Low-cost airlines are fighting back when attacked as polluters, saying they do far better than their accusers say, reports the International Herald Tribune.

They claim to fly mostly modern fuel-efficient aircraft and fill more seats than traditional airlines, thus causing less pollution per passenger.

Airlines are also pressing air controllers and airports to shorten routes and landing approaches not only to save the planet, but to save money.

Low-cost carriers are "the most environmentally friendly sector of the industry," John Hanlon, head of the Brussels-based European Low Fares Airlines Association.

"Investment in new aircraft reduced fleet age among ELFAA members to just 3.9 years," Mr Hanlon said. That compares with a global airline average of 11 years, industry sources said.

Commercial aviation in general, he says, plays a far smaller role in generating global carbon dioxide emissions than road traffic and power plants, and it produces only slightly more than ocean shipping that is also under fire.

The US Federal Aviation Administration said cars and trucks represent 21 per cent of greenhouse gases, power plants 33 per cent. Aviation comes in at less than three per cent. The US aviation market consumed 5 per cent less fuel in 2006 than in 2000, while moving 12 per cent more passengers, according to the FAA.