science

That's one part the movie for Project Hail Mary missed from the book, that's disappointing. Sunlight is decreasing, so they bring in a climate scientist to figure out how to produce as much greenhouse gasses as possible. He's really disturbed by it obviously, but sees it needs to be done. They end up melting the ice caps to release Methane, because it's more potent and decay into less potent CO2 in a reasonable time frame, so they can stop when things are solved.