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In North America, what are the "types" of major initiatives for limiting/reducing carbon emissions? By "type", I mean what form do they take (ie. carbon taxes, cap & trade, regulated limits, etc.). I get the impression there is now quite a range of initiatives being undertaken by individuals, companies, municipalities and state/provincial governments. However, there seems to be a definite lack of leadership from national governments in Canada and the Uniited States. Is there an opportunity here for entrepeneurs and investors?