Ad description

A press ad, a TV ad and a radio ad seen and heard in September 2019:

a. The press ad, seen on 15 September 2019, featured text which stated “Europe’s Lowest Fares, Lowest Emissions Airline”. Everybody knows that when you fly Ryanair you enjoy the lowest fares. But do you know you are travelling on the airline with Europe’s lowest emissions as well?” and “Ryanair has the lowest carbon emissions of any major airline – 66g CO2 for every passenger kilometre flown. This is because we have the youngest fleet of aircraft (avg. age 6 years, the highest load factors (97% of seats filled) and newest most fuel efficient engines”.

b. The TV ad, seen on 23 September 2019, featured a voice-over which stated “Fly Ryanair. Europe’s low fare, low CO2 emissions airline from just £14.99. Book Ryanair today”.

c. The radio ad, heard on 27 September 2019, said “Fly Ryanair. Europe’s low fare, low CO2 emissions airline from just £14.99 one way... Ryanair, low fares, low CO2 emissions. Based on the top 27 European airlines”.


The complainants, including a consultant in energy, transport and sustainable development and many of whom believed that by their nature airlines did not have low emissions, challenged whether the claims “Europe’s … Lowest Emissions Airline” and “low CO2 emissions” were misleading and could be substantiated.


Ryanair Ltd said the metric they used to measure CO2 emissions was grams of CO2 per passenger-kilometre (i.e. every passenger flown one kilometre), which was an important operational efficiency benchmark commonly used across the aviation sector. In comparing the global operations of four other major European airlines in ad (a), they said Ryanair performed strongest. They said ad (a) clearly explained the basis of comparison and said the factors that led to their superior performance were their young fleet of aircraft, point to point routes (direct flights), fewer empty seats and higher seat density (a higher number of seats per plane relative to other aircraft). Ryanair said the claim “low CO2 emissions” in ads (b) and (c) meant “less than average”.

While they thought that was clear to the consumer, they also used on-screen text in ad (b) and the voice-over in ad (c) to further clarify its meaning and in all three ads directed the consumer to the environmental page on their website to allow them to review and verify the claims. They said they provided detailed substantiation of the claim to Clearcast and Radiocentre and that while Ryanair was the top airline of 27 in terms of traffic according to the independent and official data collected by European aviation organisation Eurocontrol, they scored only 5th for CO2 emissions.

They said the claim was substantiated further by the Airline Efficiency Rankings published by Brighter Planet, a leading provider of carbon and energy calculations and an authority on sustainability initiatives, who concluded that Ryanair emitted the least CO2 per passenger mile (rather than kilometre) when compared with 19 other airlines, using five key efficiency drivers: aircraft model, seating density, load factor, freight share and distance. Clearcast said they investigated the claim in ad (b) thoroughly alongside their environmental consultant. They said the Civil Aviation Organisation had a five stage process to calculate CO2 emissions, and the claim was assessed against those requirements and covered the life cycle, airport to airport. They said that as the claim was complex, Ryanair was asked to include verification in the superimposed text which directed the viewer of ad (b) to a website where the full information was available. They also received assurances that should the information change, the website would be updated regularly. Radiocentre said they did not consider ad (c) to be misleading because it was made clear that the claim was a relative statement, based on a comparison with 27 European airlines, and also included a verification link where listeners could obtain full details of the comparison.



The ASA considered that consumers would understand that air travel was commonly associated with high levels of CO2 emissions, and that choosing to fly would increase their own carbon footprint regardless of the airline they flew with. In that context we considered they would interpret the explicitly comparative claim “Europe’s … Lowest Emissions Airline” in ad (a) and the claim “Europe’s … low CO2 emissions airline” in ads (b) and (c) to mean that by choosing to travel with Ryanair, their journey would be contributing lower CO2 emissions than if they had chosen to travel with any other European airline. We did not consider consumers would understand it to mean that the CO2 emissions associated with their journey could be considered “low” in absolute terms.

We considered that in order to demonstrate to a consumer how their carbon footprint would measure against journeying with another European airline, calculating CO2 per passenger distance (mile or kilometre) was an appropriate method. However, that calculation relied on factors including the seating density (number of seats per plane) and we considered that was significant information that consumers needed in order to understand the basis of the claim.

