Pressenza Pressenza International Press Agency Copenhagen, 07/12/09 Over the next two weeks, 100 world leaders are expected to attend the UN conference that has been described by some scientists as the most important the world has ever seen. We play highlights from the opening ceremony with the mayor of Copenhagen, Ritt Bjerregaard; Rajendra Pachauri, the chair of the Intergovernmental Panel on Climate Change; and Yvo de Boer, the executive secretary of the UN Framework Convention on Climate Change, speaking on Sunday.

While protests are expected to start later this week in Copenhagen, tens of thousands of people marched throughout Europe on Saturday calling on world leaders to reach an agreement to reduce emissions in Copenhagen. Protesters took to the streets in Belfast, Glasgow, Paris, Brussels, Berlin and London. The largest protest was in London, where organizers of the Stop Climate Chaos protest put the crowd total at 50,000. Participants in the march included Britain Climate and Energy Secretary Ed Miliband, actor Peter Capaldi and former BBC weather presenter Michael Fish.