Carbon footprint of The European Society of Clinical Microbiology and Infectious Diseases conference in Amsterdam 2019 We calculated air travel distances and their associated carbon emissions for the 29th annual meeting of the European Society of Clinical Microbiology and Infectious Disease (ECCMID) that was held from 13 - 16 April 2019 in Amsterdam, the Netherlands. For all participants, information on country of origin formed the starting point for calculations; no details on the city of residence were shared. For countries with fewer than 100 participants, the capital city was assumed as point of departure. For countries with more participants, we arbitrarily divided participants over the largest 5 or 10 cities (depending on country’s geographical size), following the relative size of these largest cities.
We then conservatively assumed a direct flight while traveling; for long-haul flights this is likely to generate a conservative estimate of travel distance and carbon emissions since journeys may involve (multiple) connections. For all participants from The Netherlands, Belgium, Luxembourg and destinations in France, Germany, and the UK where the total one-way travel distance by train was within 6 hours, we conservatively assumed train travel. We then calculated distances between the presumed airport of departure and Schiphol International Airport in Amsterdam along a geodesic (great circle) path. This distance was translated to CO2 equivalent emissions (CO2e) using the mean emission factors per km and per passenger of three independent sources: the UK Department for Environment, Food and Rural Affairs (DEFRA), the French Agence de la transition écologique (ADEME) and the non-profit organization MyClimate. These emission factors take into account i) direct emission of radiatively active substances (e.g. CO2); ii) emission of chemical species that alter radiatively active substances; iii) emission of substances that trigger generation of aerosol particles or change natural clouds [1].
We conservatively assumed economy travel only; Premium Economy, Business and First-class seating are associated with ∼ 1.5, ∼ 2 and ∼ 3 higher emissions, respectively [1]. This resulted in in estimated CO2e emissions ranging from 0.5 kg/km for flights shorter than 350 km to 0.18 kg/km for long-haul flights. For train-travel, we assumed CO2e emissions of 22 g/km [1; 2]. CO2e were translated into average European household emissions assuming 14 tons of CO2 per household per year [3,4] and Artic ice lost by assuming 3m2 per ton of CO2 [5]. Time lost during traveling was calculated using average flight times reported by google and conservatively adding 2 hour per one-way journey for short flights and 3 hours for long-distance flights. Total travel kilometers were expressed as equivalent of journeys to the moon assuming an average distance of 384,400 km [6]; of note, this only refers to distance and not to fuel usage or CO2e emissions.
1.Barret D, 2020. Estimating, monitoring and minimizing the travel footprint associated with the development of the Athena X-ray Integral Field Unit. Exp Astron 49: 183–216. 2. Bousema T, Burtscher L, van Rij RP, Barret D, Whitfield K. The critical role of funders in shrinking the carbon footprint of research. Lancet Planet Health. 2022;6(1):e4-e6. 3. https://ec.europa.eu/eurostat Accessed December 2022. 4. milieucentraal.nl Accessed December 2022. 5. Notz D, Stroeve J. Observed Arctic sea-ice loss directly follows anthropogenic CO2 emission. Science. 2016;354(6313):747-750 6. https://spaceplace.nasa.gov/moon-distance/en/ Accessed December 2022.
