A study commissioned by European aviation trade associations has found that while rail travel has lower CO2 emissions per passenger kilometre than air travel, the benefits of shifting short-haul flights to rail are limited and are not a silver bullet for curbing emissions. The study also cautions that a shift can generate other environmental, social and economic costs, and could compromise efforts to decarbonise short-haul aviation through developing new technology. Its report says multiple factors need to be considered when assessing the optimal policy for short-haul aviation in Europe, including the environmental cost of building new rail infrastructure. The heads of the associations call upon policymakers to take all of this into account when considering how to optimise the decarbonisation of European regional transport. Another study in 2020 concluded a modal shift to railways could result in a potential reduction of 4 to 7 million tonnes of CO2 from intra-European aviation but only if the speed and quality of cross-border rail services improved and measures were taken to discourage air travel.

The results of the new study carried out by economics and finance consultancy Oxera for European industry associations covering airlines, air navigation, airports and manufacturers are published in a report, ‘Short-haul flying and sustainable connectivity’. It concludes that although a direct comparison of emissions shows rail has lower emissions per passenger than air travel, a modal shift from air to rail is complex and far from simple. If short-haul travel is banned then some passengers may choose to travel by car instead, which could lead to higher emissions, it says.

Among the arguments raised by the study is that for many short-haul routes with a lower traffic frequency, or at airports without a good high-speed rail connection, rail cannot be economically viable as it is based on a different business model with lower occupancy and speed rates. The industry also points to the importance of regional airports and airlines in ensuring local economies are able to access bigger economic centres.

“They are key to the EU’s cohesion policy and essential tools to reduce territorial and social inequality,” said the associations in a joint statement.

The Oxera report says building new railway lines has a high environmental cost due to the carbon emissions associated with cement and steel production, along with emissions from the fuel used for construction of infrastructure, plus significant impact on biodiversity and damage to wildlife habitats. The study also found there is unlikely to be sufficient rail capacity to accommodate all air passengers on a given route, meaning new railway lines would need to be built and new rolling stock procured.

“This would have significant environmental impacts, and the carbon payback period for such an investment needs to be considered alongside the timeline in which short-haul air travel is expected to decarbonise,” says the report.

It also argues that the gap over time between air and rail CO2 emissions will be reduced as new short-haul hybrid-electric aircraft start to be used on regional routes by 2030 and becoming more widespread by 2040. “As the routes most likely to decarbonise first, short-haul flights within Europe will play a significant role in rolling out lower carbon disruptive technologies and thereby accelerating wider aviation decarbonisation,” commented the associations.

Overall, concludes the report, all these factors need to be taken into account in deciding on the optimal policy for short-haul aviation in Europe. “Providing a range of transport options and encouraging intermodality between them is likely to offer the best solution from a social, economic and environmental perspective.”

The 2020 study carried out for campaign group Transport and Environment found that no European plan exists to improve the speed and quality of international rail services on distances between 200 and 1,000 km. Proposed improvements of railway services mainly focus at national level, with some exceptions for cross-border connections, which reflects the organisation of the railway sector in national companies and a strong involvement of national governments.

The study looked at the benefits of having high-speed rail between most large European cities, as well as the net speed of trains increasing by 10% on all connections competing with aviation and 50% more night trains to offer an alternative for daytime aviation trips. It concluded that around 4 to 7 MtCO2 from intra-European aviation may be avoided by a modal shift from air to rail if these approaches could be met. This corresponds with 6-11% of the CO2 emissions from intra-EU-31 aviation and with 2-4% of CO2 from all aviation fuel consumption in EUR-31, alongside the added benefit of reducing aviation’s non-CO2 climate impacts. To achieve these emission reductions would require both to improve speed and quality of international rail services and to discourage air travel.

A white paper published last year by global consultancy Egis, ‘The future of aviation in a world of sustainable travel’, argued that while high-speed rail projects boast many economic and social benefits, they come at a cost correlated to the transport distance and network, with a need for physical infrastructure along the route and the physical restrictions of geography and urban areas. As most projects today need to be started from scratch, this exposes governments and financers to lengthy returns on investments, considerable risks and high costs. The UK’s High Speed 2 500km rail project linking the north and south of England has an estimated $233 million cost per km, more than twice originally budgeted.

