Browse e-KNOWBASE

Category FAQs Search : Urban Farming

Question: Environmental impacts and resource use of urban agriculture: a systematic review and meta-analysis

Answer: Environmental merits are a common motivation for many urban agriculture (UA) projects. One
powerful way of quantifying environmental impacts is with life cycle assessment (LCA): a method
that estimates the environmental impacts of producing, using, and disposing of a good. LCAs of
UA have proliferated in recent years, evaluating a diverse range of UA systems and generating
mixed conclusions about their environmental performance. To clarify the varied literature, we
performed a systematic review of LCAs of UA to answer the following questions: What is the scope
of available LCAs of UA (geographic, crop choice, system type)? What is the environmental
performance and resource intensity of diverse forms of UA? How have these LCAs been done, and
does the quality and consistency allow the evidence to support decision making? We searched for
original, peer-reviewed LCAs of agricultural production at UA systems, and selected and evaluated
47 papers fitting our analysis criteria, covering 88 different farms and 259 production systems.
Focusing on yield, water consumption, greenhouse gas emissions, and cumulative energy demand,
using functional units based on mass of crops grown and land occupied, we found a wide range of
results. We summarized baseline ranges, identified trends across UA profiles, and highlighted the
most impactful parts of different systems. There were examples of all types of systems—across
physical set up, crop type, and socio-economic orientation—achieving low and high impacts and
yields, and performing better or worse than conventional agriculture. However, issues with the
quality and consistency of the LCAs, the use of conventional agriculture data in UA settings, and
the high variability in their results prevented us from drawing definitive conclusions about the
environmental impacts and resource use of UA. We provided guidelines for improving LCAs of UA,
and make a strong case that more research on this topic is necessary to improve our understanding
of the environmental impacts and benefits of UA.

(Source: , 23 Sep 2021)

Source Link: https://iopscience.iop.org/article/10.1088/1748-9326/ac1a39/pdf