Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122, Piacenza, Italy.
Research Group on EcoIndustrial System Analysis, Department of Environmental Science, Aarhus University, Frederiksborgvej 399, Postboks 358, DK-4000, Roskilde, Denmark; Aarhus University Centre for Circular Bioeconomy, Denmark.
J Environ Manage. 2021 Dec 15;300:113713. doi: 10.1016/j.jenvman.2021.113713. Epub 2021 Sep 20.
Food production and consumption have been recognized as a major source of environmental impacts. To ensure food security and a sustainable food system, dietary changes have been identified as one of the valuable strategies to reduce impacts on the environment while promoting human health. The vast majority of scientific literature has been focused on the effects of food consumption on climate change while neglecting to assess the degree of water scarcity impacts due to water consumption embodied in food. The research paper investigates the nexus between food consumption and impacts on water consumption adding important findings to a more recent growing body of studies estimating the water footprint (WF) of different dietary scenarios. This study uses the Water Footprint Network methodology and the AWARE (Available Water REmaining) characterization model to assess both the WF and the blue WSF (water scarcity footprint), respectively, of four Danish diets: standard, carnivore, vegetarian and vegan. In order to make them comparable, a total intake of 2000 kcal person day was set as energetic reference for all the diet scenarios considered. Using detailed trade and production data of agri-foods, we were able to assess the location of primary production and consequently to reveal countries mainly affected by water scarcity associated with import to satisfy Danish diets consumption. We found that while the vegan scenario scored the best environmental profile requiring 1489 L/cap/day calculated with the volumetric WF approach, it has the largest potential impacts on blue WSF of 10,477 L/cap/day. This study has shown that more than 90% of impacts on water consumption occur outside the national borders, as a consequence of large quantities of fruits and nuts imported by countries already threatened by high water scarcity conditions such as USA and Mediterranean regions. This methodological approach may be used to compare environmental performances of recommended dietary guidelines and to assess impact scenarios of new trade policies, protecting local water scarcity levels.
粮食生产和消费已被确认为环境影响的主要来源之一。为了确保粮食安全和可持续的粮食系统，饮食变化已被确定为减少对环境影响同时促进人类健康的有价值策略之一。绝大多数科学文献都集中在食物消费对气候变化的影响上，而忽略了评估由于食物消费所包含的用水量对水资源短缺的影响程度。本研究论文探讨了粮食消费与水资源消耗之间的关系，并为最近越来越多的研究估计不同饮食情景的水资源足迹（WF）提供了重要发现。本研究使用水资源足迹网络方法和可用水剩余（AWARE）特征化模型，分别评估了丹麦四种饮食的 WF 和蓝水足迹（WSF）：标准饮食、肉食饮食、素食饮食和纯素饮食。为了使它们具有可比性，设定了 2000 千卡/人天的总摄入量作为所有考虑的饮食情景的能量参考。使用农产品和食品的详细贸易和生产数据，我们能够评估初级生产的位置，并因此揭示出主要受进口以满足丹麦饮食消费的水资源短缺影响的国家。我们发现，虽然纯素饮食情景的环境状况最佳，按体积 WF 方法计算，人均需水 1489 升/天，但它对蓝水 WSF 的潜在影响最大，为 10477 升/天。本研究表明，超过 90%的水资源消耗影响发生在国界之外，这是由于美国和地中海等已经受到高水资源短缺条件威胁的国家大量进口水果和坚果所致。这种方法可以用来比较推荐的饮食指南的环境绩效，并评估新贸易政策的影响情景，以保护当地的水资源短缺水平。
