This policy brief is a living document with a set of policy recommendations that will evolve across the series of policy briefs as it integrates the outcomes of COALESCE case clinics on four topics: Climate, Water, oceans and soils, Health, and Artificial Intelligence and Digital Transformation. While the case clinics inform the challenges that are raised in the Evidence and main findings section of each of the policy briefs, the recommendations are intended to be overarching. This policy brief draws together the main conclusions from SwafS-19 projects that pertain to the role of informal science engagement organisations, as well as drawing on the outcomes of the series of COALESCE case clinics carried out with representatives of different organisations, on the topic of public engagement on climate change, as one of the key topics addressed within COALESCE. The COALESCE project aims to create a sustainable European Competence Centre for Science Communication and an associated Science Communication Academy. COALESCE: Coordinated Opportunities for Advanced Leadership and Engagement in Science Communication in Europe. doi: 10.3030/101095230