This commentary considers the separate but interconnected evolution of science communication and environmental communication as fields of research and practice, and argues for better mutual understanding between the fields, including an understanding of necessary differences. It notes that the repertoires of science communication and environmental communication overlap but have different emphases. Environmental communication emphasises public allegiances with a view to persuasion; science communication has focussed on public understanding and appreciation of science. The potential and the need for closer cooperation are growing as the authority of science is challenged in political arenas. Both fields recognise the important contributions of science to public sense-making and informed decision-making on major issues. Increasing engagement with the science that underpins environmental issues could benefit environmental communicators. In political contexts, science communication could learn from environmental communication's greater attention to advocacy and symbolic representations. This Commentary offers a view of EC and SC and their relations that draws on the experiences of the authors, all with a foot in both camps. The Commentary is based on a 'practice reflection' paper and panel the authorsall members of the scientific committee of the PCST, the global network for science communicationpresented at the International Environmental Communication Association conference, COCE 2017. Guided by the maxim that "good fences make good neighbours", the panel sought to clarify differences as well as similarities between EC and SC.We note the considerable interest in both EC and SC in looking across the fences between them. Of 108 research articles published in the journal, Science Communication and 237 published in the journal Public Understanding of Science in 2014-17, 30% and 27%, respectively, were on environmental topics; in both journals just over 60% of these papers on environment were on climate change. With little modification, this material could have been published in an environmental communication journal, though the foci may have been somewhat different.A search in Public Understanding of Science, 2014-17, on 'environmental communication' produces mainly passing mentions or bibliographical or biographical references (journal title, publication title or author's declared research interest). Just one use of the phrase is found in a substantive treatment of environmental communication (Sakellari, 2014), referring to Brulle (2010) on 'environmental melodrama'. A search in Environmental Communication, 2014-17, on 'science communication' produces many passing references, but also several (e.g. Suldovsky et al, 2017;Lee et al, 2017;Burke et al, 2016) that deal with science communication in terms of formal study and theoretical reflection.There is an apparent asymmetry in the respective interest in each other's topic-fields, with SC showing more interest in EC's than vice versa, but also asymmetry in the respective ...