Addressing climate change with behavioral science: A global intervention tournament in 63 countries.

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions' effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior-several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people's initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors.

The impact of anxiety and intolerance of uncertainty on climate change distress, policy support, and pro-environmental behaviour.

OBJECTIVES: As the threat of climate change continues to grow, bolstering individual-level support for climate change initiatives is crucial. More research is needed to better understand how individual difference factors, such as climate change anxiety and intolerance of uncertainty (IU), may shape how people perceive climate change and respond to climate change messaging. To date, the majority of published studies have not taken these individual difference factors into consideration, and IU has been particularly neglected in the climate change literature. This study examined the independent effects of climate change anxiety and IU on three climate change-related outcomes: climate-related distress, support for climate change policies, and behavioural engagement. METHODS: Participants were Florida residents (N = 441) who completed an online survey, including measures of climate change anxiety and IU. Participants then watched a video describing climate change consequences and completed three outcome measures: post-video distress, climate change policy support, and behavioural engagement. RESULTS: Controlling for demographic covariates, both climate change anxiety (ß = .43, p < .001) and IU (ß = .27, p < .001) were associated with greater post-video distress, but only IU independently predicted greater policy support (ß = .10, p = .034) and behavioural engagement (ß = .12, p = .017). CONCLUSIONS: Our findings suggest that IU may be an important factor in promoting pro-environmental behaviour and policy support, but climate change anxiety may increase emotional distress without boosting meaningful behaviours or support. Our findings highlight the potential influence of cognitive factors on climate change engagement and suggest that invoking uncertainty rather than anxiety may be more effective in catalysing effective environmental engagement.