ANALYSIS ON NATIONAL LEVEL CO_2 EMISSION REDUCTION SCENARIOS IN MAIN COUNTRIES

摘要

In this paper we review the scenarios whose time horizon are up to and beyond the year 2050, and attempt to clarify their characteristics. Regarding mitigation scenarios in particular, we pay special attention to the targets and their grounds for reductions in CO_2 emissions. We also conduct a quantitative analysis, such as the structure of energy supply and demand, and the factors behind substantial reductions, hi mitigation scenarios, it is assumed that energy intensity and carbon intensity will be improved at a pace three times those of the historical change rates in order to achieve the reduction targets. The combined share of low-carbon technologies such as nuclear and renewables is at least about 30 percent, and CCS technologies tend to be introduced when the CO_2 emission reductions rate from base year surpasses 40 percent. Sector-wise decomposition showed the industrial and the transportation sectors have major contribution of CO_2 emission reduction, and the combined share is about 60 percent.