I smoke....a lot. If I quit, can I sell my surplus carbon credits?
You're thinking too small, form two corporations - one is you planting trees in your back yard to carbon bank, the other is a holding company that buys your cigarettes wholesale which you lose in tragic but unclaimed small inventory fires every 20 minutes or so. Buy and sell carbon credits between the two and put any excess carbon bank capacity into the exchange.
You'll be a California millionaire in no time, and probably get some kind of conservation award from Governor Moonbeam.