A roadmap towards a low-carbon society in Japan using backcasting methodology: Feasible pathways for achieving an 80% reduction in CO2 emissions by 2050

The purpose of the study is to analyze feasibility and a roadmap of a low-carbon society in Japan by 2050, while satisfying required demands. Future technology roadmaps, CO2 emission pathways and energy mix transitions leading Japan are calculated using the AIM/Backcasting Model based on backcasting methodology with taking into consideration that one of the keys for technological market penetration is the preferences of consumers. Under the CO2 emission target of 80% reduction as compared to 1990 level by 2050, it is found from the results that the target is feasible in Japan by implementing actions toward low-carbon society as early as possible. From the perspective of minimizing the total costs, it would be best to target a reduction rate of 16–20% in 2020, 31–35% in 2030 and 53–56% in 2040 within the range of Scenarios A and B. During this process, major investment will be needed in the early stage of the analytical periods, especially in the residential, commercial and transport sectors. However, viewed in the long term, this can be recovered by reduction in energy consumption. Moreover, the analysis suggests that returns that balance the total investment may be possible.