Open letter from NGOs to government: aviation and shipping must be fully included in net zero legislation

A group of leading environmental NGOs has written an open letter to the government in support of the Climate Change Committee’s recommendation that international aviation and shipping emissions (IAS) should at last be formally included within the UK carbon budgets. IAS are now the only emissions category not so included, resulting in a situation where aviation emissions are insufficiently controlled by policy and the industry is in a privileged position compared to all other businesses. In its 6th Carbon Budget Report published in December, the CCC identified reasons why IAS exclusion from the UK carbon budget can no longer be justified. These include their inclusion opening up the possibility of the two sectors achieving lower emissions; the UK’s overall emissions reduction strategy should be integrated across the whole economy; doing this would set a good example to other countries; and there is no longer any justification, in terms of difficulty of calculation, for omitting them from carbon budgets. The CCC said inclusion of IAS  will “ensure that the UK takes full responsibility for these emissions and that, where necessary, effort in other sectors can be altered to ensure overall UK emissions are within the necessary limits”. 




24th February, 2021

The AEF (Aviation Environment Federation)

The Government will soon be deciding whether or not to accept the recommendation of its independent climate advisors, the Climate Change Committee (CCC), to formally include emissions from International Aviation and Shipping (IAS) in future carbon budgets. This policy step would be complementary to UK negotiations at the international level to set a long term goal for the aviation sector globally, CCC argues.

We believe that a decision on inclusion of international aviation in the UK’s carbon budgets and net zero legal target is a crucial test of the Government’s confidence in its own plans for a green industrial revolution (which includes the ambition for zero carbon flying to become a reality) and of its willingness to hold the aviation industry to account for their net zero promises.

Given the significance of this decision, we have written an open letter (copied below) directly to Boris Johnson about it, together with Greenpeace, Friends of the Earth, Green Alliance, Possible and Transport & Environment.

The Letter:

From: Aviation Environment Federation, Friends of the Earth, Green Alliance, Greenpeace, Possible and Transport & Environment


Rt Hon Boris Johnson MP
10 Downing Street

24th February 2021

Dear Prime Minister,.

Inclusion of International Aviation and Shipping emissions in carbon budgets: open letter

Your Government will this spring be preparing legislation for the sixth carbon budget – the first to be legislated since the UK committed to achieve net zero emissions by 2050 at the latest.

We are writing to highlight one specific aspect of that legislation which we consider essential to its integrity, and to the UK’s credibility in claiming climate leadership. This is the recommendation that emissions from international aviation and shipping (IAS) are formally included in the sixth (and future) carbon budgets, as advised by the Climate Change Committee (CCC) in its December report.

Aviation presents unique challenges in terms of decarbonisation. The setting up of the Jet Zero Council, and funding initiatives focussed on developing new technologies and fuels to cut emissions, will be seen as greenwash unless they are accompanied by meaningful policies that apply across the whole aviation sector.

Similarly, while the Sustainable Aviation coalition has set out its ambition to achieve net zero emissions by 2050, it is difficult to have confidence in the industry’s plans in the absence of policy mechanisms to hold it to account. Despite claims from the industry that it is moving in the right direction, emissions from commercial UK aviation were higher in 2019 – the year
before the Covid pandemic hit – than any single previous year ever.

Inclusion of IAS in carbon budgets is a straightforward policy measure that would begin to address this problem. As well as ensuring accountability, it would help to create the right market conditions and investor confidence to drive ambition and innovation, and to ensure that aviation development is in line with the Government’s wider decarbonisation agenda.

Until now, these emissions have not been formally included in national targets, but instead allowed ‘headroom’ in the setting of budgets for other sectors pending, for accounting purposes, the outcome of international negotiations in relation to the EU Emissions Trading Scheme and the UN CORSIA mechanism.

We share the CCC’s view, however, that the UK should no longer delay policy action on this issue. Adjusting our domestic legislation to include IAS emissions would not impede UK negotiations on international targets and measures, and would reflect similar moves in Europe to take responsibility for international aviation emissions.

Last December, the European Union took the decision to include international aviation emissions in its NDC, and France has very recently cancelled plans to expand Charles de Gaulle Airport: it now deems those plans incompatible with its climate commitments.

In the year of the Glasgow COP, our own policies on climate change, and the extent to which the Government is acting in line with the advice of its climate experts, will inevitably come under the spotlight.

