Back in the Middle Ages, the Catholic Church and some other unaffiliated snake oil salesmen, sold what were called indulgences. These indulgences offered penance for a variety of sins and could either commute or completely eliminate one’s arduous trip through Purgatory. Today, we have a similar situation; we have an entire market of carbon credit traders. Basically, you buy offsetting carbon credits (for someone, probably in a third world country, to plant trees or something like that) to make up for your “carbon footprint.”