“Major challenges of our time…become particularly tangible in urban space. It is therefore, now more than ever, 25 years after the Earth Summit in Rio, that local governments play a key role in implementing the concept of sustainable development,” says Dieter Salomon, Lord Mayor, Freiburg, Germany and Member of the Executive Board, Deutscher Städtetag. But he highlights local governments are more than just implementers. “They are catalysts of change.”