An activist from the Gorilla Organization poses on London's Millenium Bridge

An activist from the Gorilla Organization poses on London's Millenium Bridge

Greenpeace activists collect samples of sediment from Samrong canal

 Greenpeace activists collect samples of sediment from Samrong canal

Members of global rights group Amnesty International celebrate the 16th International Day of the World's Indigenous Peoples

Members of global rights group Amnesty International lead hundreds of other activists wearing colourful masks in a march to celebrate the 16th International Day of the World's Indigenous Peoples, in Manila 

A girl wears a mask during a protest against the air show

A girl wears a mask during a protest against the air show at San Lorenzo beach 

Activists covered in food coloring made

Activists covered in food coloring made to look like oil protest BP's Gulf oil spill in Mexico City 

A Greenpeace activist, with her body covered in fake oil

"Stop Deep Sea Drilling" Greenpeace
A Greenpeace activist, with her body covered in fake oil, takes part in a protest outside the European Commission headquarters in Brussels

Pictures of the Decade : Climate activists Lesley Butler and Rob Bell "sunbathe"

Climate activists Lesley Butler and Rob Bell "sunbathe" on the edge of a frozen fjord in the Norwegian Arctic town of Longyearbyen. Global warming became one of the world's major concerns of the decade amid mounting evidence that human activity is disrupting the climate. By 2007 the Intergovernmental Panel on Climate Change was saying it was "very likely" - at least 90 percent certain -- that humans are to blame for most of the observed warming trend of the past 50 years. It also said that warming of the planet was "unequivocal." Taken on April 25, 2007 by Francois Lenoir