How freighters are shrinking their carbon footprint

The air cargo industry stands at a critical juncture in its sustainability journey. While dedicated freighter operations represent a vital component of global trade, enabling the swift movement of goods across continents, they also contribute significantly to aviation's carbon footprint. As pressure mounts from regulators, customers, and stakeholders to decarbonise, cargo operators are increasingly focused on actionable strategies to reduce emissions without compromising the speed and reliability that define their service.

According to the International Air Transport Association (IATA), air cargo accounts for roughly 15% of commercial aviation’s CO2 emissions.

Unlike passenger aviation, where belly cargo can leverage flights already scheduled for travellers, dedicated freighters must justify every flight on cargo demand alone. This distinction makes the environmental challenge more acute, but it also creates opportunities for targeted innovation. From fleet modernisation and sustainable aviation fuel adoption to operational optimisation and ground handling improvements, the industry is pursuing multiple pathways toward net-zero ambitions.

The strategic imperative of fleet renewal
For operators like DHL Express, fleet modernisation sits at the heart of their decarbonisation strategy. “Fleet renewal is essential for DHL's sustainability efforts, as newer freighters like the Boeing 777F are more fuel-efficient and have a higher payload capacity,” explains Travis Cobb, EVP Global Network Operations & Aviation at DHL Express. Transitioning to these modern aircraft helps achieve significant fuel savings and reduce CO2 emissions, aligning with DHL's sustainability targets and enhancing operational efficiency.

DHL has committed to achieving net-zero emissions by 2050, with an interim target of reducing carbon emissions per shipment by 50% compared to 2020 levels by 2030. Fleet renewal plays a central role in this trajectory, as newer aircraft not only consume less fuel but also integrate more seamlessly with emerging technologies and operational practices designed to minimise environmental impact. “Dedicated freighter operations, such as those using the Boeing 777F and Airbus A330F, are designed for cargo transport, allowing for better space utilisation and fuel efficiency. Unlike passenger aircraft, which may not be optimally scheduled for cargo,” says Cobb.

“Collaboration with governments and regulatory bodies is crucial to establish policies that promote SAF adoption, helping DHL meet its ambitious climate goals.”
Travis Cobb, DHL Express

The importance of fleet efficiency extends beyond dedicated freighters to the belly cargo model as well. Andrea Ayala, Environmental Sustainability Senior Manager at United Airlines, emphasises that “belly cargo carried on passenger aircraft typically has a significantly lower greenhouse gas emissions (GHG) intensity than cargo carried on dedicated freighters, as it leverages flights that are operating regardless of cargo demand.” United Cargo’s strategy prioritises maximising belly utilisation across a modern, fuel-efficient widebody fleet that includes newer, more fuel-efficient aircraft, optimising network flows to reduce unnecessary repositioning or empty legs. “By filling otherwise empty space on passenger aircraft, cargo helps improve passenger airline GHG emissions intensity per flight, spreading fuel burn across both passengers and freight,” Ayala explains.

Cobb highlights DHL’s belly cargo operations in partnership with aircraft operators. For example, DHL works with IAG to use SAF for all belly freight operations out of London.

Sustainable aviation fuel (SAF): the biggest lever today
While fleet renewal provides immediate benefits, industry leaders consistently point to sustainable aviation fuel as the most impactful tool currently available for reducing aviation emissions. “With the use of Neste MY Sustainable Aviation Fuel, greenhouse gas emissions can be reduced by up to 80% over the fuel’s life cycle, compared to using conventional jet fuel,” states Mario Mifsud, Vice President Renewable Fuels Sales & Trading EMEA & APAC at Neste. This dramatic reduction stems from SAF’s production from renewable waste and residue raw materials. “Neste’s SAF is made from used cooking oil and animal fat waste, both renewable waste and residue raw materials,” Mifsud adds.

DHL has set an ambitious target of using 30% SAF in its air fleet by 2030, supported by large-scale agreements with suppliers including Neste, BP, Shell, Phillips 66, World Fuel Services, and Cosmo. The company's GoGreen Plus service enables customers to participate directly in emission reductions by choosing SAF-powered transport for their shipments. Similarly, United Airlines has emerged as a leading SAF user, with Ayala noting that at various points over the years, physical blended SAF has been purchased by United at the following United locations: Chicago, San Francisco, Houston, Washington, D.C., London and Amsterdam.”

