Thesis: Ph. D. in History, Anthropology, and Science, Technology and Society (HASTS), Massachusetts Institute of Technology, Program in Science, Technology and Society, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (pages 147-159).My dissertation, "Changed Climate: Networking, Professionalization, and Grassroots Organizing in U.S Environmental Organizations," explores the efforts of four established U.S. environmental NGOs to change their organizational cultures and routine practices to develop grassroots activism for climate change advocacy. I find that although actors within and outside the environmental movement recognize a collective failure to influence the U.S. policy process on climate change issues, t...