IndiGo, Air India Express among lowest carbon emitting airlines: Cirium global review

For the ranking, Cirium considered aircraft variances, unique flight weight differences, total time spent by an aircraft burning fuel (ground and air), cabin configuration, and fuel efficiency attributes of an aircraft
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VELANKANNI RAJ B

IndiGo and Air India Express have been ranked 5th and 10th in a global list of lowest carbon emitting airlines prepared by aviation analytics firm Cirium.  The study analysed carbon dioxide emissions per available seat kilometre (ASK), an aviation industry metric that measures passenger capacity of an airline.

Wizz Air of Hungary ranked first among major airlines with an industry low emission of 53.9 grams of carbon dioxide per ASK in 2024. IndiGo and Air India Express recorded emissions of 58.2 grams and 60.5 grams per ASK, respectively, in 2024.

Frontier Airlines of US and Pegasus of Turkiye were ranked second and third in the global review. The top-ranked airlines operate young fuel efficient aircraft (like Airbus A320Neo) and use high-density cabin configurations, spreading emissions over more passengers.

Among the 10 major airlines, IndiGo’s fleet is the youngest with average weighted age of 4.1 years. In case of Air India Express it is 6.9 years.

“We chose grams of CO2 per ASK which we call emission intensity as our core metric because ASKs can capture what airlines can actually control: aircraft efficiency, seat density, and route optimisation. Under our methodology carriers flying newer fuel efficient aircraft with higher density configurations naturally perform better, “ said Mike Malik, Chief Marketing Officer, Cirium.

For the ranking, Cirium considered aircraft variances, unique flight weight differences, total time spent by an aircraft burning fuel (ground and air), cabin configuration, and fuel efficiency attributes of an aircraft.

Published on July 2, 2025