How to accommodate twice as many passengers in the air while drastically reducing greenhouse gas emissions? The aviation sector has embarked on a forced and complex march towards decarbonisation.
+ What does air traffic represent?
The aviation sector carried 4.5 billion passengers in 2019, producing 900 million tonnes of CO2, or around 2% of global emissions. It projects twice as many passengers by 2050, so twice as much CO2 if nothing is done.
However, if it has always sought to gain in efficiency, environmental pressure has increased under the effect of movements such as the “Flygskam” (“shame of taking the plane”), which appeared in Sweden in 2018.
Between 2009 and 2019, airlines improved their energy efficiency by 21.4%, according to the International Air Transport Association (Iata). Not enough to prevent the sector’s emissions from growing.
+ What are the commitments?
The Iata committed at the beginning of October to “net zero emissions” of CO2 in 2050, when it aimed until now only to halve them. In this, it joins the airlines, airports and European manufacturers.
At state level, the European Union wants to reduce its emissions by 55% by 2030 compared to 1990, including for air travel, and the United States wants to reduce emissions from commercial aviation by 20% d ‘by 2030, compared to the current trajectory.
+ What are the levers to achieve this?
Europeans hope that technological and infrastructure improvements – new materials, more fuel-efficient engines, better management of the air traffic system, aircraft running on hydrogen or using more electricity – will make it possible to achieve nearly half of the expected gains. , when Iata thinks they will only help up to 14% of the effort.
To achieve “net zero emissions”, the roadmaps all rely on carbon offsetting mechanisms (such as planting trees), to the chagrin of NGOs for whom this only shifts the problem.
+ What role for sustainable fuels?
It is central. “If there is a miracle solution to decarbonize aviation, it is sustainable fuels,” said Brian Moran, responsible for sustainable development at Boeing. The Iata even relies two-thirds of the decarbonisation effort on these sustainable aviation fuels (SAFs), produced from cooking oils, algae, wood residue or other products of ” biomass “.
The European Commission intends to establish an obligation to incorporate 2% SAF in aviation kerosene in 2025, 5% in 2030 and up to 63% in 2050. Boeing and Airbus plan that their planes will be able to fly with 100% of SAF from the end of this decade.
SAFs cost four times more than kerosene and most importantly are not available. They represented less than 0.1% of the 360 billion liters of fuel used by aviation in 2019.
A new sector must therefore emerge in order to increase volumes and lower prices. The EU wants to encourage this with a progressive taxation of kerosene for internal flights to the EU, the United States by offering a tax credit.
+ Is it really possible?
Airbus boss Guillaume Faury believes that technological innovations on airplanes, and in particular hydrogen airplanes, will be ready, “but it is not just the airplane, we need the regulators, the energy “.
But biomass is a finite resource. “It has been estimated that by 2050, advanced biofuels from residues will cover 11% of air transport needs”, explains to AFP Jo Dardenne, at Transport and Environment (T&E), a European federation bringing together around fifty NGOs.
The sector therefore relies on future synthetic fuels, or e-fuels, made with hydrogen produced from renewable electricity and with CO2 captured in the atmosphere.
But producing e-fuels representing 10% of the current consumption of aviation kerosene is equivalent to the total electricity production of Spain and France combined, observes Timur Gül, head of the International Energy Agency. (IAE).
“The technologies that we want to develop to reduce air emissions are going to be extremely energy intensive”, abounds Ms. Dardenne, according to whom a “paradigm shift” is necessary: we must “reduce demand” that is to say. say fly less.