Global scenarios of air pollutant emissions from road transport through to 2050.

This paper presents global scenarios of sulphur dioxide (SO(2)), nitrogen oxides (NO(x)), and particulate matter (PM) emissions from road transport through to 2050, taking into account the potential impacts of: (1) the timing of air pollutant emission regulation implementation in developing countries; (2) global CO(2) mitigation policy implementation; and (3) vehicle cost assumptions, on study results. This is done by using a global energy system model treating the transport sector in detail. The major conclusions are the following. First, as long as non-developed countries adopt the same vehicle emission standards as in developed countries within a 30-year lag, global emissions of SO(2), NO(x), and PM from road vehicles decrease substantially over time. Second, light-duty vehicles and heavy-duty trucks make a large and increasing contribution to future global emissions of SO(2), NO(x), and PM from road vehicles. Third, the timing of air pollutant emission regulation implementation in developing countries has a large impact on future global emissions of SO(2), NO(x), and PM from road vehicles, whereas there is a possibility that global CO(2) mitigation policy implementation has a comparatively small impact on them.