Impacts of different biomass burning emission inventories: Simulations of atmospheric CO2 concentrations based on GEOS-Chem

Biomass burning has substantial spatiotemporal variabilities. It contributes significantly to the dynamics of global CO2 distributions and variances. Quantifying the impacts of biomass burning emissions on atmospheric CO2 concentrations is essential for global and regional carbon cycles and budgets. In this study, we performed several numerical experi-ments by switching and replacing inventories to estimate the impacts of four biomass burning emission inventories on atmospheric CO2 concentration simulations in 2006-2010 based on the global chemical transport model, GEOS-Chem. The results highlighted similarities and differences in the annual and seasonal variability of biomass burning emissions and simulated CO2 concentrations at global and regional scales. Based on four different biomass burning emission inventories, we found that biomass burning emissions could lead to a global CO2 concentration increase of 2.4 ppm annually. Africa contributed the largest global CO2 emissions among all continental regions, where the max-imum CO2 concentration increase could reach 7.9-13.0 ppm in summer. Model evaluation results showed that simu-lation using the Quick Fire Emissions Database (QFED) as the model priori biomass burning emission inventory had the best performance compared with the satellite and surface observations. The sensitivity of simulated CO2 concentra-tions to the uncertainties in different biomass burning emission inventories was high in southern South America and most areas of the Eurasian continent, and low in central Africa and Southeast Asia. This study furthers our under-standing of the critical role of biomass burning in atmospheric CO2 and indicates an urgent need to improve the accu-racy of biomass burning emission estimates in CO2 simulations.

Automated summary

Biomass burning has significant variability in space and time, impacting global CO2 distributions and variances. Quantifying the effects of biomass burning emissions on atmospheric CO2 concentrations is crucial for carbon cycles and budgets. This study used numerical experiments to estimate the impacts of four biomass burning emission inventories on CO2 concentration simulations, highlighting similarities and differences in emissions and simulated CO2 concentrations at global and regional scales.