UN Climate Change Summit Enters Final Week  Greenpeace demonstrate against climate change with the Four Horsemen of the Apocalypse - Pestilence, War, Famine and Death outside Parliament on December 14, 2009 in Copenhagen, Denmark. Politicians and environmentalists are meeting for the United Nations Climate Change Conference 2009 that runs until December 18. Some of the participating nation&#x27;s leaders will attend the last days of the summit.