Fresh vegetables available on Northern European markets usually originate from a high number of sources. Environmental impacts for these goods typically arise from the resources used in production and the long-distance transport in air-conditioned trucks.
As such, environmental impacts are mainly attributed to direct energy consumption, water use, and nutrient supply. The aim of this paper was therefore to investigate and evaluate possible solutions to reduce the environmental impacts of vegetables available on urban markets in Northern Europe.
This study hypothesizes that for the production of lettuce and tomatoes in Northern Europe, a 4-step solution, i.e., 1) local production, 2) climate-controlled efficient greenhouses, 3) decoupled aquaponics, and 4) combined building architecture with waste heat and green waste reuse, will enable a low environmental impact.
Berlin was defined as a case example and used simulation results from a proven greenhouse simulator as input to a comparing life cycle assessment of fresh lettuce and tomato.
The assessment included a list of 12 midpoint environmental impact categories, e.g., global warming potential with the 100-year horizon (GWP100; kg CO2 eq.), depletion of fossil fuel reserves (FRS; kg oil eq.), and water use (WCO; m³ water).
Most impact categories decreased systematically when increasing the complexity of the local vegetable production.
Compared to the mix of vegetables from different locations available on the market, the complete 4-step solution reduced WCO from water consumption to water-saving: i.e., from 14.2 L or 3.3 L to −10.1 L or −0.21 L per package of 500 g tomatoes or 150 g lettuce, respectively.
GWP100 and FRS were below the values of the available market mix, e.g., GWP100 decreased with 8.7% in tomatoes and 49.9% in lettuce. In conclusion, with the right set-up, local vegetable productions in urban regions can surpass the imported mix on environmental performance in Northern Europe.
Source: Körner, Oliver & Bisbis, Mehdi & Baganz, Gösta & Baganz, Daniela & Staaks, Georg & Monsees, Hendrik & Goddek, Simon & Keesman, Karel. (2021). Environmental impact assessment of local decoupled multi-loop aquaponics in an urban context. Journal of Cleaner Production. 313. 127735. 10.1016/j.jclepro.2021.127735.