Building tall has its advantages. It means people can live closer to work. Fewer commuters means a lower carbon footprint, less congestion. Car-dependent urban sprawl is largely a consequence of the growth of the car industry in the 1960s: new towns — Milton Keynes, Telford — were designed for car owners, and that pattern persists today. New developments, with a few exceptions, are car-dependent, remote from jobs and public transport, built at low densities, and also include new commercial space. Low-density cities have much higher transport emissions per head of population. The Centre for Cities calculates that moving from spacious Telford to busy Brighton is a quick way to help the planet: your transport emissions are likely to fall by a third.