When cyclist Anna Hughes stopped flying 10 years ago, it seemed like a radical fringe idea. But now the founder of Flight Free UK has convinced thousands of people to join her — and to avoid flying due to the climate impacts of air travel.
Her campaign is just one part of a no-fly movement that is spreading rapidly across Europe and has given birth to a new phrase: flygskam, or Swedish for flight-shame, which means feeling guilty about jetting off on vacation.
"It has become a social norm that you think holiday, you think flight," says Hughes, who no longer goes anywhere that cannot be reached by bike, train, or boat.
"Most people are unaware of how flying affects the environment."
That awareness is growing fast though, as climate concerns have sparked a public backlash against flying that would have been almost unthinkable even a year ago.
One of its most prominent advocates is Greta Thunberg, the 16-year-old Swedish activist, who is currently sailing to New York to attend a climate summit next month because she has forsworn air travel.
For airlines, the sudden take-off of this movement presents a potentially dangerous challenge. Airline passenger growth shows signs of weakening in countries where flygskam is catching on.
There has been a 3 per cent drop this year in the number of passengers for domestic flights going through 10 of Sweden's state-owned airports, compared to last year.
The movement has not only taken aim at summer holiday flights, but also at airport expansion plans including Heathrow in London.
"This is an existential question for us," says Rickard Gustafson, chief executive of Scandinavian Airlines (SAS), which is based near Stockholm.
"If we don't clearly articulate a path to a sustainable aviation industry, it will be a problem."
He says the issue of passengers attitudes to emissions was not considered a priority when he brought it up at the board of the International Air Transport Association, on which he sits. But that has now changed. "Six months later this was a hot topic," says Gustafson.
Even if it is not yet hitting the bottom line, airline executives have begun to take emissions impacts and climate risks more seriously. "Aviation needs to reinvent itself," admits Johan Lundgren, chief executive of easyJet.
The problem for the aviation industry is there are few technological solutions available that will help it reduce emissions and address the potential consumer backlash.
"The basic trouble is that humankind has not worked out how to put a passenger jet on a long-distance flight yet without burning through something on the order of 100 tonnes of fossil fuels," says Mike Berners-Lee, a carbon footprint specialist and professor at Lancaster University.
"We have to bite the bullet on aviation, because we just don't know how to do it in a low-carbon way."
Airlines account for about 2 per cent of carbon dioxide emissions globally. But the headline figures obscure the broader impact of air travel.
When planes fly through the sky they also emit other substances that have a significant warming effect — such as nitrogen oxide, and contrails, the long thin clouds of frozen vapour that are visible from the ground.
A growing body of research shows the climate impact of aeroplanes is about twice as much as their CO2 emissions alone would suggest — closer to 5 per cent of human-caused warming.
Volker Grewe, professor of atmospheric physics at the German Aerospace Centre (DLR), says these "non-CO2 effects", such as particle emission, nitrogen dioxide and contrails, are a major contributor to planes' warming impact.
"Aircraft are flying at higher altitude of 10-12km and whatever emissions they produce at that altitude remains longer in the atmosphere," he says.
"That is the big difference between aviation and surface transportation, which doesn't have these additional effects."
The threat of a consumer backlash over emissions is not a complete surprise for the industry. Some executives have been trying to focus attention on emissions for at least a decade. Iata, the aviation industry body, made a commitment in 2009 that the entire industry would halve emissions by 2050, relative to 2005 levels.
"It's very ambitious," says Chris Goater, an Iata spokesman. "We have a big responsibility and it is a huge challenge to deal with this."
Some airlines, especially in European countries with particularly environmentally-engaged customers, have made their own specific pledges. SAS has said it will cut emissions by 25 per cent by 2030 and is aiming to run domestic flights on biofuel.
IAG, which owns British Airways and Spain's Iberia, has pledged to invest US$400 million ($627.8m) on developing alternative fuels over a 20-year period, while United Airlines has said it will spend up to US$2 billion annually on fuel-efficient aircraft and has partnered with biofuel producers.
Dutch carrier KLM even launched a campaign urging passengers to fly less. It includes tips such as "consider making video calls instead of meeting face to face" and "explore other travel options" like the train for shorter trips.
With the rise of flight shame, airlines are racing to find an answer for how to decarbonise and reduce their climate impact. But the challenge is that there are no easy ways to reduce emissions meaningfully — at least not in the near term.
Underscoring the difficulty of the problem, different airlines are taking quite separate approaches to reducing the emissions of their flights. Willie Walsh, chairman of IAG, acknowledges there is no simple, short-term solutions for the airline industry.
"Therefore aviation needs to use some of its money to provide incentive to others and we'll only do that where, you know, these are real carbon reductions," he says.
Some airlines, including IAG, believe one of the most promising areas is alternative low-carbon fuels, which could be used in existing aircraft, but with a lower carbon footprint.
These include biofuels, which can be made from plants, waste or algae, and synthetic fuel, a substance resembling jet fuel that can be manufactured using renewable energy.
Others are pinning their hopes on electric aircraft and hybrid battery-fuel designs.
At present, the only one of these technologies that is being used commercially is biofuels, albeit at a very small scale. United Airlines, for example, has partnered with California-based AltAir Fuels, which supplies the airline with biofuel made from agricultural waste. It has also partnered with Fulcrum BioEnergy, which is developing waste-to-fuel refineries.
"We see this as the future in this space," says Aaron Robinson, senior sustainability manager at United Airlines. He is optimistic about using waste for biofuels given that it is cheaper to acquire than crops.
