Climate change in Japan 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
Honshu Honshu experiences frequent earthquakes (the Great Kantō earthquake heavily damaged Tokyo in September 1923, and the earthquake of March 2011 moved the northeastern part of the island by varying amounts of as much as while causing devastating tsunamis). The highest peak is the active volcano Mount Fuji at , which makes Honshu the world's 7th highest island. There are many rivers, including the Shinano River, Japan's longest. The Japanese Alps run the length of Honshu, dividing the northwestern (Sea of Japan) shore from the southeastern (Pacific or Inland Sea) shore; the climate is generally humid subtropical in the southern and