Because 90% of the electricity consumed in Stockholm is supplied by hydro and nuclear plants, there is the potential to significantly reduce emissions by electrifying the transport sector.

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Going forward, we're going to have to build on the momentum that we've established here in Copenhagen to ensure that international action to significantly reduce emissions is sustained and sufficient over time.

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Since power plants that burn natural gas emit about half the amount of the greenhouse gases as coal-fired power, some say that the gas drilling boom has helped the U.S. become the only major industrialized country to significantly reduce greenhouse emissions.

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It is a comprehensive solution: but this is entirely independent of whether it would reduce emissions significantly.

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This will allow truckers to reduce emissions significantly (diesel emissions include nitrous oxides, particulate matter, and other air toxics and they are a major source of pollution in some areas).

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Major auto manufacturers are already heavily invested in developing advanced technologies that can significantly reduce fuel use and greenhouse gas emissions beyond the existing model year 2012-2016 targets.

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And one of the biggest questions here is whether a carbon tax would actually reduce U.S. greenhouse-gas emissions significantly.

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