Supporters of the 'moonshot' idea to deal with global warming, now have a very literal new interpretation. The researchers propose shooting plumes of Moon dust into space to deflect sunlight away from Earth.
This seemingly odd-and-crazy concept is outlined in a recent research paper. This idea involved creating a 'sun shield' in outer space by mining the Moon to dredge up millions of tons of dust, then ballistically hurling it to a point in space around Earth. In this way, it is hoped that partially floating Moon dust grains will block sunlight from entering Earth.
"A really exciting part of our research was the realization that natural Moon dust grains are just the right size and composition to efficiently scatter sunlight from Earth," said Ben Bromley, a theoretical astrophysicist at the University of Utah, United States who led the research, as quoted. from The Guardians.
"Because it takes less energy to launch these grains from the surface of the Moon, compared to Earth launches, the idea of the 'moonshot' really stood out to us," he continued.
Bromley and two other researchers considered that various properties of materials, including coal and sea salt, could dim the Sun by as much as 2% if fired into space. The team ultimately chose dust found on the Moon. But millions of tons of this dust must be mined, sifted, and loaded into ballistic devices, such as electromagnetic rail guns, and fired into space every year to maintain this solar shield.
"Flying this projective and mining equipment to the moon will be a project with significant impact," said Bromley. He added that this concept may require placing a new space station in an area called the L1 Lagrange point, which is found between the Earth and the Sun, to direct the dust into an orbit that can provide shade for Earth for as long as possible.
"Such an approach is like a well-tuned dimmer switch, leaving our planet untouched," said Bromley, comparing the method's advantages to other solar geoengineering concepts that have raised concerns about the environmental impact of spraying reflective particles on Earth's atmosphere.
However, Moon dust must continue to be pushed into space to avoid global warming, or risk the so-called 'termination shock', in which temporary cooling is suddenly stopped and the Earth is allowed to heat up rapidly. But Bromley insisted that research of this kind would not replace humanity's main task of jointly reducing global warming emissions.
"Nothing can distract us from reducing greenhouse gas emissions on this Earth. Our strategy may only be a moonshot, but we must explore all possibilities, if we need more time to do a big task for our Earth," he said.
Various efforts to deal with an increasingly hot Earth, including efforts to reflect sunlight, are still considered controversial and relatively limited only to the issue of the climate crisis. Still, the idea is attracting attention amid rumors that countries are not quick enough to reduce emissions enough to prevent disasters.
Ted Parson, an environmental law expert at the University of California Los Angeles (UCLA), said the concept of mining Moon dust is a scientifically interesting speculation, but impossible to put into practice. Partly because of the enormous cost and lack of control compared to geoengineering options done on Earth.
"There seems to be a slight increase in interest in space-based geoengineering schemes more broadly. This idea has long been rejected as impractical and due to technical and cost considerations. But I find it interesting and in the future there may be more strange ideas coming out," he said .
Meanwhile, opponents of solar geoengineering, whether on Earth or in space, argue such concepts are unhelpful and potentially harmful to Earth and its inhabitants.
"The idea of mining the Moon or near-Earth asteroids and artificially blocking some of the Sun's rays is not a solution to the ongoing and intensifying climate crisis," said Frank Biermann, professor of global sustainability governance at the University of Utrecht, Netherlands.
"What is needed is a massive reduction in greenhouse gas emissions, which will require rapid technological advances and a socio-economic transition. Moon Mining is not the answer we need," he concluded.