Are Airlines Trustworthy or Misleading on Voluntary Carbon Offsets? Research exposes the good, the bad and the ugly.

Are Airlines Trustworthy or Misleading on Voluntary Carbon Offsets?


comments no comments

Research from three leading universities* recently assessed the trustworthiness and misleading communications of 37 airlines on voluntary carbon offsets (VCO).  Given the increasing public concern over deceptive tactics around environmental information on websites across industries, this research studies VCO from an environmental communication perspective and studies the ability of VCO messages to convey information that allows customers to recognise what carbon offsetting is and how it works. 

NOW summarised their study and findings on reliable communications that warrant our trust and the devious comms that deceptively cause consumers to believe what is not true.

First, this study sheds light on the role of words in VCO green marketing through an exploratory lexical analysis; future research can employ advanced linguistic and semantic analysis. 

Second, it offers a glimpse of carbon offset corporate communications and paves the way for future consumer behaviour research. Studies on the effect of perceived greenwashing on consumers are still limited and show a negative impact on attitudes towards brands, trust, or perceived brand integrity.

Finally, the study provides a nuanced understanding of current VCO messages and contributes valuable insights to support existing efforts to improve the persuasiveness of VCO messages to alter consumer behaviour; for example, whether misleading tactics lead to increased purchase intent or willingness-to-pay in voluntary carbon offsets. Going forward, those, and other, related questions may be addressed through discrete choice experiments that systematically vary message attributes by the type and nature of the claims.


The airline industry is a major contributor to global warming and it is decarbonising more slowly than other sectors. Previous studies have underplayed the sector’s carbon emissions and the impact of its growth. A lack of strict laws to mitigate greenhouse gas emissions presents major challenges to decarbonise the industry. 

Aviation has witnessed sustained multi-decade growth, contributing 3.5% of the carbon footprint in 2018. While COVID-19 has slowed down aviation’s growth and traffic is forecasted to recover at a lower rate than pre-pandemic projections, recovery will likely remain dependent on fossil fuel. 

A carbon offset and carbon reduction scheme to lower CO2 emissions for international flights was developed  by the International Civil Aviation Organization (ICAO) in 2016 to curb the aviation impact on climate change. Their unrealistic goal was to have carbon neutral growth from 2020. 

Since 1960, air traffic volume has increased more rapidly than emissions, but the current technical and operational measures, and an increased switch to aviation biofuels are insufficient to drive the deep, sustained reductions needed to reach net-zero emissions. Market-based measures, such as offsetting schemes, are needed.


Voluntary Carbon Offsetting (VCO) is “a way for individuals or organisations, in this case airline passengers and corporate customers, to neutralise their proportion of an aircraft’s carbon emissions on a particular journey by investing in carbon reduction projects”. It is still in an embryonic stage with only 10% of air passengers purchasing VCO credits. 

VCO passes on the responsibility of reducing the carbon footprint to travellers by asking them to make a monetary contribution, which is then invested in environmental projects that reduce or sequester greenhouse gas emissions. 

Whilst we are aware of the need to fly less, it is not within the general interest of the travel industry to do so and it is improbable from a consumer perspective, once the sector recovers post covid-19. 


Academics mainly speak of VCO as a form of greenwashing and report that airlines’ poor communication and low transparency on carbon leads to low awareness and credibility amongst customers. 

Customers’ perceived greenwashing on environmental advertising affects their trust and attitudes towards brands. VCO has been identified as a marketing problem when it is used as a promotional tool with Easyjet and Virgin Atlantic being accused of greenwashing. 


The research adapted the work of Carlson et al. (1993) who developed a matrix to recognise problem areas in environmental advertising and added to the literature by showing that the same claims can be both trustworthy and misleading  for different reasons, by combining two typologies of type and nature of claim.

The TYPE OF CLAIM focused on the Product (environmental attributes of carbon offsetting or the airlines’ offsetting program characteristics), the Process (production technique and operational process of the carbon offsetting programme), the Fact (Independent facts about flying or carbon offsetting and the environmental) and Image (claims that enhance credibility and reputation such as supporting an environmental cause or the use of third-party certifications).

The NATURE OF THE CLAIM categorise the ‘seven sins of greenwash:

1. Fibbing – claims that are simply false

2. Hidden trade-off – depict VCO projects in a positive light without considering the negatives

3. No-proof – not substantiated by supporting information or by a reliable third-party certification

4. Vague – poorly defined or too broad or use jargon so consumers are likely to misunderstand

5. Irrelevant – may be truthful but provide additional, non-related information

6. The lesser of two evils – may be true but distract consumer from the greater eco impacts

7. Worshiping false labels – gives the impression of third-party endorsement such using false certifications or refer to an untrustworthy standard or body.


