This article is based on an official press release from Airbus.

In a closely coordinated chase across the sky, the aviation industry is taking aim at one of its most visible and complex climate challenges: condensation trails. While carbon dioxide emissions have long dominated sustainability discussions, recent scientific consensus highlights that non-CO2 emissions account for a significant portion of commercial aviation’s total climate warming impact.

To address this, Airbus, the German Aerospace Center (DLR), and engine manufacturer Pratt & Whitney have launched ECLIF-X (Emissions and Climate Impact of alternative Fuels – X). According to an official Airbus press release, this joint research campaign utilizes a “flying laboratory” to investigate the effects of fuel composition on aviation’s non-CO2 impact.

Running from 2025 to 2027, the ECLIF-X campaign captures real-time data on how low-sulphur and low-aromatic fuels interact with advanced engine combustors. At AirPro News, we recognize this initiative as a critical step toward understanding and mitigating the formation of climate-warming contrails before new environmental regulations take full effect.

The ECLIF-X Campaign: A High-Altitude Chase

The Emitter and the Sniffer

The methodology behind the ECLIF-X campaign involves two aircraft flying in tandem at cruising altitude. The “emitter” is an Airbus A321XLR test aircraft (registration MSN11058), powered by Pratt & Whitney PW1100G-JM engines. Research reports indicate these engines are equipped with the TALON-X rich-burn combustor, a technology specifically designed to reduce soot emissions. During the tests, the A321XLR is flown with three different types of fuel to compare their respective emission profiles.

Following closely behind is the “sniffer,” DLR’s heavily instrumented Falcon 20E research aircraft. Drawing on over 30 years of atmospheric research expertise, DLR scientists pilot the Falcon 20E directly into the exhaust wake of the A321XLR.

Flying at distances of just 50 to 300 meters, the Falcon 20E captures precise, real-time data on the physical and chemical properties of the emissions before they dissipate.

This proximity allows researchers to analyze the exhaust plume in real-time, providing unprecedented insights into the immediate atmospheric reactions triggered by different fuel blends.

Decoding the “Sticky Seed” Problem

How Contrails Form and Trap Heat

Contrails are line-shaped ice clouds that form when hot, humid engine exhaust mixes with cold, high-altitude air. Depending on atmospheric conditions, these contrails can persist and spread into cirrus clouds that trap outgoing infrared radiation from the Earth. According to industry research, studies suggest that non-CO2 effects could represent anywhere from 35% to roughly two-thirds of aviation’s total accumulated climate impact.

Airbus refers to the microphysics of contrail formation as the “sticky seed” problem. Conventional jet fuel contains aromatic compounds, which are the primary precursors for soot particles during combustion. These soot particles act as the foundational condensation nuclei, or “seeds,” for contrails. Furthermore, even trace amounts of sulphur in jet fuel result in the formation of sulphuric acid. This acid coats the soot particles, making them “sticky” and highly attractive to water vapor.

By utilizing fuels with low aromatics and low sulphur, such as highly refined Sustainable Aviation Fuels (SAF), engines produce significantly fewer soot particles and less sulphuric acid. Fewer seeds mean fewer ice crystals, resulting in contrails that are thinner, shorter-lived, or completely prevented.

Building on Previous Success

The current campaign builds upon the landmark ECLIF3 study, which concluded in 2024. Data from ECLIF3 proved that flying on 100% SAF reduced the number of contrail ice crystals by 56% and cut the overall climate-warming impact of contrails by at least 26% compared to conventional jet fuel.

Regulatory Urgency and Future Operations

EU ETS and NEATS Compliance

The ECLIF-X research arrives at a critical regulatory juncture. As of January 2025, the European Union Emissions Trading System (EU ETS) requires airlines to monitor and report their non-CO2 effects. With the first verified reports due in 2026, the industry faces immediate pressure to understand and quantify these emissions.

The introduction of the EU’s Non-CO2 Aviation Effects Tracking System (NEATS) means airlines are now legally required to track these metrics. Research initiatives like ECLIF-X provide the foundational science necessary to create accurate monitoring, reporting, and verification (MRV) models for the commercial aviation sector.

