The estimation of urban air quality change in South Korea under the carbon net-zero scenario

This study analyzed the potential impact of a carbon net-zero scenario on the atmosphere in the Republic of Korea, specifically relating to the changes in the surface ozone (O3) concentration, aerosol composition, pH, and water content. The energy transition causes changes in the use of fossil fuels and the composition and concentration of air pollutants form anthropogenic sources. Here, we found that O3 may increase even if nitrogen dioxide decreases, due to nonlinearity of O3 chemistry. We estimate that the O3 concentration in Korea will change from-18% to 36% in 16 cities and provinces if NOx emissions are reduced by 90%. Additionally, owing to the energy transition under the carbon net-zero scenario in Korea, we deem that the excessive concentration of ammonia will intensify. Furthermore, using the thermodynamic equilibrium model, Simulating Composition of Atmospheric Particles at Equilibrium (SCAPE) II, we estimate an increase in concentration of gas-phase ammonia, in the pH of aerosols, and a decrease in water concentration of aerosols as the concentrations of nitrate and sulfate decrease. Intensive research and proper management strategies for air quality at the district level should be developed to address this issue.