Can We Cool the Planet by Brightening Clouds?

Sarah Doherty, an atmospheric scientist and program director of the Marine Cloud Brightening Project at the University of Washington, has spent her career measuring how tiny particles in the atmosphere shape our climate, from the Arctic to Antarctica. In her talk, she explained how ship exhaust passing through low ocean clouds leaves bright trails called ship tracks, and how her team hopes to recreate that effect in a controlled way by spraying fine sea salt into clouds so they reflect more sunlight back to space.

We shaped the talk’s narrative arc with Sarah and redesigned her slides. We sent Sarah a speaker kit so we could film her talk remotely, ensuring her video and audio would be broadcast quality, then edited the final video. Sarah showed that brightening clouds in just a few targeted regions could cool the entire planet, and she set up the evening’s next speaker, Sean Garner of PARC, who showed how his lab is building the tools to make sea salt particles at exactly the right size.