Wiley Interdisciplinary Reviews: Climate Change
Three Decades of Scientific Debate on the Additionality of Forest Carbon Offsets: Are We Going in Circles?
2026-08-01
Carbon markets continue to be central to climate governance despite well‐documented integrity issues. Among the most difficult issues in the debate on market integrity is the question of additionality. Here, we review the scholarly literature on additionality in carbon markets focusing on forest projects, which have gained renewed impetus under the carbon removal agenda. We analyze the literature through three overarching and overlapping periods: (1) the period following the adoption of the Kyoto Protocol, when scholars discussed how to operationalize additionality in early carbon market mechanisms; (2) the emergence of markets for avoided deforestation in particular under the REDD+ scheme, when discussions centered on establishing deforestation baselines at national levels; and (3) the present Paris era where new quasi‐experimental methodologies promise to fix credibility issues. Throughout these three periods, scholars have continuously sought to improve approaches. While technological advances and more sophisticated approaches have been introduced, the scholarly chase of additionality in carbon markets continues to grapple with the fact that additionality can never be proven and by the tradeoff between environmental integrity and market flexibility. Thus, old problems and solutions continue to resurface, wherefore we argue that the scholarly discussion on additionality in many ways has been going in circles. The continued commitment to improving additionality assessments has had the unfortunate and unintended effect of lending support to non‐transformation of the climate governance system. We argue, therefore, that it is time to abandon the chase of additionality and the notion that forest carbon offsets can legitimize ongoing emissions elsewhere. This article is categorized under: Policy and Governance > Multilevel and Transnational Climate Change Governance The Carbon Economy and Climate Mitigation > Policies, Instruments, Lifestyles, Behavior Policy and Governance > Private Governance of Climate Change