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Yearning to fly

We all know the benefits of travel — but a substantial increase in flying seems unsustainable at a time when aviation’s share of emissions is set to rise and most of the world has pledged to keep global warming at 1.5 C.

From “PPE” to “flattening the curve,” the COVID-19 era has added a host of new phrases to our popular lexicon.

One of the most perplexing has to be “revenge travel,” which speaks to the zealous need many of us have to experience sunnier climes after a year or two in a pandemic holding pattern.

No one is quite sure who minted the expression; some people in the tourism business find it a bit distasteful. But it was on full display this past summer, as the mortal risk of COVID-19 subsided and travel returned in force. Airports around the world — including, infamously, Toronto’s Pearson — buckled under the strain.

While the episode produced endless accounts of flight delays and estranged luggage, it showed that, pandemic or no pandemic, we have an unrelenting desire to travel. Just look at the backlog of passport applications, which became a minor scandal for the Canadian government.


One surprising effect of the lockdowns in the early days of the pandemic was a marked drop in carbon emissions, including from aviation. This, combined with a new reliance on video-conferencing, led to “a realization among many of us that there are alternatives to travelling long distances by air to do business,” said Daniel Bresette, executive director at the Environmental and Energy Study Institute (EESI) in Washington, D.C.

But that hasn’t dimmed the desire to fly for fun.

“There is a segment of the population that really feels that COVID set them back in their aspirations for visiting places or catching up on holidays and seeing family,” said Adeniyi Asiyanbi, an assistant professor of geography at the University of British Columbia Okanagan who studies forest-based climate action. “And the last thing they want to think about is precisely emissions.”

Many observers say the current growth trajectory is unrealistic — and that the aviation industry isn’t being frank about it.

The subtext of revenge travel is that getting on a plane to see the world is our right. And the tourism industry, battered by a couple of years of severe turbulence, is happy to accommodate.

To give a sense of just how much we fly, there were nearly 39 million flights worldwide in 2019; that was up from 25.9 million in 2009.

The Environmental and Energy Study Institute estimates that global air travel traffic is at about two-thirds of pre-pandemic levels, but projects that North America will return to pre-pandemic levels this year or next, with international markets likely to catch up a couple of years later. Thereafter, EESI expects air passenger traffic to grow by about three to four per cent per year.

We all know the benefits of travel — it allows us to marvel at Earth’s riveting beauty and gain a finer understanding of other cultures. But a substantial increase in flying seems unsustainable at a time when aviation’s share of emissions is set to rise and most of the world has pledged to keep global warming at 1.5 C below pre-industrial temperatures.

This summer alone, we’ve seen drought and forest fires in Europe and devastating flooding in Pakistan, which climate scientists see as linked to climate change — and that’s at (about) 1.2 C of warming.

Many observers, including some who have worked in aviation, like former pilot Todd Smith, say the current growth trajectory is unrealistic — and that the industry isn’t being frank about it.

Said Smith, “There’s a hesitancy to be honest and objective about this.”

Taking to the skies

Seeing the scenes of anguish at airports in recent months, one could forget that air travel used to carry a certain romance.

Commercial flight dates back to about 1919, but it didn’t really become popular until the 1940s.

“After the Second World War, you’re really into the age of mass tourism,” said Emily Thomas, author of The Meaning of Travel: Philosophers Abroad.

The notion of jet-setting grew during the so-called golden age of flying from the ‘50s to the ‘70s, when Western economies boomed and boarding a plane held the promise of fine dining and impeccable service. While the images of stewardesses for airlines like Pan Am now feel jarringly sexist and retrograde, the flying experience had an undeniable glamour.

Corporate cost-cutting in the intervening years has eliminated some of the perks and made flying more mundane, but that hasn’t hurt demand. In fact, while worldwide air travel has been on an upward trajectory since 1945, the trend greatly accelerated after 2010 — before being brought down to Earth, so to speak, by the COVID-19 pandemic.