“United’s long-standing SAF initiatives, including offtake agreements, have the potential to allow SAF to be integrated across high-volume international hubs and long-haul routes, where cargo demand is strongest.”
Andrea Ayala, United Airlines

One of SAF's greatest advantages is its seamless integration with existing operations. “One of the big advantages of SAF is that it is a drop-in fuel, meaning it works seamlessly with existing aircraft engines and fueling infrastructure,” Mifsud explains. “Current jet fuel specifications, such as American Society for Testing and Materials (ASTM) and the UK Ministry of Defence’s Defence Standard (Def Stan), allow SAF to be blended up to 50% with conventional jet fuel. Once blended with conventional jet fuel, it is certified as a regular jet fuel and ready to be used. This compatibility means that even older widebody cargo aircraft can benefit from SAF without requiring costly retrofits.

For cargo transported on passenger networks, SAF deployment offers particular advantages. “SAF is deployed at the aircraft level, meaning both passengers and cargo benefit simultaneously,” Ayala notes. “This allows cargo customers to participate in decarbonisation efforts today through book-and-claim, even when physical SAF is not available at every origin airport.” Book-and-claim models, where the physical delivery of SAF is decoupled from its environmental benefits, provide companies with flexible options to reduce air freight emissions. As Mifsud observes, “Book and claim models, in which the physical delivery of the SAF is decoupled from its environmental benefits, provide companies an easy and viable option to reduce the emissions of their air freight. More and more airlines and logistics companies offer their customers this option, for example, DHL’s Go Green Plus service.”

Scaling SAF production and availability
Despite SAF’s proven benefits, availability remains the industry’s biggest challenge. Neste, the world’s leading producer of SAF and renewable diesel, is working to address this constraint. “Our current SAF production capability is 1.5 million tonnes per annum (about 1,875 billion litres), which is set to grow to 2.2 million tonnes per annum once the expansion of our renewables refinery in Rotterdam, the Netherlands, is completed in 2027,” Mifsud reveals. He adds that Neste’s renewables refinery in Singapore is currently the world's largest SAF production facility.

Ayala identifies the primary challenges as “supply availability, cost, and geographic distribution,” noting that “SAF production today remains limited relative to global aviation demand, and supply is often concentrated in select regions.” Scaling SAF requires “continued investment in production capacity, supportive policy frameworks and incentives and infrastructure development at major international hubs,” Ayala adds. United continues to work with producers, airports, governments, and industry partners to expand SAF availability.

The cost barrier, while significant, should be viewed in context. “The cost of SAF is indeed a barrier to full-scale adoption, but should be put into the right perspective,” Mifsud argues. “The impact of using SAF on ticket prices or per weight unit of freight is relatively minor with current volumes of SAF being used, as examples from the aviation industry show.” Growing customer demand for emission reductions, combined with regulatory drivers such as the EU's ReFuelEU aviation mandate, is creating momentum for broader SAF adoption across both passenger airlines and dedicated cargo operators.

Operational efficiency and smart planning
Beyond fuel and fleet, operational optimisation plays a crucial role in reducing emissions intensity. DHL's Fuel Optimisation Programme focuses on reducing aviation emissions through better flight planning and engine technology. Cobb emphasises that the company “will continue transitioning to efficient aircraft like the Boeing 777F while implementing innovative practices to enhance efficiency and reduce environmental impact, all while meeting the growing demand for its express logistics services.”

For United Cargo, operational decisions around cargo load factors and shipment profiles directly affect fuel burn. “Cargo load factors directly affect aircraft weight and fuel burn, making smart planning and optimisation essential,” Ayala explains. United Cargo focuses on optimising shipment mix and density, balancing payload across routes to avoid unnecessary fuel penalties, leveraging digital tools to improve forecasting and load planning. “High-value, time-critical, and temperature-sensitive shipments are routed through the most efficient aircraft and networks available,” she adds. These operational decisions help improve emissions intensity per tonne-kilometre, aligning cargo performance with United’s broader sustainability objectives.

The ground handling dimension
While flight operations dominate the carbon footprint of air cargo, ground handling represents an important area where immediate action is possible with existing technology. Manuel Berger, Global Head of Sustainability at Swissport, notes that “emissions from ground handling are a small share of total air cargo emissions, which are largely driven by air operations and ground transportation. However, he emphasises that “unlike aircraft decarbonisation, which will require a major technology revolution, we are already introducing many solutions that are currently available to reduce the ground handling emissions share.”

