Third Report - Net zero and the UK aviation sector

The government's response

What the committee recommended 37

1. 1
   Non-CO2 climate impacts of aviation remain unquantifiable and poorly understood Conclusion · paragraph 30
2. 2
   Commission and support research into aviation's total environmental effects for net zero strategy Conclusion · paragraph 31
3. 3
   Inclusion of international aviation emissions in Sixth Carbon Budget sends positive signal Conclusion · paragraph 49
4. 4
   Legislation for international aviation emissions commitment significantly delayed by government Conclusion · paragraph 50
5. 5
   Lay draft statutory instrument defining international aviation and shipping emissions before Parliament Recommendation · paragraph 51

See all 37 recommendations and conclusions

Sources

• Third Report - Net zero and the UK aviation sector ↗The committee's report, HC 404, parliament.uk
• Sixth Special Report - Net zero and the UK aviation sector: Government Response to the Committee’s Third Report ↗The government's response, 3 April 2024, parliament.uk

Recommendations and conclusions 37

1. 1
   Non-CO2 climate impacts of aviation remain unquantifiable and poorly understood Conclusion · paragraph 30 Conclusion (the committee's words)

   The impact of conventional aviation activity on climate is still not fully quantifiable. While the contribution of aviation to levels of atmospheric CO and other greenhouse 2 gases is quantifiable and substantial, the climate impact of other emissions from aviation is currently not well understood and difficult to quantify. Measures to decarbonise the sector are vital: but removing carbon dioxide from aviation activity is unlikely to eliminate its overall impact on the environment. The Government has acknowledged the contribution of non-CO2 effects from aviation in the development of its strategy for decarbonising aviation, and is examining methods of mitigating non-CO2 effects from aviation which uses fuels which have a reduced carbon footprint.
2. 2
   Commission and support research into aviation's total environmental effects for net zero strategy Conclusion · paragraph 31 Conclusion (the committee's words)

   We consider that any strategy designed to reduce the impact of UK aviation activity on global warming ought to encompass the environmental effects of aviation in their entirety. We therefore recommend that the Government actively commission, promote and support research into the total environmental effects of aviation, with a view to incorporating the emerging consensus into all future iterations of its strategy for net zero aviation.
3. 3
   Inclusion of international aviation emissions in Sixth Carbon Budget sends positive signal Conclusion · paragraph 49 Conclusion (the committee's words)

   The Government’s decision to include international aviation emissions in the UK’s budgets with effect from the Sixth Carbon Budget has sent a very positive signal about the UK’s resolve to address carbon emissions from UK aviation by the use of policy instruments. Establishing a requirement to bring aviation emissions within the Sixth Carbon Budget target by 2037, rather than leaving budgetary headroom for them as in previous budgets, removes ambiguities around the issue and obliges the Government to address the complexities around accounting for the UK’s share of international aviation emissions.
4. 4
   Legislation for international aviation emissions commitment significantly delayed by government Conclusion · paragraph 50 Conclusion (the committee's words)

   We are nevertheless concerned that legislation to give effect to this commitment has not been brought forward for approval by Parliament, over two and a half years since the commitment was originally made and over two years since the Government promised to legislate “within twelve months”.
5. 5
   Lay draft statutory instrument defining international aviation and shipping emissions before Parliament Recommendation · paragraph 51 Recommendation (the committee's words)

   We recommend that the Government lay before Parliament for approval, without further delay, a draft statutory instrument under section 30 of the Climate Change Act 2008 to define the emissions from international aviation and international shipping which are to be reckoned as emissions from sources in the United Kingdom.
6. 6
   Varying projections for UK aviation emissions reductions by 2050 lack reliability Conclusion · paragraph 52 Conclusion (the committee's words)

   The outputs from the modelling undertaken by the Climate Change Committee, the Government and Sustainable Aviation vary as to the projections of likely emissions reductions from UK aviation by 2050. In some instances these variations are substantial, and tend to reduce overall confidence in the reliability of the projections from each source.
7. 7
   Commission comparative analysis of UK aircraft emissions models with Climate Change Committee. Recommendation · paragraph 53 Recommendation (the committee's words)

