This article shares how LUCRA scientist Gaétan Herold and his supervisor Dr. Mariane Schneider (Ghent University) navigate the paradox of working towards a fossil-free future while questioning the carbon cost of their own scientific travels – and how turning a dilemma into an adventure can open up new perspectives.

Phasing out fossil fuels is essential to limit the consequences of ongoing human-made climate emergency by achieving ambitious climate goals (Shukla et al., 2022). This is why LUCRA exists: The project aims to produce bio-based succinic acid, a molecule that is often derived from petrochemical processes.

Like many scientists in the field of circular and biobased economy, we, the LUCRA project team members, face a paradox. Every day we work toward a fossil-free future, yet we often travel to project meetings or conferences, frequently by plane (Ciers et al., 2018). Unfortunately, aviation is not emission-free, and realistically, it won’t be in the coming decades. It remains one of the few economic sectors where a complete phase-out of fossil fuels is not technically feasible in the near future (Bardon & Massol, 2025; Belcher et al., 2025; Shukla et al., 2022).

Aviation related emissions are not a marginal issue. A round trip to New York emits about 1.9 tonnes of CO₂-equivalent. A round trip from Brussels to Crete that would have been necessary for a LUCRA meeting this June results in approximately 750 kg of CO₂eq.

For comparison:

Estimated greenhouse gas emission savings in one year (tonnes of CO₂eq)

^{Source: ADEME, 2024; Carbone 4, 2024; Ritchie, 2024.}

To stay within the limits of the Paris Agreement, many experts recommend an emission target of 2 tonnes CO₂eq per person per year (including all activities, travel, food, goods, housing, etc.) (O’Neill et al., 2018). In that context, air travel stands out as fundamentally incompatible with our climate goals.

Yet as scientists, we also must develop the technologies needed to phase out petroleum. Along with fundamental changes to the economic system, these innovations are essential if we want to meet global climate targets (Shukla et al., 2022). Cooperation projects like LUCRA and other Horizon Europe or CBE JU initiatives are therefore crucial – but they often require travel to meet and coordinate with the academic and industrial partners from different European countries, or to present their concept and results at conferences for dissemination and exploitation purposes.

So, are we polluting for the greater good?

That’s a difficult question, and I don’t pretend to have a universal answer. Sometimes yes (for instance, field work in remote places to understand our climate), sometimes probably not. What I can share is how I feel about my own situation. I am not comfortable emitting large amounts of CO₂ – even in the name of a biobased future – especially when alternatives exist.

That’s why I choose not to fly, also not for LUCRA meetings. Sometimes it’s relatively easy: partner destinations like Birmingham or Madrid are well-connected by high-speed rail from Western Europe. Other times it’s more complicated – like last year’s meeting in Turku (Finland), or this year’s in Chania (Crete), where geography and limited public transport make the journey long and difficult. It’s here that the ethical dilemma might become a fantastic adventure.

This year I shared a part of the journey to Crete with my supervisor Dr. Mariane Schneider, who, for the same reasons, avoids flying as much as she can.

A trip across Europe

My journey began with a day and night across Italy, heading all the way to Lecce. I spent the weekend in this beautiful baroque city before meeting Mariane in Bari after she crossed Italy in a night train.

There, we enjoyed a gelato at the port before boarding a very comfortable overnight ferry to Patras. From there, we began our crossing of mainland Greece, mainly by train, but also by bus.

This allowed us to discover the beautiful ruins of ancient Corinth with just a few other visitors, and eventually even alone, as the sun slowly approached the horizon. The next day, we hiked up to the medieval Acrocorinth fortress – what a view over the whole region.

However, as our goal was Crete, we continued to Athens. There, we enjoyed the atmosphere, the museums, and the historical ruins of this incredible city. Since it was during a local festival, we even got to see an opera: Turandot by Puccini, performed in the Odeon of Herodes Atticus. An opera night in a theatre built in the second century AD (160–174 AD) – that’s not something you experience every day!

From Athens, we took the ferry to Heraklion, where we visited the incredible archaeological museum and the Minoan palace of Knossos. The site has been partially reconstructed with some historical liberties, but it’s still very much worth a visit. The area around also has a nice wine-growing region where we could taste the local production. We spent the night in a small mountain town called Archanes, before heading to Rethymnon, a fantastic former Venetian and Ottoman port.

From there, we continued to Chania, where our colleagues from all over Europe joined us for a few days of productive workshops and meetings,and very interesting biotechnological discussions and perspectives for the future of LUCRA, with a beautiful view over the harbour. On top of that, we also got to enjoy the delicious traditional food.

