The climate change policy debate is obviously heating up in the City of Lights, eight months ahead of the landmark COP21 Paris Summit that is expected to produce a “universal agreement on climate.” The mayors of 26 European big cities and metropolises representing more than 60 million inhabitants, convened in Paris yesterday to commit to addressing the major causes of greenhouse gas emissions: polluting transport, old and/or poorly isolated buildings and energy supply. Their goal is to use their collective investment capacity ($11 billion) to green their local economies through new requirements for public contracts. Besides supporting each other along that path, they will also push for policies in Brussels that align with their commitment.