ALBERT

Description: Feeding a growing, increasingly affluent population while limiting environmental pressures of food production is a central challenge for society. Understanding the location and magnitude of food production is key to addressing this challenge because pressures vary substantially across food production types. Applying data and models from life cycle assessment with the methodologies for mapping cumulative environmental impacts of human activities (hereafter cumulative impact mapping) provides a powerful approach to spatially map the cumulative environmental pressure of food production in a way that is consistent and comprehensive across food types. However, these methodologies have yet to be combined. By synthesizing life cycle assessment and cumulative impact mapping methodologies, we provide guidance for comprehensively and cumulatively mapping the environmental pressures (e.g., greenhouse gas emissions, spatial occupancy, and freshwater use) associated with food production systems. This spatial approach enables quantification of current and potential future environmental pressures, which is needed for decision makers to create more sustainable food policies and practices.

Description: Food production, particularly of fed animals, is a leading cause of environmental degradation globally.1,2 Understanding where and how much environmental pressure different fed animal products exert is critical to designing effective food policies that promote sustainability.3 Here, we assess and compare the environmental footprint of farming industrial broiler chickens and farmed salmonids (salmon, marine trout, and Arctic char) to identify opportunities to reduce environmental pressures. We map cumulative environmental pressures (greenhouse gas emissions, nutrient pollution, freshwater use, and spatial disturbance), with particular focus on dynamics across the land and sea. We found that farming broiler chickens disturbs 9 times more area than farming salmon (∼924,000 vs. ∼103,500 km2) but yields 55 times greater production. The footprints of both sectors are extensive, but 95% of cumulative pressures are concentrated into 〈5% of total area. Surprisingly, the location of these pressures is similar (85.5% spatial overlap between chicken and salmon pressures), primarily due to shared feed ingredients. Environmental pressures from feed ingredients account for 〉78% and 〉69% of cumulative pressures of broiler chicken and farmed salmon production, respectively, and could represent a key leverage point to reduce environmental footprints. The environmental efficiency (cumulative pressures per tonne of production) also differs geographically, with areas of high efficiency revealing further potential to promote sustainability. The propagation of environmental pressures across the land and sea underscores the importance of integrating food policies across realms and sectors to advance food system sustainability.

Description: Feeding humanity puts enormous environmental pressure on our planet. These pressures are unequally distributed, yet we have piecemeal knowledge of how they accumulate across marine, freshwater and terrestrial systems. Here we present global geospatial analyses detailing greenhouse gas emissions, freshwater use, habitat disturbance and nutrient pollution generated by 99% of total reported production of aquatic and terrestrial foods in 2017. We further rescale and combine these four pressures to map the estimated cumulative pressure, or ‘footprint’, of food production. On land, we find five countries contribute nearly half of food’s cumulative footprint. Aquatic systems produce only 1.1% of food but 9.9% of the global footprint. Which pressures drive these footprints vary substantially by food and country. Importantly, the cumulative pressure per unit of food production (efficiency) varies spatially for each food type such that rankings of foods by efficiency differ sharply among countries. These disparities provide the foundation for efforts to steer consumption towards lower-impact foods and ultimately the system-wide restructuring essential for sustainably feeding humanity.

Description: Mariculture (marine and brackish water aquaculture) has grown rapidly over the past 20 years, yet publicly-available information on the location of mariculture production is sparse. Identifying where mariculture production occurs remains a major challenge for understanding its environmental impacts and the sustainability of individual farms and the sector as a whole. We compiled known mariculture locations and applied a simple production-allocation approach to map remaining global mariculture locations across 73 countries using the key determinants of distance to shore and ports, and average productivity (tonnage) of known farms. Our map represents 96% of reported fish and invertebrate mariculture production for 2017, but excludes algae which constitutes half of global mariculture production. We provide, for the first time, a publicly available spatial database of known and estimated mariculture locations. We discuss the utility and limitations of the existing data and our modeling approach, and highlight the key data gaps and future challenges for mapping aquaculture. Our results provide a vital resource for mariculture and environmental researchers, but we emphasize the need for a standardized, ground-truthed global spatial database of aquaculture locations and farm-level attributes (e.g., species, production type) to better understand the distribution of production and adequately plan for future growth.