A revenue-neutral tax (like GP proposed) could, in theory, change behavior. I don't know enough about human behavior to say how it would work in practice.

Let's say that instead of taxing carbon, we pay people a bonus for emitting a below-average amount of carbon (proportional to the amount that they are below average by). If the amount is in a certain range, it will be too small an amount for wealthy people to care about, but large enough for poorer people to do things within their means (e.g. carpooling) to try to get it.

The results would hit certain geographic areas much worse than others, and (if priced enough to change behavior) would also probably depress car sales, which are two reasons why the federal fuel tax has been flat for over 30 years.

Think about how much easier that is to game though.

The original suggestion could be collected at point-of-sale for carbon emitting products. Gasoline, airplane tickets (based on average for the flights), even electricity are easy to measure and charge at the point of sale.

In your example, the person has to prove how much they didn’t emit, which is way harder in practice, to get the credit.

> Let's say that instead of taxing carbon, we pay people a bonus for emitting a below-average amount of carbon (proportional to the amount that they are below average by). If the amount is in a certain range, it will be too small an amount for wealthy people to care about, but large enough for poorer people to do things within their means (e.g. carpooling) to try to get it.

So you're saying that the government should incentivize poorer people to sell one of the last bits of their functional autonomy for what would be trivial amounts? "We'll just hang onto to this for a bit until you decide to stop going anywhere or make friends at work".