It has been recognized worldwide that the utilization of an enormous amount of fossil fuel has created various adverse effects on the environment, including acid rain and global warming. An increase in average global temperatures of approximately 0.56 K has been measured over the past century. This increase is called global climate change or global warming. The gases with three or more atoms that have higher heat capacities than those of O 2 and N 2 cause the greenhouse effect. Carbon dioxide (CO 2 ) is a main greenhouse gas associated with global climate change. Nitrous oxide (N 2 O), chlorofluorocarbons (CFCs), methane (CH 4 ) are other important greenhouse gases. Collectively, they are projected to contribute, directly, about as much potential global warming over the next 60 years as CO 2 . Three trace gases, HFCs, PFCs, and SF6, would be regulated under the 1997 Kyoto Protocol because of their global warming potential and for their potential growth of concentrations in the atmosphere. HFCs have been widely approved as substitutes for CFCs.