By contrast, while air transport requires significant infrastructure at points of arrival and departure (airports) and to a certain extent along the route (air navigation services), it can currently offer considerably larger economies of scale and greater flexibility at less of a financial and commercial risk than high-speed rail, says Egis.

However, it acknowledges the size of high-speed rail networks is growing considerably in Europe, with Spain, France, Germany and Italy adding a total of 800 high-speed trains to the network by 2030 and for over €100 billion to be invested on an EU level. In parallel, the European long-distance passenger-rail market is going through a phase of mass liberalisation through a regulatory overhaul that will present incumbents and new entrants with the opportunity to open new untapped routes between towns, cities and countries.

High-speed trains are being considered as a viable substitute to short-haul flights more seriously than ever before, said the paper.

However, said William McMaster, Senior Consultant, Aviation at Egis and author of the paper: “While a modal shift from air to rail is increasingly considered as a means of reducing transport emissions, the idea is not as simple as it sounds.

“We have seen opinion polls in Europe showing that the population generally favours short-haul flight bans, and an even greater majority support a carbon tax on flights. Yet paradoxically, only one in two travellers would be willing to take a greener mode of transportation if it took longer than the typical flight – showing that more people want action taken than are willing to act themselves. This suggests demand alone may not be a strong driver for change.”

Yet the major investment and regulatory liberalisation that are taking place in the high-speed rail sector have seen highly disruptive effects on air transport routes, pointed out McMaster. Following 25 years of Eurostar services connecting London with Paris in 2 hours and 16 minutes, a 44% reduction in airline seats (pre-pandemic) has resulted over a period during which air passenger numbers grew by over 200%, he reported, with similar trends elsewhere in the world, notably China.

“However, road and air transport investments could be more attractive than high-speed rail when physical aspects like geography or the economics of public budgets come into play,” he added. “The economic characteristics and overall lower net present value of high-speed rail mean that these networks may struggle to provide a compelling business case.”

US aircraft and engine manufacturers have called on the new Biden administration to provide sustained government support to help achieve its climate goals. In an open letter to Transportation Secretary Pete Buttigieg, FAA Administrator Steve Dickson, Climate Envoy John Kerry and National Climate Advisor Gina McCarthy, the US Aerospace Industries Association (AIA) said action should be taken in three key areas: measures to accelerate the production and use of sustainable aviation fuels (SAF); enhancement of public-private partnerships to accelerate development of next-gen aircraft and engine technology; and delivery of national airspace modernisation. The letter says that while AIA members would be contributing to climate targets through more efficient aircraft technology, it calls for a “holistic approach” to tackling aircraft CO2 emissions through short-term tools such as SAF, operational improvements and market-based measures. The AIA recommends the administration supports a blender’s tax credit that would incentivise greater SAF production. The blender’s tax credit is a policy option included in the Sustainable Aviation Fuel Act legislation introduced in November by California Democrat Congresswoman Julia Brownley. Meanwhile, Boeing is seeking to intervene on behalf of the Environmental Protection Agency, which is being sued by 12 US states, the District of Columbia and three NGOs over the agency’s recent decision to finalise aircraft GHG emissions standards.

SAF, says the AIA, offers the most effective way of reducing the environmental impact of flying in the short-term but is not being produced currently in sufficient quantities to be an economically viable option for airlines today. As well as a blender’s tax credit, it recommends government support for SAF be provided through increased R&D funding, the adoption of policies to encourage sustainable fuel production specifically for aviation and increased military procurement and use of SAF by the government to help grow the market.

Although the FAA had already made significant progress in delivering enhancements to the National Airspace System, says the letter, the administration is asked to prioritise realisation of the improvements, which it says are expected to deliver 2.8 billion gallons of fuel savings through until 2030. This, it says, can be achieved by implementing performance-based navigation (PBN) routes to enable aircraft to fly shorter, more direct routes, and ensuring PBN implementation is complemented by continued efforts to promote community involvement in changes to airspace structure, “which will deliver improvements in both noise and climate impacts.”

