Boston Globe: Representative Edward J. Markey, the chairman of the special House committee on global warming, today unveiled sweeping legislation to cut greenhouse gas emissions and raise billions of dollars to create alternative sources of energy. The bill – the culmination of more than 40 hearings by Markey’s committee – marks the starting point for a new legislative battle against global warming, a centerpiece of congressional Democrats’ agenda for the immediate future. Markey, a Malden …