The Large Cities Climate Leadership Group, also known as the C40 Cities (and originally as the C20 Cities) is a group of committed to the reduction of urban carbon emissions and adapting to climate change. It believes it has an important role to play as cities contain around 50% of the world's population, consume 75% of the world's energy, and produce 80% per cent of its greenhouse gas emissions. The Large Cities Climate Leadership Group held their 2nd summit in New York from May 14-17 2007. Delegations were expected from 45 cities.