Scenario analyses of Japan's energy systems toward net-zero emissions by 2050 and the Japanese Government's 7th Strategic Energy Plan

In 2020, the Government of Japan declared its commitment to net-zero emissions by 2050, subsequently submitting as its nationally determined contribution (NDC) a 46 % reduction in emissions by 2030 relative to 2013 levels. In February 2025, the government announced NDCs of 60 % and 73 % reductions by 2035 and 2040, respectively, which are in line with linear reductions to net-zero by 2050. At the same time, the government published its 7th Strategic Energy Plan and provided the outlook for 2040 energy supply and demand meeting the emissions reduction target. This study conducts scenario analyses using the global energy models, DNE21+ and DEARS, that served as the basis for the outlook as determined by the government. The scenario analyses focus on the price of energy in Japan relative to prices overseas due to the current status of Japan's CO 2 emissions and changes in its industrial structure. The reductions in GDP and steel productions under a low growth scenario which assume conservative technology improvements are 13 % and 41 %, respectively, for achieving the 73 % reduction in emissions. A risk-hedge scenario will achieve emissions reductions of 61 % by 2040 and 79 % by 2050 without such large economic damages. Scenario developments and their implications for energy and emissions reduction policies, i.e., the 7th strategic energy plan, are discussed. • Energy scenarios for 2040 and 2050 in Japan developed using energy systems models. • Development of a risk-hedge scenario responding to multiple uncertainties. • Importance of keeping relative prices of energy in the strategy of Japan. • Japanese energy plan focusing on net-zero measures and the risk-hedging strategy.