Agenda 21 is a non-binding action plan of the United Nations with regards to sustainable development. It was adopted by 178 governments at the United Nations Conference on Environment and Development (UNCED) held in Rio de Janeiro, Brazil, in 1992. The purpose of Agenda 21 is to promote sustainable development globally by addressing social, economic, and environmental issues.

Principles of Agenda 21:
1. Integration of Environment and Development:
- This principle emphasizes the importance of integrating environmental considerations into all aspects of development planning and decision-making. It recognizes that environmental protection and sustainable development are interconnected and that both must be addressed simultaneously.
- By integrating environmental and development goals, Agenda 21 aims to ensure that economic growth is sustainable in the long term, without compromising the ability of future generations to meet their own needs.
2. Public Participation:
- Agenda 21 emphasizes the importance of involving all stakeholders, including government, civil society, and the private sector, in the decision-making process. It recognizes that sustainable development requires the active participation of all members of society.
- Public participation ensures that the interests and concerns of all stakeholders are taken into account when developing policies and programs related to sustainable development. It also promotes transparency and accountability in the decision-making process.
In conclusion, Agenda 21 is a comprehensive action plan that promotes sustainable development by integrating environmental and development goals and emphasizing public participation in decision-making processes. By following the principles outlined in Agenda 21, countries can work towards achieving a more sustainable and equitable future for all.