Design And Analysis Of Urban Food System Strategies For Multiple Sustainability Objectives

Abstract

Globally, there is rising interest in urban food systems. The food system encompasses the linkages between food production and consumption, the institutions who govern them, and the associated multiple sustainability outcomes of environment, economy, equity, human health and well-being (UNEP 2016). Cities thus require tools necessary to evaluate their food system in light of multiple sustainability objectives. This dissertation contributes to the literature by exploring food supply systems to cities from a trans-boundary perspective, linking multiple sustainability outcomes with actions that seek to address health and well-being within the city. We develop spatially disaggregated footprints to assess the multiple environmental impacts of water, GHG, land of both current urban food demand and future scenarios in multiple cities in India and the U.S. Key findings, organized by chapter are described below. The developed methods include five main steps of: 1) quantifying community-wide food demand (across homes, business, and industry); 2) estimating current local production; 3) estimating origins of production serving urban demand by agri-food type, quantifying spatially informed second order impacts (energy/GHG for irrigation); 4) quantifying current in- and trans-boundary environmental impact (energy/GHG, water, and land in Chapter 3). Applied to Delhi India, the analysis finds 10% of food by mass provided by local production. Further, food was the largest contributor to the city water footprint (accounting for both green and blue water) across infrastructure sectors. Food activities also shaped both in-boundary energy and water flows, particularly with the activities of cooking, and urban agriculture respectively. Chapter 3 uses a baseline from Chapter 2 to assess the contribution of city-scale actions to the overall food system’s environmental impacts (expanding to include land, GHG/energy, water). Applied to Delhi, India, the analysis demonstrates that city-scale action can rival typical food policy interventions that occur at larger scales, although no single city-scale action can rival in all three environmental impacts. In particular, ii improved food-waste management within the city (7% system-wide GHG reduction) matches the GHG impact of pre-consumer trans-boundary food waste reduction. The systems approach is particularly useful in illustrating key tradeoffs and co-benefits. For instance, multiple diet shifts that can reduce GHG emissions have trade-offs that increase water and land impacts. Improving the nutrition status for the bottom 50% of the population to the median diet is accompanied by proportionally smaller increases of water, GHG, and land impacts (4%, 9%, and 8%, systemwide): increases that can be offset through simultaneous city-scale actions, e.g., improved food-waste management. Chapter 4 analyses the food systems of 9 different cities within a single country (India). Taking into account differences of unique economies, socio-cultural characteristics and supply chains finds variation across food systems. This work connects urban food demand of consumers and producers incorporating differences of diet and socio- economic data with supply chain data with location of production to inform food miles and environmental impacts across cities. The ratio of consumers to producers largely shapes community-wide food demand, as well as substantial differences in residential diet. Differences of residential diet result in a variation of per capita resource use of 91% (range of 600-1,148; median of 771 m3/capita) for water, 35% for greenhouse gas (GHG) (1st and 2nd order impacts) (range of 0.29-0.45; median of 0.39 t CO2e per capita) and 141% for land (range of 0.12-0.28; median of 0.14 ha per capita). The computation of GHG impacts includes 2nd order impacts (emissions from irrigation), which exhibit even greater variation of 1326% across city per capita consumption (range of 0.02 to 0.29; median of 0.18 t CO2e) accounting for 6-63 % of total combined 1st and 2nd order GHGs. Levels of under-nutrition also vary by city, with the average residential diet of all but two cities (Pondicherry and Delhi) falling below the national recommendations for caloric intake. Three cities (Ahmadabad, Rajkot, Chennai) fall below the recommended protein intake, suggesting an important role for cities in national food security agendas. Food miles vary between cities, with the range of 196 (Pondicherry) to 1,137 (Chennai) km/ton. It is interesting to note, however, that even the highest, (Chennai) is less than U.S. average of >1600 km/t. We also evaluate supply chain risk in terms of the water scarcity of food producing regions that serve cities. The food producing locations on average, are less water scarce than the watersheds local to the urban environments, suggesting the water-intensive large-scale agriculture would be best located at a distance from urban centers, away from competing demands. Chapter 5 further expands the systems framework to the U.S. This work compares the Indian analyses of Pondicherry and Delhi with Minneapolis (Hennepin County) and New York City in the United States, illustrating the wide-spread applicability of these methods, despite differing levels of data availability and substantial differences of food system structure (i.e. differences of diets, levels of local production, processing, etc). This work combines bottom-up and top-down methods to overcome data limitations of the U.S food system, specifically with respect to community-wide flows encompassing homes, businesses, and industries as well as assessing the sensitivity of the supply chain to location of production. The baseline analysis of the four cities finds that 2nd order contribution to GHG impact of per capita food demand is much lower in the U.S. than India due to a higher contribution of meat emissions to total diet and greater energy efficiency of irrigation in the U.S. The scenario analysis provides similar findings across all four cities, with diet change and food waste management as key levers to mitigate environmental impact, though with the distinction of pre-consumer food waste playing a larger role than Indian cities, while post-consumer waste management is more important in U.S cities. Over all, the methods of this dissertation can inform policy in diverse cities despite some data limitations. This provides a timely contribution to cities eager for analysis tools that will help guide progress towards the many objectives of urban food systems.