Sustainability in the Air
Sustainability In The Air
How Southwest Airlines maintains affordability while pursuing sustainability
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How Southwest Airlines maintains affordability while pursuing sustainability

In this episode, we talk to Helen Giles, Managing Director of Environmental Sustainability at Southwest Airlines.
Transcript

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In this episode of our ‘Sustainability in the Air’ podcast, Helen Giles, Managing Director of Environmental Sustainability at Southwest Airlines, speaks with SimpliFlying CEO Shashank Nigam and shares how the low-cost carrier is integrating sustainability into its operations. 

Here are the key highlights of the conversation:

  • Balancing growth and sustainability (5:44)

  • The critical role of sustainable aviation fuel (10:10)

  • Carbon offsetting and consumer engagement (14:26)

  • The potential of hydrogen and new-generation aircraft (22:44)

  • Maximising operational efficiency (26:17)

  • Contrail reduction and mitigation (29:55)

  • Promoting circularity throughout operations (35:40)

  • Rapid Fire! (43:38)

Keep reading for a quick overview of the episode.



Why balancing growth and sustainability matters

It is often argued that growth in aviation comes at the detriment of sustainability.

Giles, however, believes that growth and sustainability need not be mutually exclusive, adding that airline growth can accompany environmental benefits, such as introducing more fuel-efficient aircraft, which would reduce carbon emissions intensity.

Southwest incorporates operational efficiency in every way possible to ensure both cost and carbon savings. This efficiency is not only limited to aircraft but extends to ground support equipment, with a shift towards electrically powered systems over combustion-based ones. The airline also plans to increase its use of sustainable aviation fuel (SAF).

Southwest’s philosophy is to provide affordable, accessible air travel, thereby democratising the skies, explains Giles. She stresses the importance of an equitable energy transition, especially in regions like the US and New Zealand, where alternative transportation infrastructures are limited and communities rely heavily on air travel.

Giles also advocates for a balanced approach, where growth in aviation is aligned with efforts to reduce carbon intensity and overall emissions, aiming to achieve net zero by 2050 while keeping air travel accessible to all.

Helen Giles, Managing Director of Environmental Sustainability at Southwest Airlines in conversation with Shashank Nigam | Sustainability in the Air

5 ways Southwest Airlines plans to reach net zero

1. Sustainable Aviation Fuel

Giles discusses the critical role of SAF in achieving net zero goals, especially for Southwest Airlines. Southwest has set an ambitious target of replacing 10% of its total jet fuel consumption with SAF by 2030, a significant leap from the current global usage of less than 0.1%.

“​​10% might not sound like a lot, but it’s a big jump from the less than 0.1% that exists globally today. And we’re the largest domestic carrier in the US. So for Southwest, that 10% translates to about 300 million gallons. So we’re really focusing on securing a diversified portfolio of SAF to hit our 2030 goal, but also beyond that.”

A key focus for Southwest is scaling up second-generation SAF, which is produced using non-food crops. To this end, Southwest has invested in SAFFiRE Renewables, a company set up as part of a Department of Energy (DOE)-backed project to develop and produce scalable SAF. SAFFiRE will utilise DOE’s technology to convert corn stover, a widely available waste feedstock in the US, to renewable ethanol, which will then be upgraded to SAF.

Giles also outlines Southwest’s policy that SAF must be affordable relative to conventional jet fuel. Long-term contracts and government incentives are seen as crucial in making SAF economically viable:

  • E.g., in Nov 2023, Southwest entered a 20-year deal to buy up to 680 million gallons of SAF from USA BioEnergy LLC, starting in 2028.

  • Giles cites examples like Fischer Tropsch gasification, where producers use waste biomass and carbon capture and sequestration technologies to produce carbon-negative SAF, which benefits from government incentives such as the Clean Fuel Production Credit and California’s Low Carbon Fuel Standard.

2. Carbon offsetting and carbon removals

Giles also discusses the evolving role of carbon offsets in Southwest’s sustainability strategy. Initially considered a bridging solution while scaling up SAF and other technologies, Giles notes a shift in focus where offsets are used to decarbonise unavoidable emissions outside of the value chain.

“We aren’t counting offsets towards our voluntary goals. Our path to net zero roadmap shows how we can get there without using offsets, but our plan has a lot of dependencies. You know, if things fall through like SAF scaling, the modernisation of air traffic control, the industry may very well need offsets to hit these goals because they’re quite ambitious.”

She also touches on the challenge of engaging consumers in offsetting efforts, acknowledging a gap between intention and action, and suggests more targeted communication strategies to involve genuinely interested customers.

