Myth: We can cool the planet by putting solar reflectors in space

If we need to, we can put gigantic reflectors into space, to stop some of the sun’s rays from reaching us. This will cool the planet.

Fact:

 This idea is another example of ‘solar geoengineering’. It has the advantage of being less dangerous than putting sulfate aerosols into the stratosphere. However, it would be prohibitively expensive, as it can cost up to US$400 million to put a large satellite into space. No one knows how many of these reflectors would be needed to cool the atmosphere. Whatever the cost, it would be much cheaper to simply stop emitting greenhouse gases.