Cambridge Carbon Impact: Evaluating carbon credit claims and co-benefits

While decarbonising economies is a global imperative, offsetting residual emissions remains an essential interim step in avoiding climate breakdown. Carbon credits can be purchased on the voluntary market, but genuine concerns exist as to whether credits, in their current state, will enable the transition to net-zero by 2050. The Cambridge Carbon Impact project seeks to rebuild trust through an independent assessment of carbon credits, using the best methods and data available. By evaluating carbon credits across all dimensions of additionality and risk, and reporting performance through inter-comparable metrics, we aim to clarify concerns, address them where possible and flag them where not, and so allow prospective buyers to make offsets that have the kind of impacts they want. We report the number of credits needed to have the same climate impact as one tonne of CO2 sequestered into geological storage, which we dub one Permanent Additional Carbon Tonne (PACT).