Unpacking the task of synthesis when weaving knowledge systems for biodiversity assessments

Abstract The pivot towards evidence‐based conservation since 2000 has inspired global environmental assessments to gather evidence across multiple knowledge systems, including through co‐production with Indigenous Peoples and local communities. Knowledge co‐production is highlighted as a strategy for transformative change towards a just future that conserves nature. The multiple evidence base (MEB) approach, one method for co‐production developed alongside the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), identifies five tasks in co‐production (mobilize, translate, negotiate, synthesize, apply) and centres the roles of diverse actors, their knowledge institutions and collaborative processes. The synthesis task is arguably the most challenging, involving knowledge conflicts, incommensurability, tensions between diversity and consensus, political and power dynamics—yet little guidance exists in literature about how to navigate these challenges. Here, we address this knowledge gap with a state‐of‐the‐art literature review of the synthesis task, iterated with reflections among our co‐author team of Indigenous and non‐Indigenous participants in three assessments for IPBES. Our analysis uses the MEB categories of actors, institutions and collaborative processes, with a dissonance theoretical perspective to tackle political dimensions. We synthesize practical steps for IPBES and highlight key areas for action to more broadly stimulate evidence synthesis as a means of transformative change: working with diverse actors to address power dynamics and asymmetries for productive conflict; crafting co‐governance institutions that embed justice and a rights‐based approach together with attention to healing trauma; and encouraging processes that enable productive contestation of ideas using tools such as framing analysis and minority/majority messages. Fostering co‐productive reflexivity and learning across epistemic, normative, cognitive and relational domains underpin the development of the political capabilities to navigate dissent. Promoting leadership by Indigenous and local knowledge actors, strengthening and funding opportunities to practice their knowledge for their own purposes as well as for co‐production and navigating differences in how time is perceived are vital. Science–policy interfaces that seek transformative, rather than incremental, change will always be characterized by the opposing discourses and narratives that underpin the political dynamics of socially just synthesis across knowledge systems. Implementation of our guidance will assist knowledge co‐production efforts to progress transformative change. Read the free Plain Language Summary for this article on the Journal blog.