The 8 billion milestone: Risk perceptions of global population growth among UK and US residents

In November 2022, the global human population reached 8 billion and is projected to reach 10 billion by 2060. Theories, models, and evidence indicate that global population growth (GPG) increases the likelihood of many adverse outcomes, such as biodiversity loss, climate change, mass migrations, wars, and resource shortages. A small body of research indicates that many individuals are concerned about the effects of GPG, and these concerns are strongly related to the willingness to engage in mitigative and preventative actions. However, scientific understanding of the factors that influence GPG risk perceptions remains limited. To help address this research gap, we conducted a study of the perceived risk of GPG among UK and US residents (N = 1029) shortly after the "8 billion milestone." Our results confirmed that GPG is perceived as a moderate-to-high risk and these perceptions have a strong positive relationship with the willingness to engage in and support risk management actions. Our participants believed that the worst effects of GPG were yet to come but would largely be geographically and socially remote. Despite their willingness to engage in risk management actions, our participants reported low self-efficacy and that governments (cf. individuals and communities) have the greatest capacity to influence GPG. Risk perceptions were strongly predicted by worldviews and were higher among our UK (cf. US) participants. We also found that the perceived benefits of GPG were low and found no evidence to suggest that risk perceptions were affected by exposure to media coverage of the 8 billion milestone.