Sustainability of ICT4S 2026

Introduction

The ICT4S conference series has from its beginning in 2013 had an interest in the environmental impact of the conference, and in this year we have focused our presentation on the climate impact.

In 2023, the organisers in Rennes were the first to also have a dedicated web page on Sustainability. The conference in Stockholm 2024 continued and developed that practice. During the planning of this years conference, the two sustainability chairs, with support from two colleagues, have written a paper on climate impacts of conferences, with data from ICT4S in Stockholm 2024 and the SCORAI Europe conference in Lund 2025. At the time of ICT4S 2026, the paper is under revision after a first round of major revisions.

The data from ICT4S 2024 and SCORAI 2025 is clear – from a climate perspective what matters are the flights to the conferences, and especially the intercontinental flights. The potential contributions to climate effects of conferences that are usually brought up in the literature are:

• Transport
• Food and catering
• Conference material
• Digital communication

However, at ICT4S conferences, food is usually vegetarian, and therefore, the contribution is probably on average negative, since some of the participants will eat less resource intensive food during the conferences days. It could be that the many servings of coffee and other catering leads to slightly more climate impact than the average day for the participants, but the total extra impact from ICT4S-catering is low.

When it comes to conference material, the ICT4S 2026 did print the program but again, the impact of this is hardly measurable in relation to the travel impacts.

In the paper mentioned above, the climate impact of the hybridization during ICT4S 2024 and SCORAI Europe 2025 were calculated. The conclusion was that the impact was below 0.01 %, thus, hardly measurable. This gives an idea of the large differences in impact from travel and hybridization, and indicates that reducing footprint for hybridization should probably not be a focus area.

Before continuing to discussing results of the travel to the conference, we also note that the local transport during ICT4S 2026 in Bern was very low, since the distances in Bern were very short for most participants, leading to mainly walk being used during the week. Thus, impact from local transport may have been negative, since probably some of the participants would have used car, had they been home. In any case, the impact is small.

Since transport to the conference is such a dominating factor for total conference emissions, we put quite some efforts into creating data on them. At ICT4S 2024, participants were asked to fill out their planned transport mode when registering. This method was further developed for the SCORAI Europs 2025 conference, when a climate calculator from travel.co2 was added to the registration. This way, we had quite detailed information regarding the particpants planned travel to and from that conference. A very similar method was used for ICT4S 2026.

Transport

The total GHG-emissions from ICT4S 2026 were 0.25 tonnes/participant. This is slightly higher than the emissions from ICT4S 2024 in Stockholm and from SCORAI Europe 2025 in Lund. The factor that explains this is that there were proportionally more inter-continental flights to ICT4S 2026 than to the other two conferences, even if the emissions were still low in comparison to many other conferences. We have found emissions between 0,23 and 2.6 tonnes per participant in 23 other conferences reported in the literature (Höjer et al, submitted).

We could also see that the share of intra-continental flights compared to long-distande train was lower in Bern than in Lund, and Lund had a lower share than Stockholm. This seems reasonable as an effect of Bern being easily reachable by train from more locations than Lund and even more so than Stockholm.

A discussion that we think is more and more needed is why we go to conferences. The data from ICT4S 2026 shows that emissions were high for those coming from over-seas, but this is not to be seen as a suggestion that we should not have intercontinental travellers to conferences. Instead, we hope it will lead to discussions on how much we need to fly and whose responsibility it is. Saying that long-distance travel is a problem, does not mean that we should stop flying. But It does suggest that there may be a limit to how much flying is reasonable.

We summarise thoughts from this years discussions in the follwing questoins, to be further discussed in all communities.

Are GHG-emissions from conferences a problem to discuss?

• If not – how can they be defended?
• If yes – how can they be reduced?
• Through more hybrid participation?
• Fewer conferences/researcher?
• Regional hubs?
• …?

Who should act to reduce emissions?

• Authorities through general regulations/incentives?
• University management (e.g. through internal regulations)
• Those who take decision regarding location of the conferences?
• Conference organisers?
• Individual researchers?

In the following graphs, we present some data regarding the greenhouse gas emissions from ICT4S 2026

For more info regarding method and results from ICT4S 2024 and SCORAI Europe 2025, see Höjer, Lehner, Coroama, Schien Lowering the climate impact from academic conferences – lessons learned from two Swedish cases, revised version submitted in June 2026.