BERLIN (dpa-AFX) - No single technology can be decisive for more climate-friendly aviation, according to a report by the Office of Technology Assessment at the German Bundestag (TAB). According to an analysis presented on Wednesday, in which innovative propulsion systems for more climate-friendly air traffic were examined, no currently possible strategy is sufficient in itself to achieve the emission targets.

What is needed is a mix of technologies. According to the TAB, this includes electric drives, more sustainable fuels from waste or biomass, green hydrogen (H2), the optimization of fuels, a more sustainable aircraft design and a reduction in emissions through increased efficiency.

According to the TAB, no quick fixes are to be expected for either engines or new fuels. "The aviation sector is characterized by comparatively long development and approval periods for new technologies." The development and approval of new aircraft designs or engines is estimated to take up to 15 years, with market penetration then taking up to another 30 years.

Another problem is that, due to the close global networking of air traffic, a uniform energy supply must be guaranteed at all airports, the TAB report continues. Parallel infrastructures would entail additional costs. "For this reason, too, a switch to a fundamentally different energy supply is not to be expected in the medium term."

According to the TAB, the optimization of flight operations will initially play a key role. Aerodynamic improvements such as particularly smooth surfaces or curved wingtips reduce fuel consumption. Flight planning at airline and air traffic management level also has the potential to reduce emissions. This involves, for example, improved airspace management to avoid detours, efficient flight procedures such as a slower descent, climate-oriented optimization of speed and flight profiles and increased aircraft utilization. Targeted taxation is one measure to accelerate such developments.

Regardless of the climate crisis, the number of flights is increasing worldwide. This has consequences: "By 2050, 60 percent more CO2 emissions could be produced than in 2019", according to the TAB report. In Germany, the number of passengers carried rose from around 136 million in 2004 to around 227 million in 2019.

Stefan Gossling from Linnaeus University in Kalmar (Sweden) sees the "most important approach to reducing emissions" barely discussed in the TAB report: reducing the demand for flights. This involves, for example, taxing long-haul flights in particular, which cause the largest contributions to emissions. "Around 25 percent of flights with the longest routes account for 70 percent of emissions."

The climate impact of air traffic is considerable. According to estimates, international aviation accounts for around 3.5 to 5 percent of man-made global warming, as stated in the TAB report./kll/DP/stw