The current public debate about the carbon footprint of flying is simplistic and largely ill-informed. The single best article The Generalist has so far come across was written by Chris Finch and published in the December 2019 issue of Geographical magazine. The following facts and quotes are drawn from this lengthy and detailed piece.
- On any single day there will be at least 200,000 planes in the air around the world.
- 64 million tonnes of cargo are transported annually by aircraft.
- Worldwide aviation released 905 million tons of carbon dioxide into the atmosphere in 2018. according to the International Air Transport Association (IATA), the trade group for nearly 300 airlines.
- This is only 2% of the 42 billion tonnes emitted annually from human-made sources but the real problem is that the number of people flying is increasing rapidly.
- Worldwide there were 4.3 billion passengers travelling along some 22,000 routes in 2018.This was double the number at the turn of the millennium.
- IATA figures predict this will expand to 8.2 billion annually over the next 20 years which will result in a dramatic rise in carbon emissions from around 500 million tonnes in 2015, to nearly 2,000 tonnes by 2050 in a worst-case scenario.
- In other sectors, progress is being made towards decarbonising but technological improvements in aviation are being offset by the huge increase in demand for flights, Even the most modern planes still consume tens of thousands of litres of jet fuel as they have done in the past.
|Source: EARTH TIMES|
- Offsetting is used by airline s and many corporations to cancel their carbon footprint by environmental activities like planting trees, capturing methane from landfills, installing renewable energy.
- Roger Tyers, a research fellow in environmental sociology at the University of Southampton , believes that offsetting is more robust than it was 10 years ago and that some schemes do have measurable benefits but says: '
'The idea that you can fly neutral - that it's a scientific, robust means of cancelling out your emissions - I think that's highly questionable. Very few people offset their flights, probably less than 5% and that’s being generous. In growth markets such as China you probably won't see offsetting at all. So if it remains voluntary then it's not going to go anywhere close to making flying sustainable under the status quo. It would need to be something on a mandatory level, but then I would still argue that the whole concept of carbon offsetting is maybe not the path we should go down.’
- Instead of looking at consumers to solve the problem it has been suggested that national legislation could be used to force the airline industry to reduce its emissions. But according to Alice Larkin, professor of climate scienece and energy policy at Manchester University:
‘Governments are nervous about being too heavy-handed with regulation to actually remove some of the very high carbon choices from people. Also they are protecting an industry where there are lots of prospects for employment, particularly in country such as the UK where we lost a lot of our manufacturing.’
THE PARIS AGREEMENT
I an early draft of the Paris Agreement there was some text about aviation and shipping but this removed. This was because the assumption was made that domestic flights - which produce 1/3rd of global aviation emissions - would be covered by the commitments made by individual countries.
The remaining 2/3rds was pased onto two UN agenencies: the International Civil Aviation Organization (ICAO) and International Maritime Organization (IMO). The latter has set a 50% reduction target.
The ICAO has set up the Carbon Offsettting and Reduction Scheme for International Aviation (CORSIA). This plans to do offsetting on an immense scale in order to keep carbon emissions from international civil aviation at 2020 levels, which they claim will save 2.5 billion tonnes of carbon dioxide between 2021 and 2035. According to Roger Tyers:
`What concerns me most about CORSIA is that passengers will assume that, because there's this scheme at a global level, it's fixed. That the industry has got this under control and therefore nobody needs to worry about it anymore. That kind of moral licence to carry on flying - maybe fly more - and just keep growing the industry is a big concern.’The plan will not be mandatory until 2027. China and India, the world's two most populous countries, are not currently among the signatories.
TECHNOLOGICAL SOLUTIONS: ELECTRIC AIRCRAFT
The car industry has moved swiftly towards battery-driven electric vehicles but such a shift is more difficult for the aviation industry.
- A battery capable of powering transcontinental flight would, with today's technology, be a hundred times heavier than its equivalent weight in jet fuel. Short-haul flights might be more realistic in the medium term.
- Airbus are working with Rolls-Royce and Siemens to build E-Fan X a hybrid electric aircraft with a proposed launch date of 2030
- Boeing is working on a similar project with start-up Zunum Aero
- The Pipistrel Alpha Electro G2 two-seater being built in Slovenia is designed as a precurosor for short haul commercial flights
- The Israeli firm Eviation is aiming to produce its nine-seater Alice electric aircraft ready for use by 2022.
- easyJet is in partnership with Wright Electric with the intention of making its most popular route all-electric within the next 10-20 years.
According to Scott Cohen, Professor of tourism and transport at the University of Surrey:
'Technological optimism leads to inertia among policy makers. They don't have to act now, because they buy into the idea that a technological solution is on the horizon. Unfortunately, such optimism clashes with the need for imminent decarbonisation in an industry that works on manufacturing timetables of a decade or more into the future.
'Say you switch to hydrogen. You're not going to roll that out globally overnight. Maybe you then need 20 to 30 years until you bring everyone globally on to that kind of same page in terms of your infrastructure. So there's a certain lock-in and path dependency that we're not going to break out of in time. By the time the fix is there, the world's on fire.’
