Australia’s Qantas Airways' B747s and A380s have helped it hit bottom ranking in terms of transpacific flight pollution, according to think tank the International Council on Clean Transportation.

China's Hainan Airlines and Japan’s All Nippon Airways tied for the 'greenest' flights, while Qantas burned on average 64 per cent more fuel per passenger-kilometre than those two top-ranked airlines.

 

“There’s a large gap in fuel efficiency on transpacific flights, leading to excess carbon emissions,” study co-author Brandon Graver said.

 

How much cargo is carried and flying aircraft at their maximum payload, typically thanks to freight, had the greatest impact on fuel efficiency, Graver added.