By Robert McLachlan and Paul Callister
New Zealand at COP26
On 10 November 2021 at COP26 in Glasgow, New Zealand along with twenty-two other countries joined the “International Aviation Climate Ambition Coalition”, committing to “Preparing up-to-date state action plans detailing ambitious and concrete national action to reduce aviation emissions and submitting these plans to ICAO well in advance of the 41st ICAO Assembly” . This Assembly of the UN’s International Civil Aviation Organization will take place in September 2022.
What would “ambitious and concrete action” to reduce aviation emissions look like for New Zealand?
Aviation is not only a large industry and a large emitter. It also underpins other sectors of the economy like tourism and trade, and it links globally dispersed families, even though an estimated 80% of the world’s population have never set foot on a plane. All of these aspects are particularly acute for New Zealand, whose geography and infrastructure influence even domestic travel. If a domestic Sustainable Aviation Fuel (SAF) industry were to develop, then agriculture, land use, and renewable energy use would be implicated as well. Psychologically, the rapid rise of cheap and comfortable air travel and its continued glamorisation in the media has built support for the status quo and made addressing its emissions more difficult politically.
If there is to be limited overshoot of 1.5 ºC, global net anthropogenic CO₂ emissions must decline by 45% from 2010 levels by 2030. As the chairs of the IPCC Special Report on 1.5 ºC write,
Without increased and urgent mitigation ambition in the coming years, leading to a sharp decline in greenhouse gas emissions by 2030, global warming will surpass 1.5 ºC in the following decades, leading to irreversible loss of the most fragile ecosystems, and crisis after crisis for the most vulnerable people and societies.
The Paris Agreement and the Zero Carbon Act
The 2016 Paris Agreement does not mention aviation specifically. Nevertheless, the agreement to limit warming to “to well below 2.0 ºC above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5 ºC above preindustrial levels” and to reach net zero emissions globally in the second half of this century, does include all sectors, including international aviation and shipping, as does the agreement for developed countries to undertake “economy-wide” emission reductions.
The Zero Carbon Act adopts the 1.5 ºC target, interpreted as reaching net zero emissions of long-lived gases (mostly CO₂) by and beyond 2050, along with substantial cuts in short-lived gases (mostly methane). However, international aviation is not yet included either in the targets or the carbon budgets.
The urgent need to phase out the burning of fossil fuels, New Zealand legislation, the Government’s climate goals, international agreements, and emerging international action all point towards reducing aviation emissions.
In a new report, we survey a wide range of ‘Net Zero 2050’ scenarios for aviation and how they relate to New Zealand. A summary follows below.
Key aspects of New Zealand aviation emissions
- CO₂ 4.9 million tonnes in 2019
- Per-capita 6th highest globally at 1 tonne CO₂
(cf. US 0.56t, EU 0.65t)
- 12% of CO₂ emissions, cf 2.8% globally
- Proven ability to grow emissions rapidly:
International +40%, domestic +20% in 2015–2019
- International passengers fell 97.6% in the 12 months to March 2021
- Domestic aviation CO₂ included in NZ ETS and the falling cap on emissions
- Founding member of the International Aviation Climate Ambition Coalition, committed to presenting an “ambitious and concrete national action plan” in 2022 to reduce aviation emissions
New Zealand’s aviation emissions
The factors behind aviation’s rapid growth are many, but two key ones are price and quality. Since Air New Zealand launched their Auckland–London flight in August 1982, prices have fallen 70% in real terms, while incomes have risen. Prices relative to income have fallen by a factor of 6. Long-haul flights have become steadily more reliable and comfortable over the decades.
More passengers means more flights. The Tourism Satellite Account lists more than 100 new and expanded routes during the 2015–2019 period of rapid growth, some of them extremely long, such as Auckland to Buenos Aires, Chengdu, Chicago, Doha, Dubai, and Ho Chi Minh City.
Our population has become more globally linked. In 1996, 17.5% of the New Zealand population were born overseas. In 2001, 19.5%; in 2006, 22.9%; in 2013, 25.2%, and in 2018, 27.4%. The two largest groups of migrants are from the UK (265,000 people) and China (144,000). Perhaps 1 million New Zealanders live overseas, including one in six Māori.
A lot of media attention has been focused on projects and proposals for “zero-emission” aircraft, of which the three main contenders are battery electric, hydrogen electric, and hydrogen combustion. (Emissions would be very low or zero during flight; lifecycle emissions including building the aircraft and making the fuel and providing renewable energy for it would not of course be zero.)
