This article assesses Japan's climate change policy to provide insight into the debate on sustainable societies within environmental sociology, which is contested on one side by Ecological Modernization (EM) theory and on the other mainly by political economy perspectives. Overall, this study finds that Japan's commitment to the Kyoto Protocol is unlikely to lead to a greening of the economy and lifestyles. Consistent with the claim made by EM critics, Japan's climate change policy has negative environmental and social ramifications. Japan's attempt to reduce carbon dioxide emissions by switching its primary energy source from fossil fuels to nuclear power is likely to increase the uneven distribution of nuclear risks between rural and urban areas. The promotion of nuclear power to secure increasing energy demand instead of reducing energy consumption has also contributed to a worsening of the urban environmental problem known as urban heat island.