   We recommend that the Government work with the Climate Change Committee and Sustainable Aviation on a comparative analysis of the models underpinning the projections for UK aircraft emissions, so as to reach consensus, as far as possible, on the likely impact of measures to be taken by industry and by Government on levels of emissions from UK aviation out to 2050.
8. 8
   Significant potential exists for increased operational efficiencies in UK aviation to reduce CO2. Conclusion · paragraph 76 Conclusion (the committee's words)

   There is evidently significant potential for increased efficiencies across all aviation’s operations which can lead to incremental reductions in CO2 emissions across the UK aviation sector. Efficiencies from fuel use in the current and emergent fleet of aircraft, better use of airspace and reductions in emissions from airport and aviation operations will all have a significant part to play in aviation’s contribution to reaching net zero.
9. 9
   Achieving 0.5% annual aircraft fuel efficiency gains demands significant R&D and industry incentives. Conclusion · paragraph 77 Conclusion (the committee's words)

   We agree with the Climate Change Committee that the 0.5% year-on-year improvement in fuel efficiency from the aircraft fleet requires considerable effort both in research and development activity and in incentivising the industry to renew existing aircraft fleets.
10. 10
    Maintain and enhance engagement with aviation for 2% annual CO2 reduction monitoring. Recommendation · paragraph 78 Recommendation (the committee's words)

    We recommend that the Government sustain and enhance its engagement with the aviation industry on the delivery of operational efficiencies from current and future fleets of aircraft operating through the UK, to maintain the ambition to secure 2% year- on-year CO2 emissions reductions from fuel and operational efficiencies. The delivery of these reductions must be rigorously monitored against an established baseline: should the rate of progress in reductions fall behind 2%, the potential contribution of system efficiencies to meeting the 2050 net zero target must be urgently reassessed.
11. 11
    Intensify DfT and CAA work on airspace modernisation, prioritising environmental sustainability. Recommendation · paragraph 79 Recommendation (the committee's words)

    We recommend that the Department for Transport and the Civil Aviation Authority intensify their work on airspace modernisation, bearing in mind the overarching principle of environmental sustainability.
12. 12
    Support exists for Government's aim to achieve net zero in UK airport operations. Conclusion Conclusion (the committee's words)

    We support the Government’s aim to secure net zero in UK airport operations by
13. 13
    Sustainable aviation fuels offer emissions reduction, but reliance on nascent technology is high risk. Conclusion · paragraph 109 Conclusion (the committee's words)

    Sustainable aviation fuels may offer a means of reducing the carbon emissions attributable to the lifecycle of aviation kerosene from its production to its combustion, and the Government envisions a substantial role for SAFs. There is nevertheless potential for wide variability in lifecycle emissions across the general class of fuels which the industry currently terms ‘sustainable aviation fuels’. We note that the Climate Change Committee warned in its 2023 Progress Report to Parliament that the Jet Zero Strategy approach is “high risk due to its reliance on nascent technology”, such as the rapid uptake of these fuels.
14. 14
    Government initiatives to establish domestic SAF industry and mandate are welcomed and monitored. Conclusion · paragraph 110 Conclusion (the committee's words)

    We welcome the initiatives taken by the Government to date to establish a domestic industry for the manufacture of sustainable aviation fuels, and the steps it is taking to build long-term supply chains for domestic and international aviation. We note the measures announced to date on the establishment in 2025 of a mandate for SAF use. We will monitor the outcome of the Government’s second consultation on the issue and the drafting of the secondary legislation required to implement the mandate.
15. 15
    Establish strongest safeguards in UK SAF policy to ensure significant lifecycle emissions savings. Recommendation · paragraph 111 Recommendation (the committee's words)