There are two big problems with relying on new technology to deal with aviation emissions. The first is that the new aircraft do not exist yet, so the uncertainties are large and the time spans involved mean that industry and government scenarios do not envision much role for them out to 2050. The second is their energy requirements. A study by Ian Mason considered the prospects for hydrogen aviation, finding that 42 TWh of electricity could be needed by 2050—equal to New Zealand’s entire current supply. In addition, New Zealand would be attempting to replace all the fossil fuels used in land transport, and a lot of those used in industry, with electricity and/or hydrogen at the same time. Electrolysers tend to be placed where the fuel is needed, indicating a need for a 3800 MW electrolyser at Auckland airport, a power demand equivalent to about 6 times that produced by the Manapouri power station. (About 200 MW of electrolysis is currently in existence worldwide.) Power could be provided, for example, by 14,000 MW of wind turbines, i.e., 63 copies of the Turitea wind farm that is currently under construction at a cost of $370 million.
In other words, the energy requirements are extreme.
The lion’s share of many aviation pathways focus on sustainable aviation fuels (SAF). In 2019, 0.05% of global aviation fuel was biofuel, made from food crops and waste food such as tallow and used cooking oil. These are limited in supply. Therefore, pathways with high levels of SAF look to other feedstocks, especially (for New Zealand) wood waste and logs. However, there are no such plants in commercial operation. A report from the ICCT concluded that the EU could be capable of producing 2 Mt a year of wood-based biofuel by 2035, slightly more than New Zealand’s 2019 consumption of jet fuel. Closing the apparent gap—a factor of 100—will need close attention.
New Zealand is in the process of implementing a biofuel mandate for land transport, with a target of 9% biofuel by 2035. An initial study estimates that a $520 million plant could produce 57 million litres of fuel per year, 0.7% of New Zealand’s liquid fuel consumption, and that there is enough feedstock available for 20 such plants. A wood-to-fuel plant is presently under construction in the US by Lanzatech.
E-fuels, made directly from water and carbon dioxide (sourced from the air or from flue gases) and a lot of renewable electricity, can potentially be supplied in any amount. Some small trial plants are under construction in Europe. The obstacles are cost and (if the industry were to scale up) renewable electricity supply. The ICCT estimate that at 2 euro per litre support, the EU could produce 0.23 Mt a year of e-fuels by 2035. Their cost, five times the current price of jet fuel, would increase the price of travel while also reducing emissions at the source. The energy requirements are about twice that of hydrogen.
Although New Zealand has good potential resources of both renewable electricity and of feedstock for biofuels, significant capital investment and advance planning would be required to exploit them. Nevertheless, sustainable aviation fuel mandates open up pathways in which the higher costs of sustainable fuels lead to greater focus on efficiency and lower traffic growth.
The obstacles in the way of a technological solution to aviation emissions are formidable. In addition to cost, technological readiness, feedstock supply, and environmental side-effects, there are difficult timing issues. On one hand, emission reductions are needed now, but the alternatives are not ready; on the other, it is hard to reliably forecast the future cost of different solutions in order to make the necessary decisions now.
The industry view
Air New Zealand has taken an increasingly strong line on sustainability, which has been maintained and even strengthened during Covid. Their 2021 sustainability report was the first to outline a pathway to reach net zero by 2050. It involves 75% passenger growth by 2050, with net zero to be achieved by 20% of the emissions cuts coming from new conventional aircraft; 20% from zero-emission aircraft; 50% from SAF (implying an 86% SAF mandate); 2% from operations; and 8% from offsetting.
They see a need for strong government action to establish a domestic SAF industry, first based on forestry residues with a domestic plant running by 2027, then on waste, then (from 2045) on whole logs and e-fuels, with steady progress ensured via an SAF mandate. The head of Air New Zealand’s sustainability advisory panel, Jonathan Porritt, commented that
New Zealand will always be a price-taker. By 2030, it will be the big players in the industry who will be determining that price. The only way of managing that risk is for New Zealand to ensure its own, indigenous SAF capability—and that means taking big decisions in a clear and accountable way over the next couple of years.
The Ministry of Business, Innovation, and Employment will advise on an aviation SAF mandate in 2022, with the mandate proposed to start in 2025.
