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
Climate change in China now seen as an economic problem as well as an environmental one, and China sees climate change policy as a way to gain international leadership. The government has been a vocal supporter of the Paris Agreement from its 2015 beginnings; in fact, its unwavering loyalty was a major factor in its diplomatic success. Currently, President Xi Jinping has urged countries to continue to support the agreement, even in the wake of the United States' withdrawal in 2017. Nevertheless, China still supports the "common but differentiated responsibilities" principle, which holds that since China is still developing, its abilities and capacities to