Carbon offsetting is the act of mitigating ("offsetting") greenhouse gas emissions. A well-known example is the purchase of carbon offsets to compensate for the greenhouse gas emissions caused by personal air travel.

The concept of paying for emission reductions to take place elsewhere instead of reducing one's own emissions is known from the related concept of emissions trading. However, in contrast to emissions trading, which is regulated by a strict formal and legal framework, carbon offsets generally refer to acts by individuals or companies that are arranged by commercial or not-for-profit carbon-offset providers.