A Green Recovery: Sustainability for Aviation in a Post-pandemic Landscape

On 1 January 1914, the world’s first fixed-wing scheduled passenger flight took off from St. Petersburg, Florida for a 23-minute trip to a nearby city, Tampa. The Benoist XIV airboat carried one passenger who paid US$400 – equivalent to more than US$10,000 in today’s value. Percival Fansler, founder of the St. Petersburg-Tampa Airboat Line, declared, “What was impossible yesterday is an accomplishment of today, while tomorrow heralds the unbelievable”. While the service lasted only four months, it ferried more than 1,200 passengers and was a pioneer of the market demand for air travel.

The carriage of commercial passengers and freight has grown steadily over the decades. By creating a global, convenient and rapid transport network, aviation has enabled international trade, tourism, job creation and economic prosperity. According to a September 2020 factsheet published by the International Air Travel Association (IATA), aviation provides 11.3 million direct jobs and supports another 76.4 million indirect jobs globally, contributing 4.1% of the world’s Gross Domestic Product (GDP). There were 4.5 billion air passengers in 2019, 3.6% higher than the previous year and in fact the highest annual number ever. In December 2019, IATA sanguinely forecasted that in 2020, the global airline industry would see incremental improvements in passenger numbers (up 4% to 4.7 million) and net profit (up 13% from US$25.9 billion to US$29.3 billion).

No one could see the storm coming fast and furious. COVID-19 was an unseen and unanticipated scourge that hit economies and communities hard the world over. International passenger traffic dropped 60% in 2020 with 1.8 billion air passengers compared to the previous year’s 4.5 billion, according to analysis by the International Civil Aviation Organization (ICAO). In an April 2021 press release, IATA projected a modest industry recovery in the latter part of 2021, with overall passenger numbers of 2.4 billion for the full year, an improvement upon the 1.8 billion who travelled in 2020, but well below the 2019 peak of 4.5 billion. Compared to the passenger business, air cargo had fared better throughout the crisis. IATA projected that total air cargo volumes for 2021 would reach 63.1 million tonnes, a 13.1% increase over 2020. This meant the cargo business would have recovered relative to pre-crisis levels as 2020 saw a full-year decline of 9.1% compared to 2019.

Source: ICAO Economic Impact Analysis of COVID-19 on Civil Aviation (June 2021)

While COVID-19 continues to be a clear and present challenge for the aviation industry and global economy, it has to some extent shifted attention away from a far more long-term and dangerous threat, which is that of global warming. A common theme between COVID-19 and global warming is that both crises point to the need for responsible stewardship of the physical environment. Health experts believe that the coronavirus that caused COVID-19 most likely originated in bats and made the jump to humans at one of the crowded open-air markets in Wuhan, China, where animals were slaughtered on the spot and sold as fresh meat for customers. Likewise, climate change is caused by the continual burning of fossil fuels and deforestation for agriculture and other uses, which generate carbon dioxide (CO2) and other greenhouse gases that warm the Earth.

Since the pre-industrial period (i.e. between 1850 and 1900), human activities and the consequent emission of greenhouse gases have increased Earth’s global average temperature by 1 degree Celsius. Global warming leads to harmful and potentially irreversible changes to the Earth’s long-term weather patterns, and we are seeing the tangible effects in melting glaciers, rising sea levels, extreme weather and declining biodiversity. These physical changes affect our food and water, safety, livelihoods and quality of life. Recognising the serious risks posed by global warming, 197 countries signed the Paris Climate Agreement in 2015 with the goal of limiting the increase in global average temperature to below 2 degrees Celsius by 2100 (as compared to pre-industrial levels), and pursuing a stretch target to limit warming to below 1.5 degrees Celsius.

To reach the 2 degrees Celsius goal, greenhouse emissions would need to decline by about 25% from 2010 levels by 2030 and reach net zero emissions around 2070. The more ambitious 1.5 degrees Celsius goal requires a steeper decline of about 45% from 2010 levels by 2030 and net zero emissions around 2050.

