Climate change is no longer a distant possibility but a current reality. It has become one of the defining challenges for policymakers, private industry, and civil society, and is a development, investment, economic and social issue, which affects most sectors. Milan's drive to minimise its environmental impacts and embrace sustainable development was given added impulse this year when it was chosen to host Expo 2015, an event being organised around the theme of “Feeding the Planet, Energy for Life”. Planning for Expo 2015 and beyond must go hand in hand with sustainable principles, which must include a great and innovative effort on climate change, and the City of Milan is honoured to be supported in this commitment by the World Bank. This conference will investigate how Milan can best tackle the challenges of climate change while enjoying growth that safeguards resources and opportunities for future generations, and partnering and cooperating to the development efforts of other cities in the developing world.