The entire topic of offsetting and its role in climate solutions is controversial. For example, Wim Carton discusses the supposed carbon, geographical, and temporal equivalences between positive and negative emissions, and concludes that climate justice requires their uncoupling:
Increasing carbon in terrestrial sinks simply replaces carbon that has been lost to the atmosphere over past centuries. Fossil carbon, on the other hand, is permanently locked away. Thus, burning fossil fuels moves carbon from permanent storage into the active carbon cycle, causing an aggregate increase in land, ocean, and atmospheric carbon. Once added, this additional carbon cannot be removed through natural sinks on time-scales relevant to climate mitigation.
In addition, on purely physical grounds, Kirsten Zickfeld concluded that a CO₂ emission into the atmosphere is more effective at raising atmospheric CO₂ than an equivalent CO₂ removal is at lowering it.
For these and other reasons, the NGO Climate Action Tracker recognises gross emissions only.
The issue is particularly acute for New Zealand, where mitigation pathways require forestry to rapidly and continuously increase to 2050 and beyond. Emissions from the first half of the century would be stored above ground and maintained by our descendants in the second half of the century.
EU Fit for 55, UK Jet Zero, and the IEA Net Zero scenario
Under “Fit for 55”, the EU will phase out free ETS allowances for intra-EU aviation (currently covering about half of such travel) over 2024–2027, and reduce the emissions cap of the whole ETS faster. They will tax jet fuel for intra-EU flights from 2023, with the tax rising to $250/tCO₂ by 2033. An SAF mandate will rise from 5% in 2030 to 20% in 2035 and 63% by 2050, for which only waste wood and fats and e-fuels will qualify.
Their model forecasts a baseline growth in emissions of 20% over 2015–2050, with the new proposals reducing emissions by 52% overall.
The UK’s Jet Zero has a headline goal of net zero aviation by 2050. On top of traffic growth of 54%, reductions come from demand reductions 9%; efficiency gains 36%; zero emission aircraft 4%; SAF 14%; and offsets 37%. SAF proposals are oriented around the establishment of a very large domestic industry, with 25–125 large SAF plants in the UK by 2050.
The International Energy Agency released an influential net zero study in 2021 . For aviation, their scenario involves business travel and flights longer than 6 hours held at 2019 levels; regional flights shifted to high-speed rail where feasible; total travel to increase 70% between 2019 and 2050; advanced biofuel and e-fuel use to reach 50% by 2040 and 78% by 2050; governments to define their SAF strategies by 2025 at the latest; and carbon prices across all advanced economies rising to US$130 by 2030 and US$250 by 2050.
Aviation growth and airport expansion go hand-in-hand.
In New Zealand, Auckland Airport’s long-held plans for a second runway have been put on hold by Covid, but a $1 billion airport redevelopment will go ahead. Wellington Airport is in the process of expanding; the first stage has been approved and is now under a court challenge. Christchurch Airport is proposing to build an entirely new international airport in Tarras, Otago, to serve the Queenstown–Wanaka region, again prompting environmental concerns. All three airports are partly publicly owned.
In the UK, the Balanced Net Zero pathway of the UK CCC requires no net airport expansion in the UK; but eight airports are currently planning expansions.
The growth of aviation has been tightly linked to the growth of tourism, both in New Zealand and worldwide. If aviation continues to grow, tourism will likely either continue in this role or become even more dominant. Through the 2010s the marketing of tourism continued to evolve, with talk of adventure and bucket lists for the upper middle classes in developed countries, and privilege and luxury for those on the highest incomes.
In January 2022, James Higham of the University of Otago co-edited a special issue of the Journal of Sustainable Tourism, writing in the introduction (“Code red for sustainable tourism”):
Governments need to take a leading responsibility, but we cannot currently expect this to come from national tourism administrations. […] Tourism administrations are guided by two key performance indicators: volume of (international) tourists, and volume of expenditure. Until their mandate changes, and they are required to develop metrics of success aligned with the Sustainable Development Goals and the Paris Agreement, any change will only happen as a result of other government departments that have a sustainability remit, particularly from those in charge of transport, energy and climate.
In 2021, the Parliamentary Commissioner for the Environment, Simon Upton, made tourism aviation emissions one of four key foci of a report on sustainable tourism. In view of the particular political and practical challenges of the sector, he made two modest recommendations: one, to incorporate an emissions price into the cost of air travel from New Zealand, along the lines of the UK’s departure levy, with revenues directed to decarbonisation R&D and Pacific climate finance; and two, to seek a plurilateral agreement, such as a climate club. So far, this has gone no further.