However, the disadvantage of biofuels is that they are at the moment still much more expensive than regular fuels, and would face serious land constraints to being scaled up.
At present biofuels can be manufactured on a small scale using agricultural waste and household waste, but to reach the level of production that would have a big impact on aviation emissions much more land would be needed to grow the crops that would be converted to biofuel.
As a result, many environmentalists are dismissive of biofuel as a long-term solution, particularly because a growing world population will need more food to feed itself.
To limit global warming to a 1.5C increase in temperatures would require so much biofuel that it would take up to 7m square kilometres of arable land — roughly the size of Australia — to produce that much feedstock, according to a recent report from the UN Intergovernmental Panel on Climate Change.
"If you were to replace all today's aviation fuel with biofuel, with first-generation biofuel, it would be at the expense of 2,100 calories per person per day for everyone on the planet," says Prof Berners-Lee.
"It would take almost all of humankind's calorific requirements . . . So that is absolutely not a solution."
There is one area where airlines have managed to make considerable progress in reducing emissions — by improving the efficiency of aeroplanes themselves. United Airlines, for example, says it has improved its fuel efficiency by 45 per cent since 1990, thanks in part to more efficient planes.
However these gains have been outstripped by the total rise in global air travel — airline emissions in Europe increased 26 per cent between 2013 and 2018, according to the EU.
And Iata predicts annual passenger numbers will double to 8.2bn by 2037.
For some in the industry, electric and hybrid aircraft could generate another major reduction in emissions. Several of the world's biggest aviation manufacturers, such as Boeing and Rolls-Royce, are working on electric-powered aircraft, including hybrid planes that run on a combination of fuel and battery power.
At this year's Paris Air Show, Israel start-up Eviation unveiled an electric aircraft taxi called "Alice" that can carry nine passengers for up to 1,050km.
European low-cost carrier easyJet is also confident about these technologies, which tend to be suitable for the type of short-haul flights that the low-cost carrier specialises in. The company is advising Seattle-based start-up Wright Electric as it designs an electric plane that could serve the airline for flights of less than 500km.
"We know what we think would work for easyJet, so that's why we're looking at electrification and hybrid," says Gary Smith, director of operations transformation at the carrier. He adds that biofuels are "not going to solve [easyJet's] problem".
Budget carriers such as Ryanair, easyJet and Wizz Air point out that their flights tend to be some of the most efficient, in terms of emissions per passenger per km, because they have newer fuel-efficient aircraft, no first class and usually operate full planes.
However, the total emissions for the budget carriers are still high. EU data this year revealed that Ryanair is Europe's tenth biggest polluter. The other nine were power plants.
These electric aircraft are not going to be available anytime soon. Furthermore the heavy batteries used in electric aircraft mean that they will not be suitable for long-haul flights.
For these reasons, not everyone in the industry is enthusiastic about electric planes. Walsh, of IAG — whose flights include a relatively large proportion of long-haul trips — says electric and hybrid technologies are not relevant to the business for another 25 to 30 years.
Whatever the technological challenges, industry executives realise that the passenger focus on airlines' emissions is only likely to grow.
"There is going to be more awareness of climate change," says Joszef Varadi, chief executive of Wizz Air, the Hungarian low-cost carrier. He points to the recent EU parliamentary elections where Europe's green parties gained ground.
Activists are also growing more impatient with an industry which has set lofty objectives but which does not yet have the tools to meet them. Without solutions that can reduce the climate impact of flying in the immediate future, they say that people just have to fly less.
"We are really seeing a growing no-fly movement, and that is because, even though there might be some technological solution in the long-term horizon, we really do have to tackle the growth that is happening right now," says Lucy Gilliam, an aviation and shipping expert at Transport and Environment, a Brussels based non-profit.
"We are seeing that all around, people are going, oh crikey, aviation is actually part of my footprint," she adds. "And when they look at things that they have direct control of, aviation comes up in the top three things that you can actually do to reduce your impact."
Fuel taxes: Politicians could seek to raise funds from air travel
The financial impact of flight shame has so far been limited: global air travel is still growing healthily, driven by demand in Asia — particularly China. However investors are starting to pay attention — during the latest round of corporate results in the sector, environmental issues were among the most prominent questions for executives.
Analysts say that if the flyksgam movement spreads beyond Europe — or if governments introduce punitive taxation in response — it could pose financial risks.
Countries such as Sweden have already seen a drop in air travel, and an increase in train travel, because of the movement.
Daniel Roeska, analyst at Bernstein, says there is often a discrepancy between people's vocal support for less pollution, and their willingness to actually reduce their air travel habits. But governments could still use emissions concerns as a pretext to increase air taxes in the future, he adds.
"I expect air travel to become more expensive, and this in turn will reduce the cheapest, least valuable demand in the market," says Roeska. "Likely it will lead to a period of slower growth for aviation in markets that push the emissions agenda."
Last month France announced an environmental tax on all flights leaving the country, part of President Emmanuel Macron's efforts to win over the increasing green vote.
The tax is initially quite low — it starts at roughly €1.50 ($2.61) for economy flights and goes up to €18 for business tickets — but it provides a signal about how politicians are picking up on the issue.
Activists have also started to push for more attention on fuel taxes — especially as jet fuel is exempt from taxation in many EU countries. Sweden and the Netherlands have been calling for an EU agreement to introduce an aviation fuel tax.
Written by: Janina Conboye and Leslie Hook
© Financial Times