Launching a huge dust cloud from the moon could ease global warming

One million tons of lunar dust ejected around the Earth could darken the global sunlight by 1.8%.This would lower global temperatures, but whether it’s worth the resources and the risks involved with such a strategy are unclear.

To Carissa Wong

Throwing dust clouds off the moon and blocking sunlight from reaching Earth could help curb global warming, but more than a decade of research is needed before such a strategy can be put into action. may be The risks associated with such an approach are also unknown in terms of how it will affect agriculture, ecosystems and water quality in different parts of the world.

Placing more than 100 million tons of dust between the Earth and the Sun to partially block light from reaching Earth has been studied as a way to combat climate change. Such dust particles cast shadows on the Earth by absorbing light energy or scattering light particles known as photons from the Earth.

To achieve this, the dust would have to be placed 1.5 million kilometers from Earth. At this location, the gravitational pull of the sun and earth cancels out. Here the object remains at a fixed position known as the first Lagrangian point (L1).

Various research groups have considered placing dust in the L1, but the energy from photons and charged particles emitted by the Sun, known as the solar wind, can gradually push the dust away from its desired location. This needs a fix.

Now, after running thousands of computer simulations, Benjamin Bromley of the University of Utah and his colleagues continuously fire a stream of lunar dust directly from the lunar north pole toward L1 at a speed of 2.8 kilometers per second. I have found that a better approach may be to

In this scenario, simulations suggest that each propelled dust particle blocks sunlight from reaching Earth for about five days before dispersing throughout the solar system.

Considering the gravitational pull of the Sun, the Earth, other planets, and the non-gravitational forces such as the solar wind, simulations show that maintaining a 1-million-ton mass dust shield near L1 for a year can darken the sunlight. I was. Reduces Earth by 1.8%. This is equivalent to completely blocking the sun for 6 days.

If this approach continues indefinitely or until other means of removing carbon dioxide from the earth’s atmosphere are introduced, it could offset the rise in carbon dioxide levels that has occurred since the industrial revolution. said Ben Kravitz of Indiana University Bloomington.

“If this method works, it’s certainly effective in lowering global temperatures, but it’s hard to say whether it’s worth it compared to the effort and resources used,” he says.

The simulation didn’t model the use of a machine to shoot moondust toward L1, but it could have used a railgun to propel things via electromagnetic energy, Bromley said. increase. “This is perfect because it can be fueled by several square kilometers of solar panels installed near the launch site,” he says.

But shadowing the entire globe would have different effects in different regions, says Kravitz. “Temperature, precipitation, wind and many other things change. [as a result of this strategy], and they change in different ways in different places,” he says. “These changes will, of course, lead to impacts on agriculture, ecosystems and water quality.”

Before such a strategy can be implemented, multiple institutions in different countries will need to conduct large-scale engineering studies and also get the consideration of the United Nations, said Curtis Struck of Iowa State University.

Another issue is that there can be inaccuracies in dust splashing and scattering, which can lead to unknown effects. “Is it likely that micrometeorites falling to Earth or damage to satellites orbiting Earth will be enhanced?” says Strzok. “This and many other issues have not been studied in the necessary detail.”

Moreover, considering such an approach should not replace our efforts to reduce carbon emissions on the planet. We have to keep going,” says Bromley. “Our dust shield solution simply buys us time.”