Traveling can broaden your horizons, create precious memories and even boost your mental and physical health. But it has a tremendous environmental impact, especially if you fly.

People are trying different strategies to minimize their travel footprint, but it’s hard to do better when you don’t even know the true impact of your choices. When it comes to air travel, we’re discovering that available information is inaccurate. A rash of greenwashing accusations against airlines lately, including some that have already resulted in guilty verdicts in European courts, has fliers rethinking their choices.

Impacts of Air Travel

Unless you are traveling a very long distance, driving is probably better than flying, and traveling by train is the greenest choice.

When you do have multiple options for travel, calculating travel-related carbon impacts is tricky. How do you account for variables like auto tire pollution or the plastic waste generated by different modes of transportation? What about greenhouse gas emissions besides carbon dioxide? Depending on which calculator you use, energy emissions estimates can vary by orders of magnitude.

Even with all the information, discovering the true impact of your travel choices is hard. And it turns out that airlines may have been greenwashing their sustainability efforts.

Can KLM Fly Responsibly?

Most notably, the activist group Fossil Free Netherlands filed suit against the Dutch airline KLM after the airline launched a “fly responsibly” ad campaign in 2019. They argued that air travel cannot be environmentally responsible using current technology, and that claims to the contrary constitute greenwashing.

KLM discontinued the Fly Responsibly campaign. But they did not meet Fossil Free’s request to halt sustainability-related advertising, apologize to customers, and print a rectification in major Dutch newspapers, and they moved to have the case dismissed. In 2023, the Dutch court ruled that the case had sufficient merit to proceed. The first hearing was scheduled for Dec. 6, 2023.

European Greenwashing Claims

KLM isn’t the only airline to face such claims in Europe. In June, the European consumer rights body, BEUC, lodged a complaint at the European Commission against 17 airlines, alleging their use of terms such as “sustainable”, “responsible” and “green” constitute greenwashing of air travel and are deceptive in the same way that advertising “healthier” cigarettes would be deceptive.

In 2020, a year after Ryanair was named one of Europe’s top 10 carbon emitters in a European Union report, Britain’s Advertising Standards Authority (ASA) banned an ad campaign by Ryanair claiming to have the lowest carbon emissions of any major airline in Europe. Ryanair is one of the 17 airlines included in this year’s BEUC complaint. The ASA also took action against Etihad and Lufthansa.

Lufthansa also fell foul of Austria’s consumer protection association when it lost a suit in September. The company was found guilty of misleading advertising that suggested that biofuels made its flights sustainable. In reality, only 5% of the fuel used on the advertised routes was from renewable resources.

Delta Down

The European Union is usually far ahead of the United States when it comes to consumer protection and holding corporations accountable for sustainability. But airlines in America are facing greenwashing claims, too.

In May, a consumer class action suit was filed against Delta Airlines in California’s federal court. From March 2020, when the airline announced its move towards carbon neutrality, to March 2022, when the company claims to have shifted to a focus on “decarbonization,” Delta’s claims that the company was moving towards carbon neutrality rested on the company’s use of carbon offsets. The lawsuit hinges on the effectiveness of carbon offsets, which must provide a benefit that would not have happened otherwise in order to be valid.

Travel Choices

So long as air travel relies on fossil fuels, it cannot be truly sustainable. Some airlines are taking steps towards the use of biofuels, but none of them has switched to primarily using biofuels. Some progress is being made toward electric air travel and there is even a resurgence of interest in lighter-than-air travel. But each of these solutions has its own sustainability considerations and technical hurdles to overcome.

For now, sustainable-minded traveliers need to consider whether each trip is actually necessary. Ask yourself, is a more sustainable mode of transportation is possible? Vacationers can consider trips closer to home and slow travel, while business travelers should implement best practices.

When flying is the best – or only – option, take the time to research which airlines are doing the most to become more sustainable. Unfortunately, sometimes these can be the same ones engaged in greenwashing – many corporations are not against significantly exaggerating their legitimate efforts.

Use carbon calculators like the one on Google Flights to choose the lowest-emitting flights that will get you to your destination.

If you want to offset the carbon emissions from your trip, don’t use the airline’s offset program. When even the best offset programs have uncertain value, airlines’ offset partnerships are based on a flawed system with little credibility and constitute little more than another form of greenwashing. Instead, do your own research to find the best offset program and, we suggest that you consider doubling your offest to make your flight more than carbon neutral, a net improvement in CO2 levels — if you can travel, give the atmosphere a break from greenhouse gases.

By Gemma Alexander

Gemma Alexander has an M.S. in urban horticulture and a backyard filled with native plants. After working in a genetics laboratory and at a landfill, she now writes about the environment, the arts and family. See more of her writing here.