For a CDM project activity (non-A/R) or CPA (non-A/R), the effect of the CDM project activity or CPA to reduce anthropogenic GHG emissions below the level that would have occurred in the absence of the CDM project activity or CPA; or For an A/R or SSC CPA (A/R), the effect of the A/R or SSC A/R CDM project activity or CPA (A/R) to increase actual net GHG removals by sinks above the sum of the changes in carbon stocks in the carbon pools within the project boundary that would have occurred in the absence of the A/R or SSC CPA (A/R). Whether or not a CDM project activity or CPA is additional is determined in accordance with the CDM rules and requirements.