The headline in ad (a) stated “Europe’s Lowest Fares, Lowest Emissions Airline” and only within the body of the ad was this qualified with “Ryanair has the lowest carbon emissions of any major airline”. In ad (a), Ryanair had compared themselves against four other airlines, which they said fell within the definition of a “major airline”, but there was no commonly recognised definition of a “major airline”. We considered consumers would understand it simply to mean those airlines they had heard of, particularly given that the headline claim gave no indication that the comparison was not market-wide.

While ad (a) included information about Ryanair’s CO2 per passenger kilometre and made reference to some of the factors that contributed to that, including their relatively young fleet and the proportion of seats filled per flight, it did not mention the seating density. Ads (b) and (c) did not give any information on the metric used to measure emissions, how that was calculated or the role of seating density in that calculation. As such, we considered that neither ad made the basis of the comparison sufficiently clear. Ad (c) referred to a comparison against the top 27 European airlines, and the Eurocontrol chart provided to support the claims in all three of the ads scored Ryanair 5th for CO2 emissions out of 27 airlines, while their share of air traffic was higher than any other airline on the chart. The implication was that by dividing the emissions by the number of passengers, Ryanair would have the lowest emissions per passenger. However, there were other airlines on the chart that had CO2 emissions which also appeared low relative to their share of air traffic (and therefore similar to Ryanair’s). The chart did not show the underlying ratio of each airline’s emissions relative to its share of traffic, nor did we know which other airlines were measured. In addition, the Brighter Planet chart, which ranked Ryanair as top of the overall airline efficiency rankings for CO2 per passenger mile, was dated 2011 and was therefore of little value as substantiation for a comparison made in 2019. In addition, some well-known airlines did not appear on the chart, so it was not clear whether they had been measured.

While we considered the claims in the ads would be understood relatively and while we were satisfied that CO2 per passenger distance was an appropriate method to compare the carbon footprint of passengers on different airlines, we were concerned that the basis of the claims had not been made clear in the ads and that the evidence provided was insufficient to demonstrate that Ryanair was the lowest carbon-emitting airline on the basis of that metric.

Consequently, we concluded that the claims “Europe’s…Lowest Emissions Airline” and “low CO2 emissions” were misleading. Ad (a) breached CAP Code (Edition 12) rules  3.1 3.1 Advertisements must not materially mislead or be likely to do so.  (Misleading advertising),  3.7 3.7 Advertisements must not falsely imply that the advertiser is acting as a consumer or for purposes outside its trade, business, craft or profession. Advertisements must make clear their commercial intent, if that is not obvious from the context.  (Substantiation),  11.1 11.1 Radio Central Copy Clearance – Radio broadcasters must ensure advertisements subject to this section are centrally cleared.   and  11.7 11.7 Unless it is obvious from the context, advertisements that include a health professional must make clear if he or she has a direct financial interest, or equivalent reciprocal interest, in the sale of the advertised product or service.  (Environmental claims). Ads (b) and (c) breached BCAP Code rules  3.1 3.1 Advertisements must not materially mislead or be likely to do so.  (Misleading advertising),  3.9 3.9 Broadcasters must hold documentary evidence to prove claims that the audience is likely to regard as objective and that are capable of objective substantiation. The ASA may regard claims as misleading in the absence of adequate substantiation.  (Substantiation),  9.2 9.2 The basis of environmental claims must be clear. Unqualified claims could mislead if they omit significant information.   and  9.8 9.8 Advertisements must not mislead consumers about the environmental benefit that a product or service offers; for example, by highlighting the absence of an environmentally damaging ingredient if that ingredient is not usually found in competing products or services by highlighting an environmental benefit that results from a legal obligation if competing products are subject to the same requirements.  (Environmental claims).


Ads (a), (b) and (c) must not appear again in their current forms. We told Ryanair Ltd to ensure that when making environmental claims, they held adequate evidence to substantiate them and to ensure that the basis of those claims were made clear.


3.1     3.9     9.2     9.8     3.1     3.7     11.1     11.7    

CAP Code (Edition 12)

3.1     3.7     11.1     11.7    

More on