Global assessments have to shift the focus from what is happening and what could be done, to how trends and trajectories in development can be changed (well established). The use of top-down and bottom-up methods in Part C of GEO-6-Outlooks and Pathways to a Healthy Planet for Healthy People is intended to provide science-based information for this purpose. The combined quantitative scenarios and participatory approaches also offer great potential to be more responsive to meeting the sector-and region-specific information required by decision makers. Therefore, the GEO-6 outlook analysis/assessment use: (1) model-based scenario analysis (generally referred to as the top-down approach); (2) information and knowledge from past and present initiatives, opportunities and trends (i.e. seeds of change); and (3) information resulting from integrative decision-making and participatory activities that are usually conducted at the local to regional levels (generally referred to as bottomup approaches). This will ensure greater engagement of stakeholders in knowledge development and dissemination, and implementation of resulting policies and practices in a timely manner for greater success {19.2, 19.3}. For environmental assessments to be useful to decision makers, they should account for the interactions, interdependencies and co-evolutionary pathways of human-Earth systems in proposed policy options and scientific and technological solutions-including the direct effects and the co-benefits and/or trade-offs. (established, but incomplete). Global Environmental Assessments generally rely on modelbased quantitative scenarios. While these models capture many important linkages, the social dimension is not very well represented. Moreover, it is difficult in global assessments to capture important details that are pertinent for local-level decision-making. A systemic and integrated approach is needed in scientifically based environmental assessments and future outlooks, in support of policy and investment decisions, to account for the highly complex, interdependent and continuously changing factors in assessing the human-Earth system changes {19.1}. This title is also available as Open Access on Cambridge Core at www.cambridge.org/core "The sixth Global Environment Outlook is an essential checkup for our planet. Like any good medical examination, there is a clear prognosis of what will happen if we continue with business as usual and a set of recommended actions to put things right. GEO-6 details both the perils of delaying action and the opportunities that exist to make sustainable development a reality."-António Guterres, Secretary-General of the United Nations