Bill McKibben, a chief antagonist of the proposed Keystone XL pipeline, is stepping down as chairman of the environmental group 350.org that he helped create. McKibben, an author and climate advocate, said the move will give him more time to write and to organize campaigns. He’ll remain as a senior adviser to the New York-based group that pushes for action to combat climate change. “If this sounds dramatic, it’s not,” McKibben wrote in a letter to supporters sent from Sweden , where he is receiving the Right Livelihood Award from Parliament. “I will stay on as an active member of the board, and 90 percent of my daily work will stay the same, since it’s always involved the external work of campaigning, not the internal work of budgets and flow charts.” McKibben, 53, has led 350.org since he co-founded it in 2007. The group gets its name from a […]