A man performs to appeal people to combat climate change in central Copenhagen Dec. 7, 2009. The United Nations Climate Change Conference 2009, also known as COP15, kicked off at the Bella center in Copenhagen on Monday. Varaious activities were held by the participants in and outside the conference center appealing people to combat global warming and climate change. More than 100 world leaders are to attend the conference in Copenhagen.[Xu Suhui/Xinhua]