A landmark climate change agreement has made history at the COP21 Paris climate conference when 200 nations rich and poor signed on to reduce global carbon pollution. This agreement will not solve global warming but scientist say it can cut global green house gas emissiions by half necessary to decrease atmospheric temperatures. What seemed to help was an aggreement in November 2014 between US and China to cut greenhouse gas emissions. That agreement helped pave the way for the current deal agreed in Paris yessterday, when nations all over the world signed on to similar plans.