by Peter Corbett
Planning vacations in the age of climate change has spawned yet another decision for eco-friendly travelers: What’s the cleanest and greenest way to reach their destinations? Is it planes, trains or automobiles?
It turns out buses are the cleanest travel option for reducing one’s carbon footprint on a vacation, said David Kestenbaum, director of the Certification for Sustainable Transportation Center.
“Buses and motorcoaches provide a solution (to greenhouse gas emissions), but we don’t equate buses with being ‘green,’” said Kestenbaum, who teaches sustainable development at the University of Vermont. “It’s hard to beat a motorcoach that’s loaded with at least 30 to 40 passengers.”
While airlines have pledged to cut emissions of carbon dioxide and other greenhouse gases over the next 30 years, the bus and motorcoach industry is generally considered the cleanest and most efficient method of travel for the masses. Passenger trains come in second.
Burning fossil fuels for transportation—gasoline, diesel and jet fuel—releases carbon dioxide into the atmosphere. The buildup of CO2 and other greenhouse gases—methane, nitrous oxide and hydrofluorocarbons—is causing the Earth’s atmosphere to warm and is blamed for climate change.
The American Bus Association recently reported that the motorcoach industry in 2017 achieved 280.1 passenger miles per gallon of fuel. That is based on an average fuel efficiency of 6.4 miles per gallon and an average passenger load of 43.7 riders.
By comparison, an economy car with a solo driver gets about 35 passenger miles per gallon and four people traveling in a mid-sized SUV achieve about 100 passenger miles per gallon.
Bus and motorcoach manufacturers and tour operators are in a position to market their green advantage over other transportation options. At the same time, the industry is poised to take advantage of advances in bus technology to reduce emissions.
Some travelers associate buses with dirty diesel exhaust, but particulate filters and exhaust regeneration has led to engines that are far cleaner and more efficient, Kestenbaum said.
“If you own a motorcoach company, don’t be afraid to cheerlead for the environmental advantage of traveling on buses,” he said. “It can be a factor in people’s travel decisions.”
It’s a growing concern in Europe. Travelers there can use automated airport kiosks to get an estimate of the carbon emissions from their flights. They can also make a monetary donation to offset those greenhouse gases.
Atmosfair, a German nonprofit, uses those offset funds for renewable energy projects ranging from wind and solar installations to buying efficient cook stoves for citizens of developing nations.
In Sweden, there are media reports of flygskam, or “flight-shaming.” Activists apply social pressure to encourage people to rely on trains and buses and to avoid air travel because of its larger carbon footprint. One flight from New York to Munich can produce at least 1,600 kilograms of carbon emissions, the equivalent of operating an automobile for an entire year, according to Atmosfair.
Kestenbaum said he is unsure if flight-shaming will catch on. “Maybe in limited circles. It’s yet to hit the mainstream.”
The International Air Transport Association said commercial aviation, which is responsible for about two percent of global carbon emissions, has a target to cut emissions in half by 2050, compared to a 2005 benchmark.
“Airlines have spent billions on new planes that have helped cut emissions per passenger in half since 1990,” said Alexandre de Juniac, IATA director general.
Motorcoach operators are also modernizing their fleets. Over the next 15 years, Kestenbaum predicts growing use of alternative fuels—natural gas and propane—and electric buses with improved batteries and extended range.
Grand Canyon National Park operates 30 shuttle buses fueled by compressed natural gas (CNG). Zion National Park is considering phasing out its propane-powered buses for battery-electric models.
MCI announced the first production units of its J4500e electric motorcoach are scheduled for delivery next year.
Another advance in technology comes from telematic systems that track the location, speed and other operating data of buses and other vehicles. These analytics can be used to train drivers to operate the buses more efficiently, avoiding quick starts and hard braking. These adjustments can result in fuel savings of five to 10 percent, Kestenbaum said.
Telematics can also be used to give drivers incentives to reduce idling during their trips. “Drivers need to be vigilant and ask themselves, ‘Do I need to have this vehicle on?’” he said.
Transportation has the attention of climate scientists because it contributes an estimated 29 percent of U.S. greenhouse gas emissions, according to a 2017 Environmental Protection Agency study. That’s slightly higher than the emissions from electric power generation.
Light-duty vehicles and medium and heavy trucks combined account for 82 percent of emissions from the U.S. transportation sector, while aircraft add nine percent and trains just two percent. The study did not break out a figure for buses.
A Union of Concerned Scientists study revealed that taking a motorcoach was the cleanest way to travel regardless of distance—100, 500 or 1,000 miles—or whether it was one, two or four people traveling together. A passenger train was the second-best option for one or two travelers for trips of 100 to 500 miles. Coach flights were the runner-up for trips of 1,000 miles or more for one or two travelers, according to the 2008 study.