Climate change is currently one of humanity’s greatest threats. To help scholars understand the psychology of climate change, we utilized an online survey approach to collect relevant data from 59,508 participants in 63 different countries (collected between July 2022 and July 2023). We tested 11 behaviour-change interventions designed to promote different facets of climate change mitigation across four outcomes: climate change belief, support for climate policies, willingness to share information on social media, and an effortful tree-planting behavioural task. We also measured participants’ demographic information (e.g., age, gender) and other independent variables (e.g., political orientation, perceptions about the scientific consensus). Additionally, in the control group, we also measured multiple other important independent variables such as environmentalist identity, pluralistic ignorance, and trust in climate science. We report both the raw and cleaned data, along with all survey materials, relevant analysis scripts, and data visualisations. This dataset can be used to answer a large number of relevant questions about the psychology behind climate change.