(CBC News)

What gets lost in the fervour to fly is just how few people have the wherewithal to do it. In 2017, Dennis Muilenburg, then-CEO of Boeing, told CNBC that less than 20 per cent of the world had ever been on a plane. Muilenburg framed it as a growth opportunity.

Most of that growth in the coming years is likely to come from Asia — thanks largely to a growing middle class in China, Vietnam and the Philippines.

While more people can afford to fly, the question is whether the planet can afford to accommodate more flying — at least with existing jet propulsion technology. Aviation currently accounts for about two per cent of global carbon emissions; as a point of comparison, electricity generation is about 40 per cent and road transport about 20 per cent.

Aviation’s share may not seem that big, but if it were a country, it would be producing more emissions than Germany.

EESI notes that while other sectors may exceed the environmental impact of flying, “passenger air travel was producing the highest and fastest growth of individual emissions before the pandemic.”

A stubborn emissions problem

Thanks to technological advances in renewable energy and battery storage, there has been significant progress in decarbonizing sectors like electricity and ground transportation. But keeping an airplane aloft with something other than a conventional fossil fuel is a different proposition.

Jet fuel is a mix of hydrocarbons, although it is largely based on kerosene. What comes out of an airplane’s exhaust is about 70 per cent carbon dioxide (CO2), but there’s other pollution as well, including soot, sulphates, nitrous oxides and contrails (water vapour). Contrails stay in the atmosphere for a limited time, but under certain conditions, trap infrared rays and produce a warming effect up to three times that of CO2.


The industry has long teased the possibility of cleaner travel, but a couple of developments increased the urgency to act. One was the release of the 2018 report from the UN’s Intergovernmental Panel on Climate Change (IPCC), which said that we had 12 years to enact significant climate action or face “catastrophic” effects.

The other was Swedish climate activist Greta Thunberg, who declared “our house is on fire” at the World Economic Forum in January 2019 and popularized the phrase flygskam (“flight shame”).

Rising public concern about emissions prompted the leading aerospace manufacturers — Airbus, Boeing, Dassault, General Electric, Rolls-Royce, Safran and United Technologies — to issue a rare shared statement at the Paris Airshow in June 2019. In it, they laid out the main planks of their collective climate action plan: reducing emissions by continuing to look for efficiencies in operations; expanding the use of sustainable aviation fuels (SAF); and designing “new aircraft and jet propulsion technology.”

EESI says “the growth of demand for passenger and freight traffic is a central barrier to controlling commercial aviation emissions.”

The statement also noted that “for the last 40 years, aircraft and engine technology has reduced CO2 emissions by a yearly average of over one per cent per passenger mile.”

Air Transat, for example, has put great emphasis on building a fleet “that is as modern and efficient as possible,” said Chrystal Healy, the company’s vice-president of corporate responsibility and ESG (environmental, social and governance). “That’s been our strategic priority over the last couple of years and will continue to be our focus.” This includes the company’s recent deployment of A321neo aircraft, which Healy says produces 15 per cent fewer emissions.

But the figure that matters is absolute emissions — the fact that individual flights are less carbon-polluting is all well and good, but any progress on energy efficiency is being cancelled out by growing demand. As EESI notes, “emissions from aviation have accelerated in recent years as increasing commercial air traffic continued to raise the industry’s contribution to global emissions.”

The International Council on Clean Transportation says that in 2013, commercial aviation produced 707 million tons of global carbon emissions. By 2019, it was 920 million tons, having jumped about 30 per cent in six years.

“The growth of demand for passenger and freight traffic is a central barrier to controlling commercial aviation emissions,” says EESI.

In the travel industry, there has been excited chatter about offsets, which allow people to fund carbon-mitigation projects to countervail their aviation emissions. There are two main categories: carbon removal offsets, which are activities that take emissions out of the atmosphere, such as tree-planting or technologies like carbon capture and storage (CCS) and direct-air capture; and emission reduction offsets, which reduce the amount of carbon that escapes into the atmosphere, through energy efficiency initiatives and land conservation.

