at some point some country will weigh the risks of climate change and take matters into its own hands.

Yeah, I could see that happening. Maybe even the US. Maybe Elon Musk reads a Twitter thread about geoengineering, decides it’s the solution to warming, starts a company called GeoX and convinces Trump and the Republicans to give him and GeoX $5 billion a year, he buys a bunch of jets, fills them with sulfur dioxide and has them fart out a bunch of it around the Arctic every year. GeoX stocks soar, Musk becomes the first trillionaire, and the US federal government has added only a trivial amount to its already vast debt total. It almost doesn’t matter if it works or not.