After three intense days of work, Mariane went camping on the west coast of Crete with some Greek colleagues from LUCRA for a spontaneous (the Interrail allowed to change plans), relaxed weekend before heading back.

As for me, I returned to Athens, where new adventures were waiting. I had to present LUCRA-related work at the EcoSTP and ICA conferences in Stockholm and Oslo. That meant three more weeks of train travel through Bulgaria, Romania, Germany, Sweden, Norway and Denmark before finally coming back home. But that’s another story.

Conclusion

Doing such a trip definitely is an unforgettable experience, and it shows that traveling across Europe without flying is reasonably possible. But of course, it’s not feasible for everyone. If you have a family with young children, can’t work remotely, or have lab experiments running, it can quickly become an organisational nightmare.

More generally, this raises questions about the growing amount of travel in the academic world. How often do we need to meet in person? Could we make less frequent, longer meetings with some online meetings in between? Could some international conferences be replaced by regional ones? Probably. A study from EPFL (Lausanne, Switzerland), found that researchers’ academic performance was not correlated with their travel-related CO₂ emissions (Ciers et al., 2019). But moving in that direction would mean a broader shift in the way the academia is organized – one that would not come without its challenges.

Valuable resources and FAQ

Where to Book?

Unfortunately, booking international train and ferry tickets isn’t fully standardized yet. The best starting point is the excellent website seat61.com, which provides detailed and up-to-date guides for traveling through Europe without flying.

If you’re planning an academic trip and want advice, don’t hesitate to contact me: gaetan.herold@ugent.be. I will be more than pleased to help you avoid some CO₂ emissions.

How long does it take?

• The fastest route from Belgium to Athens takes about 2 days.
• To reach Crete from Belgium, plan for almost 3 days.
• For a more relaxed experience, add stopovers to enjoy the many beautiful places along the way.

How much CO₂ is emitted?

• For a round trip from Brussels to Crete, total emissions are just under 200 kg CO₂eq – four times less than by plane.
• Most of them stem from ferries and fossil-fuel-powered trains.
• For comparison: Brussels to Madrid by train emits 30 times less CO₂ than flying!

How much does it cost?

• It depends on the route, comfort level, and season.
• A round trip to Crete usually costs around €400 for transport. Check with your university if there are any subsidies for sustainable travel.

More Advice for a Smooth Journey

• Get an Interrail Pass: Since 1988, Interrail is available to people of all ages. It’s ideal for longer journeys and gives great flexibility – and is very economical if you need to travel multiple times in a few weeks.
  For the compulsory reservations, have a look at: seat61.com/interrail
• Check vagonweb.cz for detailed information about train compositions, including whether and in which car your train has a restaurant, Wi-Fi, or bike space.
• Save on ferry cabins: In Greece, cabins on ferries can be pricey. A practical alternative is to bring a floor mattress for comfortable overnight crossings.
  
  

Bibliography

ADEME. (2024). Impact CO₂. Impact CO₂. https://impactco2.fr/

Bardon, P., & Massol, O. (2025). Decarbonizing aviation with sustainable aviation fuels: Myths and realities of the roadmaps to net zero by 2050. Renewable and Sustainable Energy Reviews, 211, 115279. https://doi.org/10.1016/j.rser.2024.115279

Belcher, A. C., Workman, M. H. W., Jefferson, A., & Ostrovnaya, A. (2025). Aviation sector decarbonisation as a case of deep uncertainty: The need for an integrative, exploratory, and interdisciplinary approach. Energy Research & Social Science, 127, 104158. https://doi.org/10.1016/j.erss.2025.104158

Carbone 4. (2024). Documentation, votre simulateur d’empreinte carbone—Nos Gestes Climat. https://nosgestesclimat.fr

Ciers, J., Mandic, A., & Toth, L. D. (2019). Correlation between academic performance and CO2 footprint of business air travel at EPFL: Is flying necessary for academic excellence?

Ciers, J., Mandic, A., Toth, L. D., & Op ’T Veld, G. (2018). Carbon Footprint of Academic Air Travel: A Case Study in Switzerland. Sustainability, 11(1), 80. https://doi.org/10.3390/su11010080

O’Neill, D. W., Fanning, A. L., Lamb, W. F., & Steinberger, J. K. (2018). A good life for all within planetary boundaries. Nature Sustainability, 1(2), 88–95. https://doi.org/10.1038/s41893-018-0021-4

Ritchie, H. (2024). Not the end of the world: How we can be the first generation to build a sustainable planet. Chatto & Windus.

Shukla, P. R., Skea, J., Reisinger, A., & IPCC (Eds). (2022). Climate change 2022: Mitigation of climate change. IPCC.