Scenario-based CO2 emissions reduction potential and energy use in Republic of Korea’s passenger vehicle fleet

• We estimated CO2 & energy reduction potentials for passenger vehicles in Republic of Korea.
• If CO2 emissions are not strongly regulated until 2020, they are not likely to reduce.
• The maximum reductions are estimated at about 5.4 Mton of CO2 and 1.9 Mtoe of energy in 2020.

This study explores the carbon dioxide (CO2) emissions reduction potential of passenger vehicles in Republic of Korea, by assuming a number of CO2 reduction routes. Historical data pertaining to important factors affecting the CO2 emissions of passenger vehicles, such as the number of registered vehicles, annual mileage, and average CO2 emissions per vehicle, were analyzed to predict the extent by which these factors would change in 2020. The results show that the total CO2 emissions from passenger vehicles in 2015 would be approximately 37.1 Mton, assuming automobile manufacturers will meet the regulations for CO2 emissions reductions for 2015. The CO2 emissions reduction route is determined in accordance with a hypothetical regulation for CO2 emissions reductions in 2020. If the CO2 emissions rates of new passenger vehicles are reduced by 3–7% per year after complying with the 2015 regulation, then total CO2 emissions and required energy would be approximately 36.5–38.6 Mton and 12.9–13.6 Mtoe, respectively. Also, if the current fuel economy competition persists until 2020, the CO2 emissions reductions will follow the plausible reduction route and consequently reach 35.1 Mton CO2 and 12.4 Mtoe energy in 2020. As a result, in order to reduce the total CO2 emissions of passenger vehicles in 2020 (compared with 2015), the value of regulated CO2 emissions in 2020 should be set to less than 103 g/km per passenger vehicle.