Fly or drive over the holidays? Neither is great for the planet
The holidays are here and you’ve got to decide whether to pack up the car or buy that plane ticket to go visit grandma.
Which is greener, flying or driving? It depends. And it involves a little math.
Either way, it can be a fraught choice. Each metric ton of heat-trapping carbon dioxide — one traveler’s share of the emissions on a one-way flight from San Francisco to New York — shrinks summer sea ice by about 32 square feet, according to recent research. Cross-country driving isn’t much better.
So a trip to see that fancy tree at Rockefeller Center sacrifices a truck-size piece of the Arctic. A round trip visit to Bangalore, with a layover in Hong Kong, could melt a small apartmentsized slab of ice.
But for Pacific Coast travel, there’s a lesser of evils. To explain, we compared the carbon that’s emitted by both forms of travel to two cities — Los Angeles and Seattle — using a calculator created by Atmosfair, a German nonprofit that offers carbon offsets for travel-related emissions.
Driving all alone in an average car? For both trips, that’s worse than flying.
Solo driving to and from Los Angeles in a 25-miles per gallon car produces a bit more carbon dioxide than an equivalent flight: About 0.3 tons versus 0.27 tons.
Similarly, driving alone to Seattle round trip, also produces more carbon than flying: 0.64 tons versus 0.51 tons.
But that conclusion flips if your vehicle is more fuelsavvy or if you invite others along on your drive to share the total emissions. Then flying is much worse.
A new Prius, getting 53
miles per gallon on the highway, generates 0.14 tons of carbon on a trip to L.A. and back. That’s only half as much as flying.
If you’ve got someone else in your Prius, merely onequarter as much carbon is emitted as two round-trip plane flights.
It gets even better with the new Tesla Model 3 with an advertised 132-mpg, the most energy-efficient vehicle on the road, according to Green Car Reports. It produces less than 0.06 tons of carbon on that trip to L.A. That’s one-quarter as much as flying. For two passengers, that Tesla trip emits less than one-eighth as much carbon.
If Tesla’s seven-seater Model X SUV is packed full with friends, that could make a polar bear’s day.
What kind of vehicle melts more ice than a flight? A Ford 150 truck, for example. Averaging 16 mpg, it generates a whopping 0.46 tons of carbon — nearly double the 0.27 tons of carbon emitted in a flight to L.A. A Hummer, Ferrari or Lamborghini are far worse.
Even if someone joins you in your pickup truck, you’re barely breaking even.
To be sure, it costs more carbon to go farther, whether driving or flying. A car trip from San Francisco to Seattle, at 810 miles, emits twice the carbon as a 378-mile trip to L.A.
But longer flights are more efficient than shorter flights. That’s because taxiing, takeoff and landing are very fuel-intensive. And every plane has to climb to a minimum altitude, regardless of how far it goes after that.
So a Seattle flight is greener, per mile, than an L.A. flight. (That assumes no stops in, say, Portland, Oregon. Nonstop flights emit less carbon than flights with connections.)
New planes are better than older ones, due to improved engineering. The most recent Atmosfair Airline Index shows that aircraft models such as Boeing 787-9, Airbus A350-900
or the A320neo achieve the greatest fuel efficiency.
The carbon footprint created by an elite Platinum traveler is far bigger than that of a poor plebe crammed in an economy seat. That’s because business class and first class seats take up more room, so fewer people are being moved by the same amount of fuel, according to a study by the World Bank.
In terms of overall impact, frequent fliers — those 12% of Americans who make more than six round trips by air a year — are worse offenders than the ordinary traveler taking a hard-earned holiday, according to an October study by the nonprofit research group International Council on Clean Transportation. Those fliers are responsible for about twothirds of all aviation emissions.
“At the end of the day, the impact of an annual holiday flight gets swamped by emissions from American frequent flyers, who on average fly 14 times per year,” said Dan Rutherford, aviation director at the International Council on Clean Transportation. “So I wouldn’t feel too guilty about flying to visit family for Christmas. Just remember to ask Santa for cleaner planes and fuels next year.”
There are ways to lessen
impacts from driving also. Regular tune-ups and wellinflated tires boost fuel efficiency. So does conservative driving: While each vehicle reaches its optimal fuel economy at a different speed, gas mileage usually decreases rapidly at speeds faster than 50 mph. According to the U.S. Department of Energy, each 5 mph you drive over 50 mph is like paying an additional $0.18 per gallon for gas.
All those gifts piled on the roof of the car? They don’t help. A large, blunt roof-top cargo box can reduce fuel economy by as much as 25% on highways, according to the DOE. Rearmounted cargo reduces fuel economy by much less.
Carbon offsets can help ease a traveler’s guilt. The money you pay for an offset — available online for $10 per metric ton — goes toward the construction of wind farms, tree planting, cleaner cook stoves and other ways to reduce greenhouse gas emissions.
Or we can simply stay home.
The planet is happiest when we turn down the thermostat and, in a kerchief or cap, with visions of sugar-plums dancing in our head, settle down for a long winter’s nap.