The University of Michigan conducted a comprehensive study that focuses on the carbon footprints of urban-grown fruits and vegetables, revealing a sixfold increase compared to conventionally grown counterparts. While this finding underscores a potential environmental concern, exceptions exist, such as lower carbon intensity for open-air urban-grown tomatoes and a narrowing emissions gap for air-freighted crops like asparagus.
How Urban Farming Can Mitigate Climate Impacts?
Jason Hawes, a doctoral student and co-lead author of the study, emphasises the study's potential for positive change in urban agriculture. He suggested that practitioners can mitigate climate impacts by cultivating greenhouse-grown or air-freighted crops and implementing changes in site design and management. This approach aligns with the broader goal of sustainable urban living, offering not only environmental benefits but also social, nutritional, and localised advantages.
Urban Farming v/s Conventional Farming
The meticulous comparison of low-tech urban agriculture sites with conventional methods reveals a significant carbon disparity: 0.42 kilograms of CO2e (carbon dioxide equivalent) per serving from urban agriculture versus 0.07 kg of CO2e per serving from conventional methods.
The study underscores the impact of key elements in urban farming, including infrastructure, supplies, and irrigation water, which contribute substantially to the overall carbon footprint.
The limited operational lifespan of urban farms contrasts sharply with conventional agriculture, which tends to be more efficient and challenging to compete with in terms of carbon footprint. Conventional farming practices, such as mono-cropping aided by pesticides and fertilisers, lead to larger harvests and a smaller carbon footprint per unit of produce compared to urban farming.
Ways to Enhance Carbon Competitiveness
The study further proposes three best practices to enhance the carbon competitiveness of low-tech urban agriculture. These include extending the lifespan of infrastructure, adopting "urban symbiosis" to repurpose material, and maximising social benefits. Prolonging the use of materials like raised beds and incorporating urban waste for agriculture can significantly reduce the environmental impact while recognizing the non-environmental benefits like improved mental health and social networks adds a holistic dimension to the appeal of urban farming.
