Bargaining powers in cooperative Carbon Dioxide Removal deployment

International cooperation has the potential to significantly reduce the costs of implementing Carbon Dioxide Removal (CDR) in line with the Paris Agreement. However, the success of interregional cooperation depends on whether a satisfying agreement can be reached. Regional bargaining powers may heavily influence the outcome of such an agreement. This paper uses cooperative game theory to assess bargaining powers in the cooperative deployment of CDR between the United States (US), the European Union (EU), Brazil, and China. We compute least-costly CDR pathways under multiple cooperative configurations using the Modelling and Optimisation of Negative Emissions Technologies (MONET) framework, assuming regional CDR targets that are proportional to greenhouse gas emissions.Then, we apply cooperative game theory to derive relative bargaining powers from the cost evaluations in MONET. We find that cooperation can lead to substantial CDR cost reductions, ranging from 11% to 43%. Furthermore, we identify two distinct types of regions that possess considerable bargaining power: 1) regions with minimal historical responsibility towards climate change but abundant resources for CDR implementation (exemplified by Brazil in this study); and 2) regions with limited domestic resources amidst large CDR targets (represented by either the USA or China, here). These findings illustrate the potential leverage certain regions in the Global South could wield in the collaborative deployment of CDR under Article 6 of the Paris Agreement.