
Eco-conscious airlines: United Airlines plans to introduce a regional US flight service aboard 100 30-passenger hybrid-electric planes, from Swedish startup Heart Aerospace, by 2028. Click on for other airlines that stand out for pioneering sustainability measures.

Widerøe: Norway-based Widerøe, the largest regional airline in Scandinavia, is on track to become one of the world's first fully emissions-free airlines. An all-electric aircraft-development partnership is set to replace the airline's entire domestic fleet by 2028.

SAS: Scandinavian airline SAS is already taking reservations for commercial hybrid-electric flights in 2028, aboard 30-passenger Heart Aerospace planes. The airline also plans to slash CO2 emissions by 25% by 2025.

Wizz Air: European low-cost carrier Wizz Air claims one of the industry's lowest carbon emissions-impact per passenger, thanks to its younger, fuel efficient fleet, high-occupancy flights and direct route network that omits carbon-emitting connecting flights.