Luke Iseman is putting sulfur dioxide into the stratosphere with high-altitude balloons and selling cooling credits to pay for it. And he doesn’t care if you approve.
Make Sunsets is maybe the most polarizing company in climate interventions right now, and I wanted to have Luke on the show so we could learn more about how they think and what their goals are. We discussed the question that if we assuming cooling the planet is necessary (and we both believe it is), does that justify acting without institutional permission? We get into the energy math on carbon removal, the governance question, and a wealthy customer who may be planning to personally fund enough deployment to measurably cool the planet.
Chapter Timestamps
01:22 — What Make Sunsets actually does and how cooling credits work
05:07 — The energy math against carbon removal: why CDR needs 20x global energy production
07:00 — Luke’s vision for 2100: nuclear energy, 10x global prosperity, and table stakes
10:50 — “We’ve been geoengineering since the industrial revolution”
15:11 — Theory of change, the wealthy customer revelation, and “are you going to stop me?”
19:40 — Deployment risks: monsoon disruption, weaponization, and the Pentagon’s response
25:27 — Luke’s critique of governance approaches being taken today
30:29 — The smallpox analogy: does innovation precede or follow institutions?
38:36 — What success looks like for Make Sunsets in 10 years (0.1°C measurable cooling)
47:39 — The Mexico ban that wasn’t, and why getting the facts right matters
53:19 — What the field needs: “bold action” vs. “analysis and meetings”
55:07 — Paul’s post-interview reflection: where he agrees and where he doesn’t
Notable Quotes
“Are you going to stop me? And unless someone is going to do that... the cat’s out of the bag. Anyone can do this.” — Luke Iseman
“Unless you are breaking the law to build nuclear reactors, I don’t want to hear about CDR from anyone proposing it as a serious climate solution.” — Luke Iseman
“People are obsessed with developing governance for something for which there’s no demand. You govern things for which there is demand.” — Luke Iseman, quoting a friend
“I have a lot more respect now for the institutions that govern things that can help make decisions, the social license and legitimacy that comes from working through much more traditional systems.” — Paul Gambill (post-interview)
“Every day that we wait to do solar geoengineering is needless lives lost, species extincted, and tipping points flirted with.” — Luke Iseman
Links and Resources
Make Sunsets: Luke’s company, where you can buy cooling credits
Termination Shock by Neal Stephenson: the novel that inspired Luke to start Make Sunsets
“Why Countries Aren’t Ready for Climate Interventions Yet” (Inevitable & Obvious)