The US aerospace industry was exploring a range of technologies for next-generation aircraft in the 2030s that would offer improvements in fuel efficiency of 15-25% compared to current aircraft, says the AIA, but “to realise these benefits, US aviation manufacturers will require support to remain competitive, given the impact of Covid-19 and the billions of dollars European governments are providing their industries to support similar efforts.”

The AIA calls for four areas of support:

• Advancing NASA’s work in enabling technologies for next-gen aircraft, such as new airframe and engine architectures, improved aerodynamics, advanced propulsion (including electrification), advanced manufacturing and lightweight materials;
• Accelerating the timetable of a NASA subsonic demonstrator ‘X-plane’ incorporating these innovations to ensure US companies can bring these technologies to maturity ahead of European competitors;
• Increasing funding for the FAA’s Continuous Lower Energy, Noise and Emissions (CLEEN) Program to accelerate near-term fuel efficiency improvements in conjunction with reductions in noise and other emissions that manufacturers need to balance; and
• Developing a comprehensive, long-term research agenda to secure US leadership in transformational aviation technologies, leveraging partnerships between industry and government agencies such as NASA, the Department of Transportation, Department of Defense and Department of Energy.

The AIA also stresses the importance of government, industry and NGOs working together through ICAO, and notes ICAO is continuing to assess the feasibility of a new long-term goal for international aviation emissions.

“To build upon achievements to date, we urge the administration to continue to prioritise multilateral solutions and maintain the leadership the US government has demonstrated in these activities,” says the letter, which mentions the aircraft CO2 standard established by ICAO in 2017 and now implemented by the Environmental Protection Agency (EPA) into domestic law.

“Following the finalisation of the EPA rule, we ask that the FAA develops regulations this year that will allow US manufacturers to certify their aircraft to the global CO2 standard.”

During the final days of the Trump administration in late December, the EPA finalised emissions standards for airplanes used in commercial aviation and large business jets that align them with the ICAO standards. Without the rulemaking, said the EPA, US manufacturers would have been at a significant disadvantage and could be forced to seek CO2 emissions certification from another country in order to market and operate their airplanes internationally.

However, the ruling is being challenged in an appeals court in Washington by the attorneys general from 12 Democrat-led states, including California, Illinois, Pennsylvania and New York, plus the District of Columbia, who contend it would not result in actual reductions of greenhouse gas emissions and is therefore unlawful.

The three environmental groups taking action are the Center for Biological Diversity (CBD), Friends of the Earth and Sierra Club, which are being represented by Earthjustice. They say the rule will not apply to in-service airplanes and will not apply to new in-production airplanes until 2028, when the EPA expects all airplanes to already comply with the standards or be phased out.

“We’re confident that we’ll stop this rule in court and we look forward to serious, science-based standards from the new Biden administration,” said Clare Lakewood, Legal Director of CBD’s Climate Law Institute.

According to a Reuters report, Boeing has asked the appeals court for approval to intervene on behalf of the EPA, noting that US participation in the work towards the ICAO CO2 emissions standard on which the ruling is based began under the Obama administration, in which Joe Biden was Vice President.

Boeing said in a statement it was essential rules should be reasonably achievable “given the billions of dollars it costs to design, build and certify new airplanes.”

It added: “Attempts to overturn regulation directly aligned with successful cooperative international efforts to combat climate change, supported by more than 190 countries, will only discourage future international agreements.”

In its ruling, the EPA said: “The ICAO Airplane CO2 Emission Standards have been adopted by other ICAO member states that certify airplanes. The action to adopt in the United States GHG standards that match them will help ensure international consistency and acceptance of US manufactured airplanes worldwide.”

It conceded though: “EPA’s assessment includes the expectation that existing in-production airplanes that are non-compliant will either be modified and re-certificated as compliant, will likely go out of production before the production compliance date of January 1, 2028, or will seek exemptions from the GHG standard. For these reasons, the EPA is not projecting emission reductions associated with these GHG regulations. However, the EPA does note that consistency with the international standards will prevent backsliding by ensuring that all new types design and in-production airplanes are at least as efficient as today’s airplanes.”

