From the very beginning of the first Earth Summit in 1992, people realized that sustainable development could not be achieved by governments alone. It would require the active participation of all sectors of society and all types of people - consumers, workers, business persons, farmers, students, teachers, researchers, activists, indigenous communities, and other communities of interest.
Agenda 21 formalized nine of these as the overarching categories through which all citizens could participate in the UN activities on achieving sustainable development. These are officially called "Major Groups". These include: women, children and youth, indigenous groups, non-governmental organizations, local authorities, workers and trade unions, business and industry, the scientific and technological community and farmers.
The Rio + 20 outcome document notes the importance of engaging the Major Groups at all levels.