text: In this policy analysis, Donn Dears writes that the fear of climate change has led the United Nations and European Union to insist that the United States cut its carbon dioxide (CO2) emissions by 80% so that worldwide emissions can be cut by around 50%, thereby limiting the level of CO2 in the atmosphere to a level some scientists believe will keep climate change in check. Congress is considering a cap & trade program for CO2 emissions rather than carbon taxes for achieving the required 80% reduction. The Presidential candidates all endorse cap & trade as a remedy to combat global warming.