The fourth Global Environment Outlook – environment for development ( GEO-4 ) places sustainable development at the core of the assessment, particularly on issues dealing with intra- and intergenerational equity. The analyses include the need and usefulness of valuation of environmental goods and services, and the role of such services in enhancing development and human well-being, and minimizing human vulnerability to environmental change. The GEO-4 temporal baseline is 1987, the year in which the World Commission on Environment and Development (WCED) published its seminal report, Our Common Future . The Brundtland Commission was established in 1983, under UN General Assembly resolution 38/161 to look at critical environment and development challenges. It was established at a time of an unprecedented rise in pressures on the global environment, and when grave predictions about the human future were becoming commonplace.