Environmental performance of urban agriculture in the global south: A comprehensive literature review and life cycle analysis approach.

Abstract

Urban agriculture is increasingly recognized as a strategy to enhance food security, mitigate environmental impacts, and strengthen urban resilience, particularly in the Global South, where rapid urbanization and vulnerabilities in the food system present significant challenges. This study applies a four-phase methodology to evaluate the environmental performance of urban agriculture systems. First, a systematic review identifies environmental indicators and dominant assessment methods. Second, life cycle inventory data are compiled to benchmark carbon emissions, water use, and land demands across urban agriculture typologies. Third, spatial and nutritional benchmarks are developed to evaluate caloric content, productivity, and trade-offs by crop type and production method. Fourth, an empirical validation applies these benchmarks to metabolic data from an informal settlement in Lima, Peru, testing assumptions about productivity, land use, and emissions in dense urban settings. Results show that hydroponic systems provide the highest productivity (12 kg/m²/year) and the lowest land demand (0.8 m²/kg), but also generate the highest emissions (1.5–3.0 kg CO₂eq/kg). In contrast, peri-urban farms emit less carbon (0.6–1.2 kg CO₂eq/kg) and better integrate with existing land-use patterns but require more water (1500–3500 L/kg) and land (1.5–3.5 m²/kg). The Lima case shows that decentralized food circulation can match rooftop farming yields and that small-scale interventions could supply 17–27 % of local food flows. However, current assessment frameworks often overlook the interactions between spatial typologies, design criteria, water management, and system resilience, as well as key co-benefits such as stormwater retention, thermal regulation, and improved well-being. This study highlights the need for a more integrated framework that incorporates urban and architectural typologies alongside operational and social variables to guide sustainable urban agriculture in low-income urban areas.