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Modern academic research is a highly globalised field, which means that, for many researchers, taking a flight to participate at a project meeting, give a talk at a conference or collect some data is an everyday occurrence. While the benefits of flying for academic purposes are undeniable, the greenhouse gas emissions associated with travelling tend to play a dominant role in the carbon budget of research institutions, often accounting for around half of the total greenhouse gas emissions generated1,2. As it becomes more and more apparent that in order to limit global warming to “well below 2°C” (the target in the Paris Agreement) our greenhouse gas emissions will have to reach net zero around mid-century, many universities have launched programs aimed at reducing emissions from travelling.

Some universities encourage researchers to avoid air travel by taking the train. Two different approaches are used to this end: First, air travel (especially short-haul) can be made less attractive by measures such as banning reimbursements for plane travel to any location easily reachable by train3 or making departments pay a mitigation fee for each business trip taken by their staff and faculty4. Second, travelling by train can be made more attractive, for example through allowing staff members to travel in first class or book single compartments for night trains. Other universities try to mitigate the effect of the air travel that cannot be avoided by supporting projects aimed at reducing carbon emissions around the world5,6 or even setting up their own carbon offsetting programs7.

While the University of Graz does not have a similar program implemented (yet), we, the Doctoral Programme Climate Change, decided to take our own measures to keep our travel emissions as low as possible (we know that avoiding travelling is the easiest way to do so, but that might not always be possible). Based on recommendations from other universities and discussions, we categorized each destination into three categories according to the effort it takes to get there from and back to Graz:

  • Low effort: Up to 7 hours train ride
    If a location can be reached by train in less than seven hours, we always take the train instead of travelling by plane. We also highly recommend this option to guest lecturers from “low effort-destinations”. “Low effort-destinations” include, among others, cities in Austria, Munich, Venice, Prague and Budapest.
  • Medium effort: 7 to 12 hours train ride
    If a train ride takes between seven and twelve hours, we recommend travelling by train whenever possible. In particular, night trains can provide a viable option to get to “medium effort-destinations”. Destinations include, among others, Berlin, Paris, Zurich and Bologna.
  • High effort: More than 12 hours train ride
    For destinations more than 12 hours away by train, we leave the choice of whether to take a plane or not to the person travelling, even though we nevertheless highly appreciate people travelling by train. However, even when travelling by plane, there are still are ways to minimize emissions. For instance, as most of the emissions from air travel arise during take-off and landing, we look for connections with as few stops as possible. Many times, it is not possible to get a direct flight to Graz, in which case we try flying to Vienna and continuing the journey by train. Similar options are considered as alternatives to other short-haul connecting flights.

While these criteria are quite straightforward, it took a lot of discussion to specify durations and requirements. Some of us would have liked to have more rigorous criteria, others pointed out the need to weigh the goal of reducing emissions against other legitimate interests (for instance, taking care of one’s family). We eventually agreed on 7 hours, since while it might sound much, travelling by plane can oftentimes take equally as long due to waiting times, queues at the airport, etc. Additionally, we added the “medium effort” category as a compromise between the groups. The long discussions involved in the decision-making process made us wonder what other people think about this topic: how many hours do you think is reasonable to ask a person for traveling by train and why?