An air passenger is seen walking through Toronto's Pearson airport.
An air passenger is seen walking through Toronto's Pearson airport. (Evan Mitsui/CBC)

UBC’s Adeniyi Asiyanbi, who researches offsets, says their efficacy is “modest at best,” and that they come with “a whole range of problems.”

The big ones are the difficulties with ensuring that emissions reductions are additional (i.e. wouldn’t have happened without the offset initiative) and permanent (e.g. that a forest won’t later be cut down or destroyed by wildfires). Then there’s the more immediate human impact — that is, some carbon offset projects marginalize local communities, which can mean excluding them from their lands. Asiyanbi said research shows many carbon offset initiatives are actually counterproductive, distracting from more effective climate action and hurting people, too.

The industry has its own initiative: the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), a global initiative in which airlines and other aircraft operators offset any growth in CO2 emissions above 2020 levels. But Asiyanbi points out that it is currently a voluntary scheme. “It doesn’t impose anything on the aviation industry. There are no sanctions. It’s not there to enforce.”

Sola Zheng, a researcher at the San Francisco-based International Council on Clean Transportation, said the emphasis on offsets has led people “to think that offsets are going to be one of the main solutions, when they’re not really solving any problems.”

She pointed out that there are almost no offsets within the airline industry itself. “It’s mostly … other sectors trying to reduce emissions on behalf of the aviation sector.”

Technological challenges

The push to decarbonize has led to a growing emphasis on sustainable aviation fuels (SAF), which Healy says are a “huge part of the industry’s road map to get to carbon neutrality by 2050.”

Air Canada has operated some flights this year from San Francisco to Vancouver, Calgary, Toronto and Montreal using SAF.

SAF is more of a category than a specific formula. For example, most SAF available today is made of fats, oils, and greases (such as cooking oil from McDonald’s) that have been refined and turned into fuel. This is known as first-generation SAF. Second-generation SAF is made up of biomass (which includes algae, animal waste and forest residue) and solid waste.

The International Air Transport Association has said that use of SAF “has been shown to provide significant reductions in overall CO2 lifecycle emissions compared to fossil fuels, up to 80 per cent in some cases.”

Air Canada wouldn’t agree to an interview for this story, but in response to a series of email questions, a spokesperson noted the airline has “long participated in research and development of SAF, with our first flights using a biofuel blend occurring in 2012.” Air Canada is also a founding member of the Canadian Council for Sustainable Aviation Fuels and a signatory to the World Economic Forum’s Clean Skies for Tomorrow 2030 Ambition Statement, whose mission is to “accelerate the supply and use of sustainable aviation fuel to reach 10 per cent of global jet aviation supply by 2030.”


Healy said part of the problem is that there is too little SAF available right now, and none of it is produced in Canada.

While SAF is more expensive than traditional jet fuel, its use is likely to increase — for example, the recent U.S. climate bill includes incentives for airlines to buy more sustainable fuel. There is also a proposal in the European Union for a “blending mandate,” in which jet fuel would contain two per cent SAF in 2025 and gradually ramp up to 63 per cent in 2050.

Another fuel source with promise is hydrogen, but both Air Transat and Air Canada see that as a longer-term development.

Given the current level and planned growth of travel, the progress on alternate fuels such as SAF and hydrogen is “negligible,” said Finlay Asher, a mechanical engineer based in Bristol, England, who spent seven years working on aircraft engine design for Rolls-Royce.

Aviation exhaust is made up of more than just CO2.
(CBC News)

Asher says biofuel currently makes up less than one per cent of jet fuel, and ramping up production of crop-based biofuels would require land-use changes (such as deforestation), which could actually lead to the release of more carbon. He says there are also issues in producing more biofuels from waste sources or “e-fuels” from renewable electricity because of scarce global resources and intense competition from other sectors.

