Why sustainable aviation is more than a flight of fancy

There's greater awareness of the climate change emergency now than there was a few years ago.

Commercial aviation is a significant emitter of greenhouse gas (GHG) emissions—and of CO2 in particular. Campaigns by Extinction Rebellion and Greta Thunberg have pushed the link between climate change and the aviation industry higher up the political agenda. A quick look at multinational agreements in the aviation sector over the last 12 years shows that the industry is aware of the situation.

So is sustainable aviation achievable?

Defining sustainability

Perhaps the most well-known definition of sustainability is from the 1987 Brundtland Report from the United Nations, which stated that sustainable development “meets the needs of the present without compromising the ability of future generations to meet their own needs.” It links political development to environmental conditions and brings them into balance with the economy.

A more recent definition organizes sustainability into three pillars: social, economic, and environmental. To be considered sustainable, an industry’s actions must meet the acceptable criteria for all three pillars.

How does the aviation industry measure up to this second definition?

From both a social and economic perspective, the aviation industry makes a significant contribution. Societies around the globe are linked through aviation, which keeps the public connected, furthers diversity and understanding, and helps different communities meet and mix. The industry is also instrumental in delivering products and services around the world, assisting economies to grow and prosper. Some 65.5 million jobs are supported by the aviation sector, which also makes up 3.6% of the world’s Gross Domestic Product (GDP). Globally, each aviation job generates $108,700 in gross value added.

Regarding the environment, however, the impact of flying is unarguably negative. Given that aviation needs to meet all three pillars for its activities to be sustainable, the industry still has work to do. 

The extent of the problem

Commercial aviation was directly responsible for 2.4% of total annual global CO2 emissions in 2018, a share that is expected to increase in the future. This is probably not surprising, given that aviation currently relies on kerosene at a time when other industries are reducing their reliance on fossil fuels.

The impact of this 2018 figure may seem small. However, if the world’s commercial aviation were a country, the industry would be within the top 10 biggest emitters, ranking about sixth between Japan and Germany. In addition to CO2 emissions, the effect of other pollutants and the fact that aviation releases emissions at an altitude where they have an increased warming effect, make it possible that the aviation industry’s total contribution to global warming is actually about 5%.

The industry is still growing, and while “flight shame” may deter some passengers from traveling by plane, it won’t put off the majority of passengers. This means future exponential growth is expected.

For example, China and India are expected to see an increase in flights by 10% per year. The United Kingdom dominates aviation in Europe and has the third-largest aviation network in the world. The UK aviation sector projects some 100,000 additional passengers on flights each year. Such increases will bring an associated boost to CO2 emissions; in the last five years, these emissions have grown by 27%, reaching 936 million tons in 2019.

The recent COVID-19 pandemic, however, might have a profound impact on these figures. The International Air Transport Association (IATA) projects an impact of -48% on the number of flights per year.

How is the aviation industry driving change?

The positive news is that the aviation industry has improved in some areas, and has identified other areas to place on more sustainable footing. In the last five years airline emissions have grown by 25%, equating to 915 million tons in 2019. However, the industry managed to decouple emissions from operations to some degree, with emissions having grown at much smaller rates than available seat kilometers.

The real focus of attention now should be on future trends.

National and international air transport are developing standards and policies to address the detrimental impacts of flying, and are also setting goals to implement sustainable practices. Awareness is growing, as well as increased leadership to drive actions that embed sustainable practices.

As well as responding to multinational agreements and frameworks on a national and industry-wide basis, commercial aviation is active on a company and collective basis. There is a range of aviation policies, targets, and goals backed up by legislation or shared agreements.

Examples of these include 2015’s ground-breaking Paris Agreement, which focused on GHG emissions, adoption strategies, and finance. The Carbon Offsetting Scheme for International Aviation (CORSIA) and the European Union’s Emissions Trading System (EU ETS) are also examples of key multinational agreements aiming to reduce the industry’s CO2 emissions. On a national scale, the UK’s commercial aviation sector committed in 2020 to make flying “net zero” by 2050.

Solutions through technology and innovation

Aviation companies have also been proactive in finding solutions to make commercial flying more sustainable. The hope is that fresh ideas, designs, and materials can reduce or remove our reliance on fossil fuels while still providing us with safe and efficient flights.

Ahead of the Paris Agreement, Virgin Atlantic carried out a test flight in 2008 using sustainable aviation fuel (SAF) to avoid some of the environmental drawbacks of kerosene. There are numerous innovations from the likes of Neste and AltAir Fuels to grow the use of SAFs. Several manufacturers of aircraft, engines, and components are also pursuing the full or hybrid electrification of flying.

While the electrification of aircraft will likely not provide substantial relief on aviation carbon emissions (due to long development and certification cycles, power supply limitations, and constraints within existing airframes), SAFs are already in use. Currently, SAFs only account for approximately 0.01% of all aviation fuel; however, this share is expected to increase.

Other examples that might speed progress on these fronts include aviation-wide efficiencies in air traffic control and airport practices, and allowing planes to fly at different altitudes to lower GHG emissions.

Instruments and measures that could help

In addition to reducing the industry’s environmental footprint through technological progress and multinational measures, governmental intervention can bring about change through instruments such as taxation.

There’s also the bold move to look at curbing the amount of flying and banning domestic flights altogether. The fact that such drastic measures are being discussed shows the appetite for governments to progress on sustainable aviation agendas. While the COVID-19 pandemic has shifted focus away from climate change temporarily, this discussion will likely reappear as the aviation industry recovers.

Are we there yet?

There’s evidence that commercial aviation has moved from a stage of awareness to one of implementation—but the industry certainly has further to go before it can claim true sustainability.

It’s certainly possible to introduce and embed sustainable practices into all areas of the aviation sector. Technology and innovation carry much of the industry’s expectations of becoming cleaner, more efficient, and sustainable. In the face of a climate emergency, decisive and rapid change is needed.