'Meet & fly: Sustainable transport academics and the Chock for elephant in the room' (vol 70, pg 64, 2018)

In this corrigendum, the authors want to provide more detail with respect to the calculations underpinning Table 1 and their limitations. Although Table 1 features “rough” or “back-of-the-envelope” estimations of travel-related carbon emissions for eighteen participants of a workshop, we believe some of our methodological choices and their implications were not sufficiently dealt with in the article. We estimated travel-related carbon emissions based on the workshop's registration list and based on the cities complying with the participants' affiliations. These choices have at least three shortcomings which were not explicitly mentioned as such in the article: (i) the workshop's registration list might differ from the attendance list; (ii) the city of affiliation might be different from that of the actual origin city; and (iii) some participants might have combined multiple events at the destination, causing the attribution of all emissions to this single workshop to be not that straightforward. In fact, we now know (i) there was one participant who had to return earlier and eventually did not make it to the workshop, (ii) there was at least one case where the city of affiliation was different from the actual origin city, and (iii) one of the participants combined several meetings in Europe by train, of which the actual workshop was only one. Although we framed our calculations as “rough” estimations and much debate is possible about how emissions should be calculated and attributed (see also footnote 1–3 of the article), it is clear that we could and should have verified these personal travel data more thoroughly and explicitly in order to arrive at a more precise emission assessment. The reader of the article should therefore bear in mind that the approach described above has resulted in inaccuracies, hence in approximations of the actual emissions at best. In this specific case, the reported emissions are likely overestimations for some of the participants. Besides these points, we want to echo the methodological concern raised in footnote 2 of the article. Although one might argue that it is the actual trips taken which cause environmental damage, we believe that an analysis of emissions should ideally start from the perspective of the individual academic (or research group), and that it should include all individual considerations made in order to decide to attend the event or not. After all, as argued by one of the reviewers of the article, it is entirely possible that the workshop was the one event per year that some of the participants allowed themselves to fly to. A quantitative assessment based on travel distances does not reveal these aspects. We regret any concern or offence we may have caused by not making clear these limitations of our data and methodology, and hope that this corrigendum now puts the record straight.