The Attributing and Verifying European and National Greenhouse gas and aerosol Emissions and Reconciliation with Statistical bottom-up estimates AVENGERS consortium unites a diverse group of experts to establish how top-down techniques can support the verification of national greenhouse gas (GHG) inventories and other regulated estimates of emissions and removals, in order to improve or supplement the methods/approaches currently used. In recognition of the need for a truly multi-actor approach the team represents experts in atmospheric inverse modelling and data assimilation, remote sensing, environmental monitoring and observation, terrestrial ecosystem modelling, policy and stakeholder interaction together with national inventory compilers. AVENGERS builds upon the heritage of previous EU projects, in particular CHE, CoCO2 and VERIFY and will advance the top-down approach for quantifying GHG and aerosol emissions, as well as reconcile and integrate approaches into a joint bottom-up and top-down framework. Based on the reconciliation AVENGERS will prepare good-practice guidelines for use of atmospheric inverse models as well as develop a Flexible Inversion Tool for Inventory Compilers (FIT-IC). Knowledge and outcomes are provided of use for policy and societal stakeholders and replicable outside of our chosen target area (Europe with a focus on Germany, Italy, Sweden, Switzerland, and The Netherlands). The uniqueness of the consortium lies in the combination of the required scientific expertise with full partner presence of official reporting agencies from exemplary EU countries (Germany, Italy, Sweden, and The Netherlands) facilitating the transfer of knowledge to key international organizations (such as UNFCCC, WMO) in the field.