CAMS-REG-UNC-v8.1: A detailed uncertainty product for the gridded CAMS-REG-v8.1 emission inventory

This dataset is described in detail in: https://essd.copernicus.org/preprints/essd-2026-77/ Independent verification of greenhouse gas emission reductions and trends in air pollution levels is receiving increasing attention. Atmospheric observations can provide such a constraint on emission estimates through inverse modelling, which requires a detailed quantification of uncertainties in prior emission inventories, observations and chemical transport models. A detailed methodology was developed to quantify uncertainties in a state-of-the-art European emission inventory: CAMS-REG. Uncertainties are estimated for all input data used to create the emission inventory and propagated to the final product. This results in separate uncertainty estimates for country-level emissions per sector and uncertainties in the spatial allocation of those emissions. Ideally, the gridded emission uncertainties should add up to the country-level emission uncertainties and for this purpose an optimization procedure was developed (only for countries with detailed emission reporting). This results in (scaled) gridded emission uncertainties and spatial error correlation lengths, which are included in the final dataset. This work follows up from previous efforts and details the first comprehensive emission uncertainty dataset for Europe. The dataset follows the same format as the CAMS-REG inventory and contains relative standard deviations in gridded emissions, per pollutant, sector, and location. Additionally, spatial error correlation lengths (in degrees and km) are provided, per pollutant, country, and sector.