Gallery: Rio+20 Conference

Activists march in protest during the United Nations Conference on Sustainable Development, or Rio+20, in Rio de Janeiro, Brazil. Photo: AP

Activists march in protest during the United Nations Conference on Sustainable Development, or Rio+20, in Rio de Janeiro, Brazil. Photo: AP

Activists march holding a banner that reads in Portuguese "Reverse Rio+20. Dilma, with what face will you arrive?" during the United Nations Conference on Sustainable Development, or Rio+20, in Rio de Janeiro. Photo: AP

People protest beside a table set with empty plates and national flags as they hold signs that read from right to left in Portuguese; "Shame, hunger" at the Copacabana beach during the UN Conference on Sustainable Development, or Rio+20, in Rio de Janeiro. Photo: AP

A Brazilian scientist demonstrates against the lack of funding for environmental science on the sidelines of the Rio+20, or UN Conference on Sustainable Development in Rio de Janeiro. Photo: AP

In this photo released by Amazon Watch, hundreds of people make a human banner that reads in Portuguese 'Rivers for life' on Flamengo beach on the sidelines of the Rio+20, or UN Conference on Sustainable Development in Rio de Janeiro. Photo: AP

People make a human banner that spells out in Portuguese 'Rivers for life' on Flamengo beach, organized by Amazon Watch, on the sidelines of the Rio+20, or UN Conference on Sustainable Development in Rio de Janeiro. Photo: AP

Pataxo Indians shout slogans against the construction of the Belo Monte hydroelectric plant in the Amazon, on the sidelines of the Rio+20, or the UN Conference on Sustainable Development, in Rio de Janeiro. Photo: AP

A worker carries crates past a fake life-sized war tank covered with bread sitting on display in the Santa Marta slum as part of a "Bread not Bombs" protest on the sidelines of the Rio+20 UN Conference on Sustainable Development in Rio de Janeiro. Photo: AP

A fake life-sized war tank covered by bread sits on display in the Santa Marta slum as part of a "Bread not Bombs" protest on the sidelines of the Rio+20 UN Conference on Sustainable Development in Rio de Janeiro. Photo: AP

Artist and activist Holger Gussefeld holds up a broken gun next to a fake war-tank covered with bread in the Santa Marta slum as part of a "Bread not Bombs" protest on the sidelines of the Rio+20 UN Conference on Sustainable Development in Rio de Janeiro. Photo: AP