Since joining the Ministry in 1992, Mr. Nakao has been involved in a wide range of environmental issues over the past 30 years, including climate change, waste management and circular economy, environmental impact assessment, nature conservation, public relations, human resources, Fukushima reconstruction, and environmental health. In the area of climate change, he has engaged in the Kyoto Protocol negotiations(1996-1997), Japan-U.S. bilateral consultation on climate change and other environmental issues as the Environmental Attaché at the Embassy of Japan in the United States (2000-2004), the whole of government planning and coordination such as Japan's NDC while on secondment to the Cabinet Secretariat (2014-2016). Until recently, he was appointed to the Institute for Global Environmental Strategies (IGES), an environmental think tank, where he advised to the Secretariat of Japan Climate Leaders Partnership(JCLP)(2023-2024).