As emissions pour into the atmosphere and world leaders struggle for solutions to a climate emergency, the controversial climate-cooling technology called solar geoengineering is entering the world’s stage. It’s an idea so powerful and full of uncertainty that even the proposal of research itself is seen as a dire risk - a moral hazard - by leading environmental activists and scientists.
But for physicist David Keith, what matters is not what’s popular but what could help reduce the harms of a heating planet. And to learn more, he plans to launch the world’s first experiment into the stratosphere. He believes that this technology has the potential to save millions of lives, preserve entire ecosystems and stabilize climate systems…But the consequences are not clear.
Until now, research in solar geoengineering has been confined to the lab and computer models as outdoor experiments like the one that Keith is pursuing have been thwarted by opponents. But in 2023 Luke Iseman and Andrew Song began their own rogue solar geoengineering campaign with their Silicon Valley start-up, Make Sunsets. For $10 a gram, they will launch a balloon filled with "planet cooling" sulfur dioxide into the stratosphere from atop their Winnebago. Each gram of SO2 is enough, they claim, to offset the warming effect of 1-ton of CO2 for one year. Make Sunsets may seem comically inept, but as suffering spreads and patience runs thin their advocacy for solar geoengineering presents a complex but unmistakable hope; what if there was a way to cool the planet – fast?
Plan C for Civilization tackles the promise and peril of solar geoengineering with exclusive verité access to its protagonist David Keith and the SCoPEx project as well as the rogue geoengineers of Make Sunsets. Solar geoengineering is emerging after more than 60 years in the shadows, and with it, a new chapter of the climate change saga.
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About the Making
The first time I met David Keith was in 2010. I’d been working on climate-centric documentaries for years at that point and become increasingly concerned about the gap between how quickly scientists said we needed to make emissions cuts and what was actually happening in the world.
It was clear right away that Keith was not an ordinary scientist. He was bold and outspoken. A contrarian. An iconoclast. He’d been publishing about solar geoengineering since the early 1990s, unapologetic about his research in this taboo chamber of science. At the time that we met, his work was in modeling and social science - no outdoor experimentation had been done in the field. But in 2015 he and his colleague at Harvard, Frank Keutsch, announced that they would launch the first solar geoengineering experiment into the atmosphere, and I knew that would be a story worth following.
For ten years I filmed and followed Keith and his work. Many things changed in science and in the world over that stretch but there are at least two things that have not; carbon emissions and temperature continue to rise, and there has never been an outdoor experiment in solar geoengineering.
It’s not at all clear whether a global deployment of solar geoengineering would be less risky than the impacts of global heating. The research is still in its infancy and the scientific and social side effects are hard to quantify. On the other hand, the planet has warmed 1.5°C and public policy, renewable energy and moral clarity have not succeeded in preventing a dangerous situation from getting worse.
Cutting emissions and carbon removal will always be the only true, safe solutions to keep heating from veering out of control. Solar geoengineering will affect weather patterns - that’s kind of the point. It could further damage the ozone layer. It could cause additional cancer deaths. And in an already unstable world it seems like the last thing we need to introduce into the governance agenda. We may decide as a global community that it’s a path we cannot and should never go down. But if we value the ecosystems and humanity of this planet, if we understand the fundamental science of the greenhouse effect then how could we simply ignore a tool with so much power to cool the planet quickly?
Ben Kalina, director of PLAN C FOR CIVILIZATION