When airplanes first caught Keith Debbage’s fancy, the term “carbon footprint” didn’t exist. It was the 1960s, and he was a kid happy to accompany his father to air shows on weekends. Never mind that watching planes was what his dad, a Royal Air Force radar operator, did at his day job. People who love flight never tire of planes.
Debbage is still a fan. Now, as a geography and entrepreneurship professor, he is able to combine his passion for flight with professional interests. The airline industry is one of his areas of study, and lately he’s been thinking a lot about one of the downsides of flight.
Jet aircraft are major polluters, and Americans – who love to travel – bear the responsibility for much of that pollution.
“Right now,” Dr. Debbage says, “about a fifth of the global carbon footprint from tourism is attributable to air travel.” Americans – just 4% of the global population – “account for 50% of all carbon dioxide emissions from airplanes worldwide.”
That sort of tidbit motivates a geographer to dig deeper. Or in this case, two geographers, both named Debbage.
Debbage’s son, Neil, is an assistant professor at the University of Texas at San Antonio. “He’s got a bigger green ethic than I do,” his father cracks. The younger geographer challenged his dad to work together on an examination of airline tourism’s carbon footprint, with the added goal of being published in a prestigious journal, the Annals of Tourism Research.
They did, and it was.
There’s been ongoing debate about whether direct flights are less polluting than itineraries with short hops and connecting flights. Often it’s a question of big planes versus smaller jets. Carbon footprint data exists for all sorts of commercial aircraft, from regional jets to the largest wide-body Boeing and Airbus planes. The Debbages looked at more than 1,000 flights originating from 10 major Northeastern airports destined for 13 popular destinations, mostly in the Sunbelt. They compared emissions generated by connecting routes vs. direct flights and found conclusive evidence.
“Bottom line is, direct routes are more green,” he says.
How green? The difference is about 100 kilograms of carbon, or about equivalent to the amount of energy needed to run a refrigerator for a year. That sounds pretty good, right?
But then there’s this: Scientists have determined that to keep global warming from exceeding 2 degrees Celsius, each person on earth must not consume more than 2,300 kilograms of carbon per year. Of that amount, 575 kilos are allocated for travel, including daily commutes and vacations.
The Debbages found a round trip between those Northeast and Sunbelt airports, even without connections, consumes “on average, two-thirds of an individual’s entire mobility budget for the year.”
It was a sobering revelation for a lifelong aviation fan. “Airline travel may be one of our worst environmental sins,” Debbage says. “It was really kind of shocking.”
Debbage’s findings on flight’s carbon footprint have netted national media coverage and invitations to present his paper at conferences in Sweden and Dubai. He flew to the Middle East aboard an Airbus A380, “probably the biggest gas-guzzler, carbon-emitter civilian aircraft in the world,” he says. The irony is not lost on him.