The number of airlines engaged in VCO dropped over the four years being studied: there were 41 airlines in 2020 compared to 44 in 2016. Comparing 2020 to 2016: 

Airlines with longer text were statistically less misleading and more trustworthy. Late adopters had longer texts, misled more and were less trustworthy than the early adopters. Also, airlines from developed countries statistically communicated more misleading information. 

VCO projects were typically managed by a third company. Having the VCO verified by a third party had no significant effect on the quality or volume of VCO information. However, providing VCO information before the ticket purchase was consistent with more trustworthy messages.


Airlines most often misled in product and image, while they seldom misled in fact data.  It is noteworthy that no airline provided false claims regarding VCO third-party certification.

Airlines most often relied on vagueness, lesser of two evils and no proof when misleading. 

Airlines misleading in product significantly increased the odds of choosing fibbing, vagueness and lesser of two evils as tactics to deceive customers.

Airlines misleading in process were also more likely to mislead by employing the lesser of two evils as a greenwashing tactic. 

Misleading product claims relied on themes and concepts such as Carbon (‘protecting’, ‘environment’), Reduce theme (‘impact’, ‘greenhouse’, ‘gas’), Tree theme (tree planting), Fly theme (‘neutral’, ‘passengers’) and Customers; and the fibbing nature of claim which contributed to misrepresenting the scientific realities of flying.

Misleading image claims relied on broader themes and concepts such as Sustainable (‘environment’), Communities (‘forest’, ‘trees’, and ‘support’), Planet or Global. Those concepts were used to depict carbon offsetting in a positive light without considering its negative attributes (hidden trade-offs). Airlines had a higher probability to employ hidden trade-off, no proof and irrelevance claims, and a lower probability to mislead using lesser of two evils.

Misleading process claims relied on themes and concepts such as Emissions (‘compliance’, ‘scheme’ or ‘trading’), Retired (related to carbon credits) and Contribution (‘offset’) supported the lesser of two evils, implying VCO is the best option to mitigate CO2 emissions.

Themes such as Carbon and Tree were also present in the lesser of two evils claims.

Four out of the six least misleading airlines were among the eight highest trustworthy airlines.

Three out of the four highest misleading airlines were among the lowest trustworthy cluster. 

Airlines in both the High and Middle misleading clusters were more likely to mislead in their product than process claims and, also, more likely to mislead in their image than process claims, relative to airlines in the Low misleading cluster.

High misleading airlines were more likely to employ fibbing as a deception tactic, followed by vagueness and lesser of two evils. 

Airlines in the Middle misleading cluster communicated VCO more often by fibbing, hidden trade-offs, vagueness, irrelevance and lesser of two evils, while they were less likely than High misleading airlines to make claims categorised as no-proof and worshiping false labels.


Overall, 56% of the carbon offsetting claims were trustworthy (938 over 1667 claims). 

Airlines, more often than not, were trustworthy in relation to their product and image. Being trustworthy in product increased the odds of providing relevant information, while in image it was more likely to provide a reliable third-party certification.

Airlines were generally trustworthy in the operational process of carbon offsetting and, statistically, they were likely to inform both on the positive and negative aspects of VCO. However, nearly no airline provided evidence to back up the claims they made.

Trustworthy claims enhanced the credibility of the offset product by referring to Carbon (with concepts such as ‘footprint’), Emissions (‘atmosphere’, ‘greenhouse’, ‘gas’), Information (‘programme’, ‘visit’, ‘read’), Calculator (‘contact’) and Service. 

Trustworthy image claims relied on specific concepts to enhance an eco-friendly corporate image such as Carbon (‘verified’), Climate (‘impact’), Air (‘footprint’), Support (‘deforestation’) and Electricity. 

High trustworthy airlines were more likely to communicate truthful claims in relation to their process and image rather than their product claims. Regarding nature of claim, Hgh and Middle trustworthy airlines were more likely to communicate VCO content that was less vague. 

High trustworthy airlines were less likely to choose the lesser of two evils, and Middle trustworthy airlines were more likely to provide additional relevant information (vagueness), compared to Low trustworthiness airlines. 

Airlines with longer text were more likely to mislead in their image than in their product claims. The timing of VCO adoption did not affect the airlines’ trustworthiness in relation to the nature of their claims.

