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The smoke stacks at American Electric Power's (AEP) Mountaineer coal power plant in New Haven, West Virginia, October 30, 2009.
Internationally, the carbon trading market has become one of the biggest commodities markets in the world. It's estimated to be worth about $175 billion dollars, which makes it a major target for crime.
So much so that Interpol, the international police force, has just issued a guide to carbon trading crime. Here to tell us more is Davyth Stewart, an intelligence officer in the Environmental Crime unit of Interpol.