The BDN Opinion section operates independently and does not set newsroom policies or contribute to reporting or editing articles elsewhere in the newspaper or on bangordailynews.com. Gwynne Dyer’s new book is “Growing Pains: The Future of Democracy (and Work).” China took a major stride forward on climate last Tuesday. President Xi Jinping, addressing the annual meeting of the United Nations General Assembly, for the first time committed China to a hard target for future greenhouse gas emissions. By 2060, he promised, his country will be carbon neutral (“net zero”).