In 2019, commercial aviation contributed about 2% of global greenhouse emissions. By 2050, the emissions could triple given the projected long-term growth in passenger air travel and freight. To reduce aviation’s emissions and steer the industry closer to the decarbonisation pathways necessary to achieve the Paris Climate Agreement’s objectives, IATA adopted a set of targets to mitigate CO2 emissions from air transport:

• An average improvement in fuel efficiency of 1.5% per year from 2009 to 2020.
• A cap on net aviation CO2 emissions from 2020 (i.e. carbon-neutral growth).
• A reduction in net aviation CO2 emissions of 50% by 2050, relative to 2005 levels.

Source: IATA Aircraft Technology Roadmap to 2050 (December 2019)

Given that the aviation industry has been battered by the COVID-19 situation, the challenge is for all players in the ecosystem to marshal the bandwidth and resources to tackle global warming. At the Global Sustainable Aviation Forum in September 2020, industry leaders reiterated that long-term climate action should be a priority alongside near-term economic recovery. Both strategies are equally important and linked. For aviation to drive global economic recovery and provide economic and social benefits, a green-minded recovery is needed to ensure a prosperous and sustainable industry for the long term. Improving fuel efficiency, for instance, helps airlines to lower costs, raise productivity and reduce their emissions. IATA has stayed the course, before and during the COVID-19 situation, in pushing for the adoption of a four-pronged sustainability strategy:

• A single global market-based measure, to fill the remaining emissions gap.
• Improved technology, including the deployment of sustainable aviation fuels.
• More efficient aircraft operations.
• Infrastructure improvements, including modernized air traffic management systems.

What is the current state of play for these sustainability strategies and other measures that can move the needle in helping the industry to “build back better” towards a green and safe future?

CORSIA as a market-based measure

Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) is a global scheme whereby airlines will purchase carbon offsets to compensate for growth in CO2 emissions above 2020 levels. This will stimulate global demand for carbon offset credits, which are certified instruments that represent an emissions reduction of one metric tonne of CO2, such as through land restoration programmes or processes to remove industrial greenhouse gases. When CORSIA was launched in 2016, it was projected to mitigate an annual average of 164 million tonnes of CO2 between 2021 and 2035, equivalent to about 18% of emissions from international air travel in 2019.

Under CORSIA, airlines would set their baseline using the average of emissions in 2019 and 2020. Because of the pandemic-induced downturn, emissions in 2020 have dropped sharply and the average of the actual emissions in 2019 and 2020 is expected to be equivalent to the sector’s total emissions in 2010. Thus, the CORSIA baseline would be about 30% more stringent than it would have been without the COVID-19 crisis. This means that as airlines recover in the post-pandemic phase, the cost of compliance with the CORSIA requirements would be significantly higher. The ICAO Council agreed in July 2020 to disregard the 2020 emissions and set the CORSIA baseline using 2019 emissions only.

Sustainable Aviation Fuels

Sustainable Aviation Fuel (SAF) is a clean substitute for fossil jet fuels. Rather than being refined from petroleum, SAF is produced from sustainable resources such as waste oils from biological origin, agricultural residues, or CO2 from non-fossil fuel sources. SAF is a drop-in fuel, which means that it can be blended with fossil jet fuel and requires no special infrastructure or equipment changes. SAF can reduce up to 80% CO2 emissions compared to conventional jet fuel. This is because of a fundamental timeframe difference – fossil fuels release carbon that has been stored for millions of years, whereas SAF releases CO2 emissions that were recently absorbed from the atmosphere during biomass production. SAF has other benefits such as much less particulate matter and pollution produced, as well as improved fuel efficiency of 1.5% to 3% because of higher energy density than conventional jet fuel.

Carbon Lifecycle of Sustainable Aviation Fuel (Source: IATA)

Airbus is partnering with Safran, Dassault Aviation, ONERA and the French Ministry of Transport to launch an inflight study at the end of 2021 to study the compatibility of unblended SAF with single-aisle aircraft and commercial aircraft engine and fuel systems, as well as with helicopter engines. This collaboration, known as VOLCAN (VOL avec Carburants Alternatifs Nouveaux), will for the first time, measure inflight emissions and contrail formation using 100% SAF in a single-aisle aircraft. The various SAFs used for the VOLCAN project will be provided by TotalEnergies. The study will support efforts at Airbus and Safran to prepare the industry for large-scale deployment of SAF, which will contribute to achieving 100% SAF certification in single-aisle commercial aircraft and the new generation of business jets.

