Life-cycle energy assessment and carbon footprint of peri-urban horticulture. A comparative case study of local food systems in Spain

In a context of oil depletion and urban population growth, the development of peri-urban agriculture is of special socio-environmental and economic interest in the articulation of local food systems. The quantification and analysis of the environmental impact of peri-urban agriculture is a fundamental element for the design of policies aimed at agrifood and urban sustainability. Based on primary data, the life-cycle assessment of the energy and carbon footprint of peri-urban horticulture in Seville (Andalusia, Spain) was carried out from a cradle-to-consumption approach. Three cases were analyzed taking into consideration their differences in terms of farm management and local supply chain: two conventional farms that sell their output through a local distribution system, and a community-supported agricultural initiative that sells its organic vegetables directly to the consumers. The cumulative energy demand for the production, transport and distribution of 1 kg of fresh vegetables to the consumer in those three cases was estimated at between 2.22 and 5.13 MJ kg−1 with a carbon footprint of between 0.117 and 0.271 kg CO2-eq kg−1. Organic farming consumed approximately 42.5% less non-renewable energy per kilogram than conventional methods, whereas direct distribution reduces greenhouse gas emissions between 63.8 and 91.3% than local supply chains. The results of this work show how the combination of low-input production systems in the peri-urban area of Seville and local supply chains is an economically viable and low energy-impact option for the production and supply of fresh vegetables in the city, especially when the output is organic and the distribution direct.