“Carry on flying” – a headline hitting the media as the UK Government publish their transport decarbonisation plan. Not a statement you usually hear when people are talking about reducing GHG emissions. It contrasts staggeringly with the voices of environmentalists, with the rise of Swedish ‘flygskam’ (flight-shaming) and Flight Free campaigns. So is flying really having that much of a negative impact?
What environmental impact does flying have?
Aviation only makes up 2% of global CO2 emissions. In the UK, flying produces 7% of annual GHG emissions. This may not sound a lot, but is still a considerable volume compared to other aspects of life, especially when you consider that CO2 emissions are probably less than half of the story of a plane’s impact. Other emissions from planes (such as particulates, NOx, water vapour, contrails and cirrus changes) at least double the effects of flying on global warming. This isn’t even considering the environmental effects of noise and air pollution near airports.
Less than a fifth of the world’s population have ever flown. Only around 5% of the world’s population fly every year. A very small number of people are consequently having a massive effect on the environment. A short-haul flight from London to Edinburgh can produce more than the annual emissions of the average person in Uganda.
When looking at an individual’s carbon footprint, the effect of flying is stark. Even the most eco-conscious vegan will have all their good work outweighed by one long-haul or two short-haul return journeys a year. Flying is the most energy intensive activity an individual can undertake. Calculate your carbon footprint and see how big the effect is of that single holiday or business flight. If you’re a regular flier, flying is likely to be the biggest source of your carbon footprint. The effect quadruples if you travel business class.
You might think that shorter flights would evidently be better for the environment than travelling long-haul. And this can be the case. But multiple short journeys or connecting trips are usually worse for the environment than long-haul flights. This is because taking off and landing are the most energy-intensive parts of flying, with around 25% of jet fuel used during takeoff alone. This makes longer journeys sometimes more efficient per mile than short-haul. However, if you’re flying extremely long-haul, then the extra fuel needed can further increase a planes carbon footprint per person. All flights still produce way more carbon per mile than other forms of public transport or most electric vehicles.
Making flying more sustainable
There isn’t a single solution that can make flying stop being bad for the environment. Actually, currently, there isn’t a solution (or mix of solutions) that can stop the potential negative impacts.
Batteries and electric planes are suggestions. Currently, there are no batteries anywhere large enough needed to fly a plane for any extensive amount of time. Jet-fuels produce 11,890 watt-hours per kilogram of energy. The best lithium-ion batteries only carry 265 watt-hours per kilogram. It is predicted that battery technology is unlikely to be anywhere good enough for long-haul flights in the next 30 years.
Making air journeys much more energy efficient is also unlikely. Airlines do a lot to make their journeys as efficient as they can, with many using bio-fuels and even asking people to close blinds to help reduce fuel consumption. Better route efficiency and air travel control – and perhaps even cancelling half-full planes – could have further positive impacts.
Offsets (like planting trees or supporting renewable production) are often sold as a solution to stop the guilt of flying. Although they can help to reduce or capture the amount of CO2 produced in your flight, there are many flaws in the system. Offset accounting is often poor, leading to questionable predictions of GHGs saved. The offsetting system is not tight enough to know whether your offset payments are having the positive effect you’re sold. It’s far better to reduce your emissions in the first place, than try and make-up for them once they’re created.
It’s evident that flying is problematic for the environment. Although many people may need to fly to see family, go on holiday or for business, the negative effect this has on the environment is clear. When possible, alternatives should be sort.
Could you holiday closer to home? Could you go to that meeting online? Could you travel more slowly via public transport and enjoy the journey? A train journey to Madrid from London could cause 6x less emissions than the equivalent plane journey. You don’t have to miss out on exploring to lower your carbon footprint.
What’s sure is that “carrying on flying” will not be helping to reduce your GHG emissions, despite the government’s claims. Technology just isn’t anywhere near there yet. It’s as important and as urgent as ever that we reduce the number of flights we take.
BBC News – Carry on flying, says government green plan – https://www.bbc.co.uk/news/business-57830168
UK Government – Written statement to Parliament: transport decarbonisation plan – https://www.gov.uk/government/speeches/transport-decarbonisation-plan
Department for Transport – Decarbonising transport – https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1002285/decarbonising-transport-a-better-greener-britain.pdf
Vox – Air travel is a huge contributor to climate change. A new global movement wants you to be ashamed to fly – https://www.vox.com/the-highlight/2019/7/25/8881364/greta-thunberg-climate-change-flying-airline
Nomadic Matt – Flight shaming: is flying bad for the environment? – https://www.nomadicmatt.com/travel-blogs/flight-shaming-flying-environment/
BBC News – Climate change: Should you fly, drive or take the train? – https://www.bbc.co.uk/news/science-environment-49349566
DW – To fly or not to fly? The environmental cost of air travel – https://www.dw.com/en/to-fly-or-not-to-fly-the-environmental-cost-of-air-travel/a-42090155
The New York Times – Flying Is Bad for the Planet. You Can Help Make It Better. – https://www.nytimes.com/2017/07/27/climate/airplane-pollution-global-warming.html
Readers Digest – Which Is Worse for the Environment: Driving or Flying? – https://www.rd.com/article/which-is-worse-for-the-environment-driving-or-flying/
Journal of Transport Geography – Greenhouse gas emissions from flying can offset the gain from reduced driving in dense urban areas – https://www.sciencedirect.com/science/article/pii/S0966692314001665#s0105
The Guardian – How your flight emits as much CO2 as many people do in a year – https://www.theguardian.com/environment/ng-interactive/2019/jul/19/carbon-calculator-how-taking-one-flight-emits-as-much-as-many-people-do-in-a-year