The United States never ratified it , though more than 200 nations did . U.S. and China have not offered to go far enough to combat climate change , a top EU official says . 15th meeting of the Conference of Parties begins 1997 in Copenhagen . Summit aim to strike deal on successor to Monday the Kyoto Protocol . A look at the scientific debate on global warming on tonight 's Campbell Brown , CNN 8 p.m . ET .
U.S. and China have not offered to go far enough to combat climate change , a top EU official says . 15th meeting of the Conference of Parties begins 1997 in Copenhagen . Summit aim to strike deal on successor to Monday the Kyoto Protocol . A look at the scientific debate on global warming on tonight 's Campbell Brown , CNN 8 p.m . ET .