Maiden flight of a Beluga super-transporter using sustainable aviation fuel from the Airbus Broughton plant in the UK (Photo: Airbus)

Currently, SAFs are more expensive than traditional jet fuel. Estimates range from two times, for some waste-based sources, to up to ten times, for synthetic fuels using carbon capture. This is mainly due to the small production runs. About 100 million litres of sustainable aviation fuel is produced annually, less than 1% of jet fuel used by the industry. Because of the environmental benefits and projected cost reductions from economies of scale, production facilities are being expanded. One of the manufacturers of SAF is Neste, a Finnish oil refining company with a refinery and regional headquarters in Singapore. Looking ahead beyond the COVID-19 economic uncertainties, Neste is investing EUR 1.5 billion to expand its Singapore operations, which will have the capacity in 2023 to produce up to one million tonnes of SAF annually. Neste will then be able to enhance its raw material pre-treatment, such as processing low-quality waste and residual raw materials.

Sustainable Aviation Fuel tanker truck at airport (Photo: Neste)

Aircraft Technology Improvements

Each new generation of aircraft has double-digit fuel efficiency improvements, i.e. up to 20% more fuel efficient. This has led to today’s modern aircraft producing 80% less CO2 per seat than the first jets in the 1950s. To formalise and complement the market-driven improvement in fuel efficiency, ICAO agreed on a CO2 emissions standard in February 2016, which applied to all new aircraft designs from 2020 and newly-built existing models from 2023.

Although currently in early stages of research and development, aerospace manufacturers are investigating fully electric and hybrid-electric aircraft. As battery technology improves, increased energy storage may make electrically-powered commercial flight a reality. Already, several small-scale demonstrators are showing how it can be used for training flights and two-person operations. The biggest challenge is overcoming the relatively low power density of batteries compared to jet fuel. With today’s technology, to electrify a Boeing 737 completely would require a battery of the same size as the plane itself. Galvanized by President Joe Biden’s ambition to slash the United States’ world-leading emissions to net zero, the American National Aeronautics and Space Administration (NASA) is working with companies to demonstrate ways to power aircraft via batteries rather than jet fuel, with the aim of phasing in electric flights within the next 15 years.

NASA’s X-57 Maxwell is an experimental aircraft designed to demonstrate that an all-electric airplane can be more efficient, quieter and more environmentally friendly than airplanes powered by traditional engines (Image: NASA)

In July 2020, UK-based Electric Aviation Group (EAG) unveiled the design of its Hybrid Electric Regional Aircraft (HERA), touted as the ‘world’s largest commercial hybrid electric plane’ that can seat 70 people and has a ‘whisper-quiet’ take-off (Image: EAG).

Honeywell has announced it is developing a power source for hybrid-electric aircraft, which will be able to run on aviation biofuel. It can be used to operate high-power electric motors or charge batteries for heavy-lift cargo drones, air taxis, or commuter aircraft. (Photo: Honeywell)

Another promising green technology is using hydrogen to power a fuel cell to generate electricity or directly combusted for mechanical power. Hydrogen produces no carbon emissions when combusted, instead the end product is water. Furthermore, hydrogen has high power density suitable for aviation – three times that of jet fuel and more than 100 times that of lithium-ion batteries. However, there are technical challenges to be overcome, such as how to store liquid hydrogen, the most promising fuel option, feasibly and safely onboard aircraft.

Efficient Aircraft Operations

Aircraft operations can encompass a broad range of activities including the flying of the airplane, the control and monitoring of the aircraft by the air traffic management system, and various airport activities. Operational opportunities to reduce fuel consumption and on-ground delays represent a big win for all stakeholders – reduced fuel costs for airlines, on-time arrivals and departures for passengers, and reduced emissions for the environment. Furthermore, operational improvements can be cost-effective as they do not require purchase of new equipment or expensive technologies.

Air Traffic Flow Management (ATFM) is one means of ensuring efficient airport operations. It entails regulating air traffic to avoid exceeding airport or air traffic management capacity, and ensuring that available capacity is used efficiently. ATFM uses updated flight information to predict traffic demand and adjusts the flow of flights into or out of congested airports to smoothen air traffic flows. The Civil Aviation Authority of Singapore (CAAS) has a Distributed Multi-Nodal ATFM arrangement with its regional counterparts for regulation of flights prior to departure, thereby avoiding airborne delays during their arrival phase which contribute to safer, greener and more cost-efficient operations.