Stefan Gössling has proposed three areas of action for national and regional tourism bodies. First, to lower emissions by focussing on closer markets, longer stays, and lobbying for regulation of aviation emissions. Second, to add value by promoting local and year-round activities. Third, to reduce financial leakage due to franchises, foreign ownership, travel booking sites, credit cards, and frequent flyer programs.
The natural experiment of Covid has revealed the startling availability of substitutes for flying, including flying less, videoconferencing (which, although not an exact substitute, has perhaps connected more people than flying ever did), substituting domestic for international tourism, substituting local tourism for distant domestic tourism, and substituting land transport for domestic air travel.
The land transport options are private vehicles or public transport, bus and train.
Low-occupancy private cars are at present even higher-emission than flying and likely to improve only slowly on a fleet-wide basis. This option is high-emission for the vast majority of car owners, and not available at all for people who do not own a car or drive.
Regional public transport is limited to buses and trains. The passenger rail network, which had eight lines totalling 2700 km in 2001 and shrank to four lines and 1340 km by 2020, now just has three short routes left, Wellington–Palmerston North, Wellington–Masterton, and Hamilton–Auckland, totalling 348 km. For tourists, there is still the train from Christchurch to Greymouth. A private coach network still exists, but suffers from infrequent service, poor quality, substandard terminals, lack of connectivity, and lack of integrated ticketing.
Until the entire inter-regional transport system is considered as a whole, it will not be possible to assess the case for specific interventions such as rail electrification, resurrection of regional passenger rail, or an upgrade to higher-speed trains.
In New Zealand, domestic aviation is included in the Emissions Trading Scheme and in the carbon budgets. The first budget period covers 2022–2025. Prices rose from $39/tCO₂ to $85/tCO₂ in the year to 18 February 2022.
Therefore, one view is that no further action is needed on domestic aviation.
However, a recent review by one of us comes to an opposite conclusion, namely that emissions pricing can’t do it alone. The behaviour change and technological transitions are too demanding in the required time frame, and prices are unlikely to be allowed to rise high enough. Complementary policies can deliver emissions reductions in a fairer and more orderly way, even under a cap on emissions.
For example, the EU is proposing to use both an SAF mandate and a fuel tax, in addition to a strengthened ETS and a cap on (EU) emissions. European support for rail is also linked to reducing intra-EU aviation. The IEA’s net zero pathway also involves significant carbon pricing along with SAF and traffic regulation.
The tax advantage of international aviation (no ETS charge, no GST, no fuel tax) is an obstacle to emissions reduction. The legal obstacles to revising it were canvassed by the Parliamentary Commissioner for the Environment. They were a primary reason for his recommendation of a distance-based air passenger duty, as a pricing option that is legally available immediately. It could form the first step in a more comprehensive pricing regime. And now that the EU is proposing to tax jet fuel the options politically open to other countries may increase.
The distribution of air travel
Air travel is strikingly unevenly distributed. A large study of EU household emissions found that 90% of EU households have air travel emissions averaging 0.1 tonnes per person; 9% average 0.8 tonnes; and the last 1% average 22.6 tonnes. The authors write that this “confirms air travel as a highly carbon-intensive luxury” and describe transport as “one of the most unequally distributed and the strongest drivers of the carbon footprints of the rich”.
The implication is that other things being equal, an increase in inequality will be associated with an increase in flying, and in increase in GDP will be associated with a disproportionate increase in flying.
Statistics New Zealand are preparing a study of the distribution of emissions of New Zealand households.
From a study in Nature Energy of the role of high socio-economic status (SES) people in the climate crisis:
High-SES status people often lead hypermobile lives, travelling by air for private and work-related purposes induced by income, business travel paid for by employers and expectations associated with status, work and ownership of multiple homes. Although the behavioural plasticity of air travel is under-researched, it may be substantial for high-SES people given the likelihood that the marginal benefits of each flight are lower for them than for lower-SES people who may fly only rarely to visit family. Changing social norms around hypermobility therefore appear to be an important potential lever to decrease GHG emissions from air travel.media exposure and the glamorisation of high-SES people), as owners and managers of organisations, and through lobbying.
The problem is not just that the high emitters have to pay more towards the transition. The harder problem is that they actually have to reduce their emissions. Ivanova and Wood regard a target of 2.5 tonnes per person by 2030 as consistent with the Paris agreement. That means average emissions falling by 70%. But the bottom half of emitters can’t reduce by very much at all, which means the top half have to do more. The situation is particularly extreme in aviation: only flyers can reduce their aviation emissions.
