If you want to make a smaller environmental impact when travelling to distant destinations, budget airlines can help you achieve that goal, an environment and business expert says.

"On the whole, [low-cost airlines] are much more environmentally friendly than full-service airlines," Jennifer Lynes, an associate professor and director of the University of Waterloo's environment and business program, told The Morning Edition on Friday.

"To achieve their low operating costs, they need to have as many seats as possible onboard the aircraft, they need to fill as many of those seats as possible, and they're very, very conscious about costs and what service they offer on board, how much luggage you can take on and all of that contributes to the overall weight of the aircraft. The lighter an aircraft is, the more fuel-efficient it is," she said.

She noted a study released about five years ago by the British flight-comparison website Liligo found budget airlines can emit as little as one-third the carbon emissions of a full-service airline.

This week, new airline NewLeaf announced it will start flying to seven Canadian cities starting Feb. 12. NewLeaf has dubbed itself an ultra-low cost carrier. On its website, the airline notes passengers should not expect free snacks or drinks.

"Your fare gets you the two essentials: a seat and a seatbelt. The rest is up to you," the website advises.

No business class

Most budget airlines do not offer an enhanced or upgraded business class, Lynes said, because about two to three times more carbon dioxide is emitted for every flight a person takes as a business class passenger. This is partly due to the fact there are fewer seats in business class, but also because the passengers are offered more service by airline attendants: they often get real glasses, ceramic plates and metal cutlery as opposed to lighter throw-away products. And they are allowed more luggage.

As well, low-cost airlines will remove things like individual video screens, which lightens the weight of the aircraft's seats.

"Any time you take a meal cart off a plane or luggage, it's going to save you a lot of money. There is one calculation, for every 1 per cent of weight reduction then it's a .75 per cent increase in fuel efficiency," she said.

Fewer flights, newer fleet is better

In the past, budget airlines would purchase older planes because they were cheaper, but that would increase their carbon footprint, Lynes said. NewLeaf, however, has gone with the 400 series of a Boeing 737. The planes are newer – from the late 1980s and 1990s – and are meant for short to mid-range flights.

She said those planes use about three litres per 100 km per passenger. That compares to 4.5 litres used for every 100 km by a Toyota Prius, or eight litres per 100 km used by a Mazda crossover SUV, like a CX-5. she said. However, more passengers in the car would improve the fuel efficiency, she added. Adding one passenger to a car will approximately double the per-person fuel-efficiency.

Plane, train or automobile?

The carbon-footprint threshold for deciding whether to fly or drive is about 500 km, she said. Anything shorter than that, it's much more energy efficient to drive or take a train, she said. NewLeaf, for example, does not currently have any flights shorter than 1,400 km.

NewLeaf has said they will only fly some routes once or twice a week, which Lynes said will mean these flights will be 80-90 per cent full.

"If they're only running once a week then that flight would be pretty full," she said. "That always improves the fuel efficiency of the aircraft" when calculating each passenger's carbon-cost footprint.

Clarifications

  • An earlier version of this story contained a typographical error regarding carbon dioxide, mistakenly referring to it as "carbon monoxide."
    Jan 08, 2016 8:53 PM ET
With files from the CBC's Jackie Sharkey