by NASA
A team of American scientists has proposed an unorthodox plan to combat global warming: creating large clouds of lunar dust in space to reflect sunlight and cool the Earth.
In their plan, we would mine dust on the moon and shoot it towards the sun. The dust would remain between the Sun and Earth for about a week, making sunlight about 2% weaker on Earth’s surface. After scattering, we added more powder.
The sentence, which includes the beginning ca 10 million tons of lunar dust into space every yearit’s clever in a way – and if it works as advertised from a technical standpoint, it could buy the world some vital time to curb carbon emissions.
Unfortunately, but also unsurprisingly, the story of the moon dust reflection it is not as simple as it seems.
Proposed measures to cool the Earth by reducing the amount of sunlight reaching the surface are often called “solar geoengineering” or “solar radiation management”. The most talked about method involves injecting a thin layer of aerosol particles into the Earth’s upper atmosphere.
However, messing with the atmosphere in this way is likely to affect precipitation and drought patterns and could have other unintended consequences, such as damage to the ozone layer.
Moon dust in space should avoid these traps, as dit would leave our atmosphere untouched.
Others have proposed deflecting sunlight with giant filters or mirrors in space or clusters of artificial satellites.
Lunar dust sounds pretty good compared to these ideas: Lunar dust is plentiful, and launching dust clouds from the Moon’s lower gravity would require significantly less energy than similar launches from Earth.
What is the problem?
Too slow, too clumsy
One of the main selling points of solar geoengineering is the Speed. Reflecting sunlight is, at best, a way to quickly stave off the damaging effects of short-term warming, buying time for renewable energy transitions and removing greenhouse gases from the atmosphere.
Total injection of aerosols into the atmosphere, for example, may require the development of special aircraft. This is certainly not a trivial task, but it can certainly be done in the next decade.
Ambitions for lunar dust would be much slower. There are several significant obstacles engineering is logistics to overcome.
At the very least, we’d need lunar bases, lunar mining infrastructure, large-scale storage, and a way to blast the dust into space.
No human has walked on the moon in more than 50 years. While China is seeking to establish a lunar base by 2028, followed by the US in 2034, a well-functioning mining and dust release system is likely are many decades away.
