Carbon could become a trillion-dollar asset class by the middle of the next decade, as governments and companies increasingly turn to market mechanisms to control greenhouse gas emissions (GHGs). The Middle East, which produces some 30 percent of the world's petroleum, is increasingly taking notice. As carbon becomes an important factor in global trade, the region’s governments and companies are turning to markets to help them meet targets and transform their economies. Inevitable expansion Carbon is traded in national or regional…