Systemic assessment of urban climate policies worldwide: Decomposing effectiveness into 3 factors

Optimism about the contribution of city policies worldwide to reduce greenhouse gas emissions is widespread. It is based, though, on partial and anecdotal studies rather than comprehensive system-wide estimates. Popular empirical indicators to support the importance of cities, such as consumption-based emissions within city borders, lack a policy connection. Here I undertake an initial assessment of the effectiveness of emissions reduction through urban climate policies. It employs a novel decomposition of effectiveness into reach, capability and stringency. This results in a qualitative estimation of current and maximum contributions of city climate policies – divided into four types – to global emissions reduction. I formalize the framework to numerically illustrate additional policy aspects. Based on the insights obtained, I suggest policy and political strategies to make better use of cities’ competences to mitigate climate change.