Climate interventions must be tailored to actions and audiences: A 60-country global megastudy Kimberly Doell, University of Vienna Mitigating climate change requires global systemic changes and personal action. The literature in the behavioural sciences has proposed and evaluated numerous interventions based on psychological theory aiming to increase individual and collective climate action. However, given the different methods used, and samples tested, it is unclear which approach is more effective at promoting sustainable behaviour, and in what context. To overcome this challenge, we have collaborated with over 250 scholars to design and deploy a megastudy which tests 11 interventions (against a control), on the same four sustainability-related outcome variables in 60 countries. We showed that interventions were differently effective for each outcome and that efficacy depended on baseline levels of belief in climate change. For example, negative emotion induction was the top intervention for stimulating a climate change-relevant post on social media, but it backfired, reducing more effortful tree-planting behaviours, Furthermore, in climate sceptics, the same negative emotion induction decreased support for climate change mitigating policies. Together, these findings suggest that effective interventions must be tailored to audience characteristics and target behaviours. ON SITE & Join Zoom Meeting https://unige.zoom.us/j/62304433455?pwd=ME9HSUtVZm1BMEFmekpZbDI2eEt3Zz09 Meeting ID: 623 0443 3455 Passcode: 855563