Canwest News Service: WASHINGTON – Democrats in the U.S. House of Representatives on Tuesday unveiled draft climate change legislation to slash America’s greenhouse gas emissions by 20 per cent by 2020, setting the stage for a protracted and intense political debate in Washington that has potentially major consequences for Canada’s energy industry. The 648-page draft bill would establish a carbon cap-and-trade system to help industry achieve the greenhouse gas reductions, but sidesteps the politically …