    We are concerned that the broad definition of what is currently considered a sustainable fuel, and the absence of a global standard for SAFs, may lead to the development of aviation fuels which cannot credibly be described as sustainable. We recommend that the Government take every opportunity to establish in its policy instruments for a UK SAF industry the strongest safeguards to ensure significant lifecycle emissions savings from the use of SAFs developed in the UK.
16. 16
    Establish clear criteria for land allocation to grow SAF feedstocks in Land Use Strategy. Recommendation · paragraph 112 Recommendation (the committee's words)

    We note with approval the Government’s criteria restricting the feedstocks to be used in UK-manufactured SAF and specifying that feedstocks are not to be obtained from land with high biodiversity value or land with high carbon stocks. We recommend that in its forthcoming Land Use Strategy the Government establish clear and unambiguous criteria as to the type of land which is to be allocated to growing feedstocks for SAF. The Government must also take every opportunity in international forums to press for the highest standards of sustainability in the production of SAF feedstocks.
17. 17
    Establish comprehensive global regulatory standards for sustainable aviation fuels through ICAO. Recommendation · paragraph 113 Recommendation (the committee's words)

    We further recommend that Ministers and officials work vigorously at the ICAO and in all other relevant international bodies for the establishment of a global regulatory standard for SAFs which is comprehensive and rigorous.
18. 18
    UK SAF Clearing House established to support producers with certification and approval. Conclusion · paragraph 114 Conclusion (the committee's words)

    We welcome the establishment of an UK SAF Clearing House at the University of Sheffield to support SAF producers through the process of certification and approval of their products for commercial use.
19. 19
    Implement a price support mechanism to incentivise investment in SAF production pathways. Recommendation · paragraph 115 Recommendation (the committee's words)

    The Government must match its ambition for the development of a domestic SAF industry with an appropriate appetite for risk and innovation in order to ensure that commercial production of truly sustainable fuels develops at pace. The introduction of a revenue certainty mechanism, via provision in the Energy Act 2023, represents a welcome initial step in this process. To this end, we recommend that the Government make swift progress on the implementation of a price support mechanism to incentivise investment for SAF production pathways.
20. 20
    Zero-emission flight shows promising long-term potential for eliminating aviation carbon emissions. Conclusion · paragraph 142 Conclusion (the committee's words)

    Zero-emission flight represents a very promising long-term prospect for achieving reductions in the CO2 emissions from UK aviation. Unlike the use of SAF, zero- emission flight technologies hold out the promise of eliminating the carbon emissions entailed in aircraft movements. We are encouraged by the significant contributions to research and development in this sector which are being undertaken by UK-based firms supported by the Government and industry through the Aviation Technology Institute.
21. 21
    Establish a 2040 target for zero-emission aircraft on essential UK connectivity routes. Recommendation · paragraph 143 Recommendation (the committee's words)

    While zero-emission flight technologies offer a route to significant reductions in aviation’s CO2 emissions, their deployment is realistically likely to be limited to short-haul flights for the foreseeable future. ZEF can play a significant role in Net zero and the UK aviation sector 53 promoting aviation as a means of connecting the UK, particularly on public service obligation routes between the UK mainland and island communities. We recommend that the Government establish a target under the Jet Zero Strategy for the full roll-out of zero-emission aircraft on a minimum number of routes essential to UK connectivity by 2040, with a view to encouraging the greater takeup of ZEF aircraft on commercially-operated short haul routes within the UK.
22. 22
    Include funding for research into non-CO2 atmospheric effects of zero-emission flight technologies. Recommendation · paragraph 144 Recommendation (the committee's words)

    Zero-emission flight is sometimes described as providing ‘guilt-free’ flying. While it is the case that ZEF technologies remove the CO2 emissions from conventional aircraft movements which are aviation’s most damaging effect on the environment, the potential effects on the atmosphere from both hydrogen and battery-electric flight are not fully known. We recommend that the Government, when promoting research into the non-CO2 effects of aviation, include in its strategy the funding of research into the effects on the atmosphere and climate of aircraft using zero-emission flight technologies.
23. 23
    Requiring airlines to price emissions through trading schemes is a constructive mechanism. Conclusion · paragraph 158 Conclusion (the committee's words)

