Silicon Valley Elite Are Pouring Money Into Blotting Out the Sun

When back-to-back hurricanes made landfall in Florida this fall, conspiracy theories followed. Among the unfounded claims circulating on social media was the idea that the US government had effective control of the weather, spinning up storms to strike areas based on political affiliation. While that’s not true, there are people working in semi-secret on technology to tweak the weather, even if they’re nowhere close to controlling hurricanes.

A growing number of Silicon Valley founders and investors are backing research into blocking the sun by spraying reflective particles high in the atmosphere or making clouds brighter. The goal is to quickly cool the planet ...