It's pretty clear by now, no one, not even Bill Gates has any concept of thermodynamics. If it weren't for the outright pollution we would all have to deal with I would love to see him go broke trying to put his plan into action. It would become insanely prohibitively expensive at some point and he would just end up making a mess, going broke.

For context, there isn't enough of any chemical on this planet that you could procure and aerosolize to "dim" any fucking thing. If you wanted to effectively "blot out the sun" or reduce it's effects, you would evaporate more water for the albedo effect to take hold, and you would have to do a fuck ton all at once, to quickly kick start a cooling phase for an ice age. We aren't even a Type 1 civilization, the amounts of energy it would take to change the climate would be INSANE, as it always has been. But people suck at scales and large numbers so they use it to fool people into giving up money and resources based on fear. People thinking they can alter the climate on a global scale is about as foolish as thinking you can speed up the heat death the universe faster, by having everyone boil a pot of water. It's all hubris and foolishness. Science has turned into a fucking joke.