Above the Battlefield: Effects of War on Aviation Emissions

Photo Credit: Shubham Shrivastava

The past five years have seen a dramatic increase in large-scale conflicts worldwide. The most notable of these is the ongoing Russia-Ukraine war that has been raging on for the past three years. The war has been brutal in all aspects, with casualties from Russia alone hitting the grim one million mark. The war continues with no end in sight. It is a given that through this conflict, geopolitical tensions have spiked all across the world, with many countries scrambling to rearm and consolidate alliances to prepare for a future conflict. However, one aspect that has been overlooked by many since the beginning of the war is the near-complete shutdown of Russian airspace to the vast majority of the world. Russia has previously utilized its airspace as leverage to ensure it receives favourable outcomes in negotiations or to coerce countries to do its bidding. It is estimated that since the war began in 2022, global aviation emissions have risen 1% or 8.2 million tons, which may not seem like a lot, but numbers can be deceiving.

Russia’s Impact on Global Aviation

Russia is by far the largest country in the world and, consequently, controls the largest airspace, spanning nearly 18 million square kilometres. Up until the start of the war in 2022, approximately 13,900 flights flew over Russia, averaging around 460 per day, with many of these serving Europe and Asia. However, with the outbreak of war, Russia banned flights from “unfriendly” countries—many of which are from Europe, North America, and Asia—from flying over their airspace, while a select few, namely from the Middle East, China, India, and a few European countries, continue operating within Russian airspace. It is estimated that over 40% of global aviation traffic is banned from using Russian airspace, forcing many carriers to circumnavigate Russia. As a result, many Western Airlines, such as British Airways and Virgin Atlantic, were forced to cancel flights that relied on using the Russian airspace and were forced to cancel their direct flights from London to Beijing. 

Closure of Ukrainian and Russian Airspace - Source: OPS Group

Consequently, many flights connecting Europe and Asia have been severely impacted. For example, Finnair flights AY073 and AY074 that connected Helsinki and Tokyo used to take 9 hours flying through Russian airspace; however, with Russian airspace now closed, the same flight that took less than 10 hours has now ballooned to 13-14 hours, with an extra 3,131km added to the trip. Not only is it more time-consuming, but each round trip now requires roughly 21,000 litres of extra fuel, producing 66 tons of carbon emissions per round trip. Finnair operates this flight four times a week, which equates to 264 tons of additional carbon emissions per week, 1,056 tons a month, and 12,672 tons a year from one route. The figure below shows the optimal/previous routes in the dotted grey line versus the current routes that are represented with dotted blue lines.

Old vs new routes taken by Finn Air from Helsinki to Tokyo - Source: Flightpaths 

Finnair is only one of the many European and Asian carriers forced to revert to Cold War-era flight routes. It is estimated that out of 90,000 global daily flights, 1,100 flights are affected by the Russian airspace closure. Due to the detours, some routes connecting Asia and Europe are emitting up to 40% more emissions. If you recall from earlier, I mentioned how the war increased aviation emissions by 1%; that increase in emissions has largely been driven by these 1,100 flights. While these flights are not the longest or the busiest, their forced detours over the years have contributed significantly to the surge in emissions. 

Beyond Europe

Unfortunately, the past few years have seen conflicts erupt across the world, notably in the Middle East, resulting in numerous airspace closures. It is estimated that since 2021, conflict zones across the world have increased by over 65%, representing a size that is double that of India. As conflicts across the world grow, they further shrink the availability of safe airspaces for airlines, causing congestion in airspaces and increasing carbon emissions. Due to the conflict, certain corridors such as Saudi Arabia and Afghanistan experienced a 100% and 500% increase in traffic, respectively. Saudi Arabia was already a crucial funnelling point into the Middle East, with 700 flights flying in and out of the airspace; however, as of June, it sees up to 1,400 flights as airlines are forced to avoid conflicts in Iraq and Iran. 

Afghanistan has also become a popular alternative for airlines as the available airspace becomes more restricted. Before 2023, Afghan airspace was largely restricted due to ongoing conflicts and the collapse of the US-led coalition in the country. Despite the airspace being deemed safe to use after the Taliban takeover, many airlines were still avoiding the airspace due to safety concerns. However, with conflicts springing up in Iran, Israel, Syria, and Lebanon, airlines were left with little choice but to use any available airspace. Afghanistan typically only saw around 50 flights per day before the Iran-Israel conflict; however, that number has jumped to an average of 280 flights in June 2025. While some airspace restrictions in Iraq, Iran, and Syria have begun to ease, only a limited number of airlines, mainly from the Gulf states and Turkish Airlines, have begun utilizing the space. The vast majority of airlines outside these regions still avoid this area. 

Before Airspace closures in Iran, Iraq and Syria - from Flightradar24

After Airspace closures in Iran, Iraq and Syria - from Flightradar24

According to air traffic flow management (ATFM) data, airspace restrictions over the Middle East have contributed to a nearly 30% increase in delays. Data from week 26 (June 23-29) show that delays rose by 3.6 minutes on average for approximately 7,564 flights per day, or 52,951 flights in total. While 3.6 minutes may seem negligible, the total extra time spent in the air adds up to 190,623 minutes or 3,177 hours from one week alone. While getting exact figures is impossible, we can get a rough estimate of the amount of emissions. From this one week alone, the extra 3.6 minutes of delays across 52,951 flights resulted in an estimated excess fuel burn of 11,671 tons of fuel burn resulting in 40,732 tons of excess CO2 emissions from one week alone. It is clear that conflicts are not only disruptive to the aviation industry but also generate an immense amount of excess carbon emissions. For perspective, this one week alone would equate to roughly the yearly emissions of 8,850 cars.

