The 1992 Earth Summit in Rio de Janeiro in 1992 was a historical event by any measure. Three major international conventions were ratified. The Rio Principles of Sustainable Development were affirmed and a global plan of action - Agenda 21 - was agreed. 20 years after the 1992 Earth Summit, the United Nations Conference on Sustainable Development (also known as Rio+20) will go back to Rio de Janeiro in Brazil and will aim at renewed political commitment for the next phase of Sustainable Development. The total participation including heads of states, government officials around the world and civil society representatives, is expected to exceed 20,000 people.