How would such a proposal be enacted to begin with?

My comment was that for a proposal like that to be passed initially, it would almost certainly need the support of a politician's respective constituents. Anything else would be political suicide and have slim-to-no chance of even getting debated. Blame it on lobbying, or career politicians, or whatever else but that's the reality in the U.S.

There's lots of ways that carbon reduction system could work. If it's largely a man-made problem there's probably many man-made solutions. But, outside of dictatorial solutions, you have to start with the democratic political will to see it changed.