Hydrogen gas, on the other hand, poses a different dilemma. In order to be viable, it needs to be compressed and turned into liquid hydrogen, which means cooling it to cryogenic temperatures of -253 C. This requires complex tanks, Asher says, with insulation, thick walls and a complicated control system. Because the tanks are so large, they increase the weight and drag of the aircraft. Incorporating them would require complete aircraft redesign, and the whole process of design, development and certification “is likely to take decades.”

There is hope for electrified air travel. Earlier this month, Air Canada announced the purchase of 30 electric-hybrid aircraft from Sweden’s Heart Aerospace, which Air Canada CEO Michael Rousseau hailed as “a step forward to our goal of net zero emissions by 2050.”

But as this piece from MIT explains, batteries will need to become significantly more energy-dense if they hope to move people and cargo for great distances. For the foreseeable future, electrified aviation will only be able to accommodate small groups for short distances.

As EESI’s Bresette put it, “It’s going to be a while before me and 200 of my closest friends board an all-electric plane in D.C. and land in Los Angeles.”

The planes Air Canada recently announced will only have capacity for 30 passengers, and won’t be ready for service before 2028.

Asher says that accommodating alternative fuels or new methods of jet propulsion ultimately requires “a radical step-change” in aircraft design.

A mockup of a blended-wing concept of the Airbus ZEROe zero-emissions hybrid-hydrogen aircraft is shown at the Airbus booth during the 2021 Dubai Airshow on Nov. 14, 2021.
A mockup of a blended-wing concept of the Airbus ZEROe zero-emissions hybrid-hydrogen aircraft is shown at the Airbus booth during the 2021 Dubai Airshow on Nov. 14, 2021. (Giuseppe Cacace/AFP via Getty Images)

“Right now, airplanes are still more or less the way they were 50, 60 years ago,” Asher says, referring to the “tube-and-wing structure,” which includes a cylindrical fuselage with wings and engines mounted off the wings. To accommodate hydrogen cooling systems or electric batteries would require investment in developing brand new aircraft, which he says can cost about $20 billion US.

A number of alternative concepts have been floating around the aviation sector in recent years, including the “blended wing” design, which features a wider and more aerodynamic fuselage and utilizes the aircraft’s entire body to produce lift (rather than just the wings). Asher says there are big questions with the concept — including where to put passengers. Such aircraft would also require reconfiguring airport infrastructure, which isn’t currently being planned.

Asher says he joined the aviation sector with the belief that he could help make it more sustainable, but found that there wasn’t much appetite for change.

“What became clear is that the technology was not being advanced as quickly as it needed to be. It was not getting adequate resources,” he said.

The reason, he says, is that “fossil fuel is just super cheap.”

The future of flying

While aviation is having an impact on the environment, the inverse is also true.

As Asher points out, higher air temperature can make it difficult for planes to take off. Climate change is also leading to more turbulence and bigger storms, which can complicate air traffic control. Meanwhile, sea-level rise is imperiling low-lying runways around the world.

So what is the future of aviation?

The industry is quite bullish, projecting continuing growth while aiming for net-zero emissions by 2050. The industry is regulated by the International Civil Aviation Organization (ICAO), a UN agency. Climate Action Tracker, which assesses the emissions targets of both countries and business sectors, says ICAO’s climate goals are “critically insufficient” and “nowhere near Paris Agreement compatible.”

Like a number of airlines, Air Transat touts the idea of “travelling responsibly,” even dedicating a page of its website to it. Indeed, the phrase “responsible tourism” has taken hold in recent years, with a number of sites and blogs dispensing advice that includes reducing plastic waste, respecting wildlife and observing local traditions. The UN has a guide of its own, called “Tips for a Responsible Traveller,” which includes “plan[ning] your transport to cut carbon emissions.”

But none of these sites suggest you stop flying.

