Sustainable Air Travel : The Story So Far
As the mobility sector marshals its efforts against the effects of climate change, we’ve seen a swath of electric and hybrid vehicles, a renewed interest in electrified mass transit, an increase in ride sharing, the development of apps for intelligent and connected multi-modal travel, but for several reasons, mostly related to the weight constraints that govern all flying vehicles, nothing resembling a zero-emission commercial aircraft… yet.
Air transport, by the numbers:
- Each year, 3.5 billion of us travel by air. More than 100 000 flights are made all over the world each day.
- If aviation were a country, it would be the world’s seventh largest carbon emitter, just after Germany. To put that in perspective, let’s keep in mind that per passenger, the fuel consumption of an Airbus A380 is less than 3 litres/100 km.
- As the price of airline tickets dropped, the demand has grown, and is projected to double by 2035.
- 2% of global CO2 emissions are produced by the aviation industry.
The aviation industry has made significant sustainability progress since its creation, and particularly in recent years. Let’s take a look at its three-pronged approach to a sustainable future.
The Three Pillars of Sustainability
Consumers, industry players and technological innovators all have important roles to play in moving aviation toward a sustainable future as quickly as possible.
1- Changes from within
The world of air travel has been working ceaselessly to lower emissions and pollution since its first days. The invention of the turbofan engine in the 1970s contributed to a drastic drop in aircraft fuel consumption, and marked an important milestone in aviation history. The widespread adoption of winglets on more than 8300 aircraft worldwide, has decreased fuel consumption by up to six percent by reducing drag. Winglets have saved over 20 billion litres of jet fuel and avoided over 56 million tonnes of CO2 emissions since the year 2000, according to the ATAG (Air Transport Action Group).
What has been done
- Collectively, the major innovations achieved by the air transport sector between 1960 and 2010 have resulted in a fivefold reduction in the consumption of kerosene, and thus CO2 emissions.
- The aviation industry, under the aegis of the ICAO (International Commercial Aviation Organization) is the first transport sector to embrace a comprehensive carbon offset program, known as CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation), who’s ambitious aim is “carbon-neutral growth as of 2020”. Over seventy countries have already opted in.
What is underway
- Lightweighting, through the use of advanced materials like composites, carbon fibre, and the impending promise of additive manufacturing (3D printing), has the potential to save fuel and cut emissions further.
- Airport are working to lower their carbon footprint: tactics like electric taxiing from gate to runway, or tapping into the local grid to avoid running the engines while passengers are boarding hold great promise. Québec-based Wattman World, expert in electric trains and shuttles, will unveil at Movin’On two of its latest models of electric airport mini-shuttles.
- Flexible navigation: By abandoning rigid, pre-planned flightplans in favour of real-time, digitally-enabled route optimization, pilots can avoid stormy weather and take advantage of favourable winds, saving over a tonne of CO2 per flight.
- And finally, bold new designs for wing geometry or even the aircraft themselves, like this Blended Wing-Body developed by Boeing in collaboration with NASA could significantly cut fuel usage, emissions, and noise, while increasing safety and carrying capacity.
2 — It starts with us
Modern passenger aircraft are highly efficient during the high-altitude cruising portion of their trajectory, so choosing longer, non-stop flights is one way to cut fuel consumption and emissions.
Minimizing luggage and choosing low-carbon transport to and from the airport are also options for the sustainability-minded air traveler.
At the risk of sounding like a growth-hating anti-capitalist, one way to reduce aviation’s polluting emissions and move toward greater sustainability is to reduce the overall mileage of global air travel. Air transport excels at high-speed, long-distance transportation of people and high-value, time-sensitive cargo. With the growing electrification of both public transportation and private automobiles, more short-to-medium distance overland trips could be made using terrestrial mobility options like high-speed rail, so that overall emissions from the transport sector decrease over time.
3- Innovative technologies
Here comes the sun
Bertrand Piccard (Movin’On 2017 speaker) and André Borschberg made history with Solar Impulse 2, a lightweight single-passenger aircraft which flew around the world using solar power alone.
That being said, when it comes to energy density, a litre of jet fuel (kerosene) packs about 15–30 times more energy than a lithium-ion battery of equivalent weight. Solar is unlikely to provide full power anytime soon, but the judicious application of advanced, lightweight solar panels could help reduce the fuel costs associated with in-flight electrical needs: climate control, lighting, entertainment, as well as the heating and cooling required for meals and beverages.
Bertrand Piccard on challenging the impossible, during Movin’On 2017.
The bio-fuel story
Bio-fuels derived from agricultural sources, algae, or even industrial waste could enable carbon-neutral aviation. According to IATA (International Air Transport Association), a total of 100,000 flights using sustainable aviation fuels (SAF) has been reached!
The ultimate goal is to produce jet fuel from sustainable sources instead of fossil fuels. If sourced intelligently and in reasonable amounts, the CO2 released by bio-fuels will soon be re-absorbed by other growing plants, a natural process known as the carbon cycle. Industry experts from the Air Transport Action Group (ATAG) predict that by using bio-fuels in combination with next-gen aircraft and engine design, the net CO2 emissions of air travel in 2050 would be half of what they were in 2005!
Good to know
- In 2008, Airbus successfully test-flew its A380, the world’s largest airliner, using a mix of conventional fuel and GTL (gas-to-liquid). GTL is considered to be an important stepping stone toward biomass-to-liquid (BTL) fuels, which could be produced from wood chips, crops, or even algae. There are already five different internationally-approved pathways for SAF production.
- Currently, 8 major airlines have forward purchase agreements for 1.5 billion gallons of SAF, an important driver for development and scalability of sustainable aviation fuels. Now to ensure that production scales up to commercially viable amounts!
- In 2016, LanzaTech employed a fermentation process to produce 1500 gallons of jet fuel using waste gases from steel mills, demonstrating that top-quality jet fuel could be produced without fossil source extraction or agricultural input.
Shooting for the stars
Ride-sharing giant Uber is looking to deploy quiet, all-electric (and eventually, autonomous) VTOL aircraft for urban ride-hailing, just like Blade Runner predicted.
Elon Musk has mused that SpaceX’s low-cost rocketry systems could also be used as ultra-high-speed ballistic passenger rockets, following a suborbital trajectory that would turn New York to Shanghai into a 60-minute trip.
So… can we fly with a good conscience?
The design and engineering of modern aircraft is one of the most complex technological feats imaginable, with a multi-year timeline. The operational lifespan of these incredible machines is measured in decades. For these reasons, change comes, but slowly. Consumer behavior, societal priorities, and industry regulation can change much more quickly. The synergy of all these elements will be needed to usher in the dream of sustainable air travel which we must make a reality.
