Global warming could be stopped by sprinkling moon dust: study

By Mark Waghorn via SWNS

Global warming could be stopped - by sprinkling dust from the moon, according to new research.

It would create a giant "space umbrella" - protecting Earth against solar radiation.

Intercepting a fraction of light mitigates the effects of climate change, say scientists.

Diverting only one to two percent may be enough to take the planet back to pre-industrial days.

Co-author Dr. Scott Kenyon, of the Harvard & Smithsonian Center for Astrophysics in Massachusetts said: "It is amazing to contemplate.

"Moon dust which took over four billion years to generate, might help slow the rise in Earth's temperature - a problem that took us less than 300 years to produce."

An analysis found launching dust to an orbiting satellite would be most effective - but is too costly and difficult.

Using lunar dirt is a much easier and cheaper alternative.

The U.S. team likened their idea to astronomical dust that forms around a star.

These rings intercept the light - re-directing it. The phenomenon helps astronomers detect new planets.

Lead author Professor Ben Bromley of Utah University said: "That was the seed of the idea.

"If we took a small amount of material and put it on a special orbit between the Earth and the sun and broke it up, we could block out a lot of sunlight with a little amount of mass."

A computer model showed the shield can cast intermittent shadows across the planet - lasting long enough to provide adequate shading.

Co-author Sameer Khan, a student at Utah, said: "Because we know the positions and masses of the major celestial bodies in our solar system, we can simply use the laws of gravity to track the position of a simulated sun shield over time for several different orbits."

The researchers mimicked dust being shot from the surface of the moon toward the sun. Inherent properties were just right to work as a sun shield.

They scattered it along various courses until identifying the most ideal trajectories on a line between Earth and the sun.

The results are welcome. Much less energy is needed to launch dust from the moon than from Earth.

The amount of dust in a solar shield is large - comparable to the output of a big mining operation here on Earth.

Furthermore, the discovery of the best locations means delivery to a separate space station may not be necessary.

In any event, positioning a platform at the closest point between Earth and the sun where gravitational forces are balanced was not as effective.

Dust was easily blown off course by solar winds, radiation and gravity. An endless supply of new dust would be needed every few days after the initial spray dissipates.

Khan said: "It was rather difficult to get the shield to stay long enough to cast a meaningful shadow."

Space sunshades have support in high places - from the Royal Society to Nasa to the European Union. They have even raised interest from the Intergovernmental Panel on Climate Change (IPCC).

First conceived by engineer James Early in 1989, the original design was a vast 1,250-mile-wide glass shield.

Prof. Bromley said: "We aren't experts in climate change or the rocket science needed to move mass from one place to the other.

"We're just exploring different kinds of dust on a variety of orbits to see how effective this approach might be. We do not want to miss a game changer for such a critical problem."

Replenishing dust streams every few days also has an advantage. Eventually, the sun's radiation disperses the particles throughout the solar system.

They do not fall onto Earth. The approach would not create a permanently cold, uninhabitable planet as in the 2013 climate disaster movie "Snowpiercer."

Prof. Bromley said: "Our strategy could be an option in addressing climate change - if what we need is more time."

The study is published in the journal PLOS Climate.