(CBC News)

Flying less has become a cri du coeur in some quarters. For example, a group called Flyingless touts itself on Twitter as “a petition calling on universities and professional associations to greatly reduce flying.” Greta Thunberg was so committed to reducing her dependence on air travel that she took a zero-carbon racing boat from England to New York to attend the UN climate conference in 2019.

The movement has spent a lot of time trying to convince people to take the train instead of flying. Some governments have rallied around the idea — for example, earlier this year, the French government banned short-haul flights in locales where a train or bus ride under 2½ hours exists. The notion of flying less has gained some awareness, but the growth projections for aviation suggest feelings of flygskam are not widely shared.

Healy said Air Transat really believes in “the positive power of travel.”

“People want to travel, and it’s not for us to tell people what they should or should not do,” she said.

While airlines envision decades of steady business, some observers have imagined a different approach to the seemingly intractable problem of emissions.

One of them is California–based sci-fi author Kim Stanley Robinson, who earned rapturous praise for his 2020 novel The Ministry for the Future, notably from the New York Times and former U.S. president Barack Obama. Drawing on climate science as well as social psychology and economic theory, Robinson’s bracing book has been touted as necessary reading because it raises difficult questions about the challenges ahead. (Robinson even spoke at the COP26 climate summit in Glasgow, Scotland, last November.)

The book is essentially a 500-page thought experiment — namely, how would we respond to a climate disaster on a scale of the Holocaust? Robinson’s novel begins with 20 million people dying in a heat wave in India. The tragedy spurs desperate action, and not all of it is civil. While the United Nations creates a department called the Ministry for the Future, some non-governmental groups take a more extreme approach. Among them is a group of environmental radicals who, in an effort to quickly drive down aviation emissions, use drones to shoot passenger planes out of the sky, effectively scaring the industry into retirement.

Asher doesn’t envision anything quite so chilling. But he says getting through the next decade — which he deems “crucial” in the fight against climate change — calls for a combination of bold regulation and changes to individual behaviour.

Suitcases waiting to be picked up at Pearson Airport in Toronto.
Suitcases waiting to be picked up at Pearson Airport in Toronto. (Evan Mitsui/CBC)

He and former pilot Todd Smith felt so strongly about the issue that they established Safe Landing, an organization made up of concerned current and former aviation employees who want airlines to bring down emissions not only to save the planet, but the industry itself.

One way is to reduce the amount of flying done by the rich. The U.K.-based consultancy Yard recently assembled a list of the celebrities with the most emissions from private jets, suggesting the worst offenders were Taylor Swift, boxer Floyd Mayweather and rapper/business mogul Jay-Z.

“We’ve got one per cent [of people] creating 50 per cent of global aviation emissions,” said Smith, who lives on a canal boat in London, England. “This polluting elite either needs to pay more … or [governments should] put in regulation to stop people from flying so much.” Asher suggests that countries could introduce a tax on frequent fliers.

More broadly, many people are suggesting a change in attitude. While most COVID-19 restrictions are no longer in effect, author Emily Thomas said that the period of reduced travel gave us an opportunity to reflect on its necessity.

“I think one of the positive impacts that pandemic lockdowns had on Westerners was reminding us that travel is a privilege, not a right,” said Thomas.

Smith and Asher say that part of what needs to happen to reduce aviation’s effect on the environment is a change in narratives — to push back on the notion, as Smith said, that flying thousands of kilometres to an all-inclusive resort is “the only way to feel human.”

Thomas believes it starts with redefining “travel.”

“There is definitely a tension here, but travel does not equal flying,” she said, noting that humans “have been travelling for thousands of years” and that commercial flight is a relatively new phenomenon.

“There are many other ways to explore the world, and the advantage of travelling by foot, bus or train is that you see more of it as you go along. Even when flying seems necessary, we can consciously reduce it to a minimum.”

Top illustration: CBC News | Editing: Janet Davison

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