Designing an Atmospheric Monitoring Network to Verify National CO2 Emissions

To achieve net-zero carbon emissions by 2050, it is vital to prioritize climate action and monitor the progress of policies with accurate emission estimates. As CO₂ emission estimates can be independently verified using atmospheric CO₂ measurements, the need for optimal CO₂ monitoring networks has increased. This study proposed an experimental method for designing national-scale atmospheric CO₂ monitoring networks. We used gridded data for fossil fuel CO₂ emissions, facilitating the selection of emission grids as potential monitoring sites. First, we determined the appropriate number of CO₂ monitoring sites, which increased in proportion to the magnitude and variability of CO₂ emissions within the region. Subsequently, the emission grids corresponding to the region were arranged in descending order of emissions. Grids were then selected at regular intervals as potential monitoring sites, aligning with the predetermined number of sites. This selection process ensured that monitoring sites were evenly distributed, ranging from areas with high emissions to those with lower emissions. Lastly, as a verification step to assess the suitability of this potential network, a transport model simulating meteorological conditions was employed to evaluate its coverage to detect the influence of CO₂ emissions. This method was applied to South Korea, and 96 candidate monitoring sites were created. The optimal CO₂ monitoring network distributed evenly across South Korea could evaluate variations in CO₂ emissions. The simple monitoring network design method proposed in this study can accelerate the installation of a national CO₂ monitoring network, ultimately enabling the verification of CO₂ emissions and supporting climate policies.