We agree with Esther Turnhout and colleagues (Nature 488, 454–455; 2012) that the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) should take citizen knowledge and non-monetary values into account to improve the science-policy interface for biodiversity protection. Even so, knowledge used to inform policy must be produced through an objective process if it is to withstand scrutiny. This demands a science-based approach.

Science sets a standard for data quality, not for who collects the data. It provides a common currency for understanding the consequences for biodiversity of actions arising from the values of different stakeholders, including local communities, hunter-gatherers, commercial exploiters and conservationists.

The role of IPBES in policy formulation means that it will inevitably meet resistance that will seek to undermine data credibility, the assessment process and the platform itself. Instead of avoidance strategies, we need mechanisms for successful negotiation of such controversies to support transformation.