Do municipal efforts ‘move the needle’ in reducing local greenhouse gas emissions? An initial assessment of US cities

Implicit in cities' decisions to engage in climate actions is the expectation that these efforts will result in significant greenhouse gas emissions reductions. Little research, however, has investigated this presumed cause-and-effect relationship in a manner that is both empirical and generalizable. This, in turn, challenges the design of evidence-based policy recommendations. We apply a difference-in-differences (DiD) approach to examine the impact that two frequently recommended capacity-building interventions—completing a greenhouse gas emissions (GHG) inventory and employing dedicated sustainability staff—have on the fossil fuel carbon dioxide (FFCO₂) emissions of the cities that have undertaken them. This is enabled by the construction of a unique dataset that combines city-level FFCO₂ emission estimates in 2010 and 2015 with multi-year survey-based data indicating the adoption of relevant local policy actions. Findings offer evidence that the completion of a community-wide emissions inventory facilitates local action that, even in a relatively short timeframe, significantly reduces emissions from onsite residential sources.