“Book more sustainably” — that was the message German airline Lufthansa marketed to travelers when it launched its new “Green Fares” in February. Lufthansa’s new program gives passengers the option to spend a little more money to purportedly reduce the climate impacts of their flights. But climate advocates were quick to criticize the program as another case of greenwashing in aviation.
Almost every major airline has an offsets-based program. Passengers are sold the idea that their share of carbon emitted during a flight can be essentially canceled out by paying to support programs that theoretically reduce an equivalent amount of emissions. Currently, the aviation industry is estimated to be responsible for around 2.5 percent of global carbon dioxide emissions.
American Airlines, for example, has partnered with Cool Effect for its offset program, and offsetting a cross-country flight only costs about $12. Southwest Airline passengers can earn frequent flier reward points for each flight they offset. Low-cost Irish carrier Ryanair advertises that its passengers can “fully offset emissions” for only a few euros.
In 2020, Delta Air Lines pledged to invest $1 billion over 10 years to reduce its carbon footprint, but missed its target in 2021. The airline then spent $137 million to buy carbon offsets to neutralize 27 million megatons of carbon dioxide emissions. Delta’s Chief Sustainability Officer Pam Fletcher now opposes buying these types of credits, though she acknowledged it was the best tool at the time.
There’s growing scientific consensus that the vast majority of carbon offset programs are unlikely to achieve any level of the emission reductions they promise. And some worry that the industry’s reliance on offsets may, in fact, be making aviation’s climate impacts even worse.
How carbon offsets work
I decided to try offsetting my carbon footprint as I planned a trip back home to the United States. In recent years, I’ve replaced the vast majority of my travel with public transportation and intercity trains, something that’s been easier to do since moving to London. But there’s one trip that I can’t easily substitute with an alternative: a transatlantic flight to D.C. to see my family in Maryland.
I typically fly British Airways. Like most airlines, British Airways offers a convenient online calculator that allows you to type in your departure and destination airports, see the per-passenger carbon emissions and elect to buy some offsets to balance it out. The calculator estimated that a round-trip economy flight from London Heathrow to Dulles International would emit 741.29 kilograms of carbon dioxide. And according to the United States Environmental Protection Agency’s carbon equivalency calculator, that one round-trip flight is the same as driving a car for 1,900 miles.
That stat sounded more than a little depressing. So when British Airways’ calculator said it would only cost about $10 to offset the whole flight, I was skeptical. I spoke with aviation industry insiders, scientists and environmental advocates to see if travelers could really absolve themselves of the impacts of a trip for the price of a beer at an airport bar.
Emissions reductions are ‘dramatically overestimated’
“Customers should be skeptical about any offsetting programs offered to them,” said Jo Dardenne, director of aviation at the nongovernmental organization Transport & Environment, which campaigns for clean transportation regulations. And many appear to be; only 1 to 3 percent of passengers buy carbon offsets, according to estimates from the International Air Transport Association (IATA), which represents the world’s biggest airlines.
Even if passengers aren’t buying them, airlines are — and they’re advertised as central to many airlines’ plans to reduce their carbon footprint. In aviation, this often means the money is funneled to programs that claim to protect forests or fund green energy projects.
“Unlike how they’re presented to travelers, offsets are not really quantified, verified tons of emissions-reductions,” said Barbara Haya, research fellow at the University of California at Berkeley’s Center for Environmental Public Policy. Instead, they’re programs that might do some environmental good but ultimately lead to “hard to estimate emissions reductions.” Haya said “in today’s offset market, those reductions are dramatically overestimated.”
Airlines, like anyone purchasing offsets on the carbon market, rely on third parties to ensure the quality of the offsets they purchase. “Airlines are not typically carbon market experts,” said Michael Schneider, assistant director of environment programs at IATA. “They’re not developing those projects. They’re basically buying from a broker.”
Dardenne likens it to paying someone else to go to the gym for you. “How can I be sure that this person is actually going to the gym? How can I be sure that this person wasn’t already going to go to the gym, anyway?”
Offsets help justify increased emissions, experts warn
The most common type of offsets purchased by the aviation industry are forestry and nature-based offsets, which numerous studies have found are mostly worthless. In January, an investigation by the Guardian into the biggest certifier of rainforest carbon offsets found that more than 90 percent didn’t represent any carbon reductions.
The promised emissions reductions hinge on impossible-to-predict claims, said Dardenne. “Nature-based offsetting schemes are dangerous because you’ll never be able to ensure in a climate emergency that a forest won’t get burned down or flooded. You can never be 100 percent sure these offsets are going to work,” she said.
“Offsetting is a climate scam” that ultimately may worsen the climate crisis, argued Dardenne. She said offsets are being used to delay action and delay regulation that can reduce emissions.
Despite offset programs, the sector’s overall carbon dioxide emissions have risen in the past decade at a rate of 4 to 5 percent. As the industry’s recovery continues, that figure is expected to increase as air passenger numbers are projected to exceed pre-pandemic levels by 2024, according to IATA.
“Offsets don’t actually reduce emissions; they just trade where emissions happen,” says Haya, adding that they can “justify ongoing or even increased emissions.” She said she’s losing hope in reforming the market after two decades in the field and is increasingly shifting her focus toward alternatives.
Truly decarbonizing aviation remains a challenge
There are signs that the industry is shifting on carbon offsets. Earlier this year, United launched its Sustainable Flight Fund, a $100 million effort to power airplanes with waste, giving customers the option to contribute a few dollars to the fund when they buy a ticket. Delta also said they are focused on decarbonization now.
In September, low-cost European carrier easyJet announced that it would stop buying offsets “in order to focus our investment into supporting our decarbonisation journey,” Jane Ashton, director of sustainability at easyJet, said in a statement.
IATA’s Fly Net Zero pledge is the industry’s commitment to achieve “net-zero carbon” by 2050, a plan premised on reducing reliance on offsets while scaling production of currently costly sustainable aviation fuels and other emergent technologies. IATA estimates sustainable fuels could reduce emissions from the airline industry by 80 percent.
Even so, IATA’s estimates suggest that offsets will remain the predominant way that the majority of the industry addresses its emissions until at least the 2040s. Similarly, the United Nations’ climate aviation scheme, CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation), also relies heavily on offsetting, as its name makes clear.
This projected continued reliance on offsets speaks to the many challenges to decarbonize an industry that runs on fossil fuels. Sustainable aviation fuels are expensive, and supply is limited.
“We are a harder-to-abate sector,” said Schneider. “We cannot just say, ‘Let’s switch to battery powered aircraft and that’s it,’” he said, referencing that electric plane concepts only have the potential to decarbonize short flights, not long-haul, which account for the majority of the industry’s emissions.
Some argue that the money being spent on questionable offsets could have a greater impact when invested in other areas such as accelerating the transition to more sustainable fuels and investing in developing decarbonization technologies.
“The absolute most important thing the aviation industry can do is to decarbonize — pay the higher cost of sustainable aviation fuels, build sustainable infrastructure, and support R&D,” Haya said. “Airlines are largely throwing their money away by buying offsets.”