This is the new reflex of some travelers who feel guilty about the thought of flying in the context of a climate emergency, hammered home with every IPCC report. Is it wise to continue using the world’s most polluting vehicles, according to the European Environment Agency (EEA)? According to him, a passenger by plane emits 285 grams of CO2 per kilometer, compared to 158 grams by car, and only 14 grams by train.
Some travelers refuse to fly, even if it means leaving their vacations on the other side of the world. Others instead turn to online CO2 calculators with the idea of offsetting their travel footprint later. Only, depending on the actors, the results are very different. Most of them are also owned by airlines, which raises the issue of potential conflicts of interest. Can we really trust these new tools? Decoding:
176 kg CO2 Paris-Madrid
The carbon footprint of airplane travel is determined by two things. First, from the burning of kerosene, which produces carbon dioxide (CO2). Second, a number of other emission factors contribute to the greenhouse effect, such as contrails, kerosene extraction, transportation, processing… To calculate it, therefore, it would be necessary – logically – to estimate these two parameters. First, CO2.
do it”It is enough to measure the distance between two reference airports, the aircraft model and the passengers. After collecting this data, calculate the fuel needed for this trip, then divide it by the number of people on board to determine each person’s share.“, he explains Figaro Matthieu Jousset, Director of Action at the GoodPlanet Foundation. In this way, we will be able to calculate the tons of greenhouse gases emitted by burning kerosene per person. It is
“This is what most airlines provide on their counters, what the law requires them to communicate“, comments Jean-Luc Manso, director of Climat Mundi, a structure that specializes in supporting companies in the ecological transition. So, based on this algorithm, Air France calculates 176 kg of CO2 per passenger for a round trip between Paris (ORY) and Madrid (MAD). According to Transavia, this figure is 180 kg. According to Adema, this corresponds to about 1,000 km by car, about 100,000 km by TGV and the consumption of 345 vegetarians or about twenty meals with beef.
Kerosene is only the tip of the iceberg
However, as you will understand, the calculation is not complete. What about other emission factors? “Herein lies the problem“, according to two experts. “Kerosene is only the tip of the iceberg– warns Jean-Luc Manso. To be completely accurate, you also have to consider contrails, those long white streaks that extend behind airplanes and are associated with the condensation of water vapor and other debris from burning fuel. They have no consequences when they disappear immediately, but in some cases they stagnate in the sky for several hours, emphasizing the greenhouse effect and therefore global warming. “They can double the carbon footprint from simple to simple.”reveals the director of Climat Mundi.
Other parameters currently not taken into account by airline carbon meters are emissions associated with device manufacturing, airport infrastructure construction, or kerosene extraction. “Factors that would push the carbon footprint numbers even higher if factored into the calculationMatthieu Jousset reports. So, taking these last parameters into account, Good Planet calculates 610 kg of CO2 emissions per passenger for the same Paris-Madrid trip. Equivalently, this corresponds to about 3,000 km by car, about 300,000 km by TGV, 1,196 vegetarian meals or 84 with beef. That’s almost four times more than Air France and Transavia…
Except that nothing in French regulations or European law obliges airlines to report this data. They are also difficult to calculate. According to Air France climate manager Antoine Laborde. “Condensation paths depend on the altitude of the plane, air humidity, time of day or night, type of engine. It is the same for the released nitrogen oxides, which on the one hand produce ozone and on the other hand destroy methane…”., he explains. Therefore, this calculation does not workconsensus of scientistsAccording to the General Directorate of Civil Aviation, which does not take them into account in its calculation either. New studies on this topic are in progress and should be determined soon.
The issue of compensation
And what about carbon offsets, the logical extension of the footprint calculation now offered by most companies? “At home, we talk more about climate actionsays Air France’s Antoine Laborde. “We invite travelers to donate to support reforestation projects“. A beneficial action for the planet, of course, but which has certain limits for environmental associations. “To me it sounds a bit like EDF working to voluntarily reduce energy consumption. Ethically it makes no sense“, complains the manager of Climat Mundi, who is also surprised by their nature.projects“. What are they? Who directs them? What margin do brokers make?
All this for himit’s just the magic formula for giving a “clear conscience.” The solution: Reduce air travel, period“. Air France logically speaks sooner.invest in a modern fleet that consumes less and therefore emits less greenhouse gases, reduce the weight on the plane, because the lighter the plane, the less fuel it consumes and fly lower, another way to limit consumption“.
[Cet article a été publié initialement en mai 2022.]
Source: Le Figaro
