The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) convenes this month to approve summaries for policymakers of the first assessments at its fourth plenary.

Despite early calls for IPBES to draw on a broader range of disciplines than did the Intergovernmental Panel on Climate Change (see E. Turnhout et al. Nature 488, 454–455; 2012), the social sciences and the humanities remain markedly under-represented. They make up less than 10% of the membership of IPBES expert groups, instead of the recommended 30%. These disciplines should play a bigger part in IPBES assessments and in implementing the first IPBES work programme for 2014–18.

The imbalance mirrors institutional and knowledge barriers between research disciplines. The IPBES Secretariat and its Multidisciplinary Expert Panel need to consult more experts from the social sciences and humanities for nominations for assessments. The panel should encourage these stakeholders to engage in scoping and reviewing activities and to register on IPBES networking sites.

One of the IPBES objectives is to include experts with “balance in the terrestrial and marine natural sciences, social and economic sciences, and arts and humanities”. The secretariat should review the disciplinary balance of all IPBES activities and products, and make the findings publicly available.