Integrating sustainability assessment tools with life cycle analysis for agroecological systems: A UK case study

Abstract

CONTEXTLife cycle analysis (LCA) is increasingly used to assess the environmental impacts of primary food production. As an alternative, impacts can be assessed at the farm level using holistic sustainability assessment tools. OBJECTIVEThe purpose of this study was to evaluate whether an integrated approach combining a “detailed and narrow” LCA with a “broad and shallow” sustainability assessment could help integrate socioeconomic and ecosystem service evaluations in LCA by including a wide range of impact criteria. METHODSTo address this overarching objective, we present results from whole-farm sustainability assessments using the Public Goods Tool (PGT), a tool developed in the United Kingdom (UK) by the Organic Research Centre, and cradle-to-farm-gate LCAs of beef, carrots and tomatoes for (i) a diverse agroecological case study farm (CSF) and (ii) a specialised agroecological production system. The use of the PGT enabled comparison with similar UK farm systems and was extended to develop biodiversity and social indices to complement the LCA. RESULTS AND CONCLUSIONSResults of the CSF demonstrated a relationship between environmental impacts and increased production efficiency, as the climate change impact per kg of product was strongly associated with higher yields, but this was less clear when impacts expressed per ha. The CSF produced less beef than the specialised system but more tomatoes and carrots, which reflects its higher labour input and less intensive production methods. The CSF generally used fewer external inputs, which decreased its overall impacts. Purchased feed contributed disproportionately to the water consumption of beef from the specialised system. PGT results highlighted the environmental benefits that can be delivered by ‘diverse’ agricultural systems and added detail to LCA results; for example the high labour input at the CSF helped generate social capital whilst partially explaining the reduced emissions from tractor operations modelled in the carrot LCA. SIGNIFICANCEWe conclude that LCA may not be the most suitable tool to consider these wider aspects of sustainability and can only provide an estimate of environmental impacts. LCA helps understand which parts of the food system have the greatest impacts, and how they could become more sustainable, but it cannot determine sustainable agriculture alone. The addition of rapid farm-level multi-criteria sustainability assessment tools can complement the LCA results, help reveal ‘blind spots’, and encourage adoption by farmers.