The Sustainable Aviation Fuel Act legislation introduced by Julia Brownley aims to incentivise SAF production and help the aviation sector reduce its carbon emissions. As well as creating a new blender’s tax credit for SAF, linked to carbon reductions, it would authorise $1 billion in federal funding for US projects that produce, transport, blend or store SAF and a further $175 million in research funding “to push the limits” of existing SAF technology. It would also require the EPA to establish an aviation-only Low Carbon Fuel Standard (LCFS) similar to California’s transportation-wide LCFS.

“As a member of the House Select Committee on the Climate Crisis and the House Transportation and Infrastructure Subcommittee on Aviation, I know the importance of, and challenges to, decarbonising the aviation industry,” said Brownley. “Aviation alone contributes 9% to US greenhouse gas emissions from the transportation sector and is therefore a critical target towards achieving our climate goals. Sustainable aviation fuel will go a long way to reducing aviation sector greenhouse gas emissions but it needs a focused federal response to make it a reality.”

Photo: Boeing

US environmental groups say the proposal by the Environmental Protection Agency (EPA) to adopt the ICAO CO2 standards for aircraft into US regulations violates the nation’s Clean Air Act because it fails to reduce greenhouse gas emissions despite the EPA’s findings that such emissions endanger public health and welfare. Moreover, they say, the proposal’s failure to consider the statutory factors laid out in the Act or analyse the costs and benefits of a range of possible emission standards, and refusal to select an alternative based on the evidence before the agency was “arbitrary and capricious”. The groups were responding to a public comment period just closed on the proposal, which has been largely supported by US aerospace and airline sectors. Although the majority of aircraft will not be subject to the standards until January 2028, the industry is calling for finalisation of its domestic adoption by the end of this year.

The aircraft CO2 standards were adopted by the ICAO Council in March 2017 and are contained in Annex 16 of the Chicago Convention. It applies to new aircraft type designs from 2020 and to aircraft type designs already in production as of 2023. Those in-production aircraft which by 2028 do not meet the standards will no longer be able to be produced unless their designs are sufficiently modified. The EPA and FAA represented the United States on ICAO’s environmental protection committee CAEP, which drew up the standards.

After legal challenges by environmental groups, in 2016 the EPA issued findings that within the meaning of section 231 of the Clean Air Act, elevated concentrations of greenhouse gas (GHG) emissions in the atmosphere endangered the public health and welfare of current and future generations, and that GHG emissions from certain classes of engines used in certain aircraft are contributing to the air pollution that endangers public health and welfare.

As such, the EPA is proposing to regulate GHG emissions from covered airplanes through the adoption of domestic GHG regulations that match ICAO’s international CO2 standards. Covered airplanes are civil subsonic jet aircraft with a MTOM greater than 5,700 kgs and larger civil subsonic turboprop airplanes with a MTOM greater than 8,618 kgs. It proposes to adopt the ICAO CO2 metric, which measures fuel efficiency, for demonstrating compliance with the GHG emissions standards. The metric is a mathematical function that incorporates the specific air range (SAR) of an airplane/engine combination – a traditional measure of airplane cruise performance in units of km/kg of fuel – and the reference geometric factor (RGF), a measure of fuselage size.

To measure airplane fuel efficiency, the EPA is proposing to adopt the ICAO test procedures whereby the SAR value is measured in three specific operating test points, and a composite of those results used in the metric to determine compliance with the proposed GHG standards. In order to be consistent with the current annual reporting requirement for engine emissions, the EPA is also proposing to require the annual reporting of the number of airplanes produced, airplane characteristics and test parameters.

The EPA says US manufacturers have already developed or are developing technologies that will allow affected airplanes to comply with the ICAO standards, in advance of its adoption, and it anticipates nearly all affected airplanes to be compliant by the respective dates for new type designs and for in-production airplanes. This includes the expectation that existing in-production airplanes that are non-compliant will either be modified and re-certificated as compliant or will likely go out of production before the production compliance date of 1 January 2028.

“For these reasons, the EPA is not projecting emission reductions associated with these proposed GHG regulations,” it states in the executive summary of the proposed rule.

