To tackle the twenty-first-century challenges for sustainability, a deeper understanding of their complexity is needed. Hence, interdisciplinary human–environment research integrating knowledge, perspectives, and solutions across scales is crucial. Yet, questions of ‘scale’ and ‘scaling’ continue to challenge human–environment research. Despite substantial scholarly attention to scales, no unified definitions and understanding exist, causing confusion among researchers. In this paper, we aim to provide clarity to the challenges and potential solutions to bridging scales in interdisciplinary human–environment research as well as identify leverage points and arenas of change that would enable it. We used a three-step methodology to (a) identify the challenges and solutions based on a survey of 82 interdisciplinary researchers, (b) prioritise the challenges and solutions based on expert elicitation, and (c) organise the solutions according to their potential for leveraging change at three system arenas: individual researchers, institutions and organisations, and the wider academic structures. The main challenges ranged from issues related to differences in research approaches, lack of resources for deeper collaborations, or conflicting perspectives on problem and scale definitions, to miscommunication. The specific solutions linked to these challenges were predominantly related to the potential of improving the research process through open communication, data sharing, or new techniques for upscaling or downscaling results. We argue that bridging scales requires open and humble conversations across disciplines on scale understandings as well as improved collaboration through data sharing, method development, result dissemination, and contribution to theory. Facilitating such collaboration requires enabling spaces of interaction across three systemic arenas: the individual researcher’s personal commitment to open communication and reflection, the research institution’s capacity to enable interdisciplinary spaces, and the wider academic system valuing and supporting interdisciplinary and cross-scale initiatives.