One of the problems with carbon credits that's hard to work around is the fact that if I avoid wasting a tonne of CO2, I get credited for saving our environment

One of the problems with carbon credits that's hard to work around is the fact that if I avoid wasting a tonne of CO2, I get credited for saving our environment. If I sell a carbon credit to fund the activity, someone else also gets credited for saving our environment. So every tonne of CO2 avoided counts twice. It's a way to inflate the progress that actually happens.