Stakeholder engagement in the co-production of knowledge for environmental decision-making

•There is growing interest in understanding the dynamics of stakeholder engagement in environmental decision-making.•Dialogue between stakeholders is the most common output from knowledge co-production processes.•Conceptual impacts are the most common and first to emerge impacts from stakeholder engagement in co-production processes.•Better documentation and improved metrics are needed to measure the societal impacts emerging from stakeholder engagement.•Improved communication and facilitation are required to mitigate power imbalances.