Finally, the study compared airlines from developed and developing countries and found that belonging to developed countries increased the probability of misleading in product over process, and image over process compared to airlines from developing countries.

Airlines from developed countries were also more likely than airlines from developing countries to be trustworthy by portraying the ecological attributes of VCO product more often than process claims, and by enhancing the eco-friendly image rather than the process. With few exceptions, the airlines’ countries’ levels of development did not significantly affect their choices of the nature of claims being misleading or trustworthy. 

Airlines from developed countries had a higher probability of employing irrelevant misleading claims and were more likely to communicate trustworthy claims in relation to the lesser of two evils criterion. 

Airlines from developing countries had a higher probability of being trustworthy in relation to vague claims.

Can customers disentangle obfuscation and misleading claims from trustworthy VCO messages?  Future work is needed on the perceived greenwashing’s effect on consumer decisions and on consumer’s distrust in VCOs.


For the aviation industry and airlines, there are three mature projects underway: flying with synthetic fuels, with electricity or with hydrogen, but there is no solution for completely sustainable flying in the near future according to recent SRF News reports.

Synthetic fuels: Airlines often talk about sustainable fuels. “SAF” CO2-free kerosene fuel is produced in very small quantities from elaborately processed waste organic waste, straw, sewage sludge, wood, frying oil and much more. Only 200 million litres of SAF are produced per year and it is between 20 to 50% more expensive than conventional fuel. According to expert Manfred Aigner from the German Aerospace Center in Stuttgart, “There is no alternative to kerosene.  You can’t really get far with batteries. You can’t fly heavy loads either. So if high-performance aircraft were to be operated, this would have to be done via alternative kerosenes that do not release fossil CO2.” The pro: The processed edible oil has up to 80 percent lower CO2 emissions than fossil fuels. 

Electric flying: There is currently a lot of research and development for electric aircraft. The first electric aircraft has been approved as a training aircraft for two people with a flight time of just under an hour. Large short- or even long-haul aircraft are a long way off. A Swedish project  for an electric 20-seater plane with a range of 400 kilometers will be ready by 2026. EasyJet is planning a short-haul electric aircraft for 190 passengers from 2030. Given the huge development effort, it is questionable whether the schedules are realistic.

Flying with hydrogen: In 1980, the former Soviet Union had tried out the technology and flew with it. Today, the technology works on the road with cars and trucks. Various research projects are currently conducting initial tests with hydrogen, however, it is likely to take years, if not decades, before commercial use.


Travellers who want to do something for the climate could fly less for more sustainability or give up flying altogether, if that’s an option. If one has to fly, it is better to offset than not offset by compensating for the CO2 carbon footprint by purchasing a voluntary carbon offsets (VCO) before travelling. Scrutinize the airline VCO offer for trustworthiness.

According to Dr. Susanne Becken, Professor of Sustainable Tourism at Griffith University, “Carbon offsetting is not a solution but only a band-aid that gains us time. When people buy carbon offsets, some think that their emission did not ‘matter’. However, the plane still took off and added carbon into the atmosphere. What the offset does is help someone else reduce their emissions. This is a relative benefit compared with the alternative scenario where the flight happens and the traveller still emits carbon as well. It is an improvement, but it will not get us to net zero. That will only be achieved if people fly less. It is still my view that if we have to fly (or emit carbon for any other activity), it is better to offset than not offset. And that is where it is critical that the provider has integrity. To my knowledge, South Pole does.”

VIEW the NOW Offset Carbon Tool for air and ground travel powered by South Pole.



Dr Mireia Guix is a lecturer in tourism at the UQ Business School, The University of Queensland. She has consulted on projects for UNEP, the European Commission and national tourism government agencies. Her research focuses on sustainability accounting and corporate social responsibility for the tourism industry.

Ms Claudia Oll´e is a graduate at the School of Hospitality and Tourism Management of the University of Surrey. Her main research interests include sustainability marketing, sustainable tourism, and tourism management. 

Prof Xavier Font is professor of Sustainability Marketing at the University of Surrey, UK, and Professor II at the UiT The Arctic University of Norway Norway. He is the University of Surrey’sPrincipal Investigator for a €23.5m Interreg project to develop  sustainable forms of tourism for coastal areas in England and France (2019–2022). In 2018-19 he has evaluated the impact of the European Tourism Indicator System on policy making across European regions, and has written a manual on sustainable tourism indicators for policy making (Interreg Mitomed+). He has consulted for UNEP, UNCTAD, UNWTO.

NOW Travel Diaries

Do you care about sustainability? Please leave a reply here.