Although this may be hard to believe, New York State is second in the US (after balmy Hawaii) in its efficient use of energy. This remarkable situation is due to a single circumstance: the very high rates of public transportation use in New York City, greater by far than anywhere else in the country. That such a single factor should – in a place of demanding climate and profligate levels of consumption – be so influential is hugely suggestive. Urban sustainability requires thinking at appropriate scales.