Cities have become crucial actors for the global governance of climate change. Their increased activity in this field is reflected by the rising number of adoptions of local climate strategies in an original sample of 274 European cities from 1992 to 2009. Using event history analysis, I find that this spread is promoted by transnational municipal networks (TMNs) successfully deploying strategies for governance by diffusion, their impact exceeding that of most alternative explanatory factors cited in the literature. Given their capacity to foster the spread of climate policy innovations among cities, TMNs can thus be expected to play a decisive role in a climate governance system that is becoming increasingly fragmented, polycentric, and transnational.
* I am grateful to Helge Jörgens, Susanne Lütz, Linda vom Hove, Steffen Wagner, and Fabrizio Bernardi, along with three anonymous reviewers and the editors of Global Environmental Politics, for comments and conversation on earlier versions of the article. This article is based on my master thesis, which was released at its full length as an FFU working paper in 2011. It can be downloaded here: http://www.polsoz.fu-berlin.de/polwiss/forschung/systeme/ffu/aktuellepublikationen/