Emissions from air traffic: the long road to climate-friendly flying

Status: 10/26/2021 4:26 p.m.

How can air traffic reduce its climate-damaging emissions? Prerequisites are fewer subsidies and a CO2 price, according to a study by the International Transport Forum. Not much will happen without political pressure.

One of the few positive consequences of the Corona crisis is that climate-damaging emissions from air traffic have decreased. For months there was hardly any flight movement in most parts of the world. As a result, less CO2 was released into the atmosphere and other climate-damaging side effects of flying simply disappeared.

If things really get going again, the states and the international community should take the opportunity, says the International Transport Forum, a partner organization of the OECD, in a study that has now been published. The states should create framework conditions that will ensure that air traffic will significantly improve its carbon footprint in the future. State aid could therefore be linked to airlines saving CO2. In principle, clear international reduction targets should be formulated and the airlines should be supported in achieving them.

CO2 price as a prerequisite for improvements

It is now time to be honest about the cost of flying, said the Transport Forum. Finally, environmental impacts must also be taken into account. First of all, climate-damaging subsidies would have to be dismantled – in Germany, for example, the rule that no energy tax is levied on kerosene. Then a CO2 price should be introduced – nationally or internationally. This can be implemented with the help of a tax. According to the study, however, a market instrument such as certificate trading would work better. According to the study’s authors, it is only when emissions cost something that there is an incentive to save.

Technical solutions for this have been under discussion for a long time. However, there is still no really viable idea – all experts agree on that. Sustainably produced fuel could be used. But all the corresponding variants are expensive, and there are definitely not enough of them.

Alternative fuels

Biofuels made from plants and fibers have no future for the experts from the International Transport Forum. The reason: They consume land, compete with food production or – like palm oil plantations – even destroy rainforest. Electric flying is not yet feasible today because the batteries are large and heavy. Airplanes wouldn’t get very far with it either.

According to the study, so-called power-to-liquids fuels (PtL), in which electrically generated hydrogen and CO2 become a liquid mixture, have more opportunities. They are to be added to conventional kerosene in the next few years, according to the so-called PtL roadmap of the federal government, which wants to promote sustainable electricity-based fuels – but only to the extent of two percent of the amount of kerosene used in 2019 by 2030. PtL is still too expensive for widespread use, and it is completely unclear where the “green hydrogen” should come from.

More efficiency is not enough

Another approach is modern aircraft types with improved energy efficiency. Research has been going on for a long time. A lot has happened in this area in recent years. But efficient doesn’t really mean climate-neutral. And so far, efficiency gains have not turned into savings because air traffic has increased massively at the same time.

In addition, air traffic is not only harmful to the climate because of its CO2 emissions. There are other side effects of flying that contribute to the greenhouse effect. These include the so-called contrails. Science is arguing here about how big the climate effect is. But it is clear that it does exist. The contrails occur with most fuels, including PtL and hydrogen, depending on the weather conditions. In order to reduce them, the airlines would have to change their flight routes to different weather conditions. According to the study’s authors, it is not to be expected that they will do this voluntarily.

Political pressure necessary

The conclusion of the International Transport Forum on the topic of climate-neutral flying is clear: Without external pressure, the aviation industry will not do much to improve here, because everything will cost a lot of money. The governments and international organizations are therefore in demand. On the one hand, by setting framework conditions, for example through emission ceilings, CO2 certificate trading and other environmental requirements. On the other hand, by supporting the industry, investing in research and development and in pilot projects for new technical solutions such as alternative drive systems.

Overall, however, the road to environmentally friendly flying is very long. Ultimately, it only helps to reduce the number of flights – for example by replacing domestic flights with express rail services. The aviation industry naturally has little interest in this. Ideas are needed to convince them of this.

source site