When you're preparing for a flight, you've got a lot on your mind, from what time to arrive at the airport to what to pack. But between comparing ticket prices and deciding whether or not to purchase in-flight WiFi, how much brain space does the environmental impact of your flight occupy?
For the average person, airline travel, which New York Times writer Elisabeth Rosenthal has called "the biggest carbon sin," is one of the largest individual contributors to climate change. In October 2013, meteorologist and Slate writer Eric Holthaus vowed to give up flying completely, after calculating that air travel accounted for almost half of his household's carbon emissions. Holthaus, admittedly, previously flew a great deal for business and pleasure, but even one cross-country flight can contribute to a significant portion of an individual's annual carbon emissions. A round-trip coach ticket from New York to San Francisco accounts for 2 metric tons of carbon dioxide—compare that with the average American, whose annual carbon footprint is roughly 19 metric tons. First class seats, which take up more space and therefore increase the amount of fuel used per passenger, leave an even bigger carbon footprint—up to nine times larger than their economy counterparts, according to a 2009 World Bank study. So while the overall environmental impact of aviation might seem relatively negligible (the aviation industry is responsible for 2 percent of global emissions, compared to 26 percent from the nation's energy supply, or 14 percent from agriculture), for frequent-flyers, air travel is a significant slice of their individual contribution to climate change.
Not every traveler might be willing to make the sacrifice that Holthaus made and give up air travel completely—but if you care about the environment, and need to travel, is there an option for reducing your individual carbon footprint? In an effort to appeal to eco-conscious travelers (and appear more eco-friendly to environmental groups and regulators), some airlines, including Delta and United, have begun offering passengers the chance to add voluntary carbon offsets to their ticket prices. Think of this voluntary offset like a $25 upgrade for a roomier seat—when you purchase a plane ticket, you can calculate the amount of carbon your individual journey will create, then donate money to remove an equivalent amount of carbon dioxide from the atmosphere. For a nonstop Delta flight from Boston to Portland, Oregon, the price of offsetting the carbon associated with the flight is $5.19. To check a bag costs almost five times that, but is that $5 actually a savvy buy for the worried traveler?
"At the end of the day, you're neutralizing your carbon emissions or maybe even making them negative," says David Krantz, program director at the Center for Responsible Travel. "You're helping solve the global problem of global warming with those five dollars."
Carbon offsetting hasn't always been this efficient, however. "Early offset programs generally erred on the side of being too flexible and not standardized," explains Peter Miller, senior scientist with the Energy & Transportation Program at Natural Resources Defense Council. "The challenge is developing an approach to counting those reductions that's credible and accurate and reliable and not so burdensome that the business that is doing it voluntarily decides not to do it. Lately, there's been a big evolution in the area of offsets."
The most recognizable—and simplistic—example of an offset is planting a tree; by calculating how much carbon that tree will sequester throughout its lifetime, a company can reasonably estimate the amount of carbon that it can offset. Other offset programs focus on preventing deforestation in areas where forests are under imminent threat from logging or industry. Still others focus on upgrading infrastructure to be more energy efficient—helping a sugar mill in the Caribbean transition to machinery that uses less fuel, for instance.
Whatever the approach, a good carbon offset program has its calculations verified by third-party standards. It's also important that any carbon offset program address the issue of additionality, which means making sure that the tree that is being planted—or the forest that's being conserved—wouldn't have been planted or conserved without the contribution. And a truly gold-standard carbon offset program does more than remove or sequester carbon—it helps support local communities by creating jobs or rebuilding biodiversity in the area.
Delta, who became the first American airline to offer a carbon offset option, works in tandem with the Nature Conservancy to fund three separate projects around the globe. The first, which focuses on an area near the Tensas River in northern Louisiana, is expected to draw over 83,000 metric tons of CO2 from the atmosphere over the next 70 years—that's the equivalent of not consuming 9,339,485 gallons of gasoline. Another project, funded by Delta passengers, avoids the emission of over 445,000 metric tons of CO2 by purchasing forests in southern Chile that would otherwise have been converted for land use—the equivalent of not consuming 50,073,141 gallons of gasoline.
"If you're a traveler and you’re greenhouse gas conscious, then this is a legitimate way of creating an offset," Geoffrey Heal, professor of social enterprise at Columbia Business School, explains. "There's nothing bogus about it. It makes sense. It works."
