Air pollution, what can be done for more sustainable flights

Air pollution: must be reduced by 90%

In 2021, the European Commission included the Corsia (Carbon offsetting and reduction scheme for international aviation)an international program approved by the ICAO (International Civil Aviation Organization) aiming at offset 80% of emissions above 2020 levels by 2035. The plan will be mandatory from 2027 for EU states: it will apply only to international flights and will be delegated to the airlines themselves. It will be up to them monitor their emissions and balance them by purchasing credits to be used in renewable sectors. A medium-term goal to reach the very challenging objective of reducing emissions produced by transport by 90% by 2050 (compared to 1990).

How much do airplanes pollute?

Since Covid, everything has changed: the collapse of world air traffic caused by the pandemic has caused the collapse of polluting emissions from civilian aircraft in recent years: come on 785 million tons of CO2 in 2019 to 408 million in 2020. The reduction in flights, it goes without saying, has led to a drastic reduction in air pollution, which according to the EEA report “Transport and Environment 2020 – (TERM) represented in 2018 13% of greenhouse gas emissions in the EU (2% globally).

Actually in Europe cars are leading the polluter ranking – according to the European Environment Agency, trains, with their 0.5% of total emissions, are the most sustainable, compared to 44% of private cars – but airplanes have the black jersey all the same. In fact, on average, they emit 285 grams of CO2 per person (roughly the same as those produced by heating the average home for a year). C.onther 104 of the cars and 14 of the trains. However, it is worth specifying at least that, over long distances, the particularly onerous environmental costs of landing and take-off do not change and therefore flying can become more sustainable than driving.

Industry and companies against air pollution

The guidelines ICAO to improve fuel consumption, they set a reduction of 1.5% per year as a threshold. «But once the objectives have been set, the sanctions must also be set», warns Viola: «So that the aeronautical industry and the companies are tied up. Airbus and Boeing, the major aircraft manufacturers, are working to produce the appropriate technology ».

And airlines try to keep up, also to respond to the growing attention of passengers towards environmental issues: so, if American Airlines has as a “science-based objective” (ie aligned with the levels indicated by scholars to keep global warming well below 2 °) the reduction of 45% of greenhouse gas emissions by 2035 compared to the levels of 2019, Air France and KLMin collaboration with Valentino, invite customers to offset CO2 emissions associated with travel, contributing an amount equivalent to the purchase of sustainable fuel by the two airlines.

According to estimates, around £ 4 would be enough to offset the environmental impact of a return flight from London to Malagafor one from London and Cape Town about 20.

Lighter aircraft and Saf

Compensation aside, in practice the aim is to combine lighter aircraft, with better aerodynamics, a sustainable aviation fuels.

First Saf (sustainable aviation fuel), biofuel derived from cooking, waste or vegetable oils, already used in combination with kerosene in many flights. It’s a business that’s taking off: Microsoft has also recently invested $ 50 million in LanzaJetwhich aims to produce 38 million liters of eco-petrol from waste fermentation by 2023.

Of course, it costs a lot more than kerosene. For this, again, to encourage its use, rules and sanctions are needed. As some European countries have done (Sweden, Norway and France) introducing obligations for airlines: when refueling aircraft on their territory they must use a percentage of Saf.

Liquid hydrogen, the new frontier

The real challenge, however, is liquid hydrogen. “The program ZEROe by Airbus is betting on the rise of this technology by 2035 ”, says Viola. Hydrogen has three times the energy density of kerosene used today, which results in better efficiency. It also requires less fuel to make the same journey.

The estimate is a fuel consumption cut of almost 70% compared to a traditional aircraft. «Hydrogen does not produce carbon dioxide, but it needs special tanks to be transported», explains Viola. We need very low temperatures, of 250 ° below zero, and the partial re-engineering of the aircraft.

Mostly, the timing is not yet clear nor whether it will be possible, in the near future, to travel only on hydrogen or if this super fuel can only be used in combination, at a minimum, with others.

It will take even longer to see an electric airliner overhead.

How could it work in Milan

While waiting for the planes to be ready, Sea (which manages Linate and Malpensa airports) and Airbus have signed a memorandum of understanding for the study and implementation of projects for the distribution of hydrogen in the two Milanese airports.

The idea would be to create a hub dedicated to production at Malpensa while only distribution should take place at Linate, loading the product into aircraft tanks.

In the meantime, shall we leave?

A trip where air pollution is really low takes time. But, in the meantime, even those who fly can do a little check before choosing the airline to leave with. Google Flights offers the possibility to compare various flights also according to the CO2 emission (thanks to the project developed by the young Ticinese Patrik Reali). It is thus possible to see at a glance how much carbon dioxide a trip produces compared to the others.

Just to get an idea: according to a report from Transition Pathway Initiative (TPI), which evaluates the preparation of companies for the ecological transition, EasyJet would be the company that produces the lowest impact in terms of CO2 emitted (here a comparison between the performance of the companies).

iO Donna © REPRODUCTION RESERVED