Carolina Schmidt, chairwoman of the COP25 and the environment minister of Chile, addresses the closing plenary of the UN Climate Change Conference (COP25) in Madrid, Spain, Dec. 15, 2019. The UN Climate Change Conference (COP25) came to an end on Sunday after an unprecedentedly long extension, as negotiators failed to reach an agreement on Article 6 of 2015 Paris Agreement about the details of carbon market mechanisms. (Xinhua/Lu Yang)