Moonshot Radio [S1:E4] - Luke Iseman: Weather Hacking: Make Sunsets, Solar Geoengineering & Climate Urgency

Who gets to control the Earth’s thermostat?In this episode of Moonshot Radio, host Linda Du speaks with Luke Iseman, founder of Make Sunsets, a startup experimenting with solar geoengineering by releasing reflective particles into the stratosphere to cool the planet.Luke’s work has ignited global debate about ethics, governance, risk, and radical action in the face of climate collapse. This conversation goes deep into the science, philosophy, and urgency behind a technology many consider taboo.Themes:Solar geoengineering explainedHow releasing sulfur dioxide (SO₂) into the stratosphere mimics volcanic eruptions to reflect sunlight and reduce global temperatures.From science fiction to startup realityHow Termination Shock inspired Luke to investigate geoengineering—and why scientific consensus existed long before public action.Why entrepreneurs act when institutions stallThe tension between academic caution, government inaction, and founder-led experimentation in an accelerating climate crisis.Cloud seeding vs. stratospheric aerosolsThe difference between traditional cloud seeding (using silver iodide) and high-altitude aerosol reflection, and why Make Sunsets chose the latter.Regulation (or lack thereof) in the stratosphereWhy international airspace law remains unresolved above ~20km, and what Luke learned from engineers who worked on Project Loon.Cooling credits & climate economicsHow Make Sunsets sells “cooling credits” directly to individuals, why governments and corporations have been slow to engage, and what this reveals about carbon markets.Carbon markets, fraud & moral hazardA critical look at voluntary carbon credits, including findings that large portions may be ineffective or fraudulent.Public backlash & political controversyFrom scrutiny by the Environmental Protection Agency to reactions from climate activists and regulators.Is geoengineering playing God?Why Luke argues that everything we already do, from flying planes to burning fossil fuels, is geoengineering, just in the wrong direction.Scaling planetary infrastructureWhat it would take to meaningfully cool the planet, from balloon launches to military-grade deployment by G20 nations.Other frontier climate ideasIncluding space-based sunshades like those proposed by the Planetary Sunshade Foundation, nuclear power revival, and climate-aligned AI infrastructure.Activism, blockchain & coordination at scaleReflections on movements like Extinction Rebellion, DAOs, crypto-enabled coordination, and what GameStop-style collective action could mean for climate.Work, automation & post-scarcity futuresDrawing on ideas from David Graeber, including critiques of “bullshit jobs” and what people might build if survival wasn’t the constraint.Immigration, innovation & global growthWhy openness to migration, experimentation, and building may matter more than any single technology.This episode doesn’t offer easy answers, but it confronts the uncomfortable reality that not acting may be the most dangerous choice of all.