In 2008, London created its Low Emission Zone (LEZ) to encourage the most polluting heavy diesel vehicles driving in the city to become cleaner.

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Imagine a deal involving emission sources in China, which has some of the world's most polluting coal-fired power plants, and California, which is on a course to become one of the most stringently controlled states in carbon emissions.

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The low emission zone - which begins in February 2008 - aims to deter the most polluting vehicles from being driven in central London by imposing charges on lorries, coaches and buses that fail to meet low emission standards.

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The government will introduce emission limits in 47 areas in 19 provinces and regions against six "heaviest" polluting industries, including thermal power, iron and steel, petrochemical and cement factories, Economic Information Daily reports.

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