Vehicular Emission Inventory and Reduction Scenario Analysis in the Yangtze River Delta, China

Vehicular emissions have become an important source of air pollution, and their effective reduction control is essential to protect the environment. The aim of this study was to establish multi-year vehicular emission inventories for ten important air pollutants and to analyze emission control policy scenarios based on these inventories. The inter-annual emission analysis results showed that the ten pollutant emissions had different change trends during the past decade. The emissions of CO, non-methane volatile organic compounds (NMVOC_S), NO_x, PM_2.5, PM₁₀, and CH₄ tended to increase first and then decrease, but the years in which they began to decrease varied; the emissions of CO₂ and NH₃ showed the most significant growth trends, increasing by 567% and 4004% in 2015 compared with 1999, while the emissions of N₂O and SO₂ showed a general increasing trend and decreased obviously in a certain year. Eight scenarios based on emission inventories were designed; compared with the BAU scenario, the ESV scenario was the most effective policy to control NO_x, PM_2.5, and CH₄ emissions; the radical AER scenario could decrease the vehicular emissions of CO, NMVOCs, PM₁₀, CO₂, N₂O, and NH₃; and the RFS scenario could reduce vehicular SO₂ emissions significantly by 93.64%.