> The only reason to call it "subsidy" is to imply that the companies are "unfairly" benefiting, but unless these externalities have actual cost to the economy instead of just imputed carbon/water tax, you'll find no resources to divert.

It very much does have actual cost, just not today or tomorrow, so it's a bit harder to calculate.

If I break your bike in the middle of winter, the cost won't actualize until spring when you would have used it, and instead have to pay for the bus. So sure, it's not a Q4 cost, but it is real nonetheless.