How airlines are working to reduce their CO2 one olive at a time

While we wait for battery-powered aircraft to take flight, airlines are using all sorts of tricks to cut fuel and weight

Beef is cancelled. Well, on many Virgin flights, anyway.

Earlier this year, Richard Branson – whose company is about to charge people $250,000 (€228,000) for a 3½-hour space flight with Virgin Galactic – announced that his company was scaling back on the amount of beef, palm oil and soy served on its planes.

It’s all part of a concerted move by a nervous aviation industry to reduce its ecological and carbon footprints, and comes alongside other ways for the transport industry – including shipping and trucking – to reduce its fuel use while also saving costs.

One of the standout suggestions is to go to the toilet before flying, so as to reduce the weight of the plane and thus increase its fuel efficiency. More recently, the Financial Times reported that glass wine bottles contribute to carbon emissions because the curved edges mean that space is wasted on trucks, whereas square packaging would allow for more wine to be transported on a single vehicle and thus save space and fuel.


American Airlines  removed one olive from the in-flight salads. This saved money on fuel costs but, astonishingly, the accumulated reduced weight of these olives reduced fuel costs over time

But are these initiatives enough – or are we merely dancing around the edge of the fires and floods that are increasingly being connected to climate breakdown?

Dr Marina Efthymiou, assistant professor in aviation management at Dublin City University's Business School, says that passengers and airlines can take small steps to reduce their impact when flying – but that it is only a part of the solution.

“If you reduce the weight of the plane in the air, whether that’s by taking less luggage, not bringing a laptop or getting rid of in-flight magazines, it can seem insignificant across one plane or when done by one person. But across all the planes that fly everyday, it can make a difference.”

Efthymiou says that removing excess weight alone is not going to eliminate the aviation industry’s carbon emissions. “It is better to talk about a complementary actions: remove excess weight but also look at sustainable biofuels, optimising the trajectory of aircrafts using newer and more fuel-efficient airplanes and not using both engines for taxiing. Together, these can decrease CO2 emissions.”

Brian Ó Gallachóir is professor of energy engineering at UCC and director of Marei, the Science Foundation Ireland Research Centre for Energy, Climate and Marine. Marei works with industry on developing strategic plans for a low-carbon transition.

He says that, while going to the toilet before flying or carrying less luggage does reduce fuel use, the impact is “negligible” in terms of the wider scale.

“Yes, air travel is a small – but growing, and significant – part of international greenhouse gas emissions,” says Ó Gallachóir. “There is growing discourse around people committing to fly less, or even not to fly at all. There is less discussion around other options for reducing emissions. Cruising, for instance, is much less emission-intensive than take-off and landing; airlines that choose less congested airports will save fuel because they won’t have to circle and wait for free space.”

Earlier this year, the UK's advertising watchdog recently rapped Ryanair over its claim to have the lowest emissions. The airline said it had the newest aircraft fleet and used the most fuel-efficient engines, as well as flying with an average of 97 per cent capacity.

“The Ryanair model – filling the plane with as many passengers as possible – is more fuel-efficient [than airlines flying with lower capacity],” says Ó Gallachóir. “In addition, new airplanes are likely to be more environmentally and cost-efficient. But Ryanair and similar low-cost carriers, by reducing the cost of air travel and making it more widely available, have contributed to a greater number of flights and, therefore, emissions.”

Both Ó Gallachóir and Efthymiou point towards “flight-shaming”, where individual passengers are effectively dissuaded from flying under threat of social disapproval – but both are wary of it.

"Flight-shaming means it can be trendy to say you won't fly, but there is a chance this is a bubble and could pass," says Efthymiou. "Ireland, for instance, is an island nation so how can we leave without planes? Boats to New York aren't really feasible. We can criticise people travelling for leisure, but that contributes to a person's cultural enrichment and, in Ireland, we have many immigrants and emigrants visiting friends and relatives."

Ireland has benefitted from inward and outward travel, they both say, so we need alternatives including sustainable biofuels.

Ó Gallachóir says that flying is unlikely to halt entirely and that island nations are particularly dependent on those transport links.

“There are more options for cars and trucks than for airplanes. But there is work being done on powering planes with renewables such as biokerosene or hydrogen, even if it doesn’t get much attention.”

Efthymiou says that climate breakdown is threatening to spiral out of control and she recognises that action is needed. “We should start reconsidering short-haul flights and looking at alternatives, particularly trains, but we also need to consider our carbon footprint with fast fashion and look at alternatives for clothes production that are less energy-intensive. There may be a ticket tax on flights, but this could end up on ticket prices, limiting flying to wealthier people, and it may mean that smaller airlines struggle to survive.”


As we talk about airlines carrying less luggage or developing sleeker planes, the European Commission says that emissions from aviation are rising fast and, this year, are predicted to have increased by 70 per cent since 2005.

Meanwhile, the International Civil Aviation Organization estimates that, by 2050, aviation emissions could have risen by between 300 and 700 per cent.

Kate Ruddock, deputy director of Friends of the Earth Ireland, says that aviation emissions are gobbling up more than their fair share of the global carbon budget.

“Any actions, short of reducing air travel, are really insignificant in the context of the sale of emissions from the industry and their contribution to the climate crisis. From our perspective, the shift to focus on how individuals can make their flight more efficient is simply a distraction – and one that has been used by the fossil fuel industry for years to guilt individuals into thinking it is their fault, or that their individual behaviours can have a fundamental impact.

“Suggesting passengers go to the toilet on land to reduce emissions from their flights, sounds a little to me like suggesting a smoker takes one less puff to reduce their risk of lung cancer. It’s not the final puff that will kill you.”


Airlines are not just trying to reduce fuel use because it’s environmentally damaging; they’re trying to reduce fuel use because it’s the single biggest cost. But what other, subtle tweaks might make a difference?

– In the 1980s, American Airlines removed one olive from the in-flight salads. This saved money on fuel costs but, astonishingly, the accumulated reduced weight of these olives reduced fuel costs over time.

– Installing ultra-light seat frames, usually made of aluminium. Lufthansa saved more than 2,000 tons of fuel by reducing the weight of their cargo containers.

– Improved tray tables which stack more efficiently and allow each cart carry one-third more trays. This has saved Virgin Atlantic millions since 2014

– Changing wing tips to reduce drag and save about two per cent of fuel

– Improved flight planning and creating more efficient routes