Airports Commission publishes discussion document on Aviation and Climate Change

The Airports Commission has published its 3rd discussion paper, on Aviation and Climate Change, through which it will assemble advice and opinion on which to base its airport decisions. The consultation period lasts till 17th May. In a thoughtful document, covering a wide range of issues in relation to aviation and climate change, it sets out the usual range of issues (carbon emissions, role of international negotiations though the EU ETS and ICAO, the role of biofuels in future, role of operational improvements, impact of aviation’s non-CO2 impacts) but it also looks at the effect of both carbon constraints on future aviation growth and the effect of UK airport capacity constraints on overall emissions.  It looks at the likely consequences of more long haul flights from the UK being taken from European hub airports, and the CO2 and climate effects of this happening more (“carbon leakage”). The Airports Commission has the problem of attempting to decide on CO2 issues at a time when the future of the ETS is uncertain, and effective progress by ICAO is not likely to be swift. Therefore UK policy on aviation carbon emissions is also on hold, with even agreement on non-CO2 impacts undecided. 



 The Aviation and Climate Change document (39 pages)

 Airports Commission seeks evidence on aviation and climate change

Airports Commission press release

5 April 2013

The Airports Commission has today (5 April 2013) published ‘Aviation and climate change’, the third in a series of discussion papers to build the evidence base to inform its assessment of the UK’s airport capacity needs.

The paper explores the science and policy around aviation and climate change that the Commission will need to consider when making its assessment of the nature, scale and timing of the UK’s aviation capacity and connectivity needs. It discusses approaches to forecasting aviation emissions and the potential carbon implications of airport capacity constraints. It also considers the climate change adaptation issues that the Commission will need to consider when making recommendations on future airport capacity.

Sir Howard Davies, the Chair of the Airports Commission, said:

Understanding this issue is a priority for the Commission. The climate change debate has moved on significantly since the government’s last review of airport capacity in its 2003 white paper. The Climate Change Act, Aviation EU ETS, and developments in climate science are all things that we will need to take into account in the course of our work . This paper attempts to summarise our current state of knowledge and invites responses to help us to develop our understanding.

The paper further demonstrates the Commission’s evidence based approach to deciding on the scale, nature and timing on any need for additional capacity. Parties are invited to submit evidence to the Commission on the issues raised in the paper, by 17 May 2013.



See also:

AEF comment on Airports Commission climate paper: forecast demand rise remains incompatible with UK climate targets

5.4.2013  (Aviation Environment Federation)AEF (the Aviation Environment Federation) has commented on the discussion paper published by the Airports Commission, on aviation and climate change. AEF notes that the paper appears keen for the UK to avoid disadvantaging itself economically through constraints on airport capacity. The paper also acknowledges that there have also been problems with the effectiveness of EU ETS in recent years due to over-supply of credits and that the ETS is currently partly suspended. The paper also appreciates that if UK aviation expands above its 2005 level, this would require “more challenging reductions” in other sectors of the UK economy. AEF comments that even with constraints on aviation growth from capacity constraints, taxes and inclusion in the ETS,  ”forecast demand growth remains significantly higher than the level compatible with climate targets. In other words, if we want to meet these targets, new measures should be considered for constraining emissions, and unconstrained aviation growth with new runways should be out of the question.”



Below are some extracts from the discussion document:

(see full text for references etc)

Mentions of the EU ETS

Page 15

The current Government is awaiting greater certainty over the future scope of the EU ETS, and the outcome of the ICAO negotiations towards a global deal on aviation emissions, before making a decision on whether the UK should retain a national emissions target for aviation.

Whilst the aim of constraining aviation emissions to 2005 levels in 2050 is not itself legally binding, legislated carbon budgets have been set on the assumption that aviation emissions out to 2050 are constant at the level of the EU ETS cap in 2020. Given that the EU ETS cap has been set with reference to average emissions between 2004 and 2006 (i.e. very close to 2005 emissions levels), a significant overshoot of 2005 aviation emissions levels in 2050 would suggest more challenging reductions in other sectors.
Page 25
It is important to note that, assuming the EU ETS (or an equivalent scheme) continues out to 2050, aviation continues to be included and that the scheme functions as intended, this would not result in any change in CO2 emissions at an EU level. In such a scenario, CO2 savings or displacement to other European countries by the UK aviation sector would all fall within the overall ETS cap, so there would in theory be no scope for emissions ‘leakage’ from UK to European airports.


Mentions of the ICAO

Page 12

The International Civil Aviation Organization (ICAO) has been debating options for a global market-based measure to tackle aviation emissions.   Market-based measures could include emissions trading schemes or emissions offsetting.

ICAO believes that such a measure would contribute to achieving a specific emissions reduction in the most cost-effective and flexible manner.   However, progress towards a global market-based measure has been relatively slow, and the ICAO Council on
9 December 2012 agreed to set up a  high-level group to try to resolve the issues that had been preventing more rapid progress. The high-level group has since met three times, most recently in March 2013. It will make recommendations that will be debated at the ICAO General Assembly in September 2013. The Airports Commission will continue to monitor the ICAO discussions as our work progresses

Alongside steps towards a global market-based measure, ICAO’s Committee on Aviation Environmental Protection (CAEP) has been debating a new CO2 standard for aircraft.
Agreement has now been reached on a system for measuring emissions and on
certification procedures. Work is continuing around the stringency and scope of the standard.

However, international rules and regulations also place some constraints around potential policies to tackle aviation emissions. For example, the 1944 Convention on International Civil Aviation (the ‘Chicago Convention’), which established the ICAO, prohibits signatory states from imposing taxes on fuels purchased for use in international aviation.

