OFFICIAL AIRLINE REPORT JULY 2025 CONTENTS Intra-Regional Highlights:CO₂Efficiency by Geography Introduction & Forewordby Jeremy Bowen •North America Region•Western Europe Region•Southeast Asia Region•Latin America Region Global Airline Rankings •Global CO₂Emissions•Major Airlines•World’s Largest Airlines by ASK 30 Inter-Regional Highlights:CO₂Efficiency by Geography •North Atlantic•Transpacific 38 Building Confidence inEmissions Data: The Importanceof ISAE 3000 Assurance Route Analysis: Top 10Performers by Route Efficiency •Long-Haul Routes•Medium-Haul Routes•Short-Haul Routes 54 Appendix 50 •Airline Codes•Airport Codes•Definition of Terms•Cirium History•Cirium Global Offices EmeraldSky: Advancing FlightEmissions Measurement inAviationby Andrew Doyle THE CIRIUMFLIGHT EMISSIONSREVIEW byJeremy Bowen, Chief Executive Officer, Cirium Welcome to theCirium Flight Emissions Review— the trusted benchmark forflightemissions calculations for the global aviation sector. As the industry faces continued pressure to decarbonize, accurate and independentemissions data is no longer a nice-to-have — it’s essential. At Cirium, we believe progressstarts with visibility. That’s why we’ve developed this Review: to give stakeholders acrossaviation a clear, data-backed view of emissions performance, built on the most accurateinformation available. The results in this Review are poweredbyEmeraldSky,Cirium’s emissions intelligencesolution. EmeraldSky combines the mostcomplete aviation data available with advanceddata modeling and emissions science. Itenables airlines, airports, lessors, and aviationsustainability stakeholders to measure andunderstandflight carbon emissions withconfidence and clarity. In 2025, EmeraldSky’s methodologyachievedISAE 3000 ReasonableAssurancefollowing independent review byPricewaterhouseCoopers(PwC) — thehighest level of assurance available underthe International Standard on AssuranceEngagements. This verification sets a new barfor emissions data reliability and makesEmeraldSky a foundation stakeholders cantrust for everything from benchmarking andoperational insights to Scope 3 disclosures. Additionally, Cirium’s EmeraldSky isofficially accredited by the RockyMountain Institute (RMI) as a qualifiedflight emissions data provider underthe Pegasus Guidelines — thefirst climate-alignedfinanceframework tailored for aviation.This accreditation validatesEmeraldSky’s methodologyfor use by banks,financiers, and other stakeholders aligning with net-zero emissions targets by 2050. Why this Review matters Today, emissions reporting across aviationis still inconsistent — often hard to compareand rarely comprehensive. This FlightEmissions Review addresses that byapplying a consistent methodology toflight-level data, enabling meaningful and faircomparisons across operators, markets, androutes. What’s included in this Review This Review takes a broader and deeperlook intoflight emissions performance thanever before. We’ve focused on four differentviews which we thought you wouldfinduseful and compelling: A foundation built on trusted data •Global Airline Rankings— Acomprehensive comparison of CO₂emissions per ASK across the world’slargest carriers, featuring the top 20major airlines and the 10 largest globalcarriers for clearer peer benchmarking. Cirium brings together the mostauthoritative aviation data sets in the world,enriched with inputs from leading industrypartners. We don’t just gather data—weconnect it, validate it, model it, and make itactionable. •Intra-Region Rankings— These rankingsfocus on average CO₂per ASK forflightsthat take place entirely within a singleregion. That same principle guides our emissionswork. By building on EmeraldSky andensuring third-party assurance, we’redelivering a new standard for accuracy,transparency, and reliability in aviationsustainability reporting. •Inter-Region Rankings— The inter-region rankings focus on averageCO₂per ASK forflights that span twodifferent global regions. We hope youfind the insights in this reportboth valuable and thought-provoking. Asthe dataset grows and the methodologyevolves, we’re committed to refining howthis information is presented. Quarterlyupdates are planned, and future editions willbe shaped by your feedback. •Improvement by Route— Highlightingspecific airport pairs with the greatestyear-over-year reductions in CO₂/ASK,giving insight into where operationaldecisions andfleet changes aredelivering results. Let us know how we can make it even moreuseful to you. Better Performance.Lower Emissions. We are here to help us allfly sustainably. Cirium EmeraldSky is empowering the aviation ito accurately measure and monitor CO₂emissio cirium.com/emeraldsky ndustryns. GLOBAL AIRLINERANKINGS GLOBAL AIRLINERANKINGS byMike Malik, Chief Marketing Officer, Cirium Which Airlines Minimize EnvironmentalImpact efficiency leaders and their best practicesrather than highlighting those with higheremissions intensity