© 2017 by Annual Reviews. All rights reserved. A review of research findings and polling data about Americans' attitudes on climate change reveals a lack of meaningful long-term change in mass opinion. Instead, the structure of Americans' attitudes toward belief in climate change's existence, concern about its consequences, and demand for policy response is similar to that regarding many other issues in contemporary US politics: stability in aggregate opinion that masks partisan and ideological polarization enhanced by communications from elites. But features of the climate change problem elicit some distinctive determinants of opinion, including individuals' trust in science, risk processing, and personal experience. Although our review of the literature and data leaves us skeptical that majority opinion will spur elected officials anytime soon to undertake the costly solutions necessary to tackle this problem comprehensively at the national level, we identify several avenues by which attitudes might promote less substantial but nevertheless consequential policy action.