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Aviation & Global Sustainability, Pt I

The international framework

Claire Waghorn
Claire Waghorn

Claire is a sustainability advisor in the aviation sector; and barrister & solicitor of the NZ High Court with a focus on international law. She has an MSc in International Relations (LSE, London); and an LLB and BA (Hons) in Diplomacy & International Relations (Canterbury University). Claire was Secretary for the Centre (2012-15) and is appointed to the Board commencing 1 July ’20.

International aviation has landed – abruptly.

The global COVID-19 pandemic has seen closed borders, on-going travel restrictions, decreasing passenger demand, airline lay-offs and bankruptcy. It is undoubtedly the biggest challenge the aviation industry has faced, to date.

Yet this is not the greatest challenge the industry will face.  COVID-19 has acted as a magnifying glass, bringing into focus vulnerabilities within the sector, most notably how aviation will respond to the global climate crises. There is always a lag between necessary technological advancements and the capacity to see these through.  Right now, they seem to be increasingly at odds.

So what future does aviation have in a post-COVID 19 world?  In this first of two parts, I discuss the international framework designed to assist aviation with sector emissions reduction, and how COVID-19 has challenged this.

ICAO climate goals

The UN Framework Convention on Climate Change (UNFCCC) sets out the current science and collective responsibilities for global greenhouse gas emissions.  The UN specialised agency for aviation, the International Civil Aviation Organisation (ICAO), guides the aviation sector towards a consensus on standards and recommended practice to address its responsibility for 3% of global emissions.

To that end, ICAO introduced, in 2020, two principal goals;

  • improve fuel efficiency annually by 2% from 2010 on; and
  • achieve carbon neutral growth from 2020.

Carbon neutrality is not an ambitious goal, but a realistic one – the intention being to reduce emissions and improve efficiencies to the greatest extent possible, then off-set any remaining emissions.  While off-setting can be viewed as a ‘band-aid solution’ for aviation, it is necessary to buy time while fossil-free technology catches up.

To achieve carbon-neutral growth, the ‘four-pillar strategy’ was introduced, mandating operational improvements, aircraft technology improvements, sustainable aviation fuels, and market-based measures in order to oversee off-setting requirements for international flights. The graph below demonstrates the ICAO strategy – pre-COVID-19.

Figure 1 ICAO ‘four pillars’ for reducing International Aviation net carbon emissions

Operational improvements

Operational improvements are the industry’s carbon reduction ‘low hanging fruit’. This includes introduction of ground power for airlines – where an aircraft can plug in to electricity, ideally generated from renewable sources, while parked on the ground, rather than burn jet fuel in their auxiliary power unit.

Likewise, improvements in air traffic management systems, such as New Zealand’s ‘New Southern Skies’ initiative, allows planes to take off and land with minimal waiting time, resulting in further emission reduction.

As airlines are encouraged back, and contracts are renegotiated between airports and airlines, there is an opportunity to mandate greater adoption of emission-saving technology. And it should be an easy sell – such operational improvements present both environmental benefits and cost savings.   For example:

If an A320 is plugged in to ground-power for 5 hours per day, over 365 days of the year:

  • The cost = US $6,000 p.a., compared to the cost of Jet A1 fuel US $130,000 p.a. 


  • Total annual cost savings = US $124,000
  • Total annual emission saving = 730 tonnes CO2-e p.a.

Aircraft Technology

The aircraft technology pillar develops steps to create more efficient aircraft operations, with the end-goal of developing electric aviation that is no longer dependent on fossil fuel.

Compared to aircraft of the 1960s, aircraft types today demonstrate an 80% efficiency improvement. Airlines have made progress in reducing emissions through maintaining a fuel-efficient fleet, the fitting of ‘sharklets’, improving approach pathways and departure climb profiles, and reducing aircraft weight.[1]  But aircraft fuel-efficiency gains are plateauing[2], and the goal now must be to move beyond fossil fuel by introducing climate-friendly technology.

It is estimated that electric aviation technology would be available to the domestic market in the 2030s, with long-haul electric technology still much further afield. Pre-COVID-19, responsibility for developing low-carbon aviation technology sat with the aeroplane and engine manufacturers, but it is difficult to see how that will play out now.