Page 13
The aim of the EU ETS, in common with the market-based measures being contemplated by ICAO, is to deliver a specific reduction in emissions in the most cost-effective way. It is also designed to incentivise investment in emissions abatement measures, since any sector that emits less than the relevant cap can sell its surplus allowances to participants in other sectors

As a result of the formation of the high-level group at ICAO, and the potential for progress towards a global measure, the EC announced in November 2012 that it would ‘stop the clock’ on the enforcement of ETS obligations on flights between European airports and the rest of the world. This was intended as a goodwill gesture, and to enable the current negotiations in ICAO to make further progress. However, the EC has stated that if ‘clear and sufficient progress’ is not evident by the ICAO General Assembly in September 2013, then it intends to reinstate ETS obligations on these flights.

page 15

The current Government is awaiting greater certainty over the future scope of the EU ETS, and the outcome of the ICAO negotiations towards a global deal on aviation emissions, before making a decision on whether the UK should retain a national emissions target for aviation.


Mentions of Aircraft induced cirrus (AIC)

page 8

Less well understood are the climate effects of water vapour, sulphates, soot, linear contrails and AIC. In these cases, as can be seen from Figure 2.1, the direction of the effect (warming or cooling) tends to be known, but in some cases there are significant uncertainties around its magnitude. The effects of AIC have proved particularly difficult to
quantify, although it is thought that they may have a potentially significant warming effect.

Overall, aviation emissions have been estimated to account for around 3.5% to 4.9% of total present-day (2005) global anthropogenic depending on whether AIC is included. (Reference 9 – Lee et al)

page 23

The DfT has developed an approach to estimating non-CO2 emissions from aviation. More recently, this methodology has not been used on the grounds of the scientific uncertainty around the effect of these emissions. Similarly, in its recent advice on the inclusion of aviation and shipping in carbon budgets, the CCC recommended that non-CO2 emissions not covered by the Kyoto Protocol34 (including NOX, contrails and AIC) should not be included in carbon budgets at present, but that options to reduce them will need to be developed over the coming years.


Mentions of Europe

Page 26

However, the Commission recognises that there is inevitable uncertainty around the international policy framework for climate change out to 2050, so we will need to understand the potential implications of UK airport capacity for global aviation emissions
under a range of scenarios. We have therefore undertaken some provisional modelling of potential CO2 emissions savings and ‘leakage’ attributable to projected capacity constraints at UK airports, based on the latest (January 2013) set of DfT forecasts.


Mentions of biofuels

Mentions of biofuels

Page 10

The prospect of rising oil prices, combined with carbon constraints arising from cap and trade schemes, has resulted in growing interest in the potential use of biofuels as an alternative to kerosene in jet engines. Recent tests by engine and airframe manufacturers
have shown biofuels use in aircraft to be technically feasible – indeed, biofuels are now officially certified for use up to 50% blend with conventional jet fuel.

However, there are important questions around their sustainability which will need to be taken into account as policy develops.
There are also significant questions around the potential for biofuels to act as a  ustainable alternative to kerosene.   Whilst biofuels use in aviation has been shown to be technically feasible, the pace and timing of biofuels penetration in the aviation sector remains uncertain, owing to the technical barriers that need to be overcome and the investment
needed to achieve commercial-scale production.

In the longer term, there are important sustainability concerns around largescale biofuels use. The CCC (Committee on Climate Change) and others have highlighted in particular:
●● Emissions from producing biofuels. These are heavily
dependent on the type of feedstock used, meaning that the potential
lifecycle GHG savings from biofuels vary significantly depending on the
production route.
●● Effects of land-use change. Where growth of biofuels feedstock results in
land-use change directly (e.g. deforestation) or indirectly (e.g.
displacement of food production), this can reduce lifecycle GHG savings

●●Competition for available biofuels.  Aviation will have to compete for scarce biofuels with other sectors such as road transport, shipping, household cooking and heating, and energy generation.
●● Tensions between biofuels and food production. Projected population growth and rising living standards in developing countries are likely to lead to increasing requirements for global food production. It is unclear whether sufficient land and water will be available for growing biofuels feedstock on a large scale.
Under the ‘likely’ scenario, a 60% increase in passengers by 2050, relative to the 2005 baseline, would be compatible with the aviation sector emissions target. Effectively, this is the level of growth that is exactly offset by fuel efficiency improvement and biofuels. The demand growth that could be accommodated within the target rises to around 135% in the ‘speculative’ scenario with its more optimistic assumptions.

[The table on page 22 shows anticipated carbon savings for aviation under the DfT’s 3 scenarios, with 2.5% use of biofuel by 2050 or 10% biofuel in the higher scenarios. These are expected to cause a 2.5% to 5% carbon saving by 2050.   AW.]

Page 22 of

Page 30

●● Supporting biofuels demonstration plant covering fuel production, refining and demonstration [biofuel demonstration plant]; and
●● Regulation to mandate biofuels uptake in aviation (subsidised or unsubsidised) [mandatory biofuels].






Notes to editors on the AC press release of 5.4.2013:

The Airports Commission was launched on 2 November 2012. Its terms of reference require that it should report no later than the end of 2013 on:

  • its assessment of the evidence on the nature, scale and timing of the steps needed to maintain the UK’s global hub status
  • its recommendation(s) for immediate actions to improve the use of existing runway capacity in the next 5 years – consistent with credible long term options

Its terms of reference also require that it should report no later than summer 2015 on:

  • its assessment of the options for meeting the UK’s international connectivity needs, including their economic, social and environmental impact
  • its recommendation(s) for the optimum approach to meeting any needs
  • its recommendation(s) for ensuring that the need is met as expeditiously as practicable within the required timescale

For interview requests or other media enquiries relating to the work of the Airports Commission please call 0207 944 3118.