Accepting the CCC’s recommendation to include IAS in future carbon budgets would make the UK the first major economy to legislate for net zero emissions from all sectors, demonstrating confidence in our ability to deliver the green industrial revolution to which you have committed, and helping to ensure integrity of the sixth and future carbon budgets in keeping the UK on track to delivering our crucial shared 2050 goal.

Yours sincerely,

Cait Hewitt, Deputy Director, Aviation Environment Federation

Miriam Turner & Hugh Knowles, Co-Executive Directors, Friends of the Earth England, Wales and Northern Ireland

Roz Bulleid, Deputy Policy Director, Green Alliance

John Sauven, CEO, Greenpeace

Alice Bell, Director of Communications, Possible

Greg Archer, UK Director, Transport & Environment UK

In CC:

Grant Shapps MP, Secretary of State for Transport
Kwasi Kwarteng MP, Secretary of State for Business, Energy & Industrial Strategy



In its 6th Carbon Budget Report published in December 2020, the CCC identified a number of reasons why IAS exclusion from the UK carbon budget can no longer be justified. These include that:

  • Their inclusion opens up the possibility for the IAS sectors to achieve more and contribute more to meeting the UK’s emissions targets.
  • The UK’s overall emissions reduction strategy should be integrated across the whole economy.
  • This would set a good example to other countries because the UK is a key player in driving strong international mechanisms.
  • There is no justification for excluding them (originally provided by section 30 of the Climate Change Act) because allocating these emissions to individual countries no longer presents fundamentally greater challenges than for other sectors already included in UK emissions targets.

See CCC’s recommendations on the  Sixth Carbon Budget report  pages 418-21

In detail, some extracts from the CCC document say:


c) Inclusion of international aviation & shipping in carbon budgets

The Climate Change Act allows the Government to decide to include the UK’s share of international aviation and international shipping (IAS) emissions in carbon budgets and the 2050 (Net Zero) target. Under section 35 of the Act, when recommending a carbon budget the Committee must also advise on whether IAS should be included with its scope. We advise that IAS emissions should be included in the Sixth Carbon Budget.

To date, IAS emissions have been accounted for, but not formally included in the budgets or 2050 target:

• Carbon budgets have been set excluding IAS emissions, but with lower emissions allowed for the other sectors to leave headroom for IAS emissions.

• The Government has recognised the need to include IAS emissions within its planning for meeting the 2050 target, both for the previous 80% target and again for the Net Zero target.1 This recognition is consistent with the approach of the Committee when recommending these targets.

However, it is important to include these emissions formally in the legislated targets, rather than only being considered as a planning assumption, to guide long-term policy approaches and infrastructure investment decisions:

• Complete scope of emissions. It is important that all sources of greenhouse gas emissions should be tackled, and that the scope of targets should reflect this. This is particularly relevant for aviation, which is likely to be the second-largest emitting sector in the UK by 2050, even with strong progress on technology and limiting demand growth. Continued exclusion from carbon budgets gives an impression of special treatment and raises questions over fairness for other sectors.

• UK influence and supplementary levers. While the primary policy approaches to tackling IAS emissions should be international, the UK is a key player in driving strong international mechanisms. Some supplementary UK policy levers are also available that would not impact on the competitiveness of the IAS sectors. It is important that the UK Government prioritises both of these avenues (see our accompanying Policy Report).

• Flexibility.   Including IAS emissions within the formal scope of the Climate Change Act targets provides extra flexibility in meeting them. Whereas their exclusion would mean that allowance has to be made outside the target for these emissions, inclusion opens up the possibility for the IAS sectors to achieve more and contribute more to meeting the UK’s emissions targets.

• Need for integration with wider Net Zero strategy. The UK’s overall emissions reduction strategy should be integrated across the economy. This includes requirements for fuelling infrastructure and supply of alternative fuels (e.g. hydrogen, ammonia, synthetic fuels) and the overall scale of greenhouse gas removals to balance remaining emissions to reach Net Zero.

• Inclusion of IAS is manageable. While the United Nations Framework Convention on Climate Change (UNFCCC) treats emissions from international aviation and international shipping separately from emissions solely within country borders, allocating these emissions to countries presents no fundamentally greater challenges than for other sectors already included in UK emissions targets:

– Emissions are already estimated and reported to the UN and can be included in UK emissions targets on the same basis. The uncertainty attached to estimates of IAS emissions is no higher than for other sectors covered by carbon budgets (Box 10.1).

