That leaves out the political side. Big companies have way more influence on governance than you and I do, and will lobby to make the law favor their business rather than outcomes that would protect the environment.
> If companies have too much influence, that can be changed.
So far it seems that it can't as long as these companies are using investors' money to lobby various governments.
> investors in oil companies are not "responsible" for warming – our consumption is.
Many people would happily use alternatives to lessen the impact of their consumption but there are companies more powerful than them trying to influence and limit their options.
