Sustainability in the Aviation Sector

The aviation sector is rapidly growing alongside technological advancement together and is becoming an integral part of world the economy important. However, this growth also brings challenges such as increasing emissions and growing environmental impacts carbon like.

According to the International Energy Agency (IEA), the aviation sector is responsible for 2–3% of global carbon emissions, a share that continues to rise. Therefore, sustainability and innovative fuel technologies are a critical importance for the sector’s future.

Sustainability

Sustainability, by definition, is the ability to ensure the perpetual existence of human life while maintaining the continuity of production and biodiversity. In other words, sustainability means meeting the needs of the present without compromising the needs of future generations.

The concept of sustainability is a holistic approach encompassing ecological, economic and social dimensions. There are three fundamental components of sustainability: environment conservation, economic growth and social development. These components must be managed in a balanced manner to achieve sustainability.

The relationship between sustainability and other components (Source: Turkish Airlines)

Sustainability in the Aviation Industry

Sustainable aviation is a promising strategy developed to overcome the challenge of achieving a cleaner, quieter and smarter future for the aviation industry. To ensure a sustainable future, a series of target and commitment have been established covering climate change, noise and local air quality. Sustainability can be applied in areas such as airframe and flight operations; aircraft propulsion systems; auxiliary aircraft energy systems; airports; air traffic control; aircraft maintenance services; ground-based aircraft; and military aviation.

The International Civil Aviation Organization (ICAO), which serves as a global forum fostering cooperation within the aviation sector, supports the achievement of sustainability in aviation. For example, ICAO brings together stakeholders in the aviation industry under the banner of the Global Coalition for Sustainable Aviation, aiming for global collaboration in sustainability. To better understand the environmental impact of aviation, its effects are grouped under three to understand categories: main.

1. Climate Change

Carbon dioxide (CO2) emissions resulting from aircraft fuel use are among the leading causes of global warming. In addition to CO2 emissions during flight, other gases that affect atmospheric heat, such as nitrogen oxide (NOx) and water vapor, are also released.

Sustainable Aviation Fuel (SAF) helps reduce environmental damage in the aviation sector by providing an alternative to fossil fuels. The SAF technology, defined as a fuel derived from renewable or waste-based sources, is still under development.

2. Local Air Quality

Flight operations and other airport activities contribute to air pollution. These activities include aircraft engine exhaust, aircraft fueling systems, airport heating and cooling systems, and ground service vehicles.

The pollutants responsible for deteriorating local air quality are also closely linked to climate change. Emissions from the combustion of fossil fuels contribute to rising atmospheric temperatures and declining local air quality.

3. Noise Pollution

Increasing airport capacities and flight numbers have led to widespread noise or sound pollution, negatively affecting human and animal life. The areas most affected by this type of pollution are the takeoff and landing corridors and their surrounding regions.

Thanks to recent advancements in technology, the noise levels of modern aircraft, measured in decibels, have decreased. The widespread adoption of next-generation aircraft aims to further reduce noise pollution.

To achieve sustainability in aviation and reach long-term net-zero targets, the following actions must be taken:

1. Improve Operational Efficiency: Improvements in all factors affecting flight duration lead to increased efficiency and reduced emissions. Increased operational efficiency enables fuel source savings. Reduced fuel consumption means fewer harmful emissions. For example, optimizing air traffic management systems can shorten flight times.

Similarly, flight routes optimized according to weather conditions and wind speed can result in shorter flights. Additionally, using renewable energy resources efficiently in ground services at airports contributes to improved efficiency.

2. Use of Sustainable Aviation Fuels (SAF): Sustainable Aviation Fuels (SAF) offer an environmentally friendly solution by significantly reducing emissions compared to fossil fuels. SAF, also known as biofuel or bio-jet fuel, can be derived from plants.

The production of SAF, derived from renewable sources or waste, is increasing over time. SAF’s greatest advantage is that it can be used in existing aircraft without requiring major modifications. Efforts to make aircraft compatible with these renewable fuels are ongoing.

3. Development of Next-Generation Aircraft: The development of next-generation aircraft powered by zero-emission, hydrogen and electricity technologies continues. These aircraft, representing a long-term goal, offer an innovative solution to sustainability in aviation.

In addition to aircraft powered by entirely different energy sources, efforts to develop aircraft with improved energy efficiency and reduced environmental impact are also ongoing. This strengthens current fleets in terms of sustainability while pursuing long-term objectives.

4. Management of Unavoidable Emissions: Finally, managing unavoidable emissions through offsetting or carbon capture technologies is a key word. Through carbon offsetting, carbon-neutral flights can be achieved.

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), established by the International Civil Aviation Organization (ICAO), aims to offset and reduce carbon emissions in aviation. Adopted in 2016, this program became effective internationally from 2020.

Sustainable Aviation Fuel (SAF)

Sustainable Aviation Fuel (Sustainable Aviation Fuel – SAF), which plays a vital role in achieving the goals of the Paris Agreement, has become a priority for the high-emission aviation sector in its pursuit of decarbonization.

SAF is defined as aviation turbine fuel containing synthesized hydrocarbons, meeting the specifications of D91 Jet-A and Jet A-91, as well as 3-23 (British) and CAN/CGSB-7566-1655 (Canada) jet fuel standards. In short, SAF is a sustainable version of Jet A and Jet A-1 fuel. The benefits of SAF include:

1. Reduction of CO2 emissions: Fossil fuels release carbon previously stored in reservoirs. In contrast, SAF recycles CO2 emissions already released into the atmosphere.

2. Improvement in air quality: When used, SAF reduces direct emissions compared to conventional jet fuel. SAF can reduce particulate matter (PM) by up to 90% and sulfur oxides (SOX) by up to 100%.

3. Fuel efficiency: SAF has a higher energy density than conventional jet fuel, resulting in a 1.5–3% improvement in fuel efficiency. This increases aircraft range, reduces flight distances and lowers emissions generated during missions.

SAF Usage

The chemical and physical properties of SAF are nearly identical to those of conventional jet fuel. SAF can be blended with conventional jet fuel and, after blending, is certified to the same standards as conventional jet fuel. Such fuels are known as “drop-in fuels” – fuels that can be directly integrated into existing airport fueling infrastructure and aircraft without requiring modifications.

SAF Supply Chain

Challenges in the SAF supply chain affect efforts to reduce aviation carbon emissions. The primary barrier to SAF adoption is insufficient availability of suitable feedstock due to high costs and low arza. Feedstocks for SAF production include biomass, waste oils and agricultural residues. Since these resources are also used in other sectors, securing sufficient feedstock for SAF production is difficult. In 2023, SAF production accounted for only 0.2% of global jet fuel consumption. While blending ratios with conventional jet fuel range from 0.5% to 3%, SAF can be used at up to 50% in some cases.

Sustainable Aviation in Türkiye

1. In line with efforts to reduce carbon emissions, Turkish Airlines (THY) launched the “Co2mission” program in 2022 to combat climate change.

2. THY operated its first flight using SAF on 2 February 2022, between Istanbul and Paris.

3. THY received the “Most Sustainable Flag Airline” award from World Finance.

4. Pegasus Airlines completed its first domestic flight using SAF on 1 March 2022, on the Izmir–Istanbul route.

5. Some airports are aiming for “Green Airport” certification by transitioning to renewable energy sources. Particularly Antalya and Istanbul Airport are actively pursuing initiatives in this area.

6. TUSAŞ Motor Sanayii A.Ş. (TEI) is conducting research on environmentally friendly jet engines. Türkiye’s domestic engine projects are significant in advancing both energy efficiency and carbon emission reduction goals.