Estuaire5.S45Estuaire is a data platform designed to monitor and reduce both CO2 and non-CO2 emissions. While current focus is primarily on CO2, regulatory trends and public attention are shifting towards more comprehensive metrics. Rather than solely considering fuel consumption, aviation stakeholders are increasingly interested in non-CO2 effects like NOx, contrails, and lifecycle impacts. We are pioneering tools that incorporate all these factors using an auditable methodology. Our capabilities include retro-engineering aircraft fuel consumption without requiring proprietary data from airlines, enabling us to provide these values to other entities such as lessors, airports and aviation suppliers.