This report covers the project “Materialåtervinning och klimatnytta – inventering och rekommendation av data” (The Climate Benefit of Material Recycling – Data Inventory and Recommendation), which started in November 2013 and will be complete in May 2015. The project is funded by the Nordic Council of Ministers, Återvinningsindustrierna, Stiftelsen Gästrikeregionens miljö, Norsk Industri and Norsk Returmetallforening. In addition to its primary focus on global warming potentials, the project identifies other environmental impact categories suitable for further study.

This project emanates from a perceived need for environmental data that can be used for communication in the recycling industry active in Norway, Denmark and Sweden. Its purpose is to compare emissions of greenhouse gases from material recycling and virgin material production, thus involving both material supply and recycling systems in the analysis. The method for estimating emissions and potential climate impact is based on life cycle assessment (LCA). The literature review is based on peer-reviewed journal articles, reports from authorities and industry associations, and inputs from stakeholders involved in the project. These stakeholders formed a reference group that supported the process in various ways throughout the project.

The reviewer was given the task to review the study report “Climate Benefits of Material Recycling – Inventory of Average Greenhouse Gas Emissions for Denmark, Norway and Sweden”.

This project emanates from discussions with recycling companies active in Sweden and their industry association, The Swedish Recycling Industries’ Association (Återvinningsindustrierna, ÅI). The discussion was partly fed by a pre-study performed at the University of Gävle in 2012, which pointed out that current figures used in Sweden for estimation or calculation of the environmental benefit of material recycling suffered from a number of shortcomings related to the underlying methodology (Hillman, 2013). Accordingly, the intention was to review and assess available studies to come up with a set of data that could be proposed for communicating the greenhouse gas performance of current recycling services, to be used by industry, organisations, and policy-makers.

Methods for collecting general information and data are described in sections 2.1 and 2.2. Then the methodology used to generate data in the studied literature – environmental life cycle assessment (LCA) – is introduced in section 2.3, and the system boundaries specific to the project are described in section 2.4.

There are a number of data choices that are central in life cycle assessments of waste treatment alternatives. Firstly, different technologies used in the processes pre-treatment, recycling and virgin material production imply differences in energy efficiency, emissions and the ratio between usable and recycled material. Secondly, the types and distances of transports affect the emissions from those parts of the life cycle. Finally, the type of heat and electricity used for the processes of pretreatment, recycling and virgin material production may have a large impact on the results. Also for complementary systems this may be crucial, for example when recycling is complemented with separate production of heat and electricity.

The following sub-section gives a short description of the primary characteristics and crucial process parameters for the different materials included in this study.

In this section, emissions data for a number of materