The Impacts of Climate Change and Climate Policies in Japan

We synthesize scientific evidence on climate change with an emphasis on observational and statistical evidence rather than climate model simulations. Avoiding duplication with the U.S. Climate Working Group (CWG) report,, we focus on Japan-specific aspects. We find no evidence from Japan that contradicts the CWG report. Observations and statistics for Japan do not show any long-term increase in the intensity or frequency of natural disasters. Although the Government of Japan plans to invest hundreds of trillions of yen to achieve net‑zero emissions by 2050, the expected reduction in global mean temperature would be at most 0.006 °C, and the reduction in heavy rainfall intensity would be at most 0.04%. Overall, Japan’s net‑zero policy does not appear to pass a cost–benefit test.