As mentioned above, Southwest’s net zero strategy significantly relies on SAFs, particularly those produced using carbon capture and sequestration (CCS), making them carbon-negative. This approach reduces lifecycle emissions and contributes to overall carbon removal targets.

While recognising the potential of Direct Air Capture (DAC) technologies, Giles points to their current limitations, such as high costs and limited supply, suggesting that promoting CCS in SAF production is a more viable approach for aviation carbon removals in the immediate future.

“I think our perspective is you obviously need carbon to create SAF, and we should be promoting the use of carbon capture and sequestration to further bring down the life cycle emissions of SAF. I think from our side, that’s probably the most likely applications for carbon capture and removals for aviation until things like DAC scale and costs come down.”

Three pillars of environmental sustainability at Southwest | Sustainability in the Air

3. The potential of hydrogen

Hydrogen offers a promising solution for decarbonising aviation, but its implementation is currently filled with challenges.

While Southwest is stoked about the development of hydrogen and hybrid-electric aircraft, current advancements in these areas are not yet aligned with Southwest’s business model, explains Giles.

She also points out that hydrogen, while offering the potential for zero emissions, is not a drop-in fuel and requires significant changes in infrastructure, aircraft design, and certification processes.

“Right now, we’re not seeing developments before at least the mid 2030s that would be relevant to our all narrow body, point-to-point business model. …from our side right now, we see hydrogen being really exciting, something that we want to continue to monitor, engage on and prepare for. We also see a lot of challenges with hydrogen, even more so than what SAF has.”

Given that aircraft typically have a lifespan of 25-30 years, Giles suggests that even after overcoming these challenges, it will take considerable time for airlines to integrate new aircraft technologies into their fleets.

Consequently, she does not foresee hydrogen playing a significant role in Southwest’s operations by 2050.

4. Maximising operational efficiency

Giles emphasises the importance of operational efficiency as a core aspect of Southwest’s brand, with a significant emphasis on modernising the fleet.

  • Introducing new aircraft models like the 737 MAX 7 and MAX 8, which offer 14% lower fuel burn compared to older models, is a critical step in reducing carbon emissions intensity.

  • Giles highlights the airline’s ambitious goals for fuel savings, targeting a reduction of 50 million gallons by 2025 and 1.1 billion gallons by 2035, relative to a 2019 baseline. These targets are part of a broader strategy to improve efficiency both in the air and on the ground.

  • Giles also addresses the need for efficient air traffic control systems to ensure better fuel savings. She acknowledges the challenges in this area and the need for collaboration with the Federal Aviation Administration (FAA) on the NextGen program, to enable more direct flight routes. This could help reduce fuel use, tarmac delays, and ground-based emissions.

“We have to find ways to save fuel both on the ground and in the air. We have a goal to electrify 50% of our ground support equipment by 2030. And we also have a goal to conserve energy in our facilities. We’re trying to find every way across our operation to conserve fuel, conserve energy, and be more efficient. And that’s going to be a key focus area for us through 2035.”

5. Contrail reduction and mitigation

Giles also outlines Southwest’s efforts in contrail reduction.

Condensation trails or “contrails” are long, thin clouds that form behind an airplane in cold and humid conditions when water vapour freezes around small dust and soot particles from the engine. Since contrails are made up of small ice crystals, they trap heat in the Earth’s atmosphere and contribute to global warming.

In 2022, Southwest joined the cross-sectoral Contrail Impact Task Force to explore the formation and mitigation of persistent contrails. The task force aims to share the latest science on the climate impact of contrails, develop strategies to avoid warming contrails, and establish a roadmap for implementing contrail mitigation tools.

Southwest has also collaborated with GE Aerospace to develop a real-time in-flight prediction system for contrails through a Department of Energy grant. GE Aerospace’s system will combine engine operational data, a hybrid physics and machine learning model, on-airplane data, and real-time satellite observations to accurately predict contrails that last more than 5 hours.

“Unlike carbon emissions, where every gallon of jet fuel has the same impact, for contrails, only 10 to 15% of flights are responsible for about 80% of the impact. So this is more of a needle in the haystack problem. Not every flight is creating a contrail. Not every contrail will become a persistent contrail, and not every persistent contrail has a warming impact.”


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‘Sustainability in the Air’ is the world’s leading podcast dedicated to sustainable aviation. Through in-depth conversations with top aviation leaders, we break through the clutter and provide a clear roadmap for a net-zero future.

Sustainability in the Air
Sustainability In The Air
Every week, Shashank Nigam, the CEO of SimpliFlying, talks to airline, airport, travel and technology executives to help make sense of the many paths to net zero, for an industry that is one of the hardest to decarbonize. Whether you're a frequent flier, an airline executive or just love travelling, if you care about sustainable global travel, then welcome aboard.