My flight shame

Paul Coster
5 min readFeb 18, 2021

I recently asked if personal emissions data could encourage people out of their cars by helping us to better understand our environmental impact. Road transport contributes to ~12% of global emissions, and makes up a higher proportion in countries like the UK (20%), New Zealand (17%) and US (23%).

Even before writing that article I’d been considering my own emissions profile…

Driving a car isn’t my issue as I haven’t owned a vehicle in over 10 years. For most of those years I’ve lived in central London and typically made journeys using active and public transport (walking, the tube and trains). For the past 5 years I’ve had a mainly vegetarian diet. So what’s my emissions weakness? Flights.

Heathrow Airport, London

Flight emissions in the spotlight

Flights produce ~2.5% (~1 billion tonnes) of global CO2 emissions (~35 billion tonnes). Despite the impact of Covid-19, their emissions are expected to triple to ~3 billion by 2050 and make up a greater proportion as other sectors decarbonise. This sector can’t decarbonise easily because the alternatives (e.g. electric or hydrogen flight) are currently inefficient and hugely expensive.

Transport contributes to ~16% (~6 billion tonnes) of global CO2 emissions, largely from road and flights. The share of emissions from passenger flights is increasing. Source: Our World in Data

In 2019, flying was rightly put under the spotlight for a simple reason: studies show that avoiding flight is one of the best actions individuals can take to reduce their emissions. Other actions include having fewer children, plant based diets and using public transport.

In Sweden, a movement called flaygskam (which translates to “flight shame”) was started by Olympic athlete Bjourn Ferry. It gained momentum after teenage activist Greta Thunberg’s mother publicly announced she would stop flying. This was followed by the tågskryt (translates to “train brag”) movement, reflecting the low carbon benefits of train travel.

In the UK, the emissions impact of Harry and Meghan’s private flight to Nice, France was reported on, which was soon compared to William and Kate’s economy class flight to Scotland. It was noted the private flight produced around 4 times the CO2 per person than an economy flight.

The UK reports highlighted that flight emissions aren’t created equally. Private and business class flights are significantly worse than economy flights on a per person basis. The fullness of the flight matters. Then there’s the ‘secondary effects’ from high altitude, non-CO2 emissions.

The chart below shows approximate economy class flight emissions per passenger, per kilometer (km) travelled.

Source: BBC

My flight emissions

I know the majority of my personal emissions are associated with flights, and that the figure would be bad. (I just wasn’t sure how bad.)

To calculate these emissions, I listed every flight I’ve made for the last 10 years. I used an online tool to find the distance between origin and destination, then multiplied by the ‘Emissions per passenger per km’ factors (including secondary effects) from above. I assumed a short haul flight to be anything under 1,000km, which covers trips from London to much of western Europe.

The figures were worse than I had thought. For the last 10 years:

  • I’ve averaged flight emissions (including secondary effects) equivalent to ~12 tonnes of CO2 per year
  • 93% of these emissions were the result of long haul flights (mostly to New Zealand or Australia, on average once per year)

In all likelihood, I’m in the 1% of ‘super emitters’ causing half of global aviation emissions, as reported by The Guardian. They note that “only 11% of the world’s population took a flight in 2018 and 4% flew abroad”. To put my 12 tonnes of CO2 in perspective, below is a comparison of my flight emissions against the total ‘per capita’ emissions from various countries.

Source: Our World In Data

I’ve estimated my non-flight emissions as 4 tonnes of CO2 per year. In London I lived close to the city, typically in small apartments or flats. I didn’t own or drive a car, and my diet was mainly vegetarian. This brings my total emissions to 16 tonnes per year, which is approximately the same as the average American.

Flight shame by country

Analysing my flight emissions made me curious as to which countries are the worst flight emitters. I quickly found this information on Our World In Data, which is an incredible resource. Below is their chart of flight emissions per capita, adjusted for tourism.

Source: Our World In Data

The UK, NZ and Sweden are in the top 10 worst emitters in the world, which is mainly driven by international flights. America rounds out the top 10, however domestic flights are the bigger issue there.

Where to from here?

When I departed for the UK in 2011, I didn’t think about the environmental impact of my flying. I invested money in my business and travel, prioritising regular travel to New Zealand or Australia to see close friends and family, returning for weddings and family events. To reduce the cost of long haul flights I travelled at off-peak times. It’s no excuse, however the relatively low cost of off-peak international flying made these trips much easier to justify.

Departing for the UK at Auckland Airport in 2011

On reflection, I should have committed to living in the UK for long periods without returning home, and set this expectation with loved ones. It’s not ideal, but technology makes it possible to maintain relationships without being there in person. I’m now acutely aware that I have a massive carbon deficit, and my long haul flying can’t continue.

I’ve recently returned to NZ after my UK businesses, Modal and All Change, were affected by Covid-19. Modal’s vision is to make public and active transport the modes of choice. The irony is not lost on me… We’re asking people to stop driving cars while I jump(ed) on planes.

In the future I hope to offset my large carbon deficit from past flights, which will require the planting of around 550 native trees and shrubs. Controlling flight emissions requires super-emitters to radically change our behaviour and, in my case, face hypocrisy.

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Paul Coster

UK and NZ based energy consultant and software entrepreneur, sharing insights into the changing worlds of electricity and transport.