Most modern economists and policymakers do not engage in the question of what consumption is luxurious, wasteful, or unnecessary . On the other hand, some go further and argue that overconsumption is built in to capitalism, and that therefore reducing emissions will require significant changes in work, production, consumption, advertising, and social norms.
The widespread realisation of ecological overshoot and its catastrophic consequences, as well as humanity’s acceleration of unsustainable resource use when confronted with the reality of climate change, has prompted a wide range of responses. One framework is the “degrowth” movement, which calls for a decrease in global resource consumption until it reaches sustainable levels.
A decent standard of living actually requires very little energy. A global study describes a lifestyle involving 5000–15000 km of annual travel per person, of which 1000 km is by air, and total energy consumption of just 15 GJ/person/year, one-twelfth of New Zealand’s present consumption.
One of that study’s authors, Julia Steinberger, Professor of Ecological Economics at Lausanne, is an active voice in the climate movement:
In the UK, the “Jump” campaign asks people to sign up to six key lifestyle changes, one of which is to limit flights to one short-haul ( < 1500 km) return flight every three years, or one long haul return flight every eight years, levels derived from a study of urban lifestyles compatible with 1.5 ºC.
Applying the “avoid, shift, improve” framework to New Zealand aviation would likely reveal that the greatest opportunities lie in “avoid”. “Shift” also has a role in domestic aviation, for example by improving land-based low-carbon public transport. As we have learned from Covid, it is possible to avoid most international air travel with unexpected ease, whereas avoiding such a large proportion of emissions so quickly from food, housing, and goods and services without disastrous side-effects would be impossible.
James Higham examined aviation in light of the UN Sustainable Development Goals, noting that ICAO and the aviation industry claim that aviation contributes positively to almost all of the Sustainable Development Goals yet ignore the two most important factors, growth and emissions. Higham writes:
… aviation is deeply embedded in not only the economic, but also the social, functions of global capitalism. Because air transport is so “tightly bound up with the reproduction and expansion of capitalist societies”, there has been a reluctance to act on the environmental impacts of aviation. Rather than confront the problem of aviation emissions, the macro-level sociotechnical regime has been consciously developed to perpetuate growth in air travel.
It is difficult to define what flights are ‘essential’. The Ngā Tūtohu Aotearoa wellbeing indicators are monitored by Statistics New Zealand. While 81% of the population reported high overall life satisfaction in 2018, this rose to 84–86% in 2020–21, during a time when international travel was almost impossible (international passenger numbers fell 97.6% in the year to March 2021 compared to the previous year.) A further measure, on ‘leisure’, is under development: it will measure people’s amount of leisure time and their satisfaction with their amount of leisure time. It seems unlikely that international travel will impact on this score. Under the Material Wellbeing Index, ability to have a holiday away from home once a year scores one point (out of 35 points in total).
Noel Cass, in a study for Oxford University’s Centre for Research into Energy Demand Solutions, consider the role of curbing excess energy consumption in a fair transition. After comparing ten possible definitions of ‘excess’, they conclude that
excess is whatever people can agree it is, based on ideas of ‘fairness’ and ‘just’ levels of consumption that can be rationalised, defended, and justified to others…any policies that are used to target excess consumption and excessive consumers must be similarly reasonable and justifiable, based on the principles of deliberative democracy and exploring options, impacts, and fairness with members of the public.
What is a fair share for aviation emissions?
There is no universally agreed approach to this question.
One possible avenue follows the carbon budgets of the IPCC . Taking the remaining global carbon budgets for 1.5 ºC and allocating aviation 2.4% of global CO₂ leaves a carbon budget for global aviation of 9600 MtCO₂, or about ten years of flying at 2019 levels.
In 2019, New Zealand was responsible for 0.54% of global aviation emissions. Retaining this share and assuming aviation recovers to 2019 levels by 2024, followed by a decline to net zero in 2050, would see the carbon budget for 1.5 ºC exhausted by the early to mid 2030s.
Under the carbon budget approach, very sharp reductions in emissions are needed. However, earlier action makes meeting the budgets easier. Ensuring that 2019 levels are never regained would make meeting carbon budgets significantly easier.
Fairness towards future generations points towards relying as little as possible on carbon sequestration (whether by forestry or CCS) and focussing on absolute emissions reductions.
