We hear more and more about the flying shame, shame to fly. Planes are pointed out as big polluters. They are thrashed, as if they were much more polluting than cars. This is false: a jet stream does not pollute more than a car.
Consumption per passenger / km of jets is similar, even a bit lower.
As I already wrote here, a jet stream of medium size, for example in Airbus A320 or Boeing-737, does not consume more than 800 l of kerosene per 100 km, (do your research on the Web to check it) carrying 200 people on average. Which gives us a consumption per person of 4 l per 100 km. Lufthansa in 2017 even set a new record, the planes of the passenger fleets required on average only 3.68 liters of kerosene to transport a passenger over 100 kilometers, an improvement of 4.5% compared to previous the year (3.85 l / 100 km in 2016).
Source: Air Journal. What’s more, every year new jets arrive that consume even less, so these figures should be revised downwards for 2020, probably around 3.5 l per 100 km / passenger, because the efficiency of jet engines per tonne kilometer has improved by 10% in the past six years. Source: Eurocontrol. However, a car with one person on board consumes an average of 7 l per 100 km on the motorway. So to reach 3.5 liters per passenger per 100 km, a car would have to carry at least two people. Except that, statistically, over the entire world fleet, planes are 80% full, while vehicles often run with 1 to 2 people on board, rarely more.
Planes have a clear advantage in terms of pollution derived from manufacturing
Planes can travel an average of at least 1 million km before being unusable, carrying hundreds of millions of passengers. So the pollution generated by their manufacture must be divided by the kilometers traveled per passenger throughout their lifetime. If we compare these figures with that of cars, there is no doubt: a car becomes normally unusable after 200,000 km. So the pollution caused by the manufacture and renewal of cars far exceeds that of airplanes. Not to mention the pollution caused by the consumption of tires. While it is true that the jets do not have a particulate filter or catalysts, it is also true that most of the pollution is produced at more than 10,000 m above sea level, far from our lungs, where particles can mix with moisture and rain.
The problem of growing air traffic
Even if jets have reduced their consumption by 10% in the past six years, the increase in flight and distances flown has offset this reduction. Indeed, the total gate-to-gate carbon dioxide (CO2) emissions of IFR traffic in the European Civil Aviation Conference (ECAC) area grew from 163 million tons in 2012 to 202 million tons in 2019, an increase of 24% over seven years. This is faster than the increase in flights, as we are seeing larger aircraft flying further, more than offsetting the increase in aircraft efficiency.
Greener planes are for tomorrow, may be even this year
Further improvements will be achieved continuously in the near future as airlines take delivery of lean-burning aircraft and begin to replace fossil fuels with sustainable alternative fuels. While these improvements alone will not be enough to fully offset the effect of traffic growth, they are a major component of the industry process which is beginning to make real changes in controlling its emissions. The world’s first fully electric commercial aircraft took off from the Canadian city of Vancouver in December 2019, and it is highly likely that 50-seat hybrid passenger aircraft could enter service by the 2030s. However, it will take a few more years before seeing 200-seat aircraft similar to the Boeing 737 or the Airbus A320 in service.
The aeronautical industry cannot simply wait while researchers try to find solutions to the technical challenges of developing electric propulsion solutions for larger airliners. This year could be a pivotal moment in the development of sustainable aviation which offers a medium-term solution to the problem of reducing emissions at a time when traffic demand is increasing.
Carbon neutral growth
Starting from 2020 on, aviation’s net carbon emissions will be capped. This means that even if air travel increases, greenhouse gas emissions will not be; sustainable fuels, or biofuels, for aircraft will play a very important role. These are products made from used oils or waste. even if they are now two to three times more expensive, the increase in their demand will allow producers to achieve economies of scale, which inevitably require them to lower their prices to those of kerosene.
