Additionality, as outlined by the UNFCCC is defined as a “reductions in emissions that are additional to any that would occur in the absence of the project activity”. Projects need to prove that the emission reduction intervention would not have happened under a business-as-usual scenario. Additionality can be understood in two contexts:
Project additionality is the scenario in which credits or offsets provide the motivation for emission reduction. The project developer needs to prove that the project will only take place in order to generate credits. For example, in South Africa, as most electricity from Eskom is derived from fossil fuels, any projects that use renewable energy would be deemed additional.
Contribution additionality is the scenario in which the support from the carbon market can make a tangible difference to the viability of a particular project. For example, in South Africa, financial contribution from the carbon market on a solar water heating project could make a significant difference to the viability of the intervention.