We conducted a one-year longitudinal study in which 600 American adults regularly reported their climate change beliefs, pro-environmental behavior, and other climate-change related measures. Using latent class analyses, we uncovered three clusters of Americans with distinct climate belief trajectories: (1) the “Skeptical,” who believed least in climate change; (2) the “Cautiously Worried,” who had moderate beliefs in climate change; and (3) the “Highly Concerned,” who had the strongest beliefs and concern about climate change. Cluster membership predicted different outcomes: the “Highly Concerned” were most supportive of government climate policies, but least likely to report individual-level actions, whereas the “Skeptical” opposed policy solutions but were most likely to report engaging in individual-level pro-environmental behaviors. Implications for theory and practice are discussed.