The Share of Research Infrastructure in Comprehensive Greenhouse Gas Budget for Five French Earth and Space Science Laboratories

To maintain global warming below 1.5°C the last IPCC report indicates global greenhouse gas (GHG) emissions should be reduced by 45% and 80% before 2030 and 2050, respectively, reaching an average of 2 tCO2e.pers-1.yr-1 on Earth. Although responsibilities vary, substantial reductions must be implemented across all aspects of society including academia. It can even be argued that, given its role in informing and alerting the public about climate and ecological change, the scientific community should have a leading role and demonstrate exemplarity in terms of reducing its environmental impact.Here, we present a broad-scope GHG budget of five laboratories of the Observatoire Midi-Pyrénées in France, in 2019. The studied laboratories comprise 90 to 260 staff members each, with study fields encompassing the solid Earth and the environment, the superficial biosphere, oceanography and glaciology, atmospheric physics and chemistry, as well as astronomy and astrophysics.To assess GHG emissions, we follow standard procedure (see Mariette et al., Environ. Res.: Infrastruct. Sustain., 2022) in which any ‘activity data’ quantifying the usage of a given resource (e.g., in kWh of electricity, or km travelled by aircraft) is multiplied with an appropriate ‘emission factor’ quantifying the unitary carbon footprint of the resource (e.g., electricity production or air-travel). The quantified budget thus includes infrastructures usage, professional travel and expenses and an estimation of the GHG footprint of research infrastructures, in particular scientific satellites. For the latter, we adapted the methodology of Knödleser et al. (Nature Astronomy, 2022), in which the GHG footprint is estimated based on the launch mass or cost of the mission and the share attributable to a given lab depends on the fraction of world author affiliated with the lab who have published articles referring to the satellite, as extracted from the Web of Science database.We find that emissions related to the lab facilities (electricity, heating, air conditioning and waste) and to individual habits (commuting and lunch meals) both reach about 1 tCO2e.pers-1.yr-1. Unsurprisingly, professional trips significantly contribute to the overall budget (2-6 tCO2e.pers-1.yr-1) and are largely dominated by long-haul air travel. However, services and equipment equally contribute with more than 3-5 tCO2e.pers-1.yr-1. These numbers vary between the studied labs but higher (lower) values for services and equipment tends to compensate for lower (higher) values for professional trips. Furthermore, for three out of five laboratories observational data from research infrastructures represents the largest share of the emissions, with about 5-10 tCO2e.pers-1.yr-1. Although this last estimate is subject to large uncertainty and shows discrepancies between research fields, it suggests that current GHG budget should include at least a first order estimate of the footprint of research infrastructures and adapt reduction strategies accordingly.