Transition policies for climatically sustainable aviation

Figures & data

Table 1. Shortcomings of CORSIA.

Issue	Critique	Reference
Non-CO2 emissions	Focus on CO2 emissions; ignoring for example methane, NOx and contrails or cloud formation, which cause significant additional radiative forcing.	Lee et al. (2009)
Partial inclusion of aviation	Exceptions exist for routes to and from Least Developed Countries, Landlocked Developing Countries and Small Island Developing States. Only 80% of international air traffic expected to be covered.	EC (2017)
Focus on “carbon neutral growth”	The offsetting mechanism of CORSIA, relating only to growth beyond 2020, is expected to cover only 25% of international aviation’s emissions over the period 2021–2035.	ICCT (2017a)
Voluntary character	Voluntary in both pilot (2021–2023) and first phase (2024–2026). Only by 2027 would most airlines participate.	Lyle (2018)
Scale of offsets needed	CORSIA will require offsetting at unprecedented scales, i.e. an estimated 142–174 Mt CO2 by 2025, and 443–596 Mt CO2 by 2035.	ICAO (2017)
Low cost forest projects	Offsetting likely to focus on low-cost projects. Some of these imply a considerable risk of carbon leakage (for example, forest fires).	Correa, van der Hoff, and Rajão (2019); Laing, Taschini, and Palmer (2016); ICCT (2016a)
New propulsion technology needed	Offsetting is more price-effective than the development and dropping in of alternative fuels, which means that new propulsion technologies will not be stimulated through CORSIA.	ICCT (2018a); IEA (2019a)

Figure 1. Policy dimensions and their relative effectiveness. *The further outside the concentric rings a policy is located, the more effective it is considered. See Methodology for further information on the positioning process.

Table 2. Policies for the transformation of the aviation sector.

Policy type^a	Individual/society	Aviation sector
Voluntary	Voluntary carbon offsets+ Option to purchase SAF flight+ Governmental communication++	Carbon labels on tickets++
Market-based	Emission levy++ Air passenger duty++ Progressive frequent flier tax++	VAT for all air travel++ Minimum fare rule++ Assigning slots based on efficiency++ Carbon-related landing charges++ Fossil fuel carbon tax+++ Staying financial aid, loans and tax relief+++ Removing subsidies+++
Regulatory	Mandatory carbon offsets+ Removal of loyalty programs++ Maximum flight quotas+++ Personal carbon allowances+++	Banning air transport advertisement++ Speed reductions++ Phasing out short-haul flights++ Staying airport expansions++ Minimum load factors++ Faster replacement of inefficient aircraft+++ Private flight synthetic fuel specification++ Denser premium seating layouts+++ Flight path changes+++ Feed-in quota+++ Annual reduction in emissions+++

Source: Babakhani et al. (2017); Larsson et al. (2018, 2019, 2020); Gössling et al. (2020); ICCT (2016b, 2018b, 2019); Jagers, Löfgren, and Stripple (2010); own policy designs.

^aPolicies apply to individuals, society, or different actors in aviation (manufacturers, airlines, airports, fuel suppliers); their effectiveness is assessed as low (+), medium (++), or high (+++) as described in the Methodology.

Table 3. Transition policies effectively addressing complexity.

Issue covered	Policy example	Mechanism
Non-CO2 (notably contrail) forcing	Flight path changes	Regulatory, technology
Curbing growth	Carbon tax	Market-based, demand
Domestic emissions from aviation	Phasing out of domestic flights	Regulatory, demand
Frequent fliers	Progressive frequent flier tax Carbon labels on air tickets	Market-based, demand Voluntary, social norm
Energy intensities – inefficient aircraft (high emissions per pax.) Energy intensities – premium classes Energy intensities – private flight	Faster replacement of inefficient aircraft Airport slots assigned on efficiency basis Air passenger duty for premium classes Synthetic fuel specification	Regulatory, technology Market-based, technology Market-based, demand Regulatory, demand
Technology change	Removal of subsidies and State aid Feed-in quota for synthetic fuels	Regulatory, technology Market-based, demand

Lee, D. S., Fahey, D. W., Forster, P. M., Newton, P. J., Wit, R. C. N., Lim, L. L., … Sausen, R. (2009). Aviation and global climate change in the 21st century. Atmospheric Environment, 43(22-23), 3520–3537.

