Additionality is the property of an activity adding something new to the context. It is a determination of whether an intervention has an effect when compared to a baseline measurement.

Additionality is a crucial component of carbon offset creation because if it is not additional, a carbon offset does not reduce greenhouse gas (GHG) emissions.

Carbon offset credits are considered additional if the emission reductions happen only because these credits can be sold. This means the reductions wouldn’t occur without the financial incentive from selling the credits. This concept is important because it ensures that the offsets lead to real, extra reductions in emissions. If the reductions would have happened anyway, even without the ability to sell the credits, then they don’t actually add any new benefits to the environment.

So, it is important that offset credits contribute to real, additional greenhouse gas reductions to make a positive impact on the electricity grid and, in turn, the environment.