Policy Brief: Fossil and biological carbon: a tonne is not a tonne
Whether biological carbon credit should be traded in carbon markets is topical, with discussions ongoing in the UNFCCC, ICAO and the California Cap-and-Trade system. To date, compliance markets have rejected the eligibility of biological carbon offsets. They are right to do so. Fossil and biological carbon operate on different parts of the carbon cycle, and on very different timescales. Fossil carbon is permanent; biological carbon is potentially and frequently subject to rapid fluxes, whether natural or manmade. For these reasons, offset credits from REDD+, afforestation and reforestation or other biological systems should not be treated as fungible with fossil carbon, but should instead be addressed through other, appropriate, policy measures.