Fluxes of Carbon Dioxide From Managed Ecosystems Estimated by National Inventories Compared to Atmospheric Inverse Modeling

The UNFCCC reporting guidelines on annual emission inventories have been encouraging comparison of national inventory reports with atmospheric measurements or atmospheric inverse modeling. We have initiated a framework to compare two CO2 atmospheric inversions with the net agricultural, forestry and other land use (AFOLU) fluxes reported by 10 parties to the UNFCCC. Our study highlights large conceptual differences or ambiguities (temporal support, spatial perimeter, scope of the processes) between inventory reports and between these reports and what the atmosphere sees. We recommend that more effort be invested into documenting the inventories in order to allow unambiguous conversion between reported values and the way they are seen by the atmosphere. We also highlight the potential of Bayesian atmospheric inversion products generated in quasi-near-real time with robust error bars and consistently across the world, to directly inform international CO2 flux accounting for the AFOLU sector in large countries or groups of countries.