Toward quantification of the feasible potential of land-based carbon dioxide removal

Global climate-change overshoot scenarios, where warming exceeds Paris Agreement limits before being brought back down, are highly dependent on land-based carbon dioxide removal (CDR). In the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6), such scenarios are supported by optimistic global assessments of the technical and economic potential for land-based CDR. However, a further type of potential-the "feasible" potential, which includes socio-cultural, environmental, and institutional factors-is noted in the AR6 but not quantified. Here, we set out research frameworks to work toward quantification of this feasible potential. We first argue that quantifying the feasible potential will substantially reduce current assessed CDR potential. Second, we demonstrate how transdisciplinary methods are improving understanding of feasibility constraints on land-based CDR. Third, we explore frameworks for synthesizing these advances during the next IPCC assessment process. We conclude that the research community should carefully consider the use of techno-economic CDR assessments in evidence for policymakers.