Setting European aviation on a pathway to decarbonisation by 2050
Thu 22 Nov 2018 – A new study, one of the first, examines whether a credible pathway to zero or near zero emissions exists for European aviation. The report, published by Transport & Environment (T&E), looks at flights within and departing Europe thus matching the scope of aviation’s inclusion in the EU’s 2030 target. It takes broadly accepted passenger and emissions growth forecasts out to 2050 and considers the role that various policies can play in reducing fuel demand from the sector, writes T&E’s Bill Hemmings (right). The report then proposes how the remaining fuel demand can be decarbonised by applying a low/zero carbon fuel blending mandate across EU aviation fuel suppliers. The mandate would be directed at advanced sustainable biofuels with the bulk of decarbonisation being achieved through the uptake of electrofuels.
Challenges are identified, including the failure of European policies intended to sustainably reduce the carbon intensity of road transport fuels, the need to agree and enforce strict sustainability fuel criteria for aviation, the heavy demand on renewables that electrofuel production imposes and the fact that aviation non-CO2 also needs addressing since its effects are largely being ignored.
The report starts by considering expected technology and operations improvements as well as stricter fuel efficiency standards and incentives to speed up fleet renewal. However, it finds they will not mitigate the expected fuel demand and emissions growth, particularly given incremental efficiency improvements from current aircraft designs are becoming ever more costly and difficult. Further operational improvements remain possible but they also do not achieve decarbonisation and require the right policies to be in place.
Carbon pricing is seen as needing to play a central role in achieving further reductions in fuel demand and various options from fuel taxation and strengthening the EU ETS, to applying VAT and ticket and per flight taxes are considered, as is modal shift. After estimating all feasible emissions reduction measures, including applying an effective carbon price of €150/tonne, the report finds fuel demand could be cut by some 12 Mtoe, or 16.9%, in 2050 compared to the business as usual scenario.
The report then examines two decarbonisation pathways – deploying sustainable advanced biofuels and renewable fuels of nonbiological origin (RFNBO), or electrofuels. While the use of such fuels can put aviation on a pathway to decarbonisation, the report finds that getting to zero emissions, the generally accepted term for decarbonisation, will be difficult because producing alternative fuels that on a life cycle basis are 100% carbon free will be very challenging. Advanced biofuels could play a role in substituting fossil fuel demand in aviation but the forecast was limited to only those advanced biofuels from wastes and residues which deliver real and sustainable reductions. Such feedstocks are incidental to other processes, and so will be limited in availability.
Strict sustainability safeguards will be needed to ensure genuine emission savings and these safeguards are not yet in place. Fuels with poor environmental and climate credentials would need to be excluded. The report finds that sustainable advanced biofuels could play a role – meeting up to 11.4% (7,500 ktoe) of the remaining 2050 fuel demand in the scenario. Supply will be further limited because non-transport sectors will also have a claim to biomass feedstocks.
To succeed in putting aviation on a pathway to decarbonisation, new types of alternative fuels will need to be brought forward and the report focuses on synthetic fuels, namely electrofuels, to close the gap. Electrofuels are produced through combining hydrogen from electrolysis with CO2. With the hydrogen production using additional renewable electricity and with the correct source of CO2 (direct air capture), such fuels can be close to near zero emissions and carbon circular. Strict safeguards will again be needed to ensure the synthetic kerosene is only produced from zero emission electricity and the CO2 from air capture.
If produced at scale, electrofuels are likely to cost between three and six times more than untaxed kerosene, and electrofuel uptake could increase airline ticket prices by 59%, resulting in a 28% reduction in projected passenger demand compared to a business-as-usual scenario. However, compared to ticket prices with an equivalent CO2 price of €150 per tonne, the ticket price increase would only be 23%. The report finds that introducing a progressively more stringent low carbon fuel standard (GHG target) on aviation fuel suppliers will leave all operators flying within or from Europe needing to purchase such fuels. These rising fuel costs will increase operating costs which will inevitably be passed onto consumers, causing a fall in demand for jet fuel compared to forecasts and reducing the volume of alternative fuels that will be required to replace kerosene.
Importantly for policy makers, the report highlights the enormous demand on renewable electricity if fuel demand remains high and electrofuels are the only way to decarbonise. Using electrofuels to meet the expected remaining fuel demand for aviation in 2050 would require 95% of the electricity currently generated using renewables in Europe. It is also important to keep in mind that other sectors will also need additional renewable electricity to decarbonise.
This report does not rule out the role that radical new aircraft designs could play in significantly reducing aviation emissions, for example hydrogen or electric aircraft. However, such aircraft are not expected to be in operation in significant numbers until the 2040s, and it will be especially challenging to replace conventional aircraft for long-haul flights. Should hydrogen aircraft technology develop more rapidly, this would not be at odds with significant investment in synthetic fuels as hydrogen is a key input for electrofuels. Decarbonising such fuel will require significant investment, and this requires certainty so there is a clear role for governments.
Aviation’s non-CO2 effects at altitude are considerable and a challenge that is barely being touched. While the report discusses these effects and identifies possible mitigation approaches, there remains a lack of policy focus and investment in scientific research preventing the report putting forward a suite of mitigation measures or estimating their effects.
T&E stresses that the European Commission must meet its obligations under the EU ETS Directive to foster further research and resulting from that, come forward with proposals on measures to address non-CO2 impacts by the start of 2020.