– While careful policy design is necessary to avoid simply pushing emissions abroad, such considerations also apply to sectors already covered by carbon budgets (e.g. manufacturing and agriculture).

– Inclusion in the UK carbon budgets does not preclude exclusion in communications to the UN, as we recommend for the UK’s 2030 NDC.

Inclusion of IAS emissions in UK climate targets does not equate to the adoption of
a unilateral policy approach to tackling these emissions, which could be argued to
undermine existing multilateral processes under the respective UN bodies (the
International Civil Aviation Authority (ICAO) and the International Maritime
Organisation (IMO)). Rather, it ensures that the UK takes full responsibility for these
emissions and that, where necessary, effort in other sectors can be altered to
ensure overall emissions are within the necessary limits.

The time has come for the UK to include IAS emissions formally in the Net Zero
target and also in the Sixth Carbon Budget, which finishes only 13 years before

We therefore conclude that IAS emissions should be included in carbon budgets as
early as possible (see section 3), and certainly formally within the scope of the
Sixth Carbon Budget and 2050 target. Alongside this, the UK should push for suitably
strong international targets and mechanisms to deliver reductions in IAS emissions.

Should the international processes through the IMO and ICAO fail to set suitable
ambition, the UK could take subsequent action to decarbonise these sectors.
Ultimately, whether via a global scheme or a domestic/more limited international
mechanism, any remaining UK IAS emissions in 2050 will need to be balanced by
greenhouse gas removals in order for the sectors to achieve Net Zero.

The Climate Change Act requires that inclusion be on the basis of international
carbon reporting practice. Bunker fuel sales are the currently agreed methodology
by which countries report IAS emissions to the UN, and are therefore the
recommended method of inclusion. Uncertainties over future emissions accounting
methods are similar in size to those in other areas of the carbon budget and are
manageable within the overall envelope of emissions (see section 2 of Chapter 2).

The Committee does not consider the Government’s previous approach of
allowing ‘headroom’ for IAS emissions to be sustainable. Under this approach since
2008, progress has been insufficient:

• The processes under the IMO and ICAO have objectives for emissions
reduction that are less ambitious than the UK has adopted under its Net
Zero target and less ambitious than required to meet the goals of the Paris

• Updated UK aviation and shipping strategies to date have been delayed
(in part due to COVID-19), while previous plans have had limited ambition.
The Clean Maritime Plan considered options for decarbonising the shipping
sector, but did not formally commit to a 2050 target or trajectory. The
previous Aviation Strategy focused more on noise, air traffic modernisation
and expansion than on CO2 emissions and climate change.

• Aviation continues to be under-taxed relative to other emitting activities,
undermining efforts to limit demand for aviation.

Excluding emissions from international aviation and shipping from carbon budgets
and leaving headroom based on their appropriate contribution is therefore not a
credible approach.

If IAS emissions follow a ‘near-BAU’ path rather than reducing as in our Balanced
Net Zero Pathway, then emissions would be around 13 MtCO2e higher in 2035.
Were that to be the case, then emissions from other sectors would need to be
comparably lower to compensate – but the headroom approach would not
automatically require that.

See full report at


See earlier:


Committee on Climate Change – recommendations to government – lots on aviation carbon changes and policies needed

The Committee on Climate Change has published its guidance for the UK government on its Sixth Carbon Budget, for the period 2033 – 37, and how to reach net-zero by 2050.  There is a great deal of detail, many documents, many recommendations – with plenty on aviation. The intention is for UK aviation to be net-zero by 2050, though the CCC note there are not yet proper aviation policies by the UK government to achieve this. International aviation must be included in the Sixth Carbon budget. If the overall aviation CO2 emissions can be reduced enough, it might be possible to have 25% more air passengers in 2050 than in 2018. The amount of low-carbon fuels has been increased from the CCC’s earlier maximum realistic estimates of 5-10%, up to perhaps 25% by 2050, with “just over two-thirds of this coming from biofuels and the remainder from carbon-neutral synthetic jet fuel …” Residual CO2 emissions will need to be removed from the air, and international carbon offsets are not permitted. There is an assumption of 1.4% efficiency improvement per year, or at the most 2.1%. There “should be no net expansion of UK airport capacity unless the sector is on track to sufficiently outperform its net emissions trajectory.”  The role of non-CO2 is recognised, but not included in carbon budgets; its heating effect must not increase after 2050.  And lots more …