Carbon Footprint Reduction by Transitioning to a Diet Consistent with the Danish Climate-Friendly Dietary Guidelines: A Comparison of Different Carbon Footprint Databases.

Dietary transitions are important for combating many of the environmental challenges humanity is facing today and reducing the global burden of disease. Different dietary patterns are associated with substantially different carbon footprints (CFs). This study aims to estimate the potential CF reduction on a transition from the current Danish diet to a plant-rich diet consistent with the Danish food-based dietary guidelines (FBDG) and to compare results obtained from the use of two different CF databases. Dietary intake data for adults aged 18-64 years from the national dietary survey 2011-2013 were used to calculate the CF of the current diet, and this was compared with the estimated CF of the plant-rich diet modelled for the FBDG. Calculations were carried out using an attributional life cycle assessment (LCA) database (AU-DTU data) and compared to calculations using a top-down hybrid consequential LCA database (BCD data). The transition from the current diet to the plant-rich diet showed a substantial estimated CF reduction of 31% with AU-DTU data, and a greater reduction with BCD data (43%). Ruminant meat reduction was the largest contributor to this CF reduction, especially with the use of BCD data, and other animal-based foods also contribute considerably to the CF reduction, especially with AU-DTU data. These results indicate that the choice of LCA methodology and CF database is important in estimation of dietary CF and for the development of guidelines to promote dietary change.

Delta Life Cycle Assessment of Regenerative Agriculture in a Sheep Farming System.

Regenerative agriculture is being used by a small number of innovative farmers in Australia and elsewhere, using a range of holistic methods that work with the land and climate, such as short duration time of controlled grazing with long rest periods for the paddock and higher proportions of aboveground biomass, to improve soil health and farm profitability. This paper uses a delta life cycle assessment, focusing only on the differences between regenerative and conventional production systems to assess the potential impact of regenerative agriculture on a full range of midpoint impact categories and end-point areas of protection for an extensive sheep system in Australia. We assess the potential improvement to the water, carbon, and biodiversity footprints of sheep production, and find that regenerative agriculture has the potential to improve environmental performance compared with current industrial agricultural practices. In particular, there seems to be considerable potential to offset a significant proportion of the on-farm climate change impacts through a combination of biosequestration in soils and aboveground biomass and using harvested biomass to offset fossil fuel use. The assessment highlights the need for additional data to confirm the findings and the potential contribution that regenerative agriculture can make to sustainability of ruminant livestock production. Integr Environ Assess Manag 2020;16:282-290. © 2019 SETAC.