The billionaire mayor urged delegates at the C40 conference in Hong Kong to wield the power of its large collective population, which accounts for about 1 in 12 people in the world. (about 570 million people). C40 is a coalition of 40 cities. It was founded in 2005 with the aim of reducing carbon emissions. Nineteen other cities are affiliate members.
The 19 of the C40 cities where statistics were available are home to more than 20 million cars and 25 member city governments represented in the coalition have oversight of taxi fleets controlling more than 1 million cabs.