And New York City Mayor Michael Bloomberg unveiled PlaNYC this summer, which includes 127 proposals to reduce greenhouse emissions by 30 percent by 2030 and a congestion charge for driving through certain parts of Manhattan.

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And he helped implement PlaNYC, a long-term scheme to build houses for up to 1m New Yorkers, link them to transport, clean up brownfields, plant 1m trees and improve air and water across the five boroughs.

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New York's ambitious PlaNYC had similar origins.

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