Challenging the food waste hierarchy.

Food waste is a multi-faceted and complex problem for urban circular economies with far-reaching environmental impacts. Effectively addressing this problem requires a comprehensive understanding of the food waste impacts on food, energy, water, and climate (FEWC) systems. Despite complex dynamics in the FEWC nexus, the most popular guidance for food waste management is the food waste hierarchy framework - which fails to account for ensuing impacts on all nexus elements. Aiming to optimise the framework, we adopt a participatory approach to develop the first comprehensive and replicable system dynamics model of the FEWC footprints of urban food waste throughout the agri-food supply chain. The quantitative model compares different food waste management options, and relevant policies in Bristol, UK (2018-2030). Unlike the guidance of the traditional waste hierarchy framework, our findings show that the preferability of each option can vary for each sector within the supply chain and for each FEWC element. Our results show that increasing food surplus redistribution in the supply sectors and reducing food waste in consumer sectors are the most preferable approaches to reduce the environmental impacts of food. Feeding food leftover to pets at household level also has a promising impact. Other options involve trade-offs between energy and carbon footprints, while having minimal impact on water footprint. We conclude that the traditional food waste hierarchy is too simplified to provide reliable guidance for environmentally sustainable food waste management and policy. Instead, we present an improved food waste hierarchy framework that accounts for the scale of preferability of each option for different sectors and different FEWC nexus elements. This novel framework thus provides more nuanced and more robust understanding of food waste impacts on the FEWC nexus in urban circular economies, thereby enabling the development of policy and management options that are optimised for environmental sustainability.

Sustainability assessment of short food supply chains (SFSC): developing and testing a rapid assessment tool in one African and three European city regions.

Recent literature demonstrates the contribution of short food supply chains (SFSC) to regional economies and sustainable food systems, and acknowledges their role as drivers for sustainable development. Moreover, different types of SFSC have been supported by urban food policies (UFP) over the few last years and actors from the food chain became part of new institutional settings for urban food policies. However, evidence from the sustainability impact assessment (SIA) of these SFSC in urban contexts is limited. Our paper presents an approach for the development of an SIA framework for different SFSC types. In addition, a practical application of the tool in four metropolitan regions (Berlin, London, Ljubljana and Nairobi) is tested. The conceptual development of the SIA framework is based on an in-depth analysis of existing SIA frameworks and methods for assessing the sustainability of agriculture, food chains and food systems and adapted to the specific needs of analysing SFSC in metropolitan regions. The operational value and utility of the framework and the tool were tested with social and natural scientists and local stakeholders. The assessment results demonstrate that SFSC seems to be more sustainable than the baseline (long global food chains) in the social dimension, but also feature specific strengths and weaknesses concerning their economic and environmental sustainability. This might give an indication for regional adjusted strategies and food chain innovations that improve the sustainability performance may be required. We found the tool useful for framing the dialogue between food chain actors, consumers and policy, because it makes benefits and trade-offs of the chain types operating in an urban-rural context more visible and communicable. Supplementary Information: The online version contains supplementary material available at 10.1007/s10460-021-10288-w.

Scale matters: the impact of organic farming on biodiversity at different spatial scales.

There is increasing recognition that ecosystems and their services need to be managed in the face of environmental change. However, there is little consensus as to the optimum scale for management. This is particularly acute in the agricultural environment given the level of public investment in agri-environment schemes (AES). Using a novel multiscale hierarchical sampling design, we assess the effect of land use at multiple spatial scales (from location-within-field to regions) on farmland biodiversity. We show that on-farm biodiversity components depend on farming practices (organic vs. conventional) at farm and landscape scales, but this strongly interacts with fine- and coarse-scale variables. Different taxa respond to agricultural practice at different spatial scales and often at multiple spatial scales. Hence, AES need to target multiple spatial scales to maximize effectiveness. Novel policy levers may be needed to encourage multiple land managers within a landscape to adopt schemes that create landscape-level benefits.