Comparing the carbon footprints of urban and conventional agriculture

Jason Hawes (1) , Benjamin Goldstein (2) , Joshua Newell (1) , Erica Dorr (3) , Silvio Caputo (4) , Runrid Fox-Kämper (5) , Baptiste Grard (6, 7) , Rositsa Ilieva (8) , Agnès Fargue-Lelièvre (3) , Lidia Poniży (9) , Victoria Schoen (10) , Kathrin Specht (11) , Nevin Cohen (8)

1 University of Michigan [Ann Arbor]
2 McGill University = Université McGill [Montréal, Canada]
3 SADAPT - Sciences pour l'Action et le Développement : Activités, Produits, Territoires
4 School of Architecture and Planning, University of Kent, Canterbury, UK
5 ILS - Research Institute for Regional and Urban Development
6 Isara
7 AGE - Agroécologie et Environnement
8 CUNY - City University of New York [New York]
9 Faculty of Human Geography and Planning, Department of Integrated Geography, Adam Mickiewicz University, Poznań, Poland
10 Centre for Agroecology, Water, and Resilience (CAWR), Coventry University, Coventry, UK
11 ILS - Research Institute for Regional and Urban Development - ILS - Research Institute for Regional and Urban Development

Urban agriculture (UA) is a widely proposed strategy to make cities and urban food systems more sustainable. Until now, we have lacked a comprehensive assessment of the environmental performance of UA relative to conventional agriculture, and results from earlier studies have been mixed. This is the first large-scale study to resolve this uncertainty across cities and types of UA, employing citizen science at 73 UA sites in Europe and the United States to compare UA products to food from conventional farms. Results reveal that the carbon footprint of food from UA is six times greater than conventional agriculture (420 gCO2e versus 70 gCO2e per serving). However, some UA crops (for example, tomatoes) and sites (for example, 25% of individually managed gardens) outperform conventional agriculture. These exceptions suggest that UA practitioners can reduce their climate impacts by cultivating crops that are typically greenhouse-grown or air-freighted, maintaining UA sites for many years, and leveraging circularity (waste as inputs).

Mots clés: LCA; modelisation; urban farming; garden; impact

Mots clés: ACV; modélisation; ferme urbaine; jardin; impact

Domaines: Sciences du Vivant [q-bio]; Agronomie

Jason Hawes, Benjamin Goldstein, Joshua Newell, Erica Dorr, Silvio Caputo, et al.. Comparing the carbon footprints of urban and conventional agriculture. Nature Cities, 2024, ⟨10.1038/s44284-023-00023-3⟩. ⟨hal-04418573⟩