    Requiring airlines to set a price on their emissions, and purchase credits for these emissions through a trading scheme, can be a constructive mechanism to ensure that the carbon cost of aviation is more adequately reflected in the cost to the consumer. This in itself may influence consumer demand for flights, depending on the availability and cost of the necessary carbon credits. Sustainable Aviation has categorised market-based measures as demand management mechanisms.
24. 24
    Free ETS allocations for aviation ending, SAF pricing needs to reflect carbon impact. Conclusion · paragraph 159 Conclusion (the committee's words)

    We welcome the decision of the UK Government and devolved administrations to end the issuing of free ETS allocations to aviation with effect from the 2026–2030 allocation period. We note that the use of SAF in aviation is currently zero-rated for ETS, even though the emissions from burning SAF in flight are currently equivalent to those from burning aviation kerosene: as the SAF market matures, consideration must be given to pricing SAF in the ETS at a level which genuinely reflects its carbon impact.
25. 25
    Implement UK ETS changes to remove conventional aviation fuel from free allocations. Recommendation · paragraph 160 Recommendation (the committee's words)

    We recommend that the Government implement its proposed changes to the UK ETS so as to remove conventional aviation fuel from free allocations, and that it consult on a methodology to include SAF in the ETS in a way which does not inhibit the development and use of SAF in UK aviation.
26. 26
    Aviation emissions offsetting mechanisms offer only a temporary, stopgap solution. Conclusion · paragraph 161 Conclusion (the committee's words)

    Offsetting mechanisms, such as CORSIA, may provide an interim step towards contributing to the removal from the atmosphere of the emissions attributable to UK aviation. We commend the Government on the work it has already undertaken at international level to secure an agreement on an international offsetting mechanism. More remains to be done, and the use of offsets to address aviation emissions is at best a stopgap measure until more effective and high-quality technologies to achieve permanent greenhouse gas removals are available.
27. 27
    Residual aviation emissions will require alternative abatement methods for net zero. Conclusion · paragraph 193 Conclusion (the committee's words)

    Aviation is a sector of the economy where emissions are recognised to be some of the hardest to abate. Under all the scenarios presented for the reduction in emissions from UK domestic and international aviation, it is recognised that there will be residual emissions which will have to be addressed by other means in order for the UK economy to reach net zero by 2050.
28. 28
    Aviation demand management is effective but lacks formal modelling in Jet Zero Strategy. Conclusion · paragraph 194 Conclusion (the committee's words)

    There is considerable dispute over the desirability of policy measures which would reduce UK aviation emissions by reducing the demand for aviation services. The Climate Change Committee has been clear that demand management is the most effective way of reducing aviation CO2 and non-CO2 emissions, and whilst there are a number of different approaches available for consideration, they have not been subject to formal modelling in the Jet Zero Strategy policy framework.
29. 29
    Jet Zero Strategy prioritises aviation growth over demand management, exceeding CCC recommendations. Conclusion · paragraph 195 Conclusion (the committee's words)

    We note that UK Ministers have so far ruled out the inclusion of active demand management measures in the Jet Zero Strategy in preference for a policy which promotes the growth of the airline industry following the pandemic. This is beyond the approach proposed by the Climate Change Committee. Although the Jet Zero Strategy commits to 70% passenger demand growth by 2050 on 2018 levels, the CCC’s Balanced Pathway for the Sixth Carbon Budget recommends a 25% demand increase over the same period.
30. 30
    Jet Zero Strategy lacks direct policies to discourage flying, relying on indirect measures. Conclusion · paragraph 196 Conclusion (the committee's words)

    While the Jet Zero Strategy contains measures to influence consumers towards more sustainable choices, and includes carbon pricing measures which will have an indirect effect on demand, it does not include any policy instruments designed to discourage flying in favour of other modes of travel or of communication. Ministers appear confident that the package of measures in the Strategy can achieve the reductions in emissions required from UK aviation, with the residual emissions accounted for by negative emissions technologies.
31. 31
    Aviation emissions reduction faces significant challenges, with carbon costs risking innovation and market distortion. Conclusion · paragraph 197 Conclusion (the committee's words)

