud would reduce the amount of solar radiation Earth receives by 1.7 %, which would offset the effects of a global increase in temperature of 3.6 degrees F (2 degrees C), but the University of Strathclyde’s Russell Bewick believes this could be enough.
“A 1.7 percent reduction is very small and will hardly be noticeable on Earth,” said Bewick, a space scientist at the University of Strathclyde. “People sometimes get the idea of giant screens blocking the entire sun. This is not the case … as [the device] is constantly between the sun and the Earth, it acts merely as a very light shade or filter.”
While the dust cloud is no less preposterous as giant mirrors in space, it is likely to be just as expensive and dangerous. While the proposed ‘space mirror’ project would cost billions, the dust cloud proposal would involve the destruction of near-Earth asteroids which could cause hazardous debris. Dust clouds would also only last so long due to the risk of getting dispersed over time by solar radiation and the gravitational pull of the planet and the sun.
“I would like to make it clear that I would never suggest geoengineering in place of reducing our carbon emissions,” Bewick said, speaking to LiveScience. “(But) we can buy time to find a lasting solution to combat Earth’s climate change. The dust cloud is not a permanent cure, but it could offset the effects of climate change for a given time to allow slow-acting measures like carbon capture to take effect.”
The team propose using a “mass driver,” a device consisting of electromagnets, in order to hurl asteroid-derived matter away from the giant rock. It would also act as a rocket to push the asteroid as well as creating sun-shielding dust.