The 26th Conference of the Parties (COP) of the United Nations Framework Convention on Climate Change (UNFCCC), held in Glasgow in November 2021, resulted in significant intergovernmental agreements, including the Glasgow Climate Pact, the completion of the Paris rulebook, and several informal deals. While Glasgow saw progress, it fell short of many observers’ expectations (see, e.g., Nature2021; Climate Action Tracker 2021). Pointing not to what was possible politically but to what was necessary scientifically, these observers highlight a significant “ambition gap” in measures needed to keep global temperatures below 1.5°C of warming.
While a “firm step forward,” observes former UNFCCC executive secretary Christiana Figueres (2021), “we actually needed a sprint.” How can the world achieve greater ambition on climate? The most recent report of the Intergovernmental Panel on Climate Change (IPCC; 2021, 12) maintains that efforts to keep 1.5°C warming within reach, the chief...