Is bio-energy carbon capture and storage (BECCS) feasible? The contested authority of integrated assessment modeling

How are novel energy, technology, and land-use systems strategies for limiting climate change judged to be 'feasible'? Controversy has arisen around the research community behind integrated assessment modeling (IAM) scenarios used in the Assessment Reports of the Intergovernmental Panel on Climate Change. This regards the role played by an unproven component in projected energy systems-a coupling of bioenergy generation with carbon capture and storage techniques (BECCS)-that allows IAMs to achieve ambitious temperature targets since adopted by the Paris Agreement. We engage members of the IAM community and a multidisciplinary range of critical experts to interrogate how the 'feasibility' of BECCS-or other novel technologies-is assessed within modeling, and use 'boundary work' to show how the kind of expertise-and by extension, the authority-held by the IAM community is being challenged. We find that the competing judgments of BECCS's feasibility, between the IAM community and its critics, reflect and reinforce different understandings of the freedom of scientific inquiry, the mutual influences of science and policy, the shape of science communication, and the necessity of reform. We ask what these claims signal for future activity in this space, and conclude with a call for 'reflexive' modeling approaches to bridge perspectives.