Protesters hold a rally near the U.S. Embassy against the ongoing Rio+20 conference on sustainable development taking place in Rio De Janiero, Brazil, on Wednesday, June 20. (AP photo)

Protesters hold a rally near the U.S. Embassy against the ongoing Rio+20 conference on sustainable development taking place in Rio De Janiero (AP photo)

A protester displays a placard during a rally against the ongoing Rio+20 conference on sustainable development, near the U.S. Embassy in Manila (AP photo)

Protesters march towards the U.S. Embassy during a rally against the ongoing Rio+20 conference on sustainable development (AP photo)

Protesters hold placards during a rally against the ongoing Rio+20 conference on sustainable development, in Manila, Philippines (AP photo)

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 (AP photo)

Pataxo Indians shout slogans against the construction of the Belo Monte hydroelectric plant in the Amazon, on the sidelines of the Rio+20 (AP photo)

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 (AP photo)

People participate in a human banner on Flamengo beach, organized by Amazon Watch, on the sidelines of the Rio+20 (AP photo)

A Pataxo Indian waits to participate in the building of a human banner on Flamengo beach, organized by Amazon Watch, on the sidelines of the Rio+20 (AP photo)

In this picture released by Amazon Watch, indigenous people along with small farmers, fisherfolk, and local residents occupy the Belo Monte Dam project during a protest at the Xingu river in the Brazilian state of Para (AP photo)

Activists pretend to cry next to a fake coffin with a sign that reads in Portuguese "National environmental politics" during the United Nations Conference on Sustainable Development, or Rio+20 (AP photo)