Climate change mitigation requires global cooperation, yet understanding the global population's willingness to act remains limited. This research addresses this gap by conducting a globally representative survey to assess the extent of individual willingness to contribute to climate action and how people perceive others' willingness to contribute (WTC). The study draws on behavioral science literature on cooperation, focusing on four key aspects: individual willingness to make costly contributions, approval of pro-climate social norms, demand for political action, and beliefs about others' support. Understanding these factors is crucial because cooperation involves costs and free-rider incentives. The study also examines the role of social norms in promoting cooperative behavior, recognizing that the existence and enforcement of norms influence individual actions through internalization or external pressure. Finally, the study investigates the importance of political action and the psychological mechanism of conditional cooperation, where individual contributions depend on perceived contributions of others. The presence of systematic misperceptions, or "pluralistic ignorance", about others' WTC could significantly hinder effective climate action.

The study draws upon a multidisciplinary literature base, including research on the foundations of cooperation in common goods dilemmas. It cites prior work highlighting the importance of costly contributions, social norms (both injunctive and descriptive), political action, and conditional cooperation in fostering collective action. References are made to studies demonstrating the role of social norms in influencing behavior through internalization (shame and guilt) or enforcement (sanctions and approval). The concept of conditional cooperators, individuals more likely to contribute when they believe others are also contributing, is central. Existing literature on pluralistic ignorance, where individuals underestimate the prevalence of certain beliefs or behaviors within their group, is also reviewed, emphasizing its potential to hinder cooperation. The review also acknowledges previous research on international attitudes towards climate policies and the importance of incorporating behavioral science into climate change mitigation strategies.

The Global Climate Change Survey, administered as part of the Gallup World Poll 2021/2022, collected data from 129,902 individuals across 125 countries, representing 96% of global GHG emissions, GDP, and population. National representativeness was ensured through random sampling (telephone or face-to-face interviews). Willingness to contribute was assessed by asking respondents if they would contribute 1% of their household income monthly to fight global warming. This relative measure accounts for income variations. The 1% figure is within the range of plausible mitigation cost estimates. The WTC measure was validated against incentivized donation and behavioral data in a US subsample, showing a significant positive correlation. Beliefs about others' WTC were elicited by asking respondents to estimate the percentage of others in their country willing to contribute 1%. Approval of pro-climate social norms was assessed by asking if people in their country *should* try to fight global warming, and demand for political action was measured by asking if their national government should do more. Translations were rigorously vetted through a multi-step process to ensure comparability across countries. Gallup's sampling weights were used to adjust for unequal selection probabilities and non-response, ensuring national representativeness. Population-adjusted weights were also created to provide globally representative statistics. The study also notes minor implementation errors in Kyrgyzstan and Mongolia and explains the corrections applied.

The survey revealed substantial global support for climate action. 69% of respondents globally stated they would contribute 1% of their income, with an additional 6% willing to contribute a smaller amount. Support varied across countries (30-93%), but in the vast majority (114 out of 125), more than half were willing to contribute. Widespread approval of pro-climate social norms (86% globally) and demand for intensified political action (89% globally) were also observed. Country-level variation in willingness to contribute 1% showed a negative relationship with GDP per capita (higher GDP, lower willingness) and a positive relationship with average annual temperature (higher temperature, higher willingness). This suggests that countries with lower resilience and higher exposure to climate change impacts show greater willingness to contribute. These patterns persisted even after controlling for continent fixed effects and other factors. A strong positive correlation existed between actual WTC and perceived WTC at both the country and individual levels, supporting the concept of conditional cooperation. However, a significant pluralistic ignorance was observed, with a 26-percentage-point gap between actual (69%) and perceived (43%) global willingness to contribute. This underestimation was prevalent in almost all countries. The size of this perception gap varied, being larger in countries with higher temperatures and smaller in wealthier countries.

The findings highlight the significant global support for climate action, challenging narratives of widespread apathy. The strong endorsement of pro-climate norms and demand for political action suggest a shared global normative judgment on the necessity of climate action. The observed conditional cooperation demonstrates the importance of beliefs about others' actions in shaping individual behavior. The substantial pluralistic ignorance, however, poses a critical challenge. The systematic underestimation of others' WTC could hinder climate action by discouraging individual engagement and reinforcing negative beliefs. The interaction between WTC, social norms, and political support underscores the need for integrated approaches to climate action. Countries with stronger pro-climate norms have enacted more climate-related policies, highlighting the potential for self-reinforcing positive feedback loops.

This study reveals strong, widespread global support for climate action but also significant pluralistic ignorance regarding the extent of this support. Addressing this perception gap through effective communication could substantially boost climate action. Future research should explore the specific communication strategies most effective in overcoming this ignorance and fostering greater cooperation.

While the study's large sample size and global coverage are strengths, several limitations exist. The cross-sectional nature of the data prevents causal inferences. The reliance on self-reported data may introduce biases. Some countries experienced minor implementation errors, though corrections were implemented. The specific measures for assessing climate action may not encompass all relevant aspects of climate behavior. The study's focus on willingness to contribute 1% of income may not fully capture the diverse range of potential contributions.