Hybrid LCA of French research activities reveals limited trade-offs for decarbonization strategies

The carbon footprint of research activities is becoming increasingly well-documented. However, the estimation of the environmental impacts of research beyond climate change remains scarce. As a result, it is difficult to assess the potential unintended consequences of climate change mitigation strategies. To address this problem, we collected activity data from a hundred research institutes in France and applied a hybrid life cycle assessment (LCA) method to estimate their impacts at the midpoint and endpoint level. As it happens for the carbon footprint (De Paepe et al., 2024), purchases dominate endpoint damages to human health and ecosystem quality, accounting for half of the damages in France. However, when extrapolating the data to carbon intensive mixes, electricity-associated damages equal or even exceed those of purchases. In addition to climate change, particulate matter, water availability and, possibly, human toxicity drive human health damages, and land occupation and acidification drive ecosystem quality impacts. Beyond these results, our methodology addresses the issues of hybridizing process-based and input-output-based LCA by comparing the inventory of emissions of the two methods. Finally, our analysis reveals that a decarbonization scenario combining five mitigation strategies reduces the per-capita carbon footprint by 29% (–2.2 t CO₂-eq). The most significant contribution comes from relocating purchases (–9.5%), followed by vehicle electrification (–8.6%), aviation reductions (–5.5%), and biomass heating (–5.3%), though the estimate for purchase relocation carries great uncertainty. In our model, this decarbonization scenario has a negative impact on just one midpoint indicator: land occupation biodiversity. Our work is thus a methodological contribution to organizational-LCA, provides a multicriteria estimate of the environmental impacts of French research and informs public decision-making on mitigation pathways for the research sector.