The aviation industry is trying to avoid a serious cut in emissions by banking on untested negative emissions technology which may be capable of pulling carbon dioxide from the atmosphere. Alice Larkin argues
'We don't know that negative emssion technologies are going to be operation at scale and in a time frame that is compatible with the Paris Agreement. Even if it turns out that all of that becomes incredibly easy...it's not a very wise approach to just continue to plan for airports and aviation expansion knowing you haven't got the technology to mitigate their emissions...We're making too many optimistic assumptions that aren't backed up by evidence.’
STOP PRESS: Jan 2020: Sustainable aviation fuel (SAF) is made available for aircraft at Zurich Airport carrying delegates leaving Davos. The journal Market Watch comments: 'Aviation biofuels exist, i.e., fuel made from plants or waste biomass that has a much lower carbon footprint, and is generally blended in with regular jet fuel. The big obstacle is making enough without competing with food production, at a low enough price.At the moment, sustainable aviation fuels (SAF), as the industry calls them, are about three times more expensive than commercial fossil-fuel derived jet fuel.' Source: elektrek.co
- In recent years the aviation industry has been experimenting with various sustainable aviation fuels (SAF), from recycled waste to mustard seeds to alcohol. Over the last 10 years over 180,000 flights have been conducted using a blend of SAF. Some10 million litres of SAF are now being consumed every year. This is less than 0.01 % of total consumed jet fuel.
- According to Christopher Paling, researcher at the Centre for Aviation, Transport and the Environment at Manchester Metropolitan University. He points out that the certification process required to get new biofuels to market is 'lengthy and costly'.
'One is ensuring they do not compete for land with food crops which will increase the price of foods globally. Another challenge is making fuels comparable in cost to current fossil fuel-derived kerosene. This single issue of cost is restricting alternative fuels to being "demonstration" projects’
- You can see a live feed of the small number of flights -mainly from Canada and Sweden - powered in part by SAF here: planefinder.net/custom/icao-fuel
FREQUENT FLIERS/PRIVATE JETS
According to Scott Cohen: 'Only two or three per cent of the global population travelled by plane in 2017. But even within that two or three per cent you have this incredible skew towards frequent flyers, in which you have a small handful of people that consume an incredible amount of the distances flown.'
- There has been a substantial rise in the number of private jets. Two-thirds of the world's private jets are owned by the ultra-rich based in North America. Ownership is encouraged by tax breaks. These jets are 10 times more carbon intensive than an equivalent commercial flight.
- Chris Fitch writes: 'A recent report calculated that a single private jet travelling between London and New York released the same emissions as a car driving non-stop for four and a half years. Until the one per cent begin flight shaming, the movement may be doomed to irrelevance.'
In Sweden in 2018, a record 32 million chose to shun flying in favour of taking a train.
- An average diesel locomotive will release between a half and a third the emissions of a plane. Modern high-speed trains emit only a fraction. Eurostar promotes its service as having 90 per cent less emissions than the equivalent budget flight.
- In China, a study of 642 routes by researchers at Beijing Jiaotong University and the Shaanxi Polytechnic Institute found that overall the introduction of high-speed rail to a route led to a drop in air travel of more than half over the following two years. The nation's three major national airlines - Air China, China Southern Airlines, China Eastern Airlines - consider rail as a major competitor.
- China is still expected to be the primary driver of global aviation growth, contributing an extra one billion passengers over the next 20 years.
- In 2007, when Taiwan opened a high-speed rail line from the north to the south of the country in competition with a popular air route, air passengers halved almost overnight. The last direct flight on the route was discontinued in 2012.
- In countries which do not have a huge rail network, rail may not be the lowest carbon option, as building a network requires a lot of steel which is carbon intensive.
- `I think we need aviation’ argues Paul Williams. ‘It's good for people to travel. It broadens peoples' minds, it internationalises people, it brings a host of economic benefits. I wouldn't want to shut down the aviation sector. But I do want it to become a lot more sustainable’.
- 'I've never been a proponent of the idea that we stop flying entirely’ says Scott Cohen, 'but there needs to be some level of moderation within it.’
- Chris Fitch writes: 'Unfortunately, we have boxed ourselves in with an incredibly short time frame in which to develop and install the necessary technology required to continue the scale of aviation currently underway without it busting the carbon budget... If one of humanity's greatest achievements is to avoid becoming a relic of a bygone era, a time when humanity could take to the skies with abandon, the aviation industry may need to simultaneously make great strides with all these potential solutions to combat the harsh realities of climate change,
TURBULENCE and CONTRAILS
- 'Climate change is going to double or triple the amount of severe clear air turbulence in the atmosphere at aircraft cruising altitudes,' explains Paul Williams, of the University of Reading. 'That's because of the way the jet stream is responding to climate change.'
- Changes in the climate will significantly affect aviation in the future. It is already creating faster eastbound transatlantic flights and slower westbound flights as the jet stream speeds up. Other potential impacts include difficulty with planes taking off - more of a challenge in warmer air - as well as increasingly volatile weather, lightning strikes and flooding of low-lying airports.
- Contrails are the name of the white lines planes leave behind them in the sky. These are actually soot-filled ice clouds that block ont-going thermal radiation, which adds to the warming of the atmosphere. A study by Lisa Block and Ulrike Burkhardt at the DLR German Aerospace Center claims that the contrail effect is accelerating and they estimate that the effect of contrails will be three times larger in 2050 than in 2006.