The great aviation fair holds its quarters at Le Bourget until Sunday, June 25. Announcements of record sales, denunciation of “aviationbashing”, “new French suicide”, presentation of the new Renault SUV (yes, at the International Air and Space Show) or call for the creation of an aircraft of the “more sober” future, the Salon oscillates between “business as usual” and more or less sincere awareness that a change is needed in this sector.
The aviation sector is responsible for 2.5% to 3% of global CO2 emissions, depending on whether or not we take into account emissions “due to the process of extracting oil, refining it, and transporting fuel “, deciphers the Political Ecology Workshop of Toulouse.
Aviation’s contribution to global warming surpasses its share of emissions and reaches almost 6%, according to the Intergovernmental Panel on Climate Change (IPCC). Contrails have indeed a significant impact in the warming process, but over a short period, unlike CO₂ emissions, which remain in the atmosphere for a hundred years.
Jean-Baptiste Djebbari, former transport minister and pilot, laments that calls for sobriety in aviation aim to “deprive millions of more modest French people of the journey of their lives”.
In reality, in the world as in France, the use of the plane concerns only a minority: in France, only 2% take the plane several times a month and 9% more than three times. per year, according to an IFOP survey in 2022 for the Jean Jaurès Foundation. 56% take it occasionally (21% once or twice a year, 35% exceptionally) while 33% of French people have never flown. It is the upper categories (executives and business leaders) who steal the most: 22% use it regularly (from several times a month to several times a year), while 62% of them use it occasionally
Worldwide, only 11% of the world’s population took the plane in 2018, and, among them, only 4% to travel abroad, according to a study by the Swedish University Linnaeus in 2020. He d It was also necessary to wait until the 1970s for air transport to become massive, while only benefiting a wealthy minority. According to the Swedish study, 1% of travelers worldwide emit 50% of CO2 from air travel. “The use of aviation is inequitably distributed around the world, probably more so than any other major emission source,” writes study director Stefan Gössling to our British colleagues at the Guardian. Indeed, a North American covers 50 times more kilometers than an African (5,967 against 123), and more than twice as much as a European (2,867 km).
The sector evokes two essential ways to achieve this: more efficient aircraft and less emitting fuels. A question that is all the more important since aviation consumes 8% of the world’s oil each year. Biofuels for aircraft have received the necessary international certification to be used on commercial flights.
Biofuels could significantly reduce CO₂ emissions from aircraft, but it all depends on how it is produced. From household waste, it could be much more virtuous than kerosene; but produced from palm oil, it would ultimately be more emitting than conventional fuels, if deforestation is taken into account.
Since 2022, French regulations require fuel suppliers to incorporate 1% of “sustainable aviation fuel” into kerosene. A recent European agreement on the ReFuelEU Aviation proposal raises this rate to 2% in 2025 and sets the target of 70% by 2050. But two issues weigh heavily on these objectives: production is far too low to hope to reach even 50% biofuel, and the cost is currently between two and four times that of kerosene.
The Paris Air Show was the occasion for discussions on projects for aircraft running on “green” hydrogen – that is to say, obtained by electrolysis of water using low-carbon electricity – projects that are not very realistic in the short and even the medium term. The collective of researchers from the Atelier d’écologie politique estimates that to ensure the current traffic of Paris-Charles-de-Gaulle airport alone, “it would take 10,000 to 18,000 wind turbines, or sixteen nuclear reactors” .
In recent decades, airplanes have made enormous progress in terms of emissions. According to Aurélien Bigo, associate researcher at the Energy and Prosperity Chair, in his book Cars, true or fake?, “in 2018, one kilometer by plane for a passenger required about five times less energy than in 1973. However, in globally, emissions were multiplied by 2.8 over the same period. The reason ? air traffic has been multiplied by thirteen in forty-five years”.
However, professionals in the sector are counting on a doubling of air traffic by 2050 (record orders bear witness to this), i.e. around 9 billion passengers per year, compared to 4.35 today. Is the carbon neutrality that the industry is aiming for by mid-century possible given this increase in passenger numbers?
If more virtuous fuels emerge, their generalization is not for tomorrow because of their price and their availability; if the hydrogen engine is presented as the panacea, it will not be a medium-term solution. It is therefore to be feared that the gains in aircraft efficiency will be erased by the drastic increase in flights expected and that greenhouse gas emissions from aviation will increase inexorably. “No technological alternative up to the challenge is ready for the next few years, or even the next decades”, summarizes Aurélien Bigo.
The engineer and energy expert Jean-Marc Jancovici pleaded on France Inter for the establishment of flight quotas during life. According to him, it would be necessary to limit each person to about four plane trips over a lifetime to make the emissions of the aviation sector bearable.
For the time being, the constraint of the States is weak and the sector sticks to self-regulation in order to achieve carbon neutrality. But this program, called “Corsia”, is already decried. A study commissioned by the European Union (EU) concludes that it could even “undermine EU climate efforts”. The document, obtained by the Transport and Environment Association, reveals that the Corsia “risks compromising the ability to achieve net zero emissions by mid-century” if it replaces existing EU climate regulations.