The 15th United Nations Climate Change Conference (COP15) opens at Bella Center in Copenhagen, capital of Demark, December 7, 2009. [Xinhua]

People walk past a mosaic wall warning the climate change at Bella Center in Copenhagen, capital of Denmark, December 7, 2009. The 15th United Nations Climate Change Conference (COP15) opens at Bella Center on December 7, and it will last to 18th. [Xinhua]