Aviation accounts for 2-3% of all global CO2 emissions and is the fastest growing emitter in the transport sector
However, this does not give the full picture of aviation's impact on the climate. Taking into account aviation's non-CO2 effects, the industry accounts for 3.5% of global effective radiative forcing, i.e. 3.5% of global warming, with the largest contributor to its warming effect being contrails.
To help the industry overcome its reliance on conventional jet fuel, both alternative fuels and revolutionary aircraft designs are necessary. Additionally, to further help minimize the sector's warming impact on the planet, technological innovation should extend beyond the aircraft itself to encompass airport operations as well as flight path optimization and rerouting for contrail avoidance. Therefore, to be able to fly more sustainably, we require a holistic transformation of the sector that takes into account both CO2 and non-CO2 effects.
Long-haul flights make up almost 40% of the sector's emissions, although they only account for 5% of all flights.
When it comes to aviation, there is no one-size-fits-all solution for decarbonizing different flight ranges. Different technologies will be suitable depending on journey length.
✅ Currently, flights < 500 km and with < 100 passengers are most suited for battery-electric flight.
✅ A portion of short and medium-haul flights could be covered by hydrogen combustion, fuel cell, and hybrid aircraft.
❕ However, electric and hydrogen based technologies are still in the testing phase and primarily focus on smaller planes (responsible for ~ 4% of the industry's annual emissions). For hydrogen aircraft, additional challenges include sourcing, transporting, and storing the hydrogen.
✅ For long haul flights, the only currently viable solution is synthetic aviation fuels (SAFs), including biofuels and e-fuels.
❕ Unfortunately, SAFs remain expensive and difficult to scale. While production has been increasing over the past 5 years, the amount of SAFs produced in 2022 only covered ~0.1% of the industry's fuel consumption.
The aviation sector is not on track for net zero by 2050
Why is it so difficult to get the aviation sector on a more sustainable path? Some of the key challenges are:
🔶 International flights make up more than 50% of the sector's emissions, even though 2/3 of flight departures are domestic. This poses severe challenges when trying to regulate these emissions. To truly reduce emissions, international cooperation that prioritizes the environment is paramount.
🔶 Time is running out fast for the sector: Aircraft built today will remain in service for the next 25 years. However, today's airplanes are still predominantly built and optimized to operate on conventional jet fuel. Entry into service of electric or hydrogen aircraft is not expected before the second half of this decade.