[generj]

Solar shades have great potential and the unintended consequences can at least be mitigated. Unlike aerosol dispersal they can be “turned off” semi trivially with onboard thrusters or specialized missions. Cost estimates were at $100 Billion 10 years ago which were doubtlessly optimistic, but Starship will dramatically lower the cost of deploying a few hundred tons of shades.

One risk of not exploring geoengineering is that cheap options for it exist and most countries are technically and economically able to engage in them. If a country feels like the burdens of climate change fall unfairly on them, the option exists to do something drastic.