Space dust fired from the moon could protect humanity from the effects of global warming, scientists have said.
Dust could be ejected from the lunar surface midway between us and the sun, they suggest. That would act as a shield, blocking enough of the sun’s radiation to mitigate the effects of climate change, according to a new paper.
Launching dust from Earth would require huge resources, even if it would be the most effective way to protect Earth, the scientists say. But it could be much cheaper to use dust from the moon instead.
Their work simulated the effects of dust kicking up from a platform on the moon to the sun. They found that the properties of dust from the lunar surface mean that it acts effectively as a sunscreen – which is important because so much of it will be needed.
“It’s amazing to think how lunar dust — which took more than four billion years to form — could help slow global warming, a problem that took us less than 300 years to produce,” says study co-author Scott Kenyon. the Center for Astrophysics.
But other scientists not involved in the work said that while the research to establish the feasibility of the dust was good, it could divert attention from simpler and more direct ways to protect humanity.
“Positioning lunar dust at the center of gravity between the Earth and the Sun can indeed reflect heat – with the right particle shape, at the right size and in exactly the right place,” says Stuart Haszeldine of the University of Edinburgh. “But this is like trying to balance marbles on a football, within a week most of the dust has been spun out of a stable web.
“Therefore, there is no natural dust accumulation at this astronomical point. There are simpler methods to reduce global warming, and people should use them now to fix the climate.”
And Joanna Haigh, emeritus professor of atmospheric physics at Imperial College London, warned that the “carefully considered” and “robust” research could warrant inaction. “Perhaps the biggest problem, however, is the suggestion that the implementation of such schemes will solve the climate crisis, when it only gives the polluters an excuse not to act,” she said.
The findings are described in a newly published paper, “Dust as a solar shield,” in the journal PLOS climate.
Even the scientists involved admit that the research may not work, stressing that their work was more interested in how the strategy might work than its feasibility.
“We are not experts in climate change, or the rocket science it takes to move mass from one place to another. We’re just researching different types of fabric in different lanes to see how effective this approach could be. We don’t want to miss a game changer for such a critical problem,” said Ben Bromley, a professor of physics and astronomy at the University of Utah and lead author of the study.
One potential problem with the plan is that the dust will need to be replenished every few days, as the sun’s radiation pushes and scatters it throughout the solar system. But the researchers note that this would also mean that the sunshade is temporary and would not fall to Earth or completely block the sun, avoiding a dystopian scenario where Earth becomes permanently cold and habitable.