Fairness to all New Zealanders requires taking the (at present) highly unequal distribution of air travel, and the luxury and inessential nature of some air travel, into account, implying that aviation emissions should reduce more rapidly than other, more equal and more essential sectors.
In place of these considerations, the dominant narrative so far has been that, first, aviation is “hard to abate”; second, that it should be allowed to grow and to consume an ever larger share of gross emissions; and third, that it should not be subject to the “polluter pays” principle.
The experience of Covid indicates that even an almost complete stop to international aviation had surprisingly little effect on the economy (GDP grew 3.4% from 2019 to 2021) or effects on wellbeing. However, there are confounding effects for both of these, namely government economic stimulus, social solidarity, and knowledge of the health risks of travel. Substitutes including telecommunications, domestic tourism, and local tourism were adopted.
Taken together, these considerations imply that a naive “net zero by 2050” pathway, with steady traffic growth and heavily reliant on offsetting and nonexistent technology, would not sufficiently fair or ambitious for New Zealand.
The three main factors that will affect aviation emissions over the next 30 years are efficiency, alternative fuels, and total travel. Zero-emission aircraft will play a limited role.
Efficiency gains could be encouraged by carbon pricing, by an SAF mandate, or by banning the operation of high-emission aircraft models.
There is wide disagreement over the potential for alternative fuels and for the speed with which they can be supplied. Proposals for SAF vary widely and rely on technology which is not yet in commercial use.
Total travel also varies widely in the different pathways. The high growth scenarios are dubious for a number of reasons.
- They rely on significant amounts of offsetting (which is not sustainable in the long term) or permanent carbon dioxide sequestration (which is unproved at commercial scale)
- They rely to some degree on technological solutions, which may not be available quickly enough.
- They have not been found to be consistent with the Paris Agreement, nor to demonstrate its principles, including fairness, responsibility, capability, and highest ambition.
- They do not take into account the need to reduce fossil fuel burning drastically in the coming decade.
- They rely on a naive interpretation of the claim that aviation is “hard to abate” which has not been sufficiently justified or interrogated—for example, by comparing to other sectors which are also challenging technologically. As things stand, climate safety points towards phasing out “hard to abate” sectors where possible.
- Other things being equal, a net zero pathway with high growth will result in greater total emissions than a net zero pathway with low or negative growth. Under a finite carbon budget, it is the total emissions that are relevant, not the endpoint.
- A net zero pathway with high growth involves devoting greater total resources (of renewable energy, land, and construction of SAF facilities) than a pathway with low or negative growth. In a transition in which all of these resources are constrained, there is a need to prioritise resources.
- The high-growth scenarios, which generally show a continued acceleration of growth continuing past 2050, do not address fundamental questions of sustainability, even if net zero were to be reached.
- They do not take into account the distribution of aviation and its resulting implications for climate justice.
The past two years have seen numerous international bodies have aligned behind a vision of net zero aviation by 2050.
The main areas of difference between industry- and non-industry-led scenarios is that the former involve more growth—they often consider growth rates as given and not as a key variable—and reject emissions pricing. Some industry proposals seek government funding and subsidies. Some also reject regulation and rely on voluntary action and aspirational goals.
While pricing international aviation is difficult, which would by itself tend to point more towards regulation of emissions, some jurisdictions are now starting to consider it. Most likely, a combination of pricing and complementary policies will be needed .
A national action plan should include consideration of the following factors.
- Adoption of the “avoid, shift, improve” framework;
- emissions pricing and the “polluter pays” principle;
- where pricing is not achievable, regulation of emissions and emissions intensity;
- the non-CO₂ effects of aviation;
- the distribution of flying in a climate justice perspective;
- the availability of substitutes, and the national strategies for those substitutes (e.g., regional public transport);
- coordination with the tourist industry;
- the rate of growth or degrowth;
- the role of airports;
- timely implementation;
- emphasis on proven technologies, such as using the most efficient existing aircraft filled as much as possible;
- the lifecycle emissions and resource requirements of SAF, including land use, renewable energy, and facility construction;
- a fair share for aviation emissions with reference to the whole population and economy, not just to frequent flyers and the aviation industry; and
- the transition to true sustainability respecting the rights of future generations.
Two key events of the past half decade reinforce the urgency of the task. The first is the proven ability of the New Zealand aviation industry to increase emissions at a staggering rate when unregulated, as observed from 2015 to 2019; the second is Covid. Ensuring that aviation emissions remain permanently well below 2019 levels requires urgent action, but would make the longer-term task significantly easier.