Andrew Song left SaaS behind to launch sulfur dioxide balloons into the stratosphere—an attempt to cool Earth by mimicking volcanoes. In this raw, unfiltered conversation, he explains the science, the stakes, and the hustle behind Make Sunsets. He talks about moral lines, market forces, and why he’s betting it all to give his kids a livable planet. If you’ve ever wondered what it looks like to actually try to save the world, this is it.