Carbon credits are, well you be the judge. Suppose my Doctor tells me I'm obese and I need to lose weight, but instead what I do is find 10 other people who want to go on a diet. I pay them each $10 per pound for their weight loss which encourages them in their diets and they each lose 5 lbs this month. Now I can walk into the Doctor and say look, I'm directly responsible for the loss of 50 lbs of body fat, aren't I wonderful.
But my situation is unchanged. If you want to be serious about reducing carbon dioxide in the atmosphere, then walk the walk - don't pay somebody else to do it for you and then congratulate yourself on how good you are.