Comparison of High-Resolution Gridded Emission Maps of Anthropogenic Carbon Dioxide in Europe: GRACED & CAMS-REG.

Gridded maps of CO2 emissions are increasingly being applied in emission change analyses and atmospheric studies. In this study, we compared two high-resolution gridded estimates of anthropogenic CO2 emissions in Europe for 2019-2021: the near-real-time Global gridded daily CO2 emission data set (GRACED, latest updated version May 2024) and the Copernicus Atmosphere Monitoring Service regional inventory (CAMS-REG, v6 for 2019-2020, and v7 for 2021). Total CO2 emissions of the two data sets are comparable, with a 2.4% emission difference, and the total emissions' spatial determination coefficient (R) at 0.1° is 0.66 in 2021. However, the sectoral emissions and spatial patterns show significant differences. At the grid level, the absolute value of the median of relative percent difference (RPD) of power, ground transportation, and shipping across the domain all reach 200%. CAMS-REG is recommended for fine-scale historical emission analysis in Europe due to its higher spatial resolution and the use of localized data sets. GRACED, with a maximum latency of 3 months, is more appropriate for applications requiring near-real-time data. This work characterizing the difference between two state-of-the-art emission maps is also valuable for atmospheric modelers who need to account for the uncertainty of a priori fossil fuel emissions when performing inverse calculations of land and ocean CO2 sinks.