 Web of Science ®Google Scholar

EC. (2017). EU climate action. Retrieved from https://ec.europa.eu/clima/citizens/eu_en

 Google Scholar

The International Council on Clean Transportation (ICCT). (2017a). International civil aviation organization’s carbon OFFSET and reduction scheme for international aviation (CORSIA). Retrieved January 8, 2020, from https://theicct.org/publications/ICAO-carbon-offset-and-reduction-scheme-international-aviation

 Google Scholar

Lyle, C. (2018). Beyond the ICAO’s CORSIA: Towards a more climatically effective strategy for mitigation of civil-aviation emissions. Climate Law, 8(1-2), 104–127.

 Google Scholar

ICAO. (2017). What would be the impact of joining CORSIA? Retrieved from www.icao.int/environmental-protection/Pages/A39_CORSIA_FAQ3.aspx

 Google Scholar

Correa, J., van der Hoff, R., & Rajão, R. (2019). Amazon Fund 10 years later: Lessons from the world’s largest REDD+ program. Forests, 10(3), 272.

 Web of Science ®Google Scholar

Laing, T., Taschini, L., & Palmer, C. (2016). Understanding the demand for REDD+ credits. Environmental Conservation, 43(4), 389–396.

 Web of Science ®Google Scholar

The International Council on Clean Transportation (ICCT). (2016a). Brother, can you spare three cents (for the climate)? Retrieved November 30, 2020, from https://theicct.org/blogs/staff/brother-can-you-spare-three-cents-climate

 Google Scholar

The International Council on Clean Transportation (ICCT). (2018a). ICAO’s CORSIA scheme provides a weak nudge for in-sector carbon reductions. Retrieved November 30, 2020, from https://theicct.org/blog/staff/corsia-carbon-offsets-and-alternative-fuel

 Google Scholar

International Energy Agency (IEA). (2019a). Are biofuels ready for take off? Retrieved January 8, 2020, from https://www.iea.org/commentaries/are-aviation-biofuels-ready-for-take-off

 Google Scholar

Babakhani, N., Ritchie, B., & Dolnicar, S. (2017). Improving carbon offsetting appeals in online airplane ticket purchasing: Testing new messages, and using new test methods. Journal of Sustainable Tourism, 25(7), 955–969.

 Web of Science ®Google Scholar

Larsson, J., Kamb, A., Nässén, J., & Åkerman, J. (2018). Measuring greenhouse gas emissions from international air travel of a country’s residents methodological development and application for Sweden. Environmental Impact Assessment Review, 72, 137–144.

 Web of Science ®Google Scholar

Larsson, J., Elofsson, A., Sterner, T., & Åkerman, J. (2019). International and national climate policies for aviation: A review. Climate Policy, 19(6), 787–799.

 Web of Science ®Google Scholar

Larsson, J., Matti, S., & Nässén, J. (2020). Public support for aviation policy measures in Sweden. Climate Policy, 20(10), 1–17.

 Web of Science ®Google Scholar

Gössling, S., Humpe, A., & Bausch, T. (2020). Does ‘flight shame’ affect social norms? Changing perspectives on the desirability of air travel in Germany. Journal of Cleaner Production, doi:https://doi.org/10.1016/j.jclepro.2020.122015

 Web of Science ®Google Scholar

The International Council on Clean Transportation (ICCT). (2016b). Cost assessment of near- and mid-term technologies to improve new aircraft fuel efficiency. Retrieved November 30, 2020, from https://theicct.org/publications/cost-assessment-near-and-mid-term-technologies-improve-new-aircraft-fuel-efficiency

 Google Scholar

The International Council on Clean Transportation (ICCT). (2018b). U.S. Passenger Jets under ICAO’s CO2 Standard, 2018–2038. Retrieved November 30, 2020, from https://theicct.org/publications/us-passenger-jets-icao-co2-standard

 Google Scholar

The International Council on Clean Transportation (ICCT). (2019). The cost of supporting alternative jet fuels in the European Union. Retrieved January 3, 2019, from https://theicct.org/sites/default/files/publications/Alternative_jet_fuels_cost_EU_20190320.pdf

 Google Scholar

Jagers, S. C., Löfgren, Å, & Stripple, J. (2010). Attitudes to personal carbon allowances: Political trust, fairness and ideology. Climate Policy, 10(4), 410–431.

 Web of Science ®Google Scholar