HARDtalk - Kumi Naidoo, Executive Director, Greenpeace International

Following the failure of the Copenhagen Climate Change talks, why do some environmentalists still believe they can limit the effects of global warming? Kumi Naidoo is the new Executive Director of Greenpeace International. After putting so much emphasis on its climate campaign, is it time for Greenpeace to ask whether it is a task which is beyond them? Kumi Naidoo talks to Stephen Sackur.