Another setback for carbon trading, following the UN climate chief's announcement that the latest climate change deal will not include a global carbon price. The deal, focused on cutting greenhouse emissions, is expected to fall short of unifying carbon trading schemes around the world. Critics have been calling for a price on carbon to help cut emissions and boost investment in low carbon energy, but so far little has been done to put fixed regulations in place. The European Union launched its first carbon trading scheme back in 2005 with hopes that the industry would be worth $2 trillion by 2020. So far the carbon trading framework has fallen short of expectation, with companies lacking financial incentive to cut emissions. Widely ranging carbon prices and regulatory difference between countries means connecting the markets has become increasingly difficult.