Another example of efficient aircraft operations is use of the Continuous Descent Operations (CDO) technique whereby aircraft would remain in a smooth continuous descent profile prior to landing, instead of descending with a stepped profile. This means an aircraft descends with reduced thrust and a quieter profile. It is also more fuel and environmentally efficient than a stepped descent. Airlines estimate that each continuous descent approach can save 150kg of jet fuel (equivalent to 500kg of CO2 emissions). Continuous descents are being implemented at hundreds of airports all over the world, including Changi Airport. The Joint Aviation Innovation Research (AIR) Lab, established by CAAS and Thales in Singapore, has worked with a start-up, Aeroficial Intelligence, on a Proof of Concept (POC) use case to generate CDO profiles and calculate CO2 emissions using AIR Lab’s Open Application Programming Interfaces (APIs). Chris Lee, the Deputy Director leading partnerships in AIR Lab shared that, “The collaboration with Aeroficial Intelligence was part of AIR Lab’s participation in the Singapore Aviation Accelerator by Starburst. It was an enriching journey for both corporates and start-ups as we worked together to leverage modern technologies to enable meaningful POCs like sustainable aviation. Most importantly, such collaboration would contribute towards building local aviation capabilities.”

Schematic descent profile of a conventional approach (red) and a continuous descent approach (green) (Source: Wikipedia commons)

By developing and scaling innovation technologies and solutions, start-ups have a growing role in making aviation more efficient and sustainable. In the UK, the Aerospace Technology Institute (ATI) and its sponsors, Boeing and GKN Aerospace, offer the ATI Boeing Accelerator programme that supports the growth of world-class start-ups and boosts the competitiveness of the UK aerospace industry. Each ATI Boeing Accelerator cohort has 8 to 10 start-ups, which will receive equity investments and the opportunity to collaborate with leading companies in the industry. AireXpert, one of the participating start-ups in the second cohort, offers a software-as-a-service platform that streamlines communications across an airline’s network during unscheduled maintenance events, thus reducing delays, operating costs and compliance risks.

Net Zero

Increasingly, businesses across different industries are taking the lead in climate action by setting net zero targets. This entails working towards overall zero CO2 emissions by balancing carbon dioxide emissions with removal through a mix of emission reduction measures and use of carbon offsets. Aviation is moving towards net zero too. The oneworld global aviation alliance – which includes major airlines such as British Airways, Qantas and American Airlines – signed a joint commitment in September 2020 to reach net zero emissions by 2050. A working group has been set up by oneworld to ensure that members collaborate on a roadmap for meeting the goal and adopting best practices throughout the coming decades.

On 24 May 2021, the Singapore Airlines Group announced its commitment to achieve net-zero emissions by 2050. Mr Goh Choon Phong, Chief Executive Officer, Singapore Airlines, said, “We have remained focused on our sustainability goals even as we navigated the COVID-19 pandemic. We know that this is also an increasingly important issue to both our customers and staff.” The Group will use multiple levers to achieve this goal. These include investing in new-generation aircraft, achieving higher operational efficiency, adopting low-carbon technology such as SAFs, and sourcing for high quality carbon offsets. The airline has started working with its partners to chart a detailed pathway to achieving net zero.

The Flight Path Ahead

Commercial aviation has to weather two storms – the more immediate COVID-19 crisis and the longer-term climate emergency. While the industry has been battered by the pandemic, it can do its part by facilitating trade and ferrying goods, including the carriage of vital vaccines to communities around the world. As for global warming, the industry has to adopt a suite of measures to reduce its carbon footprint. The path to net zero will not be easy, but each positive step in reducing emissions can improve operational efficiency, make the industry more resilient to climate-related risks, and signal to governments, customers and other stakeholders that the industry is committed to responsible growth for the long term. The world has become a global village, thanks to aviation bringing people together. Just like we need a village to raise a child, we need a concerted effort between countries and across the public, private and people sectors to tackle the twin crises of COVID-19 and climate change.