>It’s not an analogy at all

Then why are you talking about a garbage company? Your whole comment is building an analogy.

>Although I’d like to know which step in my story stops qualifying as one.

This is where it stops qualifying:

>Instead of taking the land, the government just declares that it’s legal for the garbage company to dump trash on other people’s land, and the owners just have to deal with it. This is quite different in the details from the original subsidy, but the overall effect is essentially the same.

The government saying "it's legal to do X" and all companies in any industry and any individual (what we're talking about is CO2 emissions) are allowed to do it, it's not a subsidy. It's just behavior with an externality that the government doesn't tax.

I’m talking about a garbage company because they’re an example of a polluter that can’t just dump their pollution wherever they feel like, and their pollution is much more visible. It’s not an analogy, it’s an example. Polluters aren’t analogous to companies dumping trash on your property, they are companies dumping trash on your property.

But it is tortured because the numbers are made up. Yes, there is very strong scientific consensus global warming is bad, and getting worse, but pinpointing an exact number and calling it a "subsidy" implies they know a lot more about the future than they actually do. It's untruthful and plays into the hands of those screaming "fake news!" who try to deny climate change.

"Your logic is right, but I doubt the exact number you used." is very far from saying an analogy is "tortured". It's an agreement that the analogy is correct.

I didn’t use any numbers at all. Perhaps you meant to reply to a different comment.