Impact of the 2050 carbon-neutral emission scenario on air quality in South Korea

The 2050 Carbon Neutrality Scenario (CNS) in South Korea was developed based on greenhouse gas (GHG) emission reductions and air pollution (AP) control policies. This study evaluated its potential impact on air quality in South Korea in 2050. Implementation of cost-effective and GHG-compatible AP control policies under the 2050 CNS led to projected decreases in emissions of sulfur dioxide (SO₂), oxides of nitrogen (NO_x), fine particulate matter (PM_2.5), and ammonia (NH₃) in South Korea by 56 %, 74 %, 40 %, and 27 %, respectively, relative to 2019 levels. For China and Japan, all emissions except NH₃ were projected to decrease by 50-93 % and 37-67 %, respectively. Two contrasting AP emission scenarios were developed, coupled with IPCC Shared Socioeconomic Pathways (SSP) climate scenarios for Northeast Asia: (1) no additional control measures for energy production and AP + SSP5-85 (SSP585NMC) and (2) carbon neutrality achieved by 2050 based on a GHG-compatible AP control policy + SSP1-62 (SSP162ZERO). AP modeling through 2050 was conducted using a climate-chemistry model. By 2050, the 2050 CNS is expected to significantly reduce major air pollutants, contributing to improved air quality. However, ozone (O₃) levels exhibit complex responses under SSP585NMC, with seasonal variations leading to potential increase due to rising temperatures driven by high levels of volatile organic compounds (VOCs). This suggests that while GHG-compatible policies effectively reduce primary pollutants, a mid-to long-term strategy integrating GHS and VOC controls will be crucial to achieving sustainable air quality goals under carbon neutrality.