Underpinning resurging concerns about carbon trading is the world's crisis of faith in capitalism itself. Markets have proved to be more capricious and uncontrollable than anyone imagined possible in the last year. Where does that leave the theory behind an artificial trading system set up to pursue a single, ethical goal? The economic concept is simple, but the practice itself has been fraught with complications. In Europe, since 2005, policymakers distribute permits to emit carbon to utility companies and heavy industrial polluters – at first for free.