It turns out that flying home on a commercial jet might be better for the environment than driving home in a car. According to University of Michigan transportation researcher Michael Sivak, the amount of per mile energy consumption on the average domestic flight fell by 74% from 1970 to 2010. Also, the International Council on Clean Transportation (ICCT) says that between 1968 and 2014, the fuel efficiency of new airplanes has improved by 45%.
With fuel accounting for about one-third of the airline expenses, airlines have been obsessed with cutting the amount of fuel that is used by their planes. It is said that a mere 1% in efficiency improvement can save an airline $1 million in fuel costs over the average 25 year lifespan of a plane. Airline manufacturers have been working to make planes more efficient by fine-tuning jet engines to produce more thrust and by making planes lighter and more aerodynamic.
There’s also the fundamental practice of cramming more people onto planes. Today, the average domestic flight has 84% of its seats filled. In 2002, this figure was only 70%. With this in mind, flying today uses 52% less energy than driving in transporting one person a single mile.
However, these per mile rates assume the distance of a nine mile trip for a car and 900 miles for the trip of a plane. Cars actually perform better on longer distance trips, while planes perform worse at shorter distances. This is because cars obtain better fuel efficiency on the highway, and planes use most of their energy landing and taking off. So in reality, a trip between the distances of 300 and 500 miles actually favors the automobile. And of course, it’s not like anyone is going to take an extremely short plane ride.
But if you’re planning to take a holiday trip of more than 500 miles, a plane is probably the most environmentally friendly way to travel, assuming that it is a direct flight. Of course, this also assumes that the plane is a commercial jet. Private jets with few people on board are another story entirely. And both cars and commercial jets fall short of a bus when it comes to per person fuel efficiency.