The EPA held a virtual public hearing on September 17, with participation from aircraft and engine manufacturers, aerospace and airline industry associations, environmental organisations and other interested parties. Over 120 written public comments have been submitted in response to the proposal by the October 19 closing date.

A coalition of environmental groups that first filed a suit against the EPA over a decade ago to force the agency to address GHG emissions from aircraft said the proposal violated section 231 of the Clean Air Act (CAA) as it failed to reduce GHG emissions from aircraft despite the EPA’s own endangerment findings.

“Moreover, the proposal’s failure to consider the statutory factors laid out in section 231, over-reliance on factors outside the statute, failure to analyse the costs and benefits of a sufficient range of possible emission standards, and refusal to select an alternative based on the evidence before the agency are arbitrary and capricious,” says the submission by Earthjustice, Center for Biological Diversity, Sierra Club, Friends of the Earth and Natural Resources Defense Council.

“These flaws cannot be remedied in a final rule. Instead, EPA must replace the proposal with one that meets its duties under the Clean Air Act. The final regulations must employ strong mechanisms to reduce emissions from aircraft and protect the public health and welfare and in doing so, EPA must consider the full panoply of available measures, including declining fleetwide emissions averages and operational and design improvements.

“To avoid catastrophic climate change, EPA must implement standards that far exceeds ICAO’s standards in both stringency and scope.”

The submission dismisses the EPA’s argument that US manufacturers would be at a competitive disadvantage if the US failed to adopt standards in line with ICAO’s. “EPA provides no legitimate basis for this assertion. Nothing prevents the US from adopting standards that are more stringent than ICAO’s and EPA has responsibility to do so if that is what public health and environmental protection require.”

Commenting on its own submission, Annie Petsonk, International Counsel for the Environmental Defense Fund, said: “As EPA’s own analysis indicates, the proposed standards will not drive emissions down. It simply embodies what the industry has already baked in. To justify its approach, EPA relied on a problematic estimate of the costs of doing nothing, arbitrarily ignoring the real costs of climate pollution that people across the country are facing every day.

“As the aviation industry tries to bounce back from Covid, it must put addressing the climate crisis at the core of its recovery, and government needs to lead the way. A stringent aircraft pollution standard would mean jobs building the aircraft and creating the fuels of the future. Instead, EPA’s proposed aircraft rule ignores the science and contravenes laws that require it to protect public health and the environment.

“We urge EPA to replace its proposal with standards that will actually reduce aircraft emissions, as one key element of a broader package of carrots and sticks to get the aviation industry to take real steps to cut climate pollution.”

In its submission to the EPA, the non-profit environmental research organisation International Council on Clean Transportation (ICCT) said its analysis showed new deliveries of commercial aircraft in 2019 were on average 6% more fuel efficient than required by the ICAO standards.

With some caveats, the industry response to the EPA’s proposal is supportive of legislation in line with ICAO CO2 standards, which it sees as meeting the criteria set out in the CAA’s section 231.

“Adopting the standards into US law will ensure US-manufactured aircraft and engines are available to US airlines, while fostering global competition and enabling our airlines to acquire aircraft and aircraft engines at market-driven, competitive prices,” says a joint submission by Airlines for America and the Air Lines Pilots Association International. “Especially given that, as the agency itself notes, other ICAO member states that certify airplanes have already adopted the ICAO CO2 standards, the agency needs to act to put US manufacturers on the same footing as their foreign counterparts.”

The two trade bodies said the ICAO standards would achieve GHG emissions reductions, support US policies to combat climate change and provide international uniformity. “Aircraft and the international airspace system simply could not function if aircraft and aircraft engines were subject to disparate regulatory requirements and standards.”

However, they asked the EPA to clarify in its rulemaking that the proposed US standards did not apply to in-service aircraft and disagreed with the agency’s conclusion that there could be no costs or benefits attributable to the standards.

A submission by the Aerospace Industries Association (AIA) said its members had already taken steps to ensure compliance with the proposed standards, including making plans to end production of the least fuel-efficient aircraft.

