The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has issued a call for experts to perform its global assessment (see go.nature.com/g5zc3e). The call, which closes on 5 May, emphasizes the need to nominate more social scientists (see also A. B. M. Vadrot et al. Nature 530, 160; 2016 and K. Reuter et al. Nature 531, 173; 2016).

A strong collective effort is necessary to reach scholars outside the natural sciences, because they might not consider themselves to be biodiversity researchers. To this end, IPBES is reaching out to learned social-science societies (of sociology, economics, geography, anthropology, political science and psychology, among others), to networks of scientists and to prominent interdisciplinary international programmes such as Future Earth.

A special procedure to fill gaps in expertise, including in the social sciences, was adopted at the IPBES fourth plenary (further suggestions to secretariat@ipbes.net are welcome). Success ultimately depends on governments and organizations stepping up to nominate more social scientists.