    While we note the ambition shown by the Government and by the aviation industry in proposing technological methods to reduce aviation emissions, we recognise the very significant challenges for the industry in delivering the required reductions, and note that any additional costs associated with carbon reduction, such as carbon pricing through ETS and Corsia schemes, unless fully absorbed by the sector, could reflected in ticket prices and may have further impacts on overall demand. Further such costs on the sector which limit demand may run the risk of stifling the innovation that the Government and industry strategies rely on, and may skew the international aviation market in favour of more polluting airlines in a way that the multilateral ETS and Corsia schemes are designed to avoid.
32. 32
    Government’s high-ambition Jet Zero Strategy carries risk of failing emissions targets. Conclusion · paragraph 198 Conclusion (the committee's words)

    We recognise that the Government’s decision, while consistent with a policy of promoting the UK aviation industry, carries a degree of risk. In order to deliver the emissions reductions foreseen, the high ambition scenario in the Jet Zero Strategy needs to be followed through with vigour and conviction and needs to be given the appropriate priority for delivery. Failure to follow through on the ambitions expressed will result in the UK falling behind in its delivery of emissions reductions, Net zero and the UK aviation sector 55 leaving other sectors to pick up the slack. Even if the Government maintains its high ambition, there is a risk that the aviation sector will not fulfil the confident predictions it has made for emissions reductions.
33. 33
    Climate Change Committee urges development of aviation demand management policy and technology options. Recommendation · paragraph 199 Recommendation (the committee's words)

    The Climate Change Committee has argued that demand-side measures have an important role to play in ensuring that the aviation sector delivers the necessary emissions reductions and that risks in the current approach are mitigated. That Committee has therefore urged the Government to “develop a suite of policy and technology options” to address aviation demand.
34. 34
    Five-yearly Jet Zero Strategy review timetable is too relaxed, risking late policy adjustments. Conclusion · paragraph 200 Conclusion (the committee's words)

    Ministers have committed to five-yearly reviews of progress against the Jet Zero Strategy’s targets, and have undertaken to take action to amend policy if it appears to be necessary. On the current timetable the first such review is to take place in 2027. This appears to us to be a relaxed timetable for policy review at what is a critical stage for an incipient policy. If a review in 2027 concludes that targets are unlikely to be met, the ensuing policy changes will only bear fruit in the early 2030s—arguably too late for the emissions reductions initially envisaged to be achieved.
35. 35
    Undertake initial review of Jet Zero Strategy modelling by end of 2025 for emissions targets. Recommendation · paragraph 201 Recommendation (the committee's words)

    We recommend that an initial review of the Jet Zero Strategy and the modelling underlying its ‘high ambition’ scenario be undertaken no later than the end of 2025, with a view to determining whether the Strategy remains on track to meet the interim emissions reductions projected for 2030 and 2040 as well as the overall reductions projected for 2050.
36. 36
    Aviation sector must actively engage in review of emissions reduction shortfalls. Recommendation · paragraph 202 Recommendation (the committee's words)

    The review should be undertaken with the active engagement of the UK aviation sector, which is principally responsible for delivering the reductions in emissions it has claimed are possible: any shortfalls in delivery ought to be reviewed and urgently remedied.
37. 37
    Develop policy proposals for aviation demand reduction, including frequent flyer levy. Recommendation · paragraph 203 Recommendation (the committee's words)

    Should the evidence of the review indicate that technological measures alone will not deliver the emissions reductions predicted, we recommend that Ministers reconsider the role of demand management measures in aviation emissions policy. In preparation for the outcome of that review, we recommend that the Government develop policy proposals on demand reduction, including consideration of greater use of digital technologies, reducing the cost of rail travel, and a frequent flyer levy, should these then be required.