Università della Tuscia, Dipartimento di Economia, Ingegneria, Società e Impresa, via del Paradiso 47, 01100 Viterbo, Italy.
Università degli Studi di Milano, Dipartimento di Scienze Agrarie e Ambientali, via Celoria 2, 20133 Milano, Italy.
Sci Total Environ. 2023 Dec 20;905:166845. doi: 10.1016/j.scitotenv.2023.166845. Epub 2023 Sep 12.
One popular methodology for assessing the environmental impact of livestock sector is Life Cycle Assessment (LCA), that quantifies the environmental impact of a product. Ecological Footprint (EF) performs an environmental sustainability assessment, by comparing the demand for natural capital by an economic activity with the offer of such capital within a certain territory. The aim of the study was the comparison between LCA and EF in assessing the environmental performances of milk production, assuming as case study three cattle farms with increasing levels of production intensity. Different metrics and functional units (FU) (i.e., fat and protein corrected milk, FPCM and hectare) were adopted for LCA analysis, considering some of the major impact categories. For greenhouse gases emissions, the Global Warming Potential (GWP) and the Global Temperature Potential (GTP) were considered. Both metrics were calculated assuming or not the distinction between biogenic and fossil methane. Adopting GWP as a metric, the results per kg of FPCM provided by the LCA highlighted a different trade off compared to the EF method: the farm with the highest productive intensity produced the least impactful milk in terms of GWP but had the most negative Ecological Balance (EB). The same occurred for the other impact categories. When GTP was adopted, or the hectare was considered as FU, the least intensive farm, characterized by greater feed self-sufficiency, became the one that produced the least impactful milk and had the least negative EB. The study highlighted the scientific significance of the integration between the two approaches for creating a comprehensive representation of the effects of human activities on the environment. The LCA method evaluates impacts intensity referred to a specific functional unit and its results are strongly influenced by productive efficiency; the EF method evaluates environmental sustainability of productions in relation to the territory that supports them.
一种评估畜牧业环境影响的常用方法是生命周期评估 (LCA)，它量化了产品的环境影响。生态足迹 (EF) 通过比较经济活动对自然资本的需求与特定领土内自然资本的供应来进行环境可持续性评估。本研究的目的是比较 LCA 和 EF 在评估牛奶生产的环境绩效方面的差异，假设三个奶牛场的生产强度不断提高。采用不同的指标和功能单位 (FU)（即脂肪和蛋白质校正奶，FPCM 和公顷）进行 LCA 分析，考虑了一些主要的影响类别。对于温室气体排放，考虑了全球变暖潜能 (GWP) 和全球升温潜能 (GTP)。这两个指标都是在假设或不区分生物源和化石甲烷的情况下计算的。采用 GWP 作为指标，LCA 每公斤 FPCM 的结果与 EF 方法相比提供了不同的权衡：生产强度最高的农场生产的牛奶在 GWP 方面造成的影响最小，但生态平衡 (EB) 最负。其他影响类别也是如此。当采用 GTP 或公顷作为 FU 时，最不密集的农场，其特点是饲料自给率更高，成为生产牛奶对环境影响最小、生态平衡 (EB) 最负的农场。这项研究强调了将两种方法相结合以创建人类活动对环境影响的综合描述的科学意义。LCA 方法评估与特定功能单位相关的影响强度，其结果受生产效率的强烈影响；EF 方法评估与支持它们的领土有关的生产的环境可持续性。
