Intercomparisons Of Tree Global Bottom Up Anthropogenic Emission Inventories

Air pollution from human activities plays an important role in affecting ambient air quality, climate change and human health. To provide changes in global environmental policies to reduce air pollution, emission inventories are critical as they aide in the understanding of air quality impacts across multiple scales. The state-of-the-science global bottom-up anthropogenic emission inventories are the Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants version 6b (ECLIPSEv6b) for emissions from 1990-2050, Emission Database for Global Atmospheric Research version 5.0 (EDGARv5) for emissions from 1970-2015, and the Community Emissions Data System that was released in April 2021 (CEDS) for emissions from 1750-2019. In this study, we inter-compared the global annual total and spatial variability of air pollutants among these three emission inventories (ECLIPSEv6b, CEDS, and EDGARv5) for the year 2015 for trace gases and aerosols, including black carbon (BC), organic carbon (OC), nitrogen oxides (NOx), ammonia (NH3), sulfur dioxide (SO2), carbon monoxide (CO), and non-methane volatile organic compounds (NMVOCs). We also employed the Community Atmosphere Model with chemistry version 6.0 (CAM6-Chem) within the NCAR Community Earth System Model version 2.1.3 (CESM2) to quantify the atmospheric chemistry and air quality impacts using the ECLIPSEv6b. Global annual total emissions of BC, OC, NOx, NH3, SO2, CO and NMVOCs from CEDS for the year 2015 are 6045, 13869, 122022, 59502, 92148, 566620, 149680 kilo tons/year, respectively. Compared with the emissions from EDGARv5, global annual total BC, OC and NH3 emissions in CEDS for the year 2015 are 18.43%, 18.18%, and 21.13% higher. However, global annual total CO emissions from EDGARv5 are 12.46% higher than that from CEDS. For NOx, SO2, and NMVOCs, values from CEDS and EDGARv5 are quite close, with 3.72%, 5.21%, and 0.56% differences between CEDS and EDGARv5. For ECLIPSEv6b, global annual total emissions of BC, OC, NOx, NH3, SO2, CO and NMVOCs in 2015 are 6352, 13763, 124895, 60986, 73335, 548381, 112031 kt/year, respectively. Global annual total of BC, NOx, and NH3 from ECLIPSEv6b are 5.07%, 2.30% and 2.49% higher than the values from CEDS, whereas global annual total of OC, SO2, CO and NMVOCs are 0.77%, 20.42%, 3.22% and 25.15% smaller than that from CEDS. Major sources of CEDS emissions come from eastern Asia and parts of India. A majority of NOx emissions for ECLIPSEv6b is concentrated in Asia, North America (East Coast US, Midwest US, and Mexico), South America (Brazil), and western Europe. We find that global mean summertime model simulated surface BC, primary organic matter (POM) and ozone concentrations in response to ECLIPSEv6b are 0.05 1̐Ưg/m3, 0.52 1̐Ưg/m3 and 21.3 ppb, respectively. For summertime surface BC, large impacts are found in Asia, North America, eastern Europe and southern Africa, whereas important impacts for POM are located over Asia, southern Africa, and western coast of North America. Future studies will thoroughly compare the model simulated PM2.5 and ozone impacts from ECLIPSEv6b, CEDS and EDGARv5 in CESM2 CAM6-Chem.