The uncertain and interrelated nature of urgent societal issues makes the theory and practice of the field of science communication more important and relevant than ever. At the same time, supporting constructive dialogue and exchange between different types of knowledge and expertise while maintaining trust is challenging – especially in an era of misinformation and polarisation. This policy brief summarises the outcomes from a series of individual interviews and topic-based workshops that investigated how science communication can contribute to navigating complex, urgent societal issues in four topic areas: 1) Climate emergency, 2) Water, oceans and soils, 3) Health & vaccines, and 4) Artificial intelligence & digital transformation. This policy brief is the first in a series of three documents. In this first release, we untangle the conflicts and controversies in wicked problems, by exploring the perspectives of different stakeholders involved in urgent societal issues in the four topic areas. Ultimately, we explore the question “what is effective science communication for urgent societal issues?” Together with multiple-field experts, we set an agenda to support the field of science communication in reaching its full potential as a mediator in science-society and science-policy interactions, as well as public discussions on science, which can strengthen the future of European democracies.