Members of the association ‘Agir pour l ‘Environnement’ (Act For Environment) participate in a symbolic ‘Sale of Earth Planet’ auction in Paris, as part of a demonstration on the sidelines of the UN conference in Rio, Brazil, which marks the 20th anniversary of the Earth Summit – a landmark 1992 gathering that opened the debate on the future of the planet and its resources. The conference in Rio is the largest ever organised, with some 50,000 delegates.