Forest offsets partner climate‐change mitigation with conservation

Are forest offsets an effective way to address climate change, and do they provide other benefits? In some climate‐change mitigation policies, industries and individuals can purchase offsets that compensate for their greenhouse‐gas emissions by reducing emissions elsewhere. However, offsets may undermine mitigation efforts, by potentially giving carbon credits for emissions reductions that would have occurred even without the offset program in place. We evaluate California's forest offset program – the first‐ever legally enforceable “compliance” offset program for existing forests – to determine whether offsets (1) provide additional emissions reductions that would not have occurred without the program (called “additionality”) and (2) yield other benefits. We found that California's forest offset program, comprising a small portion of the state's mitigation portfolio, does not inhibit overall emissions reductions. Further, the program advances stringent “additionality” of emissions reductions through multiple mechanisms. Finally, mitigation through forest offsets can yield a suite of important co‐benefits. Lessons from California's experience with forest offsets can help to inform other offset programs that are increasingly being developed around the world.