Even the greenest of environmentalists would have a hard time avoiding air travel, which accounts for some 2.5% of overall greenhouse gas emissions. But he or she still has options that can minimize the carbon footprint tied to a plane ticket.
A recent report from the International Council on Clean Transportation, an environmental nonprofit, compares different airlines in terms of fuel efficiency. The report found that Alaska Airlines performs the best, while American Airlines and Allegiant Air rank towards the bottom.
The difference between Alaska and Allegiant, which came dead last, is that "Allegiant would have used 26% more fuel than Alaska Airlines to provide a comparable level of transport service," the report notes. The report, which used data from 2010, attributes a third of that difference to inefficient technology, but other factors the ICCT efficiency model took into account included seating density, route circuity (essentially, the efficiency of the route itself), and operational practices.
ICCT also discovered that many of the airlines that recently underwent mergers—like Delta, Airtran Airways, and American Airlines, for example—were likely to fall below the industry average. "The least efficient airline in this ranking, Allegiant Air, also happened to have the most profitable U.S. domestic operations during the 2009 to 2011 period," researchers wrote.
But does this mean that other airlines are pursuing efficiency just to be nice to the environment? No. Here's why Allegiant is an edge case and why other airlines are spending money on cutting emissions: The International Air Transport Association has come up with a set of voluntary industry goals for fuel efficiency—one of which is decreasing fuel consumption and carbon dioxide emissions 25% by 2020. The IATA argues that these standards would cut costs by up to 6%, but without a market-based trading system for emissions, Allegiant is unlikely to feel the burn of their own engines outside of regular jet fuel costs. According to a recent AP report, the airline faces almost no competition, as it serves a niche market of small cities to vacation spots, and also skimps on other services like Wi-Fi, TVs, and recent plane models.
The ICCT also broke down how the age of the planes themselves affected fuel efficiency rankings. The results weren’t as straightforward as you might assume. Even though Virgin had some of the newest models, their fuel efficiency ranked below average. Hawaiian Airlines, by comparison, was one of the most efficient airlines on the list, despite the fact that its planes were over 10 years old.
Implementing more efficient technology, however, appears to have had a direct impact on rankings (surprise!). The report notes that Alaska Airlines’ Boeing next-generation 737 planes use winglets and high-bypass-ratio engines to reduce fuel burn, while Allegiant relied on aircraft from the early 1980s with zero winglets.
Weirdly, though, when it came to individual routes, some of the lower ranking airlines had some of the best fuel efficiencies. Between Los Angeles and New York, Virgin America had the highest fuel efficiency on the list, with 12 passenger miles per pound of jet fuel. Between Atlanta and New York, Airtran took first place.
Some routes were also just less efficient overall. No matter which airline you’re on, flights from San Francisco to San Diego had the lowest average number of passenger miles per pound of fuel. By contrast, flights from San Francisco to New York had the highest (i.e. best). After all, size of the distance isn’t everything.
With the air travel industry's consumption of oil set to double by 2030, let's hope both airlines and travelers alike are paying attention to these numbers.