Glob. Environ. Polit. 14, 107–129 (2014)

Urban policy measures can significantly contribute to the reduction of global carbon dioxide emissions given that 50–80% of those emissions come exclusively from cities. However, the success of subnational initiatives hinges on the extent to which they spread across municipalities.

Based on annual data, Lukas Hakelberg, of the European University Institute, Florence, Italy, analysed the impact of transnational municipal networks (TMNs) on the adoption of local climate strategies across 274 European cities over the period 1992–2009. He found that networks significantly helped the spread of local strategies across cities in Europe. In particular, statistical results show that learning processes, among TMNs members, led to strategy adoption. Therefore, municipal networks should be part of a polycentric governance system to tackle climate change. However, the analysis also showed that TMNs do not successfully influence the laggards among their constituencies, which mainly use membership in TMNs to signal engagement with climate strategies but do not actually fulfil their commitments.