Various problems relating to energy and the environment clearly exist, such as global warming and a steep rise in the price fossil fuels, and resources. These problems should be addressed in the medium term or long run. As for the abatement of greenhouse gas emission, active discussions have been held on the stage of world politics to achieve the long-term goal. Although various approaches have been proposed by several research institutions and countries, sufficient studies have not yet been conducted on the roles of individual countries and sectors. Specifically, in the automotive transportation sector wherein oil demand and CO2 emissions are estimated to rise in the future with the marked progress of motorization in developing countries, it is increasingly important to study these subjects. We focused on the automotive transportation sector and studied the CO2 abatement potential and its cost performance in this sector. This article reports the results of the study.