Singapore's Scoot tops Cirium's global airline emissions efficiency rankings for 2025

Ryanair Holdings

15/04/2026 10:00

HONG KONG, April 15 (Reuters) - Singapore budget carrier Scoot has been named the world's most emissions-efficient airline, according to aviation analytics firm Cirium's 2025 EmeraldSky annual review, becoming the first Southeast Asian carrier to claim the top global spot.

Here are some details:

Scoot, the budget arm of Singapore Airlines SIAL.SI, recorded CO2 per available seat kilometre (ASK) - the industry's standard measure of passenger-carrying capacity - of 51 grams, the lowest among all major airlines ranked, displacing the 2024 leader, Wizz Air WIZZ.L.

Its performance was driven by a high seat density of 242 seats per aircraft and longer average flight sectors of 2,157 km (1,340 miles).

Low-cost carriers dominated the top five globally, with Wizz Air second, TUI Airways third, Air Europa fourth and Frontier Airlines fifth.

Among the world's largest airlines by ASK, Qatar Airways, Ryanair RYA.I and Turkish Airlines were ranked the most efficient, in that order.

The results reinforce a broader industry pattern, with airlines operating younger fleets and higher seat density consistently outperforming peers on emissions efficiency.

On a regional basis, Frontier led North America, Wizz Air topped Western Europe, VietJet VJC.HM ranked first in Southeast Asia and JetSmart led in Latin America. Virgin Atlantic topped the transatlantic rankings, while Air Canada AC.TO led the transpacific corridor.

Korean Air Lines 003490.KS recorded the largest year-on-year emissions improvement on long-haul routes, with its Seoul-Seattle service cutting CO2 per ASK by 27.4% following a fleet transition to next-generation aircraft.

Cirium's EmeraldSky rankings cover the world's 100 largest airlines and are independently assured by PwC.

 (Reporting by Julie Zhu; Editing by Jamie Freed)

 ((julie.zhu1@thomsonreuters.com;))