An activist demonstrates against world's environmental policies in Mexico City, Friday, Dec. 3, 2010. This year is "almost certain" to rank among the three hottest years on record, and 2001-2010 is ... more 
An activist demonstrates against world's environmental policies in Mexico City, Friday, Dec. 3, 2010. This year is "almost certain" to rank among the three hottest years on record, and 2001-2010 is undoubtedly the warmest 10-year period since the beginning of weather records in 1850, the U.N. weather agency said Friday. The sign reads in Spanish "Don't trade with nature." less 
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Associated Press | Photo By Alexandre Meneghini
Fri, Dec 3, 2010 9:21 PM EST