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AEF Response to Jet Zero: Further Technical Consultation

29th April, 2022

AEF has submitted comments to the ‘Jet Zero’ further technical consultation which closed on the 25th of April. Following the original consultation on the draft strategy last year, updated carbon values and other new evidence became available, the Government says, which allowed it to update its modelling, leading to this new – but limited – consultation on potential scenarios to reach net zero by 2050. The final strategy for delivering net zero aviation is expected to be published in July this year. It’s unclear whether this will contain new policy proposals to deliver the Government’s desired aviation emissions pathway.

Changes that have been incorporated into the new Department for Transport analysis include:

  • Updates to the fleet mix modelling (though the forecasts of average annual efficiency improvements are unchanged)
  • Various initiatives in relation to ‘Sustainable Aviation Fuels’ (SAFs), which led to the Government increasing the anticipated volume of SAF use in its scenarios
  • Updated forecasts in relation to when zero emissions flight may become possible (though the impact on total emissions is expected to be very small even by 2050)
  • Changes to the modelling in relation to carbon costs prompted by the publication by BEIS of higher ‘carbon values’ to be used for policy appraisal
  • New evidence on the theoretical cost and availability of greenhouse gas removals

Higher assumptions about the use of SAF (which is much more expensive the fossil kerosene) and higher carbon values could both be expected to increase ticket prices and therefore reduce demand. In fact, however, the passenger demand the Government’s preferred scenario has increased to 70% above 2018 levels. The consultation invited comments specifically in relation to these changes and on the revised scenarios and emissions trajectories presented.

One of the questions asked in the consultation was about the availability of alternative, evidence-based scenarios of which the Government should be aware. Our response to the consultation included a copy of a report we commissioned from Element Energy to (i) provide their views on DfT’s assumptions and of any significant risks inherent in DfT’s approach and (ii) set out their own recommendation of a lower-risk pathway towards aviation decarbonisation, drawing on their previous work and modelling for DfT, BEIS, CCC and others. This report will have a public launch in the coming weeks.

Overall, the Government’s approach to delivering net zero aviation relies, in our view, on uncertain measures taking place in the future while allowing significant passenger and emissions growth in the short term. Our consultation response highlighted a number of areas in which the approach taken was flawed or inadequate:

  • Carbon removals can’t be simply assumed to be available at low cost and at the scale required – 15 million tonnes per annum even in the Government’s preferred ‘High Ambition’ scenario – to balance all remaining aviation emissions by 2050. Given the scale of the challenge in delivering this technology and the fact that it has never yet been rolled out in the UK, an aviation net zero scenario with low levels of greenhouse gas removals should have been included.
  • Carbon prices can’t be relied on to deliver aviation decarbonisation. Our analysis suggests that carbon prices are likely to remain too low for too long to provide strong enough market signals to drive investment in the fuels and technologies that would be needed to deliver net zero aviation by 2050.
  • Aviation demand should not be assumed to grow directly in relation to GDP. Changes in corporate and public attitudes as a result of climate change awareness are already evident at a small scale and could well grow. While the Government would prefer to avoid discussion about behaviour change to meet climate commitments, it should have modelled a scenario where aviation demand was lower.
  • Non-CO2 impacts will need policy regulation. The latest scientific research estimates that aviation has historically caused three times as much global warming as would be expected from its CO2 emissions alone. Yet no scenarios have been included that assume any impact arising from policy action on non-CO2. While policymakers have shied away from introducing non-CO2 multipliers to carbon trading systems such as the EU ETS, failure to represent non-CO2 impacts in the modelling of scenarios significantly underestimates both the scale and the nature of the challenge of achieving net zero aviation.
  • SAF uptake levels assumed in some of the scenarios are extraordinary given where we are today (with SAF representing well under 0.5% of aviation fuel), the wide cost gap between SAF and kerosene, and ongoing challenges in determining how much SAF can be sustainably produced. As with the previous modelling, the trajectories are based on a 100% emissions reduction from SAF use, an accounting convention that assumes that emissions generated through SAF production are accounted for elsewhere. Much closer scrutiny is needed of this approach, we argue, particularly given the likelihood of SAF being imported.
  • Fuel efficiency is assumed in almost all scenarios to increase from its historic level of 1.5% per year to 2% per year going forward. We’re doubtful about whether this can be achieved, particularly with the low levels of carbon pricing assumed in the short term, and the financial hit from the pandemic affecting investment.
  • The need for early action on emissions is not reflected in any of the scenarios. The Government has committed to a 78% economy-wide emissions cut by 2035 (based on 1990 levels), and yet aviation emissions are expected to make very little emission reduction compared to their 2019 high until after this date, with the majority of emissions cuts coming after 2040 in the modelling. This approach puts the 78% reduction commitment at risk. It allows demand to grow and airports to expand in the short term, making it harder to deliver the future demand reduction that may be necessary if the hoped-for technology improvements do not materialise; it increases cumulative emissions compared with a scenario where greater emissions cuts are made earlier, increasing the risk of dangerous temperature rises; and it increases the overall level of risk of not meeting the 2050 target.

Overall, presenting aviation ‘scenarios’ for consultation in the absence of policy proposals makes this exercise slightly meaningless. The difference between a desirable policy outcome and a likely one is not addressed, and the plans are largely dependent on action taking place elsewhere and at some time in the future. The scenarios place a heavy reliance on new technologies (including GGR) and fuels being developed as a result of carbon prices driven primarily through global agreement. There is no discussion of what ‘plan B’ the Government will implement if global carbon markets fail to deliver the improvements anticipated.

Compared with the original jet zero consultation, the new analysis, while addressing some of the specific criticisms that we had levelled (for example in relation to carbon pricing) strays even further into the realms of fantastical assumptions about future technologies and fuels while conveniently allowing passenger growth and even emissions to increase in the short term.

To read our full response to the Government’s technical consultation on net zero, click here.