Asklemmy

Start a fund raiser, do advertisement, (make some donations your self so that it does not look dead) - ones you get a lot of money (lets say you have doubled) - start again and repeat until you double - within 10 cycles of doublings, you reach 10 million, and keep doing until you get rich enough (lets say 10 more cycles to reach 10B) then you have 2 paths to choose - either be a hero and actual invest in research and actively reversing shit done, maybe helping displaced or other good deeds, or the mlm path, and continue the doubling cycle, keep earning - with this much money, you can now have actors and fake donations, maybe even fake researches into how you are helping, and keep growing your wealth, and maybe then escape to a tax heaven.

Apologies for the dystopian ending, but realistically a person even going full carbon negative is not even a dent. If you actually want to do good, then you realistically require trillions, and then you feed that money to politicians, and reverse launder your way towards actual green solutions.