Ben Leffel (Public Policy and Leadership) is lead author in a new study published in Cities , titled "Not so polycentric: The stratified structure & national drivers of transnational municipal networks" that has mapped the known universe of cities in these global governance networks. This analysis of over 10,000 cities and their memberships in the world's TMNs, and reveals major new insights at the city- and national-levels. 

While there is no United Nations for cities, there is a close equivalent: City governments worldwide have created and joined several governance networks covering issues from climate change to poverty alleviation. They're called "transnational municipal networks" or TMNs, and are how cities gain a voice in world affairs through networks like C40, Global Covenant of Mayors for Climate and Energy, Global Parliament of Mayors, Mayors for Peace, and United Cities and Local Governments.

Leffel been invited to speak in Barcelona alongside the Global Covenant of Mayors for Climate and Energy, Barcelona City Council and the Barcelona Centre for International Affairs, on the future of global urban leadership on climate change.