He populated his Massachusetts administration with environmentalists, including one, Gina McCarthy, who now runs the clean air division of the Environmental Protection Agency under President Obama. He railed against the “Filthy Five,” high-polluting power plants in the state. He issued a “climate protection plan” and lauded it as “among the strongest in our nation.” Under his direction, Massachusetts helped create a regional cap-and-trade program — anathema to most Republicans — intended to cut the greenhouse gas emissions that scientists believe cause global warming.