Consideration of food wastage along the supply chain in lifecycle assessments: A mini-review based on the case of tomatoes.

In recent years, increased light has been shed on the large amounts of food wasted along the food supply chain (FSC). As lifecycle assessments (LCAs) are commonly used for estimations of environmental impacts from food production, it is relevant to investigate and discuss how such wastage is reflected in foodstuff LCAs. The objective of the present paper is to review a larger set of LCAs of foodstuff in order to (1) investigate if and how wastage along the FSC is addressed and (2) explore the importance of including wastage accumulated along the FSC in terms of environmental impacts. Twenty-eight LCA case studies and two review papers, focusing on tomatoes, were reviewed and greenhouse gas (GHG) emissions chosen as indicator for the second objective. Only one third of the studies consider wastage at some part of the supply chain, in many cases in an inconsistent manner, and only in nine cases were GHG emissions from wastage included in overall systems GHG emissions. In these, wastage accounts for between 2 and 33% of total contribution to climate change. Omitting wastage when conducting LCA of foodstuff could result in underestimations of environmental impacts. Occurrence of wastage along all phases of the supply chain should be acknowledged in order to estimate environmental benefits from prevention and to identify areas where strategies with the aim of reducing wastage could be most efficient.

Household food waste separation behavior and the importance of convenience.

Two different strategies aiming at increasing household source-separation of food waste were assessed through a case-study in a Swedish residential area (a) use of written information, distributed as leaflets amongst households and (b) installation of equipment for source-segregation of waste with the aim of increasing convenience food waste sorting in kitchens. Weightings of separately collected food waste before and after distribution of written information suggest that this resulted in neither a significant increased amount of separately collected food waste, nor an increased source-separation ratio. After installation of sorting equipment in households, both the amount of separately collected food waste as well as the source-separation ratio increased vastly. Long-term monitoring shows that results where longstanding. Results emphasize the importance of convenience and existence of infrastructure necessary for source-segregation of waste as important factors for household waste recycling, but also highlight the need of addressing these aspects where waste is generated, i.e. already inside the household.

Review of LCA studies of solid waste management systems--part II: methodological guidance for a better practice.

Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs.

Review of LCA studies of solid waste management systems--part I: lessons learned and perspectives.

The continuously increasing solid waste generation worldwide calls for management strategies that integrate concerns for environmental sustainability. By quantifying environmental impacts of systems, life cycle assessment (LCA) is a tool, which can contribute to answer that call. But how, where and to which extent has it been applied to solid waste management systems (SWMSs) until now, and which lessons can be learnt from the findings of these LCA applications? To address these questions, we performed a critical review of 222 published LCA studies of SWMS. We first analysed the geographic distribution and found that the published studies have primarily been concentrated in Europe with little application in developing countries. In terms of technological coverage, they have largely overlooked application of LCA to waste prevention activities and to relevant waste types apart from household waste, e.g. construction and demolition waste. Waste management practitioners are thus encouraged to abridge these gaps in future applications of LCA. In addition to this contextual analysis, we also evaluated the findings of selected studies of good quality and found that there is little agreement in the conclusions among them. The strong dependence of each SWMS on local conditions, such as waste composition or energy system, prevents a meaningful generalisation of the LCA results as we find it in the waste hierarchy. We therefore recommend stakeholders in solid waste management to regard LCA as a tool, which, by its ability of capturing the local specific conditions in the modelling of environmental impacts and benefits of a SWMS, allows identifying critical problems and proposing improvement options adapted to the local specificities.

Local strategies for efficient management of solid household waste--the full-scale Augustenborg experiment.

A system with property-close source-separation of thirteen different solid household waste fractions in a residential area in southern Sweden, including the implementation of new systems for source-separation of food waste, waste electric and electronic equipment, hazardous waste and fat, oils and grease was monitored over a 2-year period. Continuous weighing of disposed waste and repeated waste composting analyses were used to investigate recycling behaviour of households in the area and to monitor the composition of disposed waste. Results show that 34% of the total amount of generated waste was currently diverted to material recycling. The removal of recyclables from residual waste could be significantly increased, as more than 80% of all waste in the area (bulky waste excluded) was either covered by the Producer Responsibility Ordinances on packaging and newspaper or constitutes food waste suitable for biogas production. Food waste still represented almost 30% of all residual waste in the study area and was thus the fraction with the greatest potential (on weight basis) for increased source-separation.

Life cycle assessment of a household solid waste source separation programme: a Swedish case study.

The environmental impact of an extended property close source-separation system for solid household waste (i.e., a systems for collection of recyclables from domestic properties) is investigated in a residential area in southern Sweden. Since 2001, households have been able to source-separate waste into six fractions of dry recyclables and food waste sorting. The current system was evaluated using the EASEWASTE life cycle assessment tool. Current status is compared with an ideal scenario in which households display perfect source-separation behaviour and a scenario without any material recycling. Results show that current recycling provides substantial environmental benefits compared to a non-recycling alternative. The environmental benefit varies greatly between recyclable fractions, and the recyclables currently most frequently source-separated by households are often not the most beneficial from an environmental perspective. With optimal source-separation of all recyclables, the current net contribution to global warming could be changed to a net-avoidance while current avoidance of nutrient enrichment, acidification and photochemical ozone formation could be doubled. Sensitivity analyses show that the type of energy substituted by incineration of non-recycled waste, as well as energy used in recycling processes and in the production of materials substituted by waste recycling, is of high relevance for the attained results.

Property-close source separation of hazardous waste and waste electrical and electronic equipment--a Swedish case study.

Through an agreement with EEE producers, Swedish municipalities are responsible for collection of hazardous waste and waste electrical and electronic equipment (WEEE). In most Swedish municipalities, collection of these waste fractions is concentrated to waste recycling centres where households can source-separate and deposit hazardous waste and WEEE free of charge. However, the centres are often located on the outskirts of city centres and cars are needed in order to use the facilities in most cases. A full-scale experiment was performed in a residential area in southern Sweden to evaluate effects of a system for property-close source separation of hazardous waste and WEEE. After the system was introduced, results show a clear reduction in the amount of hazardous waste and WEEE disposed of incorrectly amongst residual waste or dry recyclables. The systems resulted in a source separation ratio of 70 wt% for hazardous waste and 76 wt% in the case of WEEE. Results show that households in the study area were willing to increase source separation of hazardous waste and WEEE when accessibility was improved and that this and similar collection systems can play an important role in building up increasingly sustainable solid waste management systems.