Mayors from more than 7,100 cities on six continents announced this week that they are creating a new alliance to fight climate change at the local level.The new group — a merger of the European Union-based Covenant of Mayors and the United Nations-backed Compact of Mayors — represents a combined 600 million people in 119 countries. The initiative aims to set city-based CO2 emissions cuts, build sustainable communities, and foster the sharing of resiliency policies and technologies. “Cities are key to solving the climate change challenge,” former New York Mayor Michael Bloomberg and MaroÅ¡ Å efÄoviÄ, vice-president of the European Commission, wrote in The Guardian . “They account for most of the world’s carbon emissions, and mayors often have control over the largest sources. Cities can also act quickly to confront climate change, without the political and bureaucratic hurdles that often hold back national governments.”