Clearing the Air: The Environmental Cost of Flying
Birds, the last surviving dinosaurs, have been around for 150 million years. In 2022, a type of bird called took 11 days to fly 13,560 kilometers from Alaska to Australia without stopping for food or rest. This is so far the longest recorded ‘non-stop’ bird migration in history. Humans can not only , they can do so ten times faster, while enjoying ridiculous comforts along the way. The aviation industry is in many ways the pinnacle of human ingenuity and progress.
When I was growing up, we could not afford a plane journey. I used to ask my parents to park near the New Delhi airport runway, so we could watch and hear airplanes take off and land. The roar of a jet engine was so exhilarating as a child. It still is! In the last few decades, soaring demand for air travel has brought unparalleled connectivity, bringing people and businesses closer to one another. Unfortunately, like most other modern luxuries in the post-industrial era, air travel too has a hidden cost to society — an ecological and environmental cost that we often overlook when planning the next big vacation or ‘team summit’.
In this post, I will talk about the behavioral changes and technological advancements needed to limit aviation related emissions in the upcoming decades.
How bad is air travel?
Every time we fly, we leave behind an invisible trail of greenhouse gases that are released into our atmosphere, trapping the sun’s heat and raising Earth’s land and ocean temperature for centuries to come. As you can see in the graphic below, air travel has the highest carbon footprint among all modes of transport. If you think about it, it’s not surprising — we are talking about lifting 300 people (& their luggage) 40,000ft above the ground and carrying them across continents at 1000km/hr. Obviously, flying is an energy intensive process. Just to give you an example, one round trip from San Francisco to New York, in economy class, emits roughly 1.5 tons of per person. That’s less than what an average Filipino emits in the entire year! If all eight billion of us flew from SFO-NYC once every year, global annual emissions would increase by a staggering 25%. Let that sink in — 25%!
According to , “Aviation industry accounts for around 2.5% of global CO₂ emissions, but 3.5% when we take non-CO₂ impacts on climate into account.” Despite the sky-high emissions per km of air travel, why is the total contribution so low? The answer is simple — very small percentage of human population can afford to fly each year. According to , a popular environmental newspaper, less than 20 percent of people have flown in their lifetime. Every year, only 5 to 10 percent of the world’s population travels by plane. Even smaller percentage of people can afford a long distance flight. One of humanity’s greatest inventions remains out of reach for a majority of the world’s population. But that is changing…
Aviation trends and forecasts
In the last 15 years (pre-covid), total airline passengers have whereas human population has only increased 20% in the same period. Moreover, people are flying on average. Improvements in socio-economic conditions, artificially low jet fuel prices and better fuel efficiency of modern jetliners have all contributed to . And hence, higher demand.
Despite the temporary COVID-19 slump, America’s Federal Aviation Administration (FAA) is projecting a ~5% annual growth in air traffic over the next few decades (see below), doubling every 20 years. The increase will be even more sharp in Asia and Africa as air travel becomes more affordable for the burgeoning middle-class population. In case you missed it, the previously floundering Air India recently placed an order for , a world record for any aircraft carrier.
With the skyrocketing demand, it’s no surprise that aviation-related emissions have been increasing in recent years. As the world rallies to clean up the electricity grid and road transportation, air travel will increasingly become a larger contributor to global emissions. According to that tracks energy usage for the world’s largest economies, “From 2010 to 2019, average fuel efficiency (of airplanes) improved by 1.8% per year thanks to the introduction of . However, efficiency improvements have not kept up with demand growth, which grew at an average rate of over 5% annually between 2010 and 2019”. If we want to reverse aviation emissions trend, the equation is simple — either we need to reduce demand for air travel or we need to improve fuel & CO2 efficiency drastically. Ideally, both.
If air travel is so energy intensive, why is it so cheap? Answer — government subsidies
Jet fuel taxes are extremely low in most developed countries. EU and California are usually a beacon of hope in the fight against climate change; they have some of the strictest car emissions standards and highest petrol/gas taxes in the world. However, both EU and California go missing when it comes to taxing air travel. Governments around the world are artificially keeping airline ticket prices low, to spur economic activity. The following graphic from Germany’s DW newspaper shows that while train prices are quite close to their real social/environmental cost, there is a large disparity in airline ticket prices and air travel’s true environmental cost.
imposes a hefty $0.67/gallon tax on petrol/gas, but it levies a meager $0.02/gallon on jet fuel. does not impose any jet fuel tax whatsoever, missing out on over 34 billion Euros of additional tax revenue. If you’re interested in the economics of climate change, do check out my recent blog post about conflicting needs of capitalism and environmentalism.