AirPro News analysis

We view the ECLIF-X campaign as a pivotal transition point for airline operations. Historically, the push for Sustainable Aviation Fuel has been framed almost entirely around lifecycle carbon reduction. However, the empirical data gathered by Airbus and DLR highlights a crucial dual benefit: SAF physically alters the clouds aircraft leave behind.

Beyond fuel certification, this research paves the way for “climate-friendly routing.” As airlines and meteorologists better understand exactly how and when contrails form, flight dispatchers could soon pair clean fuels with tactical flight path adjustments to avoid atmospheric regions prone to persistent contrail formation. This operational shift will likely become a standard practice as regulatory bodies tighten non-CO2 reporting requirements.

Frequently Asked Questions (FAQ)

• What is the ECLIF-X campaign?
  ECLIF-X (Emissions and Climate Impact of alternative Fuels – X) is a joint research initiative by Airbus, DLR, and Pratt & Whitney running from 2025 to 2027 to study how fuel composition affects contrail formation.
• Why are contrails a problem?
  Persistent contrails can spread into cirrus clouds that trap heat in the Earth’s atmosphere. Studies indicate these non-CO2 emissions account for 35% to two-thirds of aviation’s total climate impact.
• What is the “sticky seed” problem?
  Soot and sulphuric acid from conventional jet fuel create “sticky” particles that attract water vapor, forming the ice crystals that make up contrails. Low-sulphur and low-aromatic fuels reduce these seeds.
• When do airlines have to report non-CO2 emissions?
  Under the EU ETS, airlines were required to begin monitoring non-CO2 effects in January 2025, with the first verified reports due in 2026.

Sources: Airbus

This article is based on an official press release from SHEIN.

On March 24, 2026, global fashion retailer SHEIN announced a new agreement with DHL Express to utilize the logistics provider’s GoGreen Plus service. This initiative integrates Sustainable Aviation Fuel (SAF) into SHEIN’s international air freight operations, marking another step in the company’s efforts to address lifecycle emissions associated with its supply chain.

According to the official press release, the partnership is designed as an early-stage pilot to help the retailer evaluate economic feasibility, certification frameworks, and operational integration. SHEIN explicitly acknowledges that the immediate emissions impact will be modest relative to its total air transport footprint, reflecting broader constraints in the global SAF market where alternative fuels represent only a fraction of conventional jet fuel supply.

We note that this move builds upon SHEIN’s previous SAF pilot programs initiated in 2025, signaling a continued corporate push to support capacity-building activities and demand signaling, particularly within the rapidly evolving Asia-Pacific (APAC) region.

Expanding SAF Pilots and Logistics Partnerships

The DHL GoGreen Plus Agreement

Under the new agreement, SHEIN will leverage DHL’s GoGreen Plus service, which utilizes an “insetting” approach to reduce Scope 3 greenhouse gas emissions. Rather than fueling specific cargo planes directly with SAF, the fuel is introduced into DHL’s broader aviation network. The resulting lifecycle emissions reductions are then allocated to SHEIN using internationally recognized carbon accounting and certification frameworks.

“Signing the GoGreen Plus agreement with SHEIN marks another important milestone in DHL Express’s commitment to driving the green transformation of air logistics. As a long-term partner in SHEIN’s global logistics network, we are pleased to work together to explore how sustainable aviation fuel can be integrated into their air cargo operations.”

Building on 2025 Initiatives

The DHL partnership is part of a broader, multi-carrier strategy. Industry research highlights that in 2025, SHEIN procured 187.3 tonnes of SAF across 14 Atlas Air charter flights, achieving an estimated emissions reduction of 579.1 tonnes of CO₂ equivalent (tCO₂e). Furthermore, the company signed a Memorandum of Understanding (MoU) with Lufthansa Cargo in August 2025 to accelerate SAF adoption.

