Most of the largest carbon dioxide emitting companies in the U.S. are failing to assess, disclose and address the financial risks posed by climate change, according to a new study of 20 of the world's largest companies. Unlike many of their foreign rivals, American industry giants such as ChevronTexaco, ExxonMobil, General Electric, Southern Company and Xcel Energy, continue to pursue business strategies that discount the global warming threat, the report details.