Land-use-driven biodiversity impacts of diets—a comparison of two assessment methods in a Finnish case study

Abstract

Abstract Purpose Agricultural land use and land-use change, especially from forests to agricultural land, to satisfy growing demand for food and feed, is a major cause of global biodiversity loss. International trade connects food consumption to land use across the world, leading consumption in one area to affect ecosystems elsewhere. However, methods for evaluating the effects of food consumption on biodiversity are still under development. Here, we evaluate two recent land-use-based biodiversity life cycle impact assessment methods, using the Finnish diet as a case study. Methods Two different land-use-based biodiversity impact assessment methods (Chaudhary and Books 2018; Kuipers et al. 2021) were used to evaluate the biodiversity impacts of five dietary scenarios: the current Finnish diet and four alternative scenarios that involve a gradual reduction in the intake of foods of animal origin. The assessment was conducted using the previously developed FoodMin model. The model assesses the climate impact and nutritional quality of diets based on 90 food product groups. The countries of origin for each product group, as well as the land occupation and land-use change associated with the products, were determined using five-year averages from national import and international yield and land-use change statistics. Results and discussion The results showed that the biodiversity impacts vary depending on the assessment method used, with the difference in the dietary impacts being 60-fold in magnitude depending on the method. Most of the impacts were related to land-use change, which was linked especially to production of feeds, leading to the dietary impacts being reduced with intake of foods of animal origin. The occupation impacts were associated with different food groups than those of land-use change and were higher than the land-use change impacts for beverages, and sugars and sweets. Trade played a significant role in biodiversity impacts of diets, with over 85% of impacts being linked to imported foods and feeds. Conclusions and recommendations A comparison of the two assessment methods for the biodiversity impact of diet scenarios showed that results obtained with these methods should not be compared in absolute terms. Also, on a product-level basis, the methods lead to different relative results, and the choice of method can affect which products appear the most burdensome. The assessment also showed that land-use change had a greater impact than land occupation. Thus, ignoring the impacts of land-use change, particularly in feed production, might underestimate the contribution of animal-source foods. Hence, both factors should be considered in future LCAs. Further research is also needed to develop and unify the biodiversity impact assessment methods, including the clarification of units, improving the accuracy of land-use change methodology, and analyzing the impacts of various agricultural management practices.