Communicating the scientific consensus on climate change: A preregistered test of the gateway belief model with a one-week time delay

While the scientific community almost unanimously agrees on the reality of anthropogenic climate change, public attitudes and beliefs lag behind. One intervention proposed to close this gap is informing the public of the high level of consensus among climate scientists. This has been incorporated into the gateway belief model, which suggests that consensus messaging increases perceived scientific consensus (PSC), thought to impact belief in human-caused climate change, worry about the issue and support for action. The present study narrowly tested aspects of the gateway belief model, specifically the effects of consensus messaging on PSC and belief in human-caused climate change, using a two-part experimental design. Follow-up measures were taken after one week to see if the effects of consensus messaging were lower after this time delay. Participants were recruited on prolific.co from the United States, with a final sample size of 659. Results showed consensus messaging had a positive effect on PSC and belief in climate change. Results also showed that after one week, consensus messaging effects were smaller. While this study found support for the gateway belief model, high pretest scores may have led to ceiling effects. The finding that consensus messaging effects were lower after one week suggests further exploration is needed on the longevity of consensus messaging. Communicating consensus is a promising intervention and could be expanded to include elements such as education and social consensus, and more understanding is needed on how consensus messaging functions in real-world settings.