In the U.S.-China Summit held on 12 November 2014， the U.S. promised to cut emissions by 26~28％ between 2005 and 2025， while China held that Chinese emissions of carbon dioxide would peak by around 2030. China， who has suffered from air pollution， has firmly implemented regulations such as cutting the amount of coal use， expansion of renewable energy， and so forth. The Barack Obama administration in the U.S. started plans to cut greenhouse gas emissions through cutting the amount of coal dust in coal mines， and expansion of facilities for renewable energy within state-owned lands. This agreement between the two countries―who have been passive in term of policies regarding climate change―is expected to have a great influence on the following agreements on climate changes in the world. Therefore existing policies on climate changes and greenhouse gas emissions shall be thoroughly examined to respond to the changes.