So there is considerable risk that electric aviation development may be deferred. If the aviation sector is at risk of falling behind with critical climate dependent innovations, and carbon emissions from long-haul flights no longer palatable, it is likely small island nations (that don’t have cross-border rail alternatives) will bear the brunt of disconnection.

Sustainable aviation fuels

Sustainable aviation fuels (SAF) generate lower carbon emissions than conventional aviation kerosene – from production to consumption. These fuels function in the same way as traditional jet fuel, so they do not require significant changes to aircraft or infrastructure.  SAF will slow carbon emissions in the short- to medium-term, as new technologies (such as electric or hydrogen) are developed.

Without ready access to an approved SAF, there are limited future carbon reduction opportunities available. If we considered Air New Zealand’s domestic flights (take-off and landing within New Zealand) in FY/2019, they produced a total 556,404 tonnes CO2-e. Allowing a blend mix of up to 50% SAF with fossil jet fuel over a year ANZ can reduce those emissions by 214,215 tonnes CO2-e.[3]

The COVID-19 global lockdown effect on the price of oil has resulted in record lows (minus US $40 per barrel).

This may have an impact on the development of SAF, as feasibility studies demonstrate a dependence on rising oil prices to make their business cases stack up. Germany, France and the UK have flagged the development of SAF as an industry for critical growth as part of their COVID-19 recovery strategies.

Market-based measures

The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) has been developed as a single global market-based measure, to make up the residual emissions gap after operational, aviation technology and sustainable fuel improvements are made.

CORSIA addresses the increase in total CO2 emissions from international aviation above 2019/2020 baseline data.  Noting domestic aviation emissions fall within the responsibility of national emissions reduction frameworks (i.e. the implementation side of the UNFCCC Nationally Determined Contributions).

Under CORSIA, airlines will be required to buy carbon offsets to compensate for their growth in CO2 emissions from 2021 onwards. Participation until 2026 was ‘opt in’ at nation-state level, including New Zealand and the majority of OECD countries[4], but not China.  From 2026 onwards, CORSIA then becomes compulsory, with the exception of very small island nations such as our Pacific neighbours.

Following the COVID-19 outbreak and subsequent grounding of international aviation, the inclusion of 2019/2020 emissions as baseline data is now being challenged by industry group ‘International Air Transport Association’ (IATA), in favour of using 2019 data alone. In terms of climate, the use of 2019 data alone sits alongside a return to business-as-usual behaviour. This may risk stranding investments in emission reductions and undermining investor confidence in aviation’s commitment to a low carbon future, including sustainable aviation fuels.[5]

The inclusion of 2020 data would be a game-changer for aviation’s carbon footprint, albeit an extremely challenging one for the airlines. The inclusion of the 2020 anomaly within baseline data would require either material reduction in sector emissions or paying the price for carbon-growth, effective immediately.


Before the ‘global grounding’, international aviation growth was pushing up against global emission reduction goals, which makes the decisions being made now even more crucial to the future of the industry – and the planet. Airlines, airports, government bail-out conditions, ICAO goals, and the CORSIA baseline will all collectively determine whether the aviation sector framework is future fit-for-purpose in a climate conscious world.

Beyond the international framework, we also have a changing global mindset to consider – a COVID-19 induced review of the way we live and interact on our finite planet.  More on this in Pt II.


[1] Scion, New Zealand Biofuels Roadmap Summary Report: https://www.scionresearch.com/__data/assets/pdf_file/0005/63293/Biofuels_summary_report.pdf

[2]Green Air, ‘New aircraft fuel efficiency improvements return to historical average but lag ICAO fuel burn goals, finds ICCT Report (18 Sept 2015), https://www.greenaironline.com/news.php?viewStory=2130

[3] Scion, New Zealand Biofuels Roadmap Summary Report: https://www.scionresearch.com/__data/assets/pdf_file/0005/63293/Biofuels_summary_report.pdf

[4] Organisation for Economic Co-operation and Development (OECD). Commonly used in place of the term ‘developed’ nations, to indicate nations with relatively well developed economies.

[5] EDF, ‘Covid-19, International Aviation and Climate Change: How Airlines’ Proposed Re-Write of International Civil Aviation Organisation Rules would Undermine the Carbon Offsetting and Reduction Schedule for International Aviation, (May 2020), https://www.edf.org/sites/default/files/documents/Impact_of_COVID_on_International_Aviation_Analysis.pdf

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