The North Star chapter of the Sierra Club is the latest statewide group to come out against a 2012 ballot question that would add a ban on same-sex marriage to the Minnesota Constitution. The influential lobby for the environment said Friday that it was jumping into the same-sex marriage debate because of its commitment to social justice. “To achieve our mission of environmental protection and a sustainable future for our planet, we must attain social justice and human rights at home and around the globe,” said Margaret Levin, the state director of the Sierra Club North Star Chapter