Fly More Sustainable Already Today
On a transatlantic flight last month, wedged between an in-flight shopping catalog and a menu displaying complimentary wine was an eye-catching brochure promising the ability to purchase carbon credits in order to offset my share of the emissions spewing from the plane’s tailpipe. As an increasingly climate-conscious American, I am also increasingly cynical about the commitments of large companies to achieve carbon neutrality, especially in industries like airlines for which carbon emissions are intrinsic to their operations. The only hope for these industries is to wade into the murky waters of carbon offsets, which promise absolution of responsibility but often fall short of legitimacy. Before assuming the worst, though, I checked myself — this was a Lufthansa flight. Aren’t progressive European countries years ahead of America? Is it possible that this program is legitimate?
The brochure’s QR code sends the passenger directly to a sleek website with slow-motion videos of forests — familiar territory for “green” American companies — promising to “fly more sustainable already today.” Suppressing my distrust, I moved on to enter my flight information, which revealed that I was responsible for 955 kg of CO2e (CO2 equivalent, a common metric when approximating the warming effect of multiple greenhouse gasses). However, instead of a black box promising instantaneous offsets, users are given the ability to choose how they want to reduce their carbon footprint. At one end of the sliding scale is the most instantaneous — and most expensive — method: “Sustainable Aviation Fuel” (SAF). At the other end is an investment into Lufthansa’s “Climate Project Portfolio” (CPP), promising an offset in up to ten years.
Lufthansa’s refreshing transparency over the timescale of carbon offsets is unusual: the carbon market standard is to sell offsets without any context. This standard generates more sales by promising instant absolution of responsibility, but distorts reality: buying most carbon offsets is an investment into programs that promise future sequestration. These types of programs make up Lufthansa’s CPP, where passengers invest into projects such as swamp renaturing or the distribution of more efficient stoves. In order to match the amount of carbon produced by Lufthansa’s direct operations, though, the CPP would have to grow to offset 13.6 million tonnes of CO2e each year from its current 48,000 tonnes. Recognizing the difficulty in scaling standard offsets, the industry is betting on the development of SAF technologies.
Creating a truly carbon-neutral fuel could be the silver bullet to the aviation industry’s sustainability issue: it would allow continued operation without threat of impending government regulation or shifting consumer behavior away from air travel. However, the viability of producing these fuels economically and at a large scale remains to be seen.
SAF as advertised by Lufthansa relies on three methods shrouded in vague, futuristic names. The simplest is using “biogenic residues” to produce fuel. First taking in wasted cooking oils and fats from settings like restaurants and mass food suppliers, producers then extract water, put the oils through a series of chemical reactions, and then refine the fuel until it is suitable for airplanes. This process is tried and true, but the 13,000 tons of fuel produced in the last year is no match for the 7.6 million tons consumed by Lufthansa. Scale and reduced cost are the biggest hurdles for this technology.
Less adopted but more promising is Power-to-Liquids (PtL) fuel, which is based on the 1923 discovery of a method to convert coal into a synthetic fuel. Chemists discovered that at high temperatures, metal catalysts enabled reactions that produced a liquid form of carbon monoxide mixed with hydrogen. For countries rich in coal but not oil, this discovery prompted investment and adoption of the technology. Today, however, coal is undesirable because of the high amount of carbon dioxide released as in combustion relative to the amount of energy supplied. In any case, producing PtL is no longer based on coal: to create PtL for airplanes today, water first passes through an electrolyser, which splits water molecules into hydrogen and water. The hydrogen is then synthesized with carbon monoxide and mixed with kerosene before being pumped into planes.
The difficulty in adapting this technology to today’s needs is twofold: creating enough clean energy and capturing enough carbon dioxide. In order for the hydrogen produced to be “green,” the electricity powering the (extremely) energy-intensive electrolysers must be renewable: otherwise, it’s just an inefficient way to create fuel, and traditional fossil fuels would be better in terms of carbon emissions. The carbon monoxide used in PtL is derived from carbon capture and sequestration (CCS), which takes many forms. Some small companies have developed expensive ways to scrub carbon from the air, but the more widespread approach is to outfit industrial smokestacks and power plants with carbon capture devices that ensnare carbon dioxide before it has a chance to contribute towards global warming. This carbon is then sold to a variety of applications, including the manufacture of PtL.
Experts are split on if hydrogen will become economically viable, but Lufthansa and other airlines are betting on it. Both hydrogen and CCS are receiving massive investment promising innovation and cost reduction, but in order for Lufthansa’s future strategy to work, both must succeed as low-cost fossil fuel alternatives. The technology promises a 90% reduction in greenhouse gas emissions, but it is far from guaranteed that PtL will become economical.
The most futuristic — and dubious — SAF technology is “Sun to Liquid” (StL). A massive array of mirrors concentrates the sun’s energy into a solar reactor, where CO2 captured via CCS reacts with water to form a gas at 15,000°C, which is then converted into a synthetic oil before being refined for use in airplanes. StL’s use of solar energy decreases the need for renewable energy inputs, making it an attractive alternative to PtL and biofuels. Lufthansa projects that the first StL-fueled flights will take off in 2024, though scientific literature is mixed on its viability — it may turn out to be all smoke and mirrors.
By relying on the future development and scaling of unproven technologies to meet goals, Lufthansa joins many other companies in claiming they are “sustainable” brands, risking misleading customers and the governments that regulate it. Whether Lufthansa’s claims are legitimate or not, it treads dangerous waters. United has received blowback for touting its pioneering investment in algae as a biofuel source — nevermind that the investment was only $5M (0.02% of annual revenue) and that the scale of possible algae production is miniscule compared to the demand for fuel. Delta was recently sued for misleading customers by advertising itself as “carbon neutral since 2020.” Lawsuits like this may occur more often as greenwashing becomes more common and controversial.
Airline consumers want to believe that their actions are not significantly harming the environment, and so are inclined to believe in the messages given by Lufthansa. “Flight shaming,” the phenomenon mostly occurring in Europe, is spreading rapidly, and the promise of annulling responsibility by donating a few euros is tempting. Lufthansa’s methodology puts the onus on the consumer, empowering travelers with a concrete action to reduce their carbon footprint while shielding the airline from responsibility.
Travelers that opt to buy carbon offsets leave the flight feeling better about themselves, thinking that they are contributing positively towards preventing global warming. However, this should be viewed as an investment into the future of sustainable aviation, not a simple give-and-take. Purchasing a carbon culpability pass ignores the reality of the complexity of carbon offsets and the intense energy consumption in all aspects of the travel industry. That said, signaling sustainability’s importance by buying into offset programs is doubtless better than inaction.
Lufthansa’s carbon emissions reduction program, while far more transparent than in the US, is still only a temporary solution. At the end of the day, any airline’s plan to reduce emissions is only economically viable if it does not reduce the number of passengers. Sleek websites and advertisements will continue to counter the message that poses the biggest threat to the industry: that the best flight for the environment is the one not taken.
Originally written for COSC 19.01: “Writing About Technology” with Professor Cal Newport
