International Journal of Life Cycle Assessment最新文献

Purpose: Agri-food systems across the globe are faced with the challenge of reducing their supply-chain emissions of greenhouse gases (GHGs) such as nitrous oxide (N₂O), carbon dioxide (CO₂), and methane (CH₄). For instance, 10% of the UK's GHG emissions are generated by agriculture, and ~ 56% of these are generated by livestock production. Numerous mitigation measures are being proposed to reduce GHG emissions from ruminants (representing 70 to 80% of total livestock emissions), particularly from beef cattle (presenting 30-40% of total livestock emissions).

Methods: To explore such potential, first, a business-as-usual (BAU) partial cradle-to-finishing farmgate scale modelling framework was developed. The BAU systems (i.e. steady-state productivity based on primary data from the North Wyke Farm Platform) were built using ensemble modelling wherein the RothC process-based soil organic carbon (SOC) model was integrated into the life cycle assessment (LCA) framework to conduct a trade-off analysis related to mitigation measures applicable to the study system. Potential mitigation measures were applied to the BAU scenario. The interventions assessed included: (i) extensification; (ii) adopting anaerobic digestion technology; and (iii) the use of the nitrification inhibitor DCD and substitution of fertiliser nitrogen with symbiotically fixed nitrogen from legumes.

Results: The partial carbon footprint for 1 kg of beef liveweight gain leaving the farmgate could be reduced by 7.5%, 12%, or 26% by adopting nitrification inhibitors, white clover introduction (pending establishment success), and anaerobic digestion for manure management, respectively.

Conclusions: The findings highlight the importance of including emissions beyond the farmgate level to analyse the carbon footprint of different management scenarios in order to assess the sustainability of agri-food production systems.

Supplementary information: The online version contains supplementary material available at 10.1007/s11367-025-02428-9.

Purpose: This study examines the climate impact of two surgical treatments for knee osteoarthritis, unicompartmental knee replacement (UKR) and high tibial osteotomy (HTO), also comparing conventional manufacturing (CM) with additive manufacturing (AM) for HTO. Factors beyond the implants themselves are considered that depend on the manufacturing method, such as surgical instruments and guides (jig), sterilisation, transport and anesthesia using data obtained first hand from manufacturers and a hospital.

Method: The relevance of the comparative results are maximised beyond a specific manufacturer's product by including uncertainty in the foreground and background life cycle inventories to represent uncertainty and variability of process characteristics, materials, and geographical location. The analysis is carried out in Brightway 2 using Ecoinvent inventory data and impacts are calculated across 18 mid-point categories. To consider possible improvement to the environmental impact of the surgical interventions, alternative electricity and surgical guide (jig) material scenarios are considered.

Results: The climate change impact of UKR, 37.9 (36.8-38.9) kg CO $_{2e}^{}$ , is highly significantly greater than that of the CM HTO, 10.7 (10.0-11.4) kg CO $_{2e}^{}$ , and AM HTO, 13.4 (13.0-13.7) kg CO $_{2e}^{}$ . The custom single-use surgical jig of the AM HTO and the use of potentially higher-carbon electricity leads to the AM HTO having an impact 1.25 (1.17-1.34) times higher than the CM HTO. But when low-carbon electricity is used and the surgical guide is made of stainless steel, this reduces to 0.78 (0.73-0.84). Initial screening of other lifecycle impact categories shows similar trends in most cases.

Conclusions: This study concludes that HTO has highly significantly lower climate change impact than UKR. AM HTO has the potential to further reduce the climate impact compared to CM HTO given low-carbon energy supply and further improvements in material choice and design optimisation. Challenges include limited availability in design skill-set for optimisation and higher cost for healthcare providers compared to CM HTO, although still lower than the cost of UKR. Our study highlights policy implications: along with being a solution for early treatment and yielding improved correction accuracy compared to CM HTO, personalised AM HTO also offers environmental benefits if designed and manufactured well.

Supplementary information: The online version contains supplementary material available at 10.1007/s11367-025-02473-4.

Purpose: Marine vertebrate populations have halved in the past decades, and invasive species are a major driver for this loss. While many model the spread of invasive species, a model to assess impacts of marine invasions, after introduction, has hitherto been missing. We present the first regionalized effect factors for marine invasions. These factors gauge differences in biodiversity impacts after invasions, enabling life cycle impact assessments to highlight biodiversity impacts from invasive species.

Methods: Alien species are species that are introduced by humans to ecosystems where they are not native. We combine data from the IUCN red list and the MarINvaders database to identify the potentially disappeared fraction of native species within each marine coastal ecoregion after alien introduction. The effect factors indicate the biodiversity impact from invasions per alien introduction. However, the IUCN red list has a performance bias between taxonomic groups, and both the IUCN and the harmonized citizen science data from MarINvaders have a geographic observer's bias. We address some of this bias by evaluating the number of threatened species per number of assessed species, as well as including machine-learning derived data for data deficient species.

Results and discussion: The resulting regional effect factors demonstrate high effects of invasions at high latitudes, which is in line with other findings. Our approach is founded on continuously growing citizen science data and so reflects the biases and uncertainties that follow with this uneven way of data sampling. On the other hand, the continuous data collection by citizen scientists will improve data coverage and thus improve the model. Vice versa, the model itself may be motivation for citizens scientists to collect more data.

Conclusion: The effect of marine invasions presented herein reflects current global information on the issue viewed in a perspective relevant for life cycle impact assessments. The developed effect factors can be used for further assessments that will aid decision-making for policies, industries, and consumers to work towards minimizing impacts of marine invasions and are developed to be compatible with different relevant fate factors.

Supplementary information: The online version contains supplementary material available at 10.1007/s11367-024-02325-7.