The European cities moving faster on clean energy than their governments

More than 6,000 cities have signed up to go further than EU climate targets. Copenhagen, Bristol and Vixji are leading the way

When heads of state go to Paris at the end of the year to negotiate a deal to tackle climate change, global city mayors will also be there, arguing that since cities are responsible for 70% of CO2 emissions, the battle should be waged, street by street, at a city level.

More than 6,000 European cities have signed up to the Covenant of Mayors, a voluntary commitment to go faster and further than EU climate targets. Their climate action plans call for, on average, a 28% cut in CO2 emissions by 2020, 8% more than the EU's 2020 target.