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Reducing emissions related to duty travel: everybody’s contribution counts

New recommendations provide guidance for making environmentally responsible travel choices


In an era where the consequences of climate change loom ever larger, reducing carbon emissions is imperative. Among the various contributors to carbon emissions, duty travel – comprising conferences and other professional engagements – is an often-overlooked source.

Travel is embedded in CERN’s DNA, with worldwide collaborations that rely on exchanges between people from all around the globe. International exchange is a pillar of scientific progress at CERN and beyond, and is particularly important for early-career researchers and those from underrepresented geographic regions.

At the same time, CERN strives to be a role model for environmentally responsible research and, in this context, to minimise its carbon emissions wherever possible. Extensive professional travel, particularly by air, has an environmental impact. CERN’s third Environment Report shows that emissions arising from travel by personnel on the CERN payroll amounted to 151 tCO2e and 827 tCO2e in 2021 and 2022 respectively, a marked reduction compared with the 3330 tCO2e reported in 2019, before the COVID-19 pandemic. Most emissions result from air travel, mainly from long-distance flights. Although they represent just a small fraction of CERN’s total emissions, acting on them is important as, whatever the scale, all actions contribute to minimising CERN’s environmental impact.

A dedicated working group was set up in 2022 to make recommendations on reducing duty-travel emissions without having a detrimental impact on CERN. The recommendations, approved by the Enlarged Directorate on 23 January 2024, recognise and integrate the crucial importance of international collaboration for the advancement of CERN’s mission and research, while encouraging everyone to collectively set an example by reducing duty-travel-related carbon emissions. The recommendations are now available in the Admin e-guide duty travel pages.

Two overarching principles apply:

  1. 1. Reducing (air) travel by considering whether virtual participation, if available, provides similar value. This will help reduce the number of trips undertaken and contribute to reducing overall emissions. In particular, single-day trips requiring air travel should be avoided if virtual participation is possible.
  2. 2. Encouraging the use of ground transportation (particularly the train) for distances up to 700 km and as transport options allow, taking into account time- and cost-efficiency.

The recommendations are accompanied by a simple decision tree to help travellers reflect before they book their trips. In addition, the new online booking tool Egencia offers several different features, including a CO2 calculator for flights. Finally, the recommendations also cover event guidelines to encourage organisers and participants to make mindful, environmentally conscious choices. These take into account the importance of in-person interactions for building and maintaining collaborations and networks, particularly for early-career professionals. They aim to ensure that effective virtual participation is possible in all events hosted by the Organization and to minimise the amount of travel required without compromising collaboration, operations, goals and opportunities for personnel.