Advito Partners with Estuaire to Enhance Their GATE4 Methodology
Leading business travel consultancy, Advito, today announced a new partnership with Estuaire, a French climate-tech company specializing in non-CO₂ aviation intelligence.
Chicago – March 24, 2026 –Leading business travel consultancy, Advito, today announced a new partnership with Estuaire, a French climate-tech company specializing in non-CO₂ aviation intelligence. The collaboration is designed to enhance Advito’s ISO certified GATE4 emissions methodology, providing a more robust assessment of aviation’s total climate impact by integrating flight-specific non-CO₂ data. Air travel emits several greenhouse gasses in addition to carbon dioxide, and their impacts have been notoriously difficult to quantify until now.
While most emissions methodologies rely on a standard multiplier to estimate the non-CO₂ effects of air travel, GATE4 can now incorporate Estuaire’s advanced modeling to calculate the flight-by-flight non CO2 impacts based on real-world variables including flight paths, altitudes, and atmospheric conditions – like temperature and cloud cover. The result is a more granular understanding of aviation’s climate footprint and clearer insight into where mitigation efforts can have the greatest impact.
“Non-CO₂ effects represent one of the most complex and least understood aspects of aviation’s climate impact,” said Julien Etchanchu, Senior Director of Sustainability Consulting at Advito. “By enhancing GATE4, we are moving beyond broad assumptions to give our clients a more accurate and actionable view of their air travel greenhouse gas emissions. This is a premium capability designed for organizations that want deeper insight and better decision-making, not just high-level non-CO2 emissions estimates.”
Estuaire’s research shows that contrail warming impacts, a major driver of aviation’s non-CO2 effects, are highly uneven across air travel, with a relatively small share of flights responsible for a disproportionately large share of total warming. Factors such as specific flight route, night flights, and seasonal conditions can significantly influence climate impact, and these insights are difficult to capture using standard measurements.
“Without calculating non-CO₂ effects, the real climate impact of air travel is a big unknown,” said Maxime Meijers, Co-Founder & CEO at Estuaire. “By modeling flights individually and accounting for atmospheric conditions, we can identify the routes and conditions that contribute most to warming. Partnering with Advito allows these insights to be applied to business travel in a way that supports informed decision-making and greater mitigation efforts.”
The enhanced GATE4 calculation is offered as an add-on to Advito’s existing GATE4 methodology. Under the model, Advito calculates a client’s CO₂ emissions and securely transfers the calculations to Estuaire, which applies its non-CO₂ modeling methodology and returns the results for seamless integration into Advito’s reporting dashboard.
The enhanced data enables Advito to provide more targeted recommendations to clients, such as identifying specific routes or travel patterns with significant climate impact beyond carbon emissions alone, highlighting opportunities to adjust travel policies to account for those differences, and influencing travelers to make smarter choices. The partnership with Estuaire reflects Advito’s continued investment in advancing sustainability methodologies and equipping travel managers with tools that go beyond industry averages to support meaningful emissions reduction.
About Advito
Advito is the consulting division of BCD Travel specializing in transforming corporate travel programs. Its intelligence-driven framework manages supplier spend and traveler behavior dynamically, ensuring travel programs run smoothly and efficiently, while meeting the needs of all stakeholders. With smart analytics, unique supplier strategies, and integrated traveler engagement, Advito elevates travel programs to new heights of sustainability, savings, and satisfaction. Advito is proud to be the first travel consultancy to develop its own ISO certified carbon reporting methodology, GATE4, and to create a dedicated practice area for sustainable business travel.
About Estuaire
Founded in 2023, Estuaire is a French climate-tech start-up specializing in the analysis of non-CO₂ aviation effects. Using advanced atmospheric and flight modeling, Estuaire helps airlines, airports, and organizations better understand and reduce the full climate impact of air travel.
Press Contacts
Erin Singleton – Senior Director Marketing, Advito