Climate-neutral flying is only possible with less air traffic


Villigen AG/Zurich – Air traffic can only be made climate-neutral by reducing the volume of flights. This is the conclusion reached by researchers at the Paul Scherrer Institute and the Swiss Federal Institute of Technology Zurich. How much depends on the type of fuel.

Researchers at the Paul Scherrer Institute(PSI) and the Swiss Federal Institute of Technology Zurich(ETH) have investigated how air travel could be made climate neutral by 2025. For this purpose, not only the direct CO2 emissions of flying were examined, but also emissions that occur during the production of fuel and infrastructure, informs the PSI in a statement. According to the researchers’ findings, the goal of climate neutrality by 2050 can only be achieved by reducing the volume of flights.

This is partly due to the important role that so-called non-CO2 effects play in climate change. This includes soot particles and nitrogen oxides emitted during kerosene combustion, as well as contrails. Although they individually form only short-lived climate drivers, they constantly add up due to increasing air traffic. “As a result, they then do unfold their enormous greenhouse potential over longer periods of time,” ETH researcher Viola Becattini explains in the statement.

Air traffic must therefore be steadily reduced in order to cool the atmosphere and push the greenhouse effect towards zero. The extent of this reduction depends on the fuel used. If fossil fuels are retained, the volume of flights must fall by 0.8 percent annually; if climate-friendly fuel, so-called sustainable aviation fuel, is used, an annual reduction of 0.4 percent is sufficient. Produced exclusively with energy from renewable sources, SAF is virtually climate-neutral. However, the production of SAF is currently still four to seven times more expensive than that of kerosene. ce/hs