“Higher (jet fuel) taxes will have an impact on passenger ticket prices. This could result in a decrease in demand and CO2 emissions savings. The study finds that ending exemptions in 2022 would have saved 35 million tons of CO2 (in Europe), with an even higher total climate impact accounting for non-CO2 effects of aviation. As the sector seeks to decarbonise, revenues raised by taxation should be partly reinvested in green technologies, including e-kerosene” — , Europe’s leading NGO campaigning for cleaner transport.
The problem with business class
Ten years ago, I got a free upgrade to Business class. I thought it was the luckiest day of my life. The insane legroom, real wine glasses instead of plastic rip-offs, comfy reclining seats with leg support. Sadly, the joy was short-lived when I learned that flying business class has 4x higher carbon footprint than economy. Going back to the earlier example, if all eight billion people were able to fly from New York <—> San Francisco in business class, the global emissions would nearly double!!
You may be wondering — ‘If it takes the same amount of energy to transport a person from point A to point B, why do business-class passengers emit more?’ You see, only a small portion of an airline’s weight comes from the passengers themselves (see figure below). For example, payload (passengers + cargo) makes up merely ~25% of max take-off weight (or MTOW). Moreover, (~5 sqft)can fit in the same space of one business-class seat (~20 sqft). Let’s consider an example — if 1000 people want to fly a route in a 100-seater airplane (with 90 economy + 10 business seats), it would take 10 trips to transport them all. The same airplane would be able to fly 130 passengers if there was no business cabin, resulting in fewer than 8 trips. The business class passengers are indirectly responsible for 2 additional flights in our example, resulting in their ginormous carbon footprint. Now, do that math for a billion people and you’ll notice why flying business class is terrible for the planet.
Business travelers also represent of an airline’s profits, despite making up only 12% of their total passengers. In many ways, business-class tickets help in subsidizing economy prices, keeping them artificially low and thus spurring even more demand for air travel. More air travelers = more potential for future growth for the airlines. Once people are hooked to low cost leisure holidays, it’ll be easy for airlines to start new routes and raise prices over time. So, business class passengers not only add to climate change during their journey, they indirectly support the rapid growth of the entire aviation industry and hence, the growing emissions that result from it.
What can you do?
According to the World Economic Forum (see image below), avoiding one long-distance flight every year is one of the best ways of reducing your carbon footprint, only behind car-free living and having one fewer child (that’s a topic for another day!).
If you must fly, of Canada has a nice graphic to minimize the emissions from your flight (see below). Flying economy is by far the most impactful step. Additionally, direct flights during daytime should be prioritized because aircrafts burn more fuel during landing/take-off and contrails are easier to form at night when there is more moisture in the air. Google flights has an emissions calculator for each flight, so, comparing flights based on emissions is another way to make an impact. Some planes are more efficient than others and hence, more eco-friendly. Lastly, when you do fly, consider offsetting your emissions through reliable agencies like carbonfund.org and cooleffect.org. Carbon offsetting has a lot of issues but it can be treated as a last resort.
“Carbon offsets are a tool for routing money toward good things: low-carbon stoves, forests, community solar energy. Remember, carbon offsets do not absolve you of your own emissions”—
Most promising solutions
I like to focus on personal actions in my blog posts. But there is a lot of work going on in the public and private sector to transform and green-ify the aviation industry. In the near term, sustainable aviation fuels or SAF are the only viable option for reducing airplane emissions. Government subsidies for SAF production are needed to scale up production. At the same time, new jet fuel tax policy can help tame air traffic demand before fully renewable fuels become mainstream. Eventually, zero-emission Hydrogen-powered air travel could become a reality by the 2040s.
You can read about some of these solutions in the appendix by clicking here.
Looking at the near term challenges with sustainable fuels, personal action is the best way to limit aviation emissions in the next two decades. We have to stop treating air travel as a convenience and more as a luxury, a luxury that should be reserved for essential travel, emergencies, humanitarian aid efforts, once-in-a-lifetime events, etc. The era of showcasing opulence on social media must stop. Partaking in exotic work trips must be put on hold till zero-emission air travel is available. As you contemplate your next vacation to Machu Picchu or consider attending a team summit in Miami, remember that fleeting personal enjoyment cannot morally justify the enduring harm inflicted upon billions of humans and trillions of organisms worldwide over centuries.
Thank you for reading and please follow my channel for more climate change related stories. Stay tuned for more climate stories.
