Much of what they do can be done without eliciting the ire of nation-states. Bike shares, pedestrian zones, insulated buildings, renovated port facilities, congestion fees, car emission limits, furnace specifications, fuel upgrades (from oil to gas to alternative energy) and white paint roofs, for example, are only some of the innovations city officials can promote to effect significant reductions in emissions and pollutants.

here states have grown dysfunctional and sovereignty has become an obstacle to global democratic action—as when the United States (or China, France, or Canada) refuses to compromise its sovereignty by permitting the international monitoring of carbon emissions on its soil—cities have increasingly proven themselves capable of deliberative democratic action on behalf of sustainability, as they have actually done in intercity associations like the C-40 or ICLEI. If presidents and prime ministers cannot summon the will to work for a sustainable planet, mayors can. If citizens of the province and nation think ideologically and divisively, neighbors and citizens of the towns and cities think publicly and cooperatively.