The report shows that Vietjet recorded emissions of 64.5 grams of CO₂ per Available Seat Kilometre (ASK), outperforming regional peers such as Singapore Airlines (66.7 grams) and Lion Air (67.1 grams). The ranking focuses exclusively on flights operating within Southeast Asia, where short- and medium-haul routes pose greater challenges for fuel optimisation.

Cirium’s assessment is based on its EmeraldSky methodology, which uses CO₂/ASK as a key metric for carbon emissions per seat offered per kilometre flown, an industry-standard indicator of operational efficiency.

Under comparable operating conditions, Vietjet’s leading position highlights its ability to optimise performance across its entire operational chain, including aircraft configuration, route network design and load management.

A key factor underpinning this achievement is the airline’s modern fleet. Vietjet primarily operates Airbus A320 and A321 aircraft, including fuel-efficient “NEO” variants that reduce fuel consumption by approximately 15–20% compared to earlier models. With one of the youngest fleets in the region, the airline has significantly lowered fuel burn and CO₂ emissions per flight.

In parallel with fleet investment, Vietjet has intensified advanced technologies in operations. These include data-driven flight analysis platforms such as SkyBreathe and fuel optimisation initiatives like SFCO2, which help enhance efficiency across its network.

The airline’s sustainability efforts have also gained international recognition. Earlier this year, Vietjet was named among the world’s Top 7 most sustainable airlines by AirlineRatings, reflecting its strong performance in emissions reduction, fuel efficiency and green aviation development. The carrier has also been acknowledged for its environmental, social and governance (ESG) achievements in markets such as Taiwan (China).

The Flight Emissions Review is an annual ranking by Cirium that independently evaluates the world’s 100 largest airlines based on actual operational data. It enables transparent comparisons of emissions performance across different markets and operational scales, providing a valuable benchmark for the global aviation industry as it advances toward more sustainable growth./.