Regionally, SHEIN is also participating in a China-based SAF pilot program organized by China National Aviation Fuel (CNAF) and the Second Research Institute of Civil Aviation of China (CASRI). Through this initiative, the retailer plans to procure an initial batch of SAF from Air China Cargo, utilizing traceability mechanisms to track usage.

“Working with partners such as DHL allows us to better understand how sustainable aviation fuel solutions may be incorporated into air cargo logistics. Initiatives like this are part of SHEIN’s broader efforts to explore how emerging approaches across the aviation sector may contribute to addressing carbon emissions associated with air transport.”

Global Bottlenecks and the Cost of Decarbonization

Production and Pricing Realities

SHEIN’s press release notes that wider adoption of SAF remains constrained by limited production capacity and higher costs. Data from the International Air Transport Association (IATA) released in December 2025 provides stark context for these limitations. According to IATA, global SAF production reached 1.9 million metric tons in 2025. While this doubled the output of 2024, it still represented only 0.6% of total global jet fuel consumption.

Growth is projected to slow slightly in 2026, reaching an estimated 2.4 million metric tons, or roughly 0.8% of global demand. Furthermore, SAF currently trades at two to five times the price of conventional fossil jet fuel. IATA estimates that this premium added approximately $3.6 billion to the aviation industry’s fuel costs in 2025 alone.

Policy Friction

The macroeconomic challenges are compounded by regulatory friction. IATA has publicly criticized certain regional mandates, arguing that they have distorted markets and increased compliance costs without guaranteeing adequate fuel supply.

“SAF production growth fell short of expectations as poorly designed mandates stalled momentum in the fledgling SAF industry… If the objective is to increase SAF production to further the decarbonization of aviation, then they [policymakers] need to learn from failure and work with the airline industry to design incentives that will work.”

The Asia-Pacific Momentum

Regulatory Shifts and Capacity Building

The press release emphasizes strengthening the demand signal for SAF in the Asia-Pacific region through capacity-building activities. Industry data shows that APAC is currently undergoing a massive shift in SAF infrastructure and regulation, transitioning from voluntary goals to concrete mandates.

Singapore implemented a confirmed goal of 1% SAF by 2026, funded by a passenger levy, while Japan is finalizing a 10% SAF mandate by 2030. South Korea, India, and Indonesia are also rolling out blending roadmaps expected to take effect around 2027.

To support this regulatory push, physical infrastructure is scaling up. Neste operates a significantly expanded SAF refinery in Singapore, and Hong Kong-based EcoCeres is expanding into Malaysia. Additionally, in May 2025, the World Economic Forum (WEF) and GenZero launched “Green Fuel Forward,” an initiative specifically designed to scale SAF demand and build regional capacity for aviation decarbonization in APAC, involving major airlines and logistics firms like DHL.

AirPro News analysis

SHEIN’s latest announcement reflects a maturing corporate approach to aviation decarbonization. By explicitly stating that the emissions impact of these early-stage pilots will be “modest,” the company avoids the pitfalls of greenwashing and aligns its messaging with the stark realities of the global SAF market. The reliance on DHL’s GoGreen Plus “book-and-claim” model highlights that, for global shippers, insetting remains the most viable mechanism to participate in the SAF economy without requiring direct physical access to alternative fuels at every origin airport. As APAC mandates like Singapore’s 2026 target take effect, corporate demand signals from high-volume freight users like SHEIN will be critical in justifying the massive capital expenditures required for regional SAF refineries.

Frequently Asked Questions

What is DHL’s GoGreen Plus service?

GoGreen Plus is a service offered by DHL Express that allows customers to reduce the Scope 3 carbon emissions associated with their freight. It uses an “insetting” or “book-and-claim” model, where DHL purchases Sustainable Aviation Fuel (SAF) and introduces it into its broader aviation network, allocating the certified emissions reductions to the participating customer.

How much of global aviation fuel is currently SAF?

According to December 2025 data from the International Air Transport Association (IATA), SAF accounts for only 0.6% of global jet fuel consumption, constrained by limited production capacity and high costs.

Why is SAF more expensive than conventional jet fuel?

