Pollution from aircraft – another reason to tax fossil fuels at their source

Photo of jet aircraft contrails
Jet aircraft contrails. Image: Wikipedia

The global civil aviation industry is on a roll. Last year the world’s airlines profited from carrying 4.38 billion passengers and 63.3 million tones of freight. According to the International Air Transport Association (IATA) the number of passengers carried per year could reach 8.2 billion by 2037, a forecast based on 3.5% compound annual growth rate. A rosy outlook indeed — for the industry. Can the good times last — for the industry?

The industry’s current prosperity is based on cheap fossil fuel and on the fact that the industry is allowed to dump its emissions into the global atmosphere at no cost to itself. According to IATA data, in 2018 a total of 38.1 million flights consumed 95 billion gallons of fuel and released 905 million tones of carbon dioxide (CO2) into the atmosphere, about 2% of global CO2 emissions. But that’s not all. Emissions from aircraft jet engines contain other pollutants such as oxides of nitrogen, unburned fuel, soot, and water vapour. Soot, for example, provides condensation sites for water vapour and the consequent formation of contrails at high altitudes (17,000 to 45,000 feet). When contrails linger or spread out thinly like natural cirrus clouds, they trap heat radiating from the earth’s surface and so add to atmospheric warming. The combined contribution to global warming made by these non-CO2 emissions, equals or exceeds that made by the aircraft’s CO2 emissions.

The industry is under pressure to reduce its carbon footprint. According to IATA ‘fact sheets’, this is what the industry plans to do: First it plans to cap its net CO2 emissions at 2019 levels. From then on, or so the industry claims, its growth will be carbon-neutral. It plans to accomplish this carbon-neutral growth by “pursuing a 4-pillar strategy” as follows:

(1) Improved aircraft technology, including the deployment of sustainable low-carbon fuels. (2) More efficient aircraft operations. (3) Better ground-based infrastructure (4) Offsetting the remaining emissions gap.

Here are some of the reasons why the industry’s plan is bound to fall short:

Engineers have made great progress in designing jet engines that are more fuel efficient and produce less CO2. And that work continues. However, a recent paper by Lisa Bock and Ulrike Burkhardt of the Institute of Atmospheric Physics, Oberpfaffenhofen, Germany, shows that more fuel efficient jet engines produce more, and longer lasting contrails. The atmospheric heating caused by such contrails cancels out the benefit from more efficient jet engines.

The industry is counting on the development of biofuels to begin replacing fossil fuels. A biofuel is any fuel that is derived from biomass, such as plant or algae material or animal waste. The International Energy Agency (IEA) anticipates biofuels reaching around 10% of aviation fuel demand by 2030, and close to 20% by 2040. In the context of what the industry says it wants to achieve, this is way too slow. Currently biofuels are much more expensive than fossil-based jet fuel, a cost premium that prevents their wider use. The bar chart below shows that for biofuels to compete with fossil jet fuel, the cost of fossil fuels must rise. A sizeable tax on the CO2 content of fossil fuels at well-head or port of entry would do the trick, but that hasn’t happened yet.

Bar chart showing aviation fuel cost comparison
Biofuels vs. jet fuel cost comparison. Image from IEA News, March 18, 2019

According to IEA News, March 18, 2019, “Ongoing research and development is needed to support the commercialisation of novel advanced aviation biofuels which can unlock the potential to use agricultural residues and municipal solid wastes.” In other words, serious work on unlocking that potential on behalf of the aviation industry, hasn’t even started.

 The forth pillar of the IATA’s 4-pillar strategy is where the industry admits that its other pillars will not do enough to mitigate all of its emissions. To mitigate the remaining emissions, the industry intends to rely on an approach developed by the International Civil Aviation Organization (ICAO), called Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA). The scheme was agreed to by ICAO’s 193 member states. This is what IATA’s ‘Fact sheet on CORSIA and carbon pricing’ says about offsetting:

Offsetting is an action by a company or individual to compensate for their emissions by financing a reduction in emissions elsewhere. Offsetting and carbon markets are a fundamental component of global, regional and national emissions reduction policies. They have operated for decades for compliance purposes and voluntary emissions reductions and continue to be an effective mechanism to underpin action against climate change.

Offsetting is more effective than a tax, as a carbon tax merely requires companies to pay for their emissions, without any guarantees that the payment will lead to any emissions reductions.

Poppycock! Carbon offsetting, like taxing carbon emissions, is a form of greenwashing — a way for industries to appear responsible while behaving irresponsibly. To argue that “offsetting is more effective” than taxing carbon emissions, is to say nothing. Neither approach works. The bottom line is this: while “offsetting and carbon pricing . . . have operated for decades” the temperature of the world’s atmosphere continues to rise.

♦ According to a paper published Aug. 14, 2019 by the Center for Climate and Security, titled ‘Climate Change Implications for U.S. Military Aircraft’, new research shows that as the environment grows hotter and more humid, the performance of military aircraft is being adversely affected. Rear Admiral David Titley, US Navy (Ret.), is quoted as follows:

“To better visualize how military operations are being impacted by increasing heat and humidity, one can look at the impacts that changing climate conditions have had on commercial airlines. Commercial airlines are fighting a losing battle with climate change. Increasing heat and humidity is driving flight cancellations and threatening the viability of various airports and flight routes. . . . We are not used to having commercial airlines disrupted because of hot weather. This is a harbinger of things to come.”

As temperature increases, air expands and becomes less dense. As humidity increases, nitrogen and oxygen molecules are displaced by lighter water molecules causing the air to become less dense. As air density decreases, aircraft performance decreases and costs increase .

“These aircraft performance impacts,” Titley says, “can be mitigated by expanding aircraft power and efficiency through wing modification, more aerodynamic design, and more powerful engines. Other mitigation strategies involve lengthening runways and decreasing payloads.”

More powerful engines, if they are fossil-fuel powered, means more emissions to mitigate.

♦ To summarize, if the aviation industry is to achieve its objective of carbon-neutral growth, it will have to cut its use of fossil fuel now, not in decades. Relying on offsetting to fudge a cap on CO2 emissions, will not do.

As the bar chart above shows, the cost of fossil jet fuel must rise by about 100 USD/bbl for alternative fuels to begin competing seriously. Alexandre de Juniac, IATA Chief, has been lobbying against a ‘Green Tax’ on aviation. He should instead lobby globally for a carbon tax on fossil fuels at the mine, well-head, or port of entry. A heavy enough tax would remove the cost premium that’s delaying the use of alternative fuels, force the fossil fuel industry to pay some of the conversion costs, and place all airlines on a level environmental playing field.