The increasing demand for time-efficient and low-emission delivery solutions has brought unmanned aerial vehicles (UAVs) to the forefront of research. While numerous studies identify UAVs as a promising alternative for electrified last-mile logistics, others highlight potential ecological drawbacks. To date, the underlying factors contributing to these divergent findings have not been systematically examined. This study conducted a comprehensive meta-analysis of the environmental impacts of drone delivery systems, focusing on the life cycle assessment (LCA) methodology. It systematically reviews existing literature on climate change (CC) and other environmental impact categories associated with various UAV components and life cycle stages using the PRISMA method and searches for the main environmental hotspots associated with delivery drones across their full life cycle. Results show significant variability in the environmental burdens attributed to different drone components, particularly batteries and electronic systems, influenced by their assumed weight shares. The study found that the relative impact of drone delivery compared to ground delivery is highly dependent on the inclusion of UAV production in the environmental assessment. Furthermore, this work addresses the question of the climate change impact over an entire drone life cycle according to the reviewed studies and how modelling assumptions and system boundaries influence the results. To enable consistent comparison across studies, the study introduced the functional unit (FU) of kg CO2-eq/kg*km. Ultimately, the findings highlight the importance of standardised LCA methodologies in UAV research to ensure consistent, interpretable and comparable sustainability evaluations.
Aster et al. (Mon,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: