More than 7,400 cities and local councils have signed up to a ‘Global Covenant of Mayors’ to fight climate change, galvanised by Donald Trump’s dismissal of scientists’ concerns for the future. “What President Trump has done is he has – unintentionally as he does with so many things – organised and focussed people who have been doing a number of good things in hundreds of different places. “Now mayors are communicating and working in a fashion that I have not seen during my seven years in office. Mr Reed said Atlanta had committed to be powered by 100 per cent renewable energy by 2035, among a raft of other measures designed to reduce greenhouse gas emissions. And he said, regardless of Mr Trump’s policies, American cities had the power to meet the carbon targets laid out in the Paris Agreement, which was ratified by Barack Obama.