“The majority of aircraft will not be subject to the standards until 1 January 2028. Nevertheless, we urge the EPA to finalise the domestic adoption of these rules by the end of this year,” said the AIA. “Airlines purchase aircraft several years in advance. They are currently deciding on aircraft that will be delivered through the end of this decade. When making these decisions, airlines will require assurances that aircraft meet the standards to operate in international markets.

“Without domestic regulations in place, the FAA would be unable to certify an aircraft as meeting the ICAO CO2 standards. In this situation, US manufacturers would be at a serious competitive disadvantage if airlines were to seek greater regulatory certainty by opting to purchase aircraft manufactured elsewhere that meet the requirements of their certifying authority’s equivalent rules, which have already been implemented in some cases.

“If this was to occur, it could jeopardise tens of billions of dollars in sales for the US aerospace industry.”

Engine manufacturer GE said the proposed rule would provide the global aviation industry with much-needed certainty and consistency as it faced the Covid crisis and its adoption would satisfy US obligations under the Chicago Convention by ensuring compliance with ICAO standards.

GE also argued that more stringent GHG standards were not appropriate and would potentially violate the Clean Air Act.

“The CAA does not require the EPA to ‘technology force’ at the risk of flight safety,” said the submission. “[It] requires EPA to refrain from changing aircraft emission standards if such a change would adversely affect safety. To maintain the trust and confidence of the flying public, it is imperative that EPA not adopt standards that could in any way be perceived as sacrificing aviation safety. The perception of the flying public matters and EPA should endeavour to avoid any erosion of public confidence in the safety of aviation. This objective is best achieved by EPA remaining aligned with the ICAO analytical criteria of technical feasibility, environmental benefit, cost effectiveness and impacts of interdependencies, which have helped ensure the continuation of aviation’s impressive safety record.

“Moreover, when preparing this proposal, EPA carefully analysed the impacts of two more stringent alternatives. These analyses show that the alternatives would lead to minimal reduction in GHG emissions, while imposing significant costs associated with deviating from the ICAO standards. Consequently, EPA appropriately decided against proposing either of these alternatives.”

While supportive of aligning EPA regulations with the ICAO CO2 standard, both Boeing and Airbus are opposed to the reporting requirements laid out in the proposal. Boeing said they were unnecessary as they were duplicative of FAA reporting requirements, “and unwise because they pose unnecessary risks to Boeing’s confidential business information and potentially the nation’s security.”

The concerns are centred on fears the EPA could make public manufacturers’ specific air range data.

“SAR data is highly sensitive, treated by Boeing and other airplane manufacturers as a trade secret and protected zealously from disclosure to competitors and the public,” says the Boeing submission. “because of the strategic value of SAR data, it can also be subject to federal export controls and sanction regimes.

“There is also a risk that someone could wrongly argue that SAR data should be considered to be emissions data or ‘related technical information’ that EPA must disclose. EPA should not collect SAR data … and should not require reporting of that data. If it nonetheless requires reporting of SAR data then EPA must ensure that data is protected from public disclosure.

“EPA need not collect SAR data to track airplane CO2 emissions performance and verify compliance. ICAO agreed to the use and public reporting of an aircraft’s [fuel efficiency] metric value for this purpose because it is sufficient by itself to enable assessment of compliance with the CO2 emissions standard, while continuing to maintain the confidentiality of manufacturers’ SAR data. Significantly, ICAO does not require public reporting of RGF – an important element of SAR data – precisely because it can be used to derive an airplane’s SAR.”

Airbus too said SAR data and the reference geometric factor were highly commercially sensitive information. It also questioned the EPA’s authority to request such information when a large number of airplanes delivered around the world would never operate within the United States.

“ICAO is the right body to create international standards,” said the Airbus submission. “Airbus believes that in the absence of a worldwide harmonisation process, regional requirements could produce unintended consequences that would harm the aviation industry. We therefore urge the EPA to adopt the proposed ICAO rule with no additional requirements.”

The ICAO Aircraft CO2 standards are contained in Volume III to Annex 16 of the Chicago Convention and were adopted in Europe by the European Parliament and Council in July 2018 (Regulation (EU) No. 2018/1139). The European Union Aviation Safety Agency (EASA) published certification specifications concerning the standard in August 2019.

Photo: Boeing