Can charging frequent flyers for their carbon solve aviation’s climate problem?

A bold plan goes up against global realities

By Mark Harris Anthropocene magazine

If you were to design a scheme to deliberately accelerate climate change, you couldn’t do much better than an airline loyalty program. The more you fly, the cheaper and easier your flights become. And in order to maintain your benefits, you have to keep flying—even to the point of making unnecessary “mileage runs” to boost you to the next tier.

Now what if that was switched around, and each flight you took in a year was instead more expensive than the last? The International Council on Clean Transport (ICCT) recently calculated that such a scheme implemented globally could raise a whopping $120 billion annually—enough to fully fund a transition from fossil fuels in aviation to more sustainable fuels. In other words, the worst of today’s polluters could foot the bill for cleaning up aviation by using  fuels made from renewable resources rather than petrochemicals.

The math is compelling, but here we look at the practical obstacles to getting such an audacious plan off the ground. At the end of the day, all climate policies come down to politics.


• • •

The More You Fly, The More You Pay


1.  Frequent polluters. Stepping aboard a jet plane is the single most damaging thing most of us can do for the climate. Taking a single flight between New York and London offsets all the good you do by going vegan for two years. And frequent flyers have an out-size impact—just 1% of the world population is estimated to account for 50% of emissions from all commercial aviation.

2.  Stepping up taxes to step down carbon. The ICCT proposes a simple solution. Everyone gets one flight a year without extra taxation, the next flight adds $9, the one after that $18, then $27, and so on. For most people, who make just a couple of flights annually, the cost will be barely noticeable. But, added to fees from those who make dozens of flights, the tax could raise over $120 billion each year—and reduce total air travel by 7%. (According to research from UK-based carbon charity Possible, nearly 90% of flights are leisure travel anyway).

3.  Jetting towards equality. A key feature of the ICCT proposal is that the taxes generated would flow from those making the most flights—typically residents of highly developed nations—to those countries with the lowest per capita income—often the first to experience the worst effects of climate change. Each country could use its money to develop new aviation fuels and technologies, or offset the impacts of aviation locally. “A differentiated, progressive climate tax is greatly needed for a sector with uneven participation from around the world,” writes ICCT report author Xinyi Sola Zheng.


• • •

Nice Idea, But Get Your Head out of The Clouds


1.  Getting turkeys to vote for Christmas. The airline industry is extremely unlikely to support any move that threatens either passenger numbers, which are only just recovering post-pandemic, or their current, lucrative frequent flyer programs. In 2020, airlines were forced to value their loyalty plans to qualify for pandemic relief: American Airlines valued its at over $19.5 billion, and United at around $9.2 billion.

2.  Green flights or green-washed flights? Airlines are hardly unaware of the concept of “flygskam,” Swedish for “flight shame” and epitomized by Greta Thunberg’s trip to the USA aboard a sailing ship. Some are now wooing more eco-conscious travelers with “green” loyalty plans that let flyers earn points by traveling with less luggage, offsetting their flights, or even buying wine from an environmentally-friendly vineyard. Of course, none of these address the plans’ essential failing of encouraging additional air travel.

3.  Who goes first? It’s difficult to see how such a tax would ever be implemented. If a country were to go it alone, it would financially discourage repeat visitors as flights became more and more expensive. And almost every country in the world has a domestic airline (and its associated frequent flyer program) to protect. Getting them all to agree would be a gargantuan political and commercial effort.


• • •

What To Keep An Eye On


1.  Domestic flight bans. In April, France banned domestic flights on routes that could be traveled via train in under two and a half hours, affecting about 12% of flights. Austria made some airline pandemic relief contingent on similar restrictions. But to make a real dent in carbon emissions, we would need either the US (nearly a billion domestic seats sold annually) or, more realistically, China (685,000) to get serious about taxing their frequent flyers.

2.  Net zero “aspirations.” Earlier this month, 193 countries in the International Civil Aviation Organization (ICAO) pledged to support an “aspirational” net zero aviation goal by 2050. If these thoughts and prayers are ever to become more concrete they will need better sustainable fuels and an enormous quantity of offsets. A recent report from Carbon Market Watch found that many offsets sold to consumers in Europe were cheap, low quality, and unlikely to represent permanent carbon sequestration.

3.  Tax relief through higher technology. Transitioning to aircraft that don’t burn fossil fuels would let travelers jaunt with an easy conscience, but don’t hold your breath. Battery- or hydrogen-powered aircraft could begin to enter operation by mid-decade, giving slower—but cheaper and greener—options for regional air travel. Sadly, there’s nothing on the horizon to replace intercontinental jets.


Image: ©Anthropocene Magazine

Sustainable aviation fuels could be even better than we thought

Jet fuels made from renewable and waste sources could eliminate contrail clouds, which are worse for the climate than an airplane’s carbon dioxide emissions.
June 24, 2021

Flying is one of the most carbon-intensive activities a person can indulge in. The aviation industry is trying to change that, and one option being considered to reduce flying’s carbon emissions is to use clean fuels made from renewable and waste sources instead of fossil fuels. Yet in 2019, sustainable aviation fuels (SAFs) accounted for a tiny 0.01 percent of global aviation fuel.

A new study now makes the case for a concerted look at SAFs. These fuels are already capable of cutting lifecycle emissions by up to 80 percent compared with conventional jet fuels.

The new paper published in the Nature journal Communications Earth & Environment shows that burning SAFs further reduces the climate warming impact of flying because it produces less soot and ice particles when cruising, resulting in far fewer contrails, the cloud-like tracks airplanes leave in the air.

Recent studies have shown that contrails contribute even more to climate warming than the carbon dioxide emissions from aircraft. Jet engines spew carbon dioxide, water vapor, and soot particles when they burn conventional fuels. The water vapor condenses on the soot and freezes in the cold high-altitude temperatures to form ice particles that make up contrail clouds.

Contrails remain in the atmosphere for hours, trapping heat from the Earth’s surface, and attracting sunlight, which makes the heating worse.

Researchers from NASA and the German Aerospace Center wanted to test how different fuels could impact an airplane’s contrails. They flew an Airbus A320 using five different types of fuels. Two were traditional jet fuels, and the other three were mixes of jet fuel with synthetic or bio-based alternative fuels. The airplane flew at a constant speed and altitude, and a NASA research plane followed the A320 at a safe distance, measuring and analyzing the emissions the A320 left behind.

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The tests showed that burning SAF mixes resulted in 50 – 70 percent fewer soot and ice particles. The ice crystals that do form are larger, so they fall quickly and melt in the warmer air below.

Taken as a whole, flying produces less greenhouse gas emissions than electricity production and transport. But the sector is also growing rapidly. Carbon dioxide emissions from aviation have risen rapidly over the past two decades, per the IEA, now accounting for about 2.8 percent of global carbon emissions. Widespread adoption of SAFs could be a meaningful step in reducing aviation’s climate impact, the researchers say.

Source: Christiane Voigt et al. Cleaner burning aviation fuels can reduce contrail cloudiness. Communications Earth & Environment, 2021.

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