Part of a Bigger Problem

Unsurprisingly, the aviation industry is very carbon-intensive, accounting for 2.5% of global emissions. However, it is estimated that only 10-11% of the world’s population has access to flights; as more countries become wealthy, their demand for flights will correspondingly increase. China, for example, is expected to have 730 million air travellers by the end of 2024; in 2014, this figure was only 391 million. India is another example of a country experiencing a boom in air travel demand, with 174 million people flown in 2024 compared to only 83 million in 2014. In 2024, global air travel by passenger volume reached 9.5 billion people; by 2030, this figure is expected to surpass 12 billion. While this is great news for the aviation industry, it underscores the need for the industry to intensify its decarbonization and sustainability efforts. 

One of the notable efforts by the industry to decarbonize is through the use of sustainable aviation fuels (SAFs), which are produced by agricultural and biomass feedstocks that can eliminate up to 94% of CO2 emissions. Since 2011, over 500,000 commercial flights have used SAFs to some capacity; however, SAF currently represents less than 2% of total aviation fuel demand, and most airlines use less than 10% of SAF mixture due to cost and availability limitations. The cost of SAFs is currently 2-5 times higher than producing regular jet fuel due to limited production capacity and competition for feedstock from various other industries, such as agriculture and transportation. In an especially price-sensitive industry like aviation, where fuel costs can make up more than 30% of operating costs, and total operating costs can exceed 90% of total revenues, airlines are understandably hesitant to adopt SAFs. Additionally, a myriad of compliance requirements, such as sustainability requirements and operational adjustments, are proving to be expensive. Singapore Airlines has already spent $150 million on compliance; however, it expects this figure to climb higher by 2030. The International Air Transport Association (IATA) projects that SAF could reach 80 to 90% of fuel supply by 2050; however, given current projects and efforts, many experts are skeptical of this projection. 

Source: Bloomberg Green

It is clear that much more aggressive action by policymakers is needed to provide more incentives to amplify fuel production, along with giving more breathing room for airlines to adopt SAF on a wider scale. 

In addition to SAFs, a variety of other innovations are being rolled out by the industry to make aviation more sustainable. For example, aircraft manufacturers like Boeing and Airbus have been developing a new generation of aircraft, like the Boeing 787 Dreamliner and the Airbus A350 XWB, that are 20% and 25% more fuel efficient compared to traditional aircraft like the 747 and A340 models. These aircraft also use advanced composite materials like ceramics and carbon fibre that improve efficiency while reducing weight, further improving fuel efficiency. Additionally, engine manufacturers are playing a big role in developing state-of-the-art engines that further reduce fuel consumption, such as Rolls-Royce’s Ultrafan engine, which is designed to use 25% less fuel in addition to being capable of using a 100% SAF mixture. It also promises to reduce nitrous oxide emissions by 40% along with a 35% reduction in noise emissions. 

Airlines and other industries are also stepping up their efforts to make aviation more sustainable. A notable example can be seen from Lufthansa Technik and BASF with their AeroSHARK aircraft skin. The technology mimics shark skin that is extremely hydrodynamic, with the same principle applied to aircraft, which helps an aircraft achieve higher levels of aerodynamics, reducing fuel burn and consequently reducing carbon emissions. The technology has been adopted by a handful of airlines across the world and has shown promising results, with 12,500 metric tons of fuel saved along with 39,000 tons of CO2 emissions avoided. 

While the industry is making notable efforts to make aviation more sustainable, it is clear that there is an uphill battle ahead to ensure that sustainability ambitions and targets can be met. While conflicts are beyond the control of any airline or governments, for that matter, airlines need to hold firm on their sustainability commitments, and policymakers need to ensure that they are creating policies and incentives to ensure that the industry can meet its sustainability commitments and reduce barriers that interfere with their efforts. The aviation industry is one of the most innovative and technologically advanced industries out there, and it is capable of achieving miracles; however, it cannot solve the sustainability problem alone, and a combined effort with governments and policymakers will be needed to ensure that a truly sustainable aviation can become a reality. 

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Appendix of calculations:

Based on the composition of aircraft types that are flown today. It is estimated that 75% of global aviation is composed of narrow-body aircraft (737, A320, E-175, etc.), and the remaining 15% is composed of wide-body aircraft (777, A330, A350, 787, etc.). The average fuel burn per hour for narrow-body aircraft ranges between 1,800 to 2,200 kg/hr, with CO2 emissions ranging from 7,900 to 9,500 kg/hr. While wide-body aircraft burn 7,000 to 9,000 kg/hr, with CO2 emissions ranging from 22,000 to 28,400 kg/hr. Now, let's assume that of the 52,951 flights, 39,713 are narrow-body aircraft and the remaining 13,238 are wide-body aircraft. Using an average fuel burn of 2,000kg/hr and 8,700kg/ hr of CO2 emissions for narrow-bodies and 8,000kg/hr for fuel and 25,200kg/ hr of CO2 emissions for wide-bodies, it is estimated that narrow-body jets burned an extra 2,382 hours of fuel, resulting in 4,764,000kg of fuel burn and 20,723,400kg of CO2 emissions while wide-bodies burned an extra 794 hours of fuel, resulting in 6,907,800kg of fuel burn resulting in 20,008,800kg of CO2 emissions. Please note that this is a simplified calculation and does not account for a variety of factors that might impact this figure (air vs ground delays, ascent and descent, holding patterns, exact aircraft compositions, exact short-haul vs long-haul flights, and more).