Legal limits to the use of CO2 removal

The Intergovernmental Panel on Climate Change (IPCC) has indicated that to hold global warming to 1.5°C, consistent with the goals of the 2015 Paris Agreement, global carbon dioxide (CO₂) emissions need to be reduced to net zero by around mid-century. This global goal can be achieved by following various technologically feasible emissions pathways, but the range of possible strategies create legal and policy uncertainty regarding the emissions reductions required by states. Pathways differ in their rates of gross and net CO₂ emission reductions, their corresponding dependence on CO₂ removal (CDR) to stay within the cumulative emissions limit imposed by the global temperature goal, and the type of CDR they intend to deploy. In the lead up to this year’s United Nations (UN) Climate Conference (COP28) in Dubai, we present scientific and legal bases for our argument that emission-reduction pathways that depend heavily on CDR may contravene norms and principles of international law.