Activists demonstrate during a protest against the United Nations Climate Change Conference in Cancun, Mexico, Dec. 5 , 2010. According to the UN weather agency, 2010 is "almost certain" to rank among the three hottest years on record, and the 2001-2010 decade is undoubtedly the warmest period since the beginning of weather records in 1850. [Xinhua]

 An activist demonstrates during a protest against the United Nations Climate Change Conference in Cancun, Mexico, Dec. 5 , 2010. According to the UN weather agency, 2010 is "almost certain" to rank among the three hottest years on record, and the 2001-2010 decade is undoubtedly the warmest period since the beginning of weather records in 1850. [Xinhua]