Swissport's approach centres on practical measures, including electrifying equipment both inside warehouses and on the ramp, improving energy efficiency in warehouses, and transitioning to renewable energy where possible. “Across Swissport’s global cargo operations, electrification is already well advanced, particularly for forklifts, 65% of Swissport Cargo forklift fleet is already electric,” Berger reports. The company is gradually expanding the use of electric tugs and cargo loaders as the technology becomes more widely available. The company is leading the sector’s green transition with more than 26% of its global fleet now electric.

Energy efficiency in cargo terminals takes on added importance for temperature-controlled and pharmaceutical shipments. Swissport operates 117 warehouses globally, and Berger explains that “energy efficiency and environmental performance are core elements of how we operate and invest.” Key initiatives include LED lighting upgrades, green energy procurement programmes, and sustainable cooling solutions. “In Dublin, for example, we developed a pharmaceutical room using R290 (propane), a natural refrigerant with significantly lower environmental impact,” Berger shares.

“One of the main limiting factors today is the charging infrastructure at airports. As this infrastructure continues to develop, electrification will play an increasingly important role in reducing emissions from ground handling activities.”
Manuel Berger, Swissport

The pace of ground handling decarbonisation often depends on airport infrastructure, particularly charging capacity for electric equipment. “The most common constraint today is the availability of sufficient charging capacity for electric equipment,” Berger observes. “While this can slow down deployment in some locations, it is a solvable, near-term challenge.”

“At Swissport, we work closely with airports, landlords and energy providers to plan infrastructure upgrades and align investments. This collaborative approach is essential to ensure decarbonisation efforts support operational resilience, safety and service quality,” he adds.

Integrated strategies for net-zero
The path to net-zero in freighter operations requires coordinated action across multiple dimensions. United Cargo operates as part of United Airlines' broader sustainability strategy. “United Cargo is a division of United Airlines, Inc. As such, it is fully integrated into United Airlines’ enterprise-wide sustainability goal, which targets net-zero greenhouse gas emissions by 2050 without relying on traditional carbon offsets,” Ayala states.

Beyond flight operations, United Cargo has established a Sustainability Volunteer Group bringing together cross-functional leaders to identify and advance cargo-specific initiatives.

Key focus areas include reducing emissions from road feeder services and trucking networks, expanding recycling and waste-reduction programmes across cargo warehouses, supporting community-based sustainability initiatives, and driving education and engagement among employees and partners. “By addressing these adjacent emission sources and operational impacts, cargo helps extend decarbonisation efforts beyond the aircraft itself,” Ayala explains.

For Swissport, sustainability extends beyond carbon reduction alone. “Swissport’s approach is anchored in SBTi-validated targets and practical actions, including electrifying equipment, improving energy efficiency, and reducing waste, particularly plastics, across cargo operations,” Berger notes. The company has achieved Platinum status from EcoVadis, placing it among the top one percent of companies globally for sustainability performance. “Sustainability is broader than carbon: embedding it into safe, efficient, and high-quality operations helps us demonstrate progress while supporting the wider industry’s journey toward net zero.”

Looking ahead
The air cargo industry's decarbonisation journey is accelerating, driven by regulatory requirements, customer expectations, and corporate commitments. By 2030, DHL aims to achieve its 30% SAF target alongside its 50% reduction in emissions per shipment, while continuing fleet renewal and operational improvements. United Cargo will benefit from SAF integration across its passenger network. “Fuel is our largest and most volatile expense. SAF is still a small part of the global fuel supply, but it’s the biggest lever United has today to both control expenses and reduce our emissions from flying. We’re already the leading airline user of SAF in the U.S., but scaling it takes teamwork across the whole industry,” adds Ayala. Ground handlers like Swissport will continue electrifying equipment and improving facility efficiency as airport infrastructure evolves.

The convergence of fleet modernisation, SAF adoption, operational optimisation, and ground handling improvements creates a comprehensive framework for reducing freighter operations’ carbon footprint. While challenges remain around SAF availability, cost, and infrastructure development, the industry's momentum is undeniable. As Berger concludes, “By focusing on what can be done today, we provide measurable results, maintain momentum, and reinforce our role as a trusted partner for airlines and airports.” This pragmatic yet ambitious approach, shared across cargo operators, fuel producers, and ground handlers, points toward a more sustainable future for global air freight.