Abstract Climate change is one of the greatest threats to humanity, necessitating immediate action to combat its consequences. Although there is a nearly unanimous scientific consensus that climate change is human‐caused, misinformation doubting its causes continues to circulate widely. In this study, we test the Gateway (mis)Belief Model (GmBM) which assumes that misinformation affects perceived scientific consensus negatively, which then cascades down to lower support for public action to mitigate climate change via changes in key beliefs about the issue. We present a reanalysis of data from two online studies in which U.S. participants ( N 1 = 207, N 2 = 755) were exposed to misinformation using a pre‐post mixed design manipulating assessments of the scientific consensus on climate change. Results showed that misinformation indeed leads to lower estimations of scientific consensus, which cascade down to lower support for public action via corresponding beliefs. However, the pattern of significance of direct effects did not exactly replicate those in the original GBM, though misinformation still had negative direct (Experiments 1–2) and indirect effects (Experiment 2) on several downstream climate outcomes. These findings are further affirmed by an internal meta‐analysis. Overall, this study highlights the negative impact of misinformation on climate attitudes and policy support.