The race to find a solution to a rapidly warming world is one of the most pressing challenges facing our planet.

One proposal to try to halt this warming is literally out-of-this-world: a giant, space-based sunshade. We’re already modifying our climate by accident, so why not do it by deliberate geoengineering?

It’s a radical idea, and it just might just work. Reducing the amount of light reaching our planet could cool the Earth quickly, even with rising carbon dioxide levels. While the asteroid which helped wipe out the dinosaurs blocked out 90% of the Sun’s rays, we would need to divert just 2-4%, it's believed, to take the Earth back to its pre-industrial climate.

Space sunshades have support in high places, from the Royal Society to Nasa, to the European Union. It’s even roused the interest of the most respected authority on global warming, the Intergovernmental Panel on Climate Change (IPCC).