But critics of offsets aren't worried about the offsets' efficacy; they're worried that offsets might quell guilt—both the consumer's and the airline's—and stymie action. A 2007 report on voluntary airline carbon offsets from the Tufts Climate Initiative concluded that "there is much validity to the argument that offsetting simply helps us assuage our guilt, whilst we continue to fail to change our lifestyles towards patterns that are more truly sustainable." And since voluntary offsets work on an elective, individual basis, their ability to combat the forces of global climate change is limited. Participation in voluntary carbon offset programs remains fairly dismal. Delta would not share the percentage of passengers who elect to participate in their carbon offset program, though a spokesperson did note that the number is low. Since instituting programs such as the Award Miles redemption program, which lets passengers pay for carbon offsets with frequent-flier miles, United has seen a 20 percent increase in participation, though from what baseline number is unclear.
"If everybody did it all the time, it would help. The problem is that very few people do it, and the people that do it don't do it all the time," Heal says.
Others worry that offset programs puts the onus on the passenger—not the airline doing the polluting. By offering offsets, airlines can appear eco-friendly without taking robust steps to actually reduce their emissions. "I think they want to be able to show that they're doing something on their own and that they're not as bad as they're painted and that they have some green instincts," Heal says. "It's not really a profit source for them, just a way of keeping regulators and environmental groups at bay."
Regulations might be on the horizon for airlines, but they're far from a sure thing. In 2011, in response to the European Union's Emissions Trading System (its attempt to curb the emission of greenhouse gases), the U.S. Congress passed an act that prohibited the implementation of the international program. The rejected bill was heavily lobbied against by domestic airline carriers; even a marginal increase in ticket prices caused by taxes or regulations, they protested, could result in revenue loss.
Some, like Alaska Airlines and Boeing, have funneled more money into research and development, hoping to create more fuel efficient jets and fuel sources—but even that comes back to the airline's bottom line, Krantz explains. "I think there is a direct incentive for the airlines to become more fuel efficient," he says. "Fuel is one of, if not the biggest, cost that they have, so any efficiencies they gain from newer engines or aircrafts will benefit them directly."
But aircraft improvements and offset programs haven't been enough to keep cries for regulations at bay. On August 5, three environmental groups, Earthjustice, Friends of the Earth and the Center for Biodiversity, filed a notice of intent to sue the EPA over airline emissions. John Kaltenstein, an attorney with Friends of the Earth, explained that the organization has historically been against offsets, calling them "a passing of the buck" that shepherds responsibility from the airline to their passengers. Vera Pardee, a senior attorney with the Center for Biological Diversity, agrees that only regulations can truly put a dent in the airline industry's carbon footprint, but adds that "once we have all emissions that can be avoided, then offsets, theoretically, are a good idea."
Optimistic appraisals see regulations coming to the airline industry in a decade or so; but in the face of global climate change, a decade might be too long to wait. So what's an individual to do in the meantime? "The truth is, there’s not a lot of other things that consumers can do for air travel," Miller explains. "If people want to reduce their emissions associated with air travel, which are substantial, offsets are a good way to do that so long as they're buying from a credible offset program."
Limiting unnecessary travel, obviously, is the most effective choice an individual can make for reducing their carbon footprint. If you're traveling short distances, try using a carbon emissions calculator to see if driving might be a more eco-friendly option. For longer trips that can't be avoided—or if you've got a travel bug you're not willing to let go of—consider where you're vacationing.
For developing countries, tourism offers a more environmentally friendly way to boost their economy, through ecotourism rather than pollution-intensive options like logging. "There are examples where people have stopped clear cutting forests because of tourism—they realize it's worth more standing than cut down," Krantz explains.
Concerned travelers can also make an impact via the airline they choose—and what time of day they fly—that can limit their carbon footprint. Flying during the day, for instance, is thought to be more eco-friendly, because an airplane's contrails reflect sunlight, limiting the amount of warming caused by emissions. And not all airlines are created equal when it comes to fuel efficiency. This 2010 report, from the International Council on Clean Transportation, lists airline carriers by fuel efficiency—if you have some flexibility with which airline you choose, consider checking the list before booking. "The difference between the most efficient airline and least efficient is 26 percent of emissions," Pardee says. Until planes can fly on solar power or wind power (or an equally renewable source of fuel) air travel will always have a carbon footprint. If you want to do your part in limiting that, carbon offsets, among other choices, might be your best bet.