Mark Maslin

So there are a group of my colleagues who are incredibly smart around the world who are looking at alternatives because they are not convinced we're going to reduce carbon emissions quick enough to keep the world in a habitable temperature.

And so what they're looking at is different ways of reflecting sunlight away from the earth to try and keep it cool.

So imagine you're on a hot day like we are today.

It's like putting up a parasol and making sure the sun doesn't hit you and therefore you can be a little bit cooler in the shade.

So what they're looking at is trying to shade the earth.

Now there is a number of ways of doing this.

One of them is by injecting aerosols.

These are small particles

into the upper atmosphere, whether it happens to be sulfur dioxide, whether it happens to be silica, or happens to be aluminium, in there to reflect sunlight.

The other one that's really left field was a suggestion that we could put mirrors in space.

The cost of that is astronomical, but the idea is you'd have mirrors reflecting sunlight from there.

So the idea is that you dim the sun slightly,

and therefore the temperature of the Earth cools down, so therefore buys us time to decarbonize.

So this isn't a fix.

It is literally my colleague saying, how can we buy us time so the transition away from fossil fuels occurs, and we can buy time to deal and suck out those emissions from the atmosphere, and so we can try to protect the Earth.

That sounds like quite a sensible idea to me.

The problem is that only deals with temperature.

It doesn't deal with things like ocean acidification.

It doesn't deal with sea level rise.

It's just a fix for temperature.