Every year, Earth Day prompts us to reflect on the environmental impact of our actions and the steps we can take towards sustainability.
In 2021, the aviation industry committed to reaching net-zero by 2050 and is vigorously working towards this target through various green initiatives.
In this article, we review a handful of innovations we can expect to see making an impact in future – not just relating to aircraft but airport operations as well.
The Environmental Challenges of Aviation
Emissions
The aviation sector is responsible for about 2.5% of global CO2 emissions. This figure is relatively small compared to other industries; data from Statista gives the following breakdown of global CO2 emissions by industry:
- The power industry is the largest contributor, responsible for 38.1% of emissions
- The transport sector on the whole contributes 20.7%
- For industrial combustion, it’s 17%
- Buildings contribute 8.9%
- Industrial processes: 8.4%
- Fuel exploitation: 6.6%
- Agriculture: 0.4%
Regardless, the specific impact of emissions at high altitudes is believed to have a more potent effect on the climate compared to ground level emissions.
Non-CO2 Emissions
At high altitudes, a range of non CO2 emissions from burning jet fuel can affect the chemical properties of the atmosphere and can be twice as impactful on the climate than CO2.
These emissions include nitrogen oxides (NO2), sulphur oxides (SOx), carbon monoxide (CO), soot (PM 2.5), unburnt hydrocarbons (UHC), aerosols, and hydroxyl compounds (-OH) in trace amounts. These emissions are mostly released at altitudes of 8-13 km above sea level.
When released in certain types of areas with high humidity (known as ice supersaturated regions), condensation trails (contrails) form, and these clouds trap heat in the atmosphere. Persistent contrails are a significant contributor to warming, along with other chemical reactions caused by NO2.
IATA has noted that it’s difficult to accurately measure their impact, but it’s generally accepted that these emissions are the most significant contributor to climate change in aviation.
So-called ‘climate sensitive zones’ are more prone to these issues due to their weather patterns. Researchindicates that optimising the speed and cruise altitude of long-range aircraft can reduce the climate impact by 30% at a cost increase of 5%.
Air Quality
Emissions can also lead to respiratory problems in humans and affect wildlife and vegetation. Near airports, NOx emissions contribute to the formation of ground-level ozone, a harmful air pollutant.
Water Pollution
Aviation contributes to water pollution through fuel spills and de-icing chemicals, and stormwater runoff from airports that may contain oil, grease, heavy metals, and other contaminants. This runoff can pollute local waterways, affecting aquatic life and water quality.
Airport Operations
Airports consume vast amounts of energy for lighting, heating, cooling, and operating equipment, contributing to the overall environmental footprint of the sector.
Airports also generate significant amounts of waste, including from passengers (e.g., food waste, packaging) and operations (e.g., maintenance, cargo handling). Proper waste management is crucial to prevent pollution and promote recycling and resource recovery.
With these points in mind, what are the most important developments underway at the moment?
Sustainable Aviation Strategies and Developments
Fuel Efficiency and Emissions Reduction
One of the primary strategies for reducing aviation’s environmental impact is improving fuel efficiency.
Over the past few decades, aircraft manufacturers have made significant strides in this area, with modern aircraft being approximately 80% more fuel-efficient than aircraft of the 1960s.
Airlines are also adopting more efficient flight practices, such as optimising flight paths, implementing more efficient boarding and disembarking processes, and encouraging passengers to travel lighter or choose direct flights.
Minimising Non-CO2 Impacts
There are several possible solutions to the issues surrounding non-CO2 emissions. Aside from using flight paths that minimise the time spent in climate sensitive areas, changing the composition of jet fuels could help. This would involve reducing the amount of certain hydrocarbons including aromatics, naphthalene, and sulphur.
However, there are reservations around such measures due to concerns about the potential for broken seals, fuel leaks, and the reduced reliability of pumps. A more appealing solution is to use sustainable aviation fuels.
Sustainable Aviation Fuels
Sustainable Aviation Fuels (SAFs) are a cornerstone for the decarbonisation of the sector, reducing carbon emissions by 80%.
SAFs are made from non-petroleum sources including biomass and agricultural residues. Airlines are beginning to integrate them into their fuel mix, although current production levels are far from meeting the industry’s needs, partly due to scalability challenges.
However, manufacturers have committed to delivering 100% SAF-compatible aircraft by 2030. Airbus have been using SAFs since 2019 for their Beluga aircraft, which are used for internal logistics purposes. In addition, they aim to source close to 100% renewable energy for their European sites by the end of the year, and this would reduce the impact of their industrial activities by up to 63% by 2030.
Hydrogen
Green hydrogen is another appealing solution, with Airbus leading the way once again. Through various partnerships, the company is developing an ecosystem to support the development of the infrastructure needed for its production and distribution. Partners include Fortescue Industries, Hiringa Energy, and Air New Zealand.
Of course, the use of hydrogen fuel would eliminate carbon emissions. On the other hand, a greater quantity of water vapour would be emitted compared to other SAFs or traditional fuels.
Contrails would therefore still develop in humid areas, but their composition would be different. They would consist of a small number of larger ice crystals, which affects their role in trapping heat. This is an ongoing area of research so we will need to wait and see whether problems arise.
On the plus side, NOx emissions would be significantly reduced when using hydrogen in jet engines; when powering electric aircrafts, NOx emissions would be eliminated completely.
Electric and Hybrid Aircraft
The pursuit of electric and hybrid propulsion technologies is another exciting development. Companies including Boeing and Airbus are investing in research to create aircraft that rely less on conventional jet engines and more on electric power, which could drastically reduce emissions and noise pollution.
Recent progress includes the agreement between Airbus and STMicroelectronics in June 2023. The agreement pertains to furthering their research on the next generation of semiconductors, which are integral to making the transition to hybrid and electric aircraft.
A lot more development is required before such craft are widely used for commercial purposes, and the batteries are costly. However, it’s possible that we’ll see electric aircraft used for short-range flights within several years.
Carbon Offsetting and Reduction Schemes
In addition to direct emissions reductions, many airlines participate in carbon offsetting schemes, allowing passengers to invest in environmental projects worldwide to compensate for the emissions associated with their flights.
Furthermore, the ICAO has initiated the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) to stabilise CO2 emissions by requiring airlines to offset their growth in emissions.
Green Airport Initiatives
Many airports are implementing measures to reduce energy and water consumption, increase the use of renewables, and manage waste more effectively. Other tactics include improving building insulation, transitioning to LED lighting, and using electric ground handling equipment.
Dubai Airport (DBX) is one example that’s leading the way. The airport continually monitors the energy consumption of thousands of devices throughout the airport, with a view to optimise usage as well as reduce costs.
Delhi Airport has set the target to become a net zero emission airport by 2030 and intend to achieve that through using hydro-based electricity. Kansai airport have similar plans.
Other ones to watch include Singapore Changi, Korea Incheon, Boston-Logan, Chicago O’Hare, Stockholm Arlanda, Hamburg, and Zurich.
Airports are also improving the efficiency of terminal and airside operations using software, and efficient operations lead to efficient energy usage.
Airports of Tomorrow
The World Economic Forum and Airports Council International established the Airports of Tomorrow initiative which seeks to overcome decarbonisation challenges. The initiative focuses on four key areas:
- Infrastructure: Regarding hydrogen and other renewables, this area focuses on the production, distribution, and storage of such energy sources within airport grounds.
- SAFs: The scaling up of SAF production in at least 300 plants.
- Financing: De-risking and scaling up sustainable finance solutions for airports.
- Blue Skies Pioneers: A start-up challenge developed in conjunction with UpLink (the WEF’s open innovation platform), which invites new innovative companies to join the community.
The Sustainable Aviation Challenge
Another UpLink initiative, the Sustainable Aviation Challenge sought to provide 16 firms with high potential for innovation in the sector with greater opportunities for development. This includes access to investors and other industry partners that can help scale up their ventures.
The chosen companies operate in various areas, from hybrid-electric aviation to the development hydrogen propulsion aircraft to cryogenic motors. Others pertain to algae biofuel, solar fuels, and waste and CO2 management.
It will be exciting to see how these companies contribute to the sector’s goals over the coming years.
Conclusion
The aviation industry’s journey toward sustainability is multifaceted, requiring collaboration amongst airlines, aircraft manufacturers, fuel producers, airports, governments, and passengers.
While challenges remain, the industry’s commitment to green initiatives is steadfast – and Earth Day reminds us of the urgency behind this commitment.
Again, airports can have a positive impact by improving the efficiency of their operations. At Zafire, we offer a suite of state-of-the-art solutions to help airports optimise every facet of their operations, from ground handling to departure control.