SAF is currently two to five times more expensive than conventional fossil jet fuel due to the high costs of feedstock collection, complex refining processes, and a lack of scaled production infrastructure globally.

Sources: SHEIN Press Release

This article is based on an official press release from Aviation Capital Group.

Aviation Capital Group (ACG), a prominent global full-service aircraft asset manager, has officially p-shed its 2025 Sustainability Report. The document marks the company’s fifth annual review detailing its progress across key environmental, social, and governance (ESG) priorities.

According to the company’s press release, the 2025 report highlights significant strides in fleet modernization and emissions reductions. As the aviation industry faces mounting pressure to decarbonize, aircraft lessors are increasingly prioritizing newer, more fuel-efficient technology to meet long-term climate targets.

The newly released data underscores ACG’s ongoing transition toward a lower-emission portfolio, supported by strategic financial mechanisms and a growing backlog of next-generation aircraft commitments.

Fleet Modernization and Emissions Reductions

In its official press release, ACG reported that new generation, lower-emissions aircraft now account for 79% of its total fleet. This shift is the result of a deliberate fleet renewal strategy executed throughout the year. During 2025, the lessor added 52 new generation aircraft to its portfolio while simultaneously exiting 36 older generation airframes.

These modernization efforts have yielded measurable environmental benefits. ACG stated that it successfully reduced its relative emissions to 13% below its 2018 baseline. Furthermore, the company noted that its portfolio’s relative emissions are now 14% below the broader aviation industry average.

Looking ahead, the lessor continues to build its pipeline of modern aircraft. As of February 2026, ACG has increased its future aircraft commitments to more than 180 aircraft, ensuring a steady influx of fuel-efficient technology in the coming years.

Financial Commitments and Corporate Governance

Beyond fleet metrics, the 2025 Sustainability Report outlines ACG’s integration of ESG principles into its financial and corporate operations. The company announced the extension and upsizing of its Sustainability Linked Loan, which now totals $575 million. Additionally, ACG signed its first Sustainability Linked Leases, aligning its leasing structures with environmental performance metrics.

On the social responsibility front, the press release highlighted that ACG contributed to more than 20 worthy causes worldwide during the 2025 calendar year.

Company leadership emphasized the importance of these initiatives in the context of broader industry goals.

“I am pleased to share ACG’s 2025 Sustainability Report, which reflects the progress we have made embedding sustainability, social responsibility and governance excellence into all aspects of our business. While the path to achieving net zero by 2050 is becoming increasingly demanding, we remain committed to shaping a sustainable future by deepening our impact as a business and broadening our influence across the wider aviation ecosystem through action, leadership, and collaboration.”

, Thomas Baker, Chief Executive Officer and President of ACG, in a company statement.

AirPro News analysis

The Leasing Sector’s Role in Aviation Sustainability

We observe that aircraft leasing companies like Aviation Capital Group play a pivotal role in the aviation industry’s transition to net-zero emissions. Because lessors finance a substantial portion of the global commercial fleet, their procurement decisions directly influence the speed at which older, less efficient aircraft are retired.

By tying financial instruments, such as the $575 million Sustainability Linked Loan and newly introduced Sustainability Linked Leases, to environmental targets, lessors create tangible economic incentives for airlines to operate cleaner aircraft. ACG’s reported metric of maintaining portfolio emissions 14% below the industry average demonstrates how aggressive fleet renewal strategies can outpace the broader market’s decarbonization curve.

Frequently Asked Questions (FAQ)

What is Aviation Capital Group (ACG)?

Founded in 1989, Aviation Capital Group is a premier full-service aircraft asset manager and a wholly owned subsidiary of Tokyo Century Corporation. According to the company, it has approximately 450 owned, managed, and committed aircraft as of December 31, 2025.

How many airlines does ACG serve?

As of the end of 2025, ACG leases its aircraft to roughly 85 airlines operating in approximately 50 countries worldwide.

What are ACG’s future fleet plans?

The company reported that its future aircraft commitments have grown to more than 180 aircraft as of February 2026, focusing heavily on new generation, lower-emissions technology.

Sources

• Aviation Capital Group