Peer Pressure and Climate Ambition: A Study of Pledge-And-Review Through Peer Analysis

With the finalisation of the first global stocktake in 2023, the Paris Agreement’s pledge and review-process is well under way. At a cursory glance, the process is working as intended: overall, countries have increased the ambition of their climate plans. However, more needs to be done to stop the upcoming and ongoing climate crisis. Given the novelty of the pledge-and-review approach for global climate governance, and the wealth of climate ambition data that is now available, more and more scholars have analysed what determinants drive climate ambition. These analyses have predominantly looked to cross-national differences such as level of democracy, level of development or dependence on fossil fuel rents as explanations for variations in climate ambition. These variables, though undoubtedly part of the puzzle, overlook one central causal mechanism through which the Paris Agreement is expected to ratchet-up ambition: peer pressure. Through norm-setting and repeated interactions, the Paris Agreement sets up a process that is meant to ramp up ambition. This process, as of yet, has been kept exogenous to analyses of climate ambition as it pertains to the Paris Agreement. To bring this process into the analysis of climate ambition, this paper zooms into the mechanics of policy diffusion and socialisation through peer groups. More specifically, the analysis estimates the extent to which peer levels of climate ambition from the first round of NDCs explains ambition levels in the subsequent round of NDCs beyond established cross-national determinants of climate ambition. This paper borrows from and aims to contribute to established research on the Paris Agreement, the drivers of climate ambition, and the broader literature on international socialisation and policy diffusion. Furthermore, the paper aims to serve as a foundation for further empirical research into the effects of peer pressure on climate ambition.