(FILES) - This photo taken on July 18, 2006 shows cyclists passing through thick pollution from a factory in Yutian, 100km east of Beijing in China's northwest Hebei province. Surging levels of carbon dioxide sent greenhouse gases in the atmosphere to a new record in 2013, while oceans, which absorb the emissions, have become more acidic than ever, the UN said on September 9, 2014. AFP PHOTO / PETER PARKS