While Massachusetts is a national leader in creating green energy sources, area environmentalists say more work is needed to reverse the potentially devastating effects climate change could have on the planet... "The signs indicate that it’s real," said Jack Clarke, director of public policy and government relations at Mass Audubon. Environmentalists say the way to slow climate change is by reducing greenhouse gases by 40 to 70 percent by 2050 through development of green, or renewable, energy sources and conservation. "The lack of urgency is pretty disturbing," he said. "By and large the environment comes in last of any evaluation...