Lights out: can dimming the sun really save us from global warming?

The Paris Agreement feels like a long time ago.

- Will Rogers-Coltman

When countries signed the deal in 2015, they set 1.5C as a watermark for the rise from pre-industrial temperatures. If reached, the severest symptoms of global warming would start to kick in - biodiversity loss, more droughts and a rise in sea levels. Alarmingly, this year a UN report stated we are likely to breach this barrier within the next five years. The recent COP30 in Brazil also proved a frustrating affair. Political manoeuvring superseded global consensus, and with the US setting a precedent - its absence from COP a glaring admission — lowering the temperature still seems a way off. It’s easy to be despondent. And many will ask if there is a way out of this mess.Enter solar geoengineering, the unlikely frontrunner in the fight against rising global temperatures. Solar geoengineering, or solar radiation modification (SRM), essentially means artificially dimming the sun. This might sound like a dastardly Dr Evil-style conceit, but in recent years the premise has been promoted from sci-fi material to a feasible weapon against rising tempe