Uncertainty associated with fossil fuel carbon dioxide (CO2) gridded emission datasets

CO2 emissions from fossil fuel combustion (FFCO2) serves as a reference in carbon budget analysis and thus needs to be accurately quantified. FFCO2 estimates from different emission inventories often agree well at global and national level, however their subnational emission spatial distributions are unique and subject to uncertainty in the proxy data used for disaggregation of country emissions. In this study, we attempt to assess the uncertainty associated with emission spatial distributions in gridded FFCO2 emission inventories. We compared emission distributions from four gridded inventories at a 1 W 1 degree resolution and used the differences as a proxy for uncertainty. The calculated uncertainties typically range from 30% to 200% and inversely correlated with the emission magnitude. We also discuss limitations of our approach and possible difficulties when implemented at a higher spatial resolution.