Riley Dunlap, Aaron McCright, and Jerrod Yarosh, “The Political Divide on Climate Change: Partisan Polarization Widens in the U.S.,” Environment: Science and Policy for Sustainable Development, 2016 Donald Trump has called climate change a hoax, while Hillary Clinton has said she believes in climate science and supports efforts to reduce carbon emissions. Partisan divides on climate change have become almost a given and part of accepted party doctrine, but this was not always so.