The global assessment (GA) of biodiversity & ecosystem services of the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) is critically assessing (2016-2019) the state of knowledge on past, present & possible future trends in biodiversity and ecosystem and their inter-linkages at the global level. The GA includes land, inland waters, coastal zones & oceans and is timed to assess the current (2011-20) and inform the next generation (2020-30) of global biodiversity goals, and to provide an initial assessment of a relevant set of the Sustainable Development Goals (SDGs). The GA is intended to be scientific-based, policy relevant, but also inclusive of different knowledge systems and values. To do so, it follows a conceptual framework (Diaz et al 2015 in Current Opinions in Environmental Sustainability) that takes into account different knowledge systems and perspectives to nature, nature’s contribution to people, and quality of life. Authors from over 60 countries, representing the natural and social sciences, and to a lesser extent the humanities, are jointly carrying out the global assessment with support from an international team of reviewers and four technical supporting units. The presentation will provide a brief overview of the evolution of global assessments and the opportunity to bring to fore a comprehensive analysis of global environment change and its implications to different sectors of society. It will discuss the challenges of considering different knowledge systems and diverse values about nature at a global scale, and the strategy developed to advance the inclusion of knowledge and issues of concern to indigenous people and local communities.