Carbon dioxide (CO2) is a major contributor to the human-induced greenhouse effect and, thus, to global warming. Locating, quantifying, and limiting its emission sources is of paramount importance in mitigating the effects of climate change. In this study, the Weather Research and Forecasting Model (WRF v4.2) with the GreenHouse Gas (GHG) chemical scheme coupled with the CarbonTracker Data Assimilation Shell (CTDAS) is used to improve the estimates of anthropogenic CO2 emissions over Greece. As a starting point for this study, the Copernicus Atmosphere Monitoring Service (CAMS) emissions database for the anthropogenic CO2 emissions was used for the simulations. Both in-situ measurements from the regional background station of Finokalia, Crete, and the urban background station of Thissio in Athens are assimilated in the WRF-GHG-CTDAS modeling framework. First results show that the CAMS database underestimates the total anthropogenic emissions over Greece by 35%, with the highest underestimation in regions with high industrial activity, such as Ptolemaida, Megalopolis, and Athens.