Climate change in Japan
The Intergovernmental Panel on Climate Change (IPCC) proposes two hypothetical future scenarios. One is Scenario "A1B" based on the assumption that a future world will have more global economic growth (the concentration of carbon dioxide will be 720ppm in 2100). The other is Scenario "B1" based on the assumption that a future world will have global green economy (the concentration of carbon dioxide will be 550ppm in 2100).
Earth Simulator calculations, reveal the daily increase in mean temperature in Japan during the period of 2071 to 2100. The temperature has increased by 3.0 °C in Scenario B1 and 4.2 °C in A1B compared to that of 1971 to 2000. Similarly, the daily maximum temperature in Japan increased by 3.1 °C in B1 and 4.4 °C in A1B. The precipitation in summer in Japan increased steadily due to global warming (the annual average precipitation increased by 17% in Scenario B1 and by 19% in Scenario A1B during the period of 2071 to 2100 compared to that of 1971 to 2000).
Currently, Japan is a world leader in the development of new climate-friendly technologies. Honda and Toyota hybrid electric vehicles were named to have the highest fuel efficiency and lowest emissions. The fuel economy and emissions decrease is due to the advanced technology in hybrid systems, biofuels, use of lighter weight material and better engineering.
As a signatory of the Kyoto Protocol, and host of the 1997 conference which created it, Japan is under treaty obligations to reduce its carbon dioxide emissions and to take other steps related to curbing climate change. The Cool Biz campaign introduced under former Prime Minister Junichiro Koizumi was targeted at reducing energy use through the reduction of air conditioning use in government offices.
Japan's capital Tokyo is preparing to force industry to make big cuts in greenhouse gases, taking the lead in a country struggling to meet its Kyoto Protocol obligations. Tokyo's outspoken governor, Shintaro Ishihara, decided to go it alone and create Japan's first emissions cap system, reducing greenhouse gas emission by a total of 25 percent by 2020 from the 2000 level.
On June 25, 2008, Tokyo Metropolitan Assembly approved bylaw for reduction program of CO2 emission start from 2010. Approx. 1,300 large offices and factories in Tokyo that consume electric power equivalent to 1,500 kilo-litre of crude oil annually must reduce CO2 emission 15-20% of average volume in last three years before this bylaw. Even with emissions trading or cap and trade but targeting reduction not is achieved by 2020, the penalty up to JPY 500,000 shall be charged. This penalty chargeable regulation is first one in Japan.
Kyoto Protocol Target Achievement Plan
Japan created the Kyoto Protocol Target Achievement Plan to lay out the necessary measures required to meet their 6% reduction commitment under the Kyoto Protocol. It was first established as an outcome of the evaluation of the Climate Change Policy Program carried out in 2004.
The main branches of the plan are ensuring the pursuit of environment and economy, promoting of technology, raising public awareness, utilizing of policy measures, and ensuring international collaboration 
- The latest global warming projection by using the Earth Simulator has been completed, Center for Climate System Research, University of Tokyo
- "EU JAPAN relations in the field of environment". European Commission. Retrieved 2008-10-03.
- Automaker Rankings 2007: The Environmental Performance of Car Companies, Union of Concerned Scientists, 10/15/07.
- World Business Council for Sustainable Development (WBCSD)
- “Gist of the Kyoto Protocol Target Achievement Plan.” United Nations Framework Convention on Climate Change. http://unfccc.int/files/meetings/seminar/application/pdf/sem_sup1_japan.pdf