This study examines the effectiveness of two scientific consensus messages on climate change—both emphasizing the reality of human-caused climate change—and an updated message that also highlights the scientific agreement that climate change is a crisis—across 27 countries. The classic message significantly reduces misperceptions of the scientific consensus (Cohen’s d = 0.47) and slightly increases beliefs in the reality and human causation of climate change (Cohen’s d = 0.06 and 0.10, respectively), as well as worry (Cohen’s d = 0.05). However, it does not directly increase support for public action. The updated message is equally effective but does not provide additional value. Both messages are more effective for audiences with lower message familiarity and higher misperceptions, including those with lower trust in climate scientists and right-leaning ideologies. Overall, scientific consensus messaging is an effective, non-polarizing tool for reducing misperceptions and shifting beliefs and worry across diverse audiences. The study also explores moderators of the effectiveness of these messages, finding that they are more effective for less familiar audiences and those with lower trust in climate scientists. The findings highlight the importance of effective communication strategies to address climate change misperceptions and encourage public action.This study examines the effectiveness of two scientific consensus messages on climate change—both emphasizing the reality of human-caused climate change—and an updated message that also highlights the scientific agreement that climate change is a crisis—across 27 countries. The classic message significantly reduces misperceptions of the scientific consensus (Cohen’s d = 0.47) and slightly increases beliefs in the reality and human causation of climate change (Cohen’s d = 0.06 and 0.10, respectively), as well as worry (Cohen’s d = 0.05). However, it does not directly increase support for public action. The updated message is equally effective but does not provide additional value. Both messages are more effective for audiences with lower message familiarity and higher misperceptions, including those with lower trust in climate scientists and right-leaning ideologies. Overall, scientific consensus messaging is an effective, non-polarizing tool for reducing misperceptions and shifting beliefs and worry across diverse audiences. The study also explores moderators of the effectiveness of these messages, finding that they are more effective for less familiar audiences and those with lower trust in climate scientists. The findings highlight the importance of effective communication strategies to address climate change misperceptions and encourage public action.