Life cycle assessment of insect farming: a review

Insect rearing for food and feed has gained momentum as an emerging sector aimed at addressing global food security and enhancing sustainability. However, several environmental studies raised concerns and questioned this growing industry, especially in the European context. This review aims to systematically summarize the current available knowledge on Life Cycle Assessments (LCA) in insect production systems, evaluate how different LCA methods and production configurations influence the environmental and sustainability outcomes and determine major trends and knowledge gaps, emphasizing what is sufficiently robust and what needs a critical re-examination. A systematic review of the available literature of peer-reviewed case studies that employed LCA methodology for insect mass was performed. Data were extracted on key methodological aspects: functional units (e.g., insect biomass, protein, fat, waste treated), system boundaries (e.g., cradle-to-gate, cradle-to-plate), allocation methods (economic, mass, system expansion), impact assessment methods (ReCiPe, TRACI, CML, IPCC), and data sources (primary and secondary databases such as Ecoinvent and Agri-footprint). The review also considered production scale, insect species, geographical distribution, and end-use purposes. A SWOT analysis was also performed to assess the internal strengths and weaknesses, and external opportunities and threats of LCA applications in insect farming, presenting implications for future research and policy. Insects have several advantages over traditional livestock; nonetheless, comparability of LCA studies is challenged by methodological disparities, most notably in the way functional units, system boundaries, allocation procedures and impact assessment methods are defined. The strength of evidence is also restricted when considering data quality of direct emissions, energy consumption, water use, and nutritional content. Consequential LCA is still scarcely used, though it can help to capture market dynamics and system-wide consequences. Feed category, energy carriers, and technological processing exert influences on environmental performance, with waste-based feeding and replacement fossil energy with renewable energy sources as recognized sustainable options. Proximity of insect farms with related industry sectors, that produce adequate feedstock, while reducing feeding stuff transportation costs, can increase sustainability. Although insect farming is considered a potential and sustainable option for future food systems, its utmost potential can be reached only through consistent knowledge, data precision improvements and more widespread use of consequential approaches, being LCA an important tool to achieve the sustainability goals. The development of consistent tools to evaluate sustainability trade-offs, increase the regulations flexibility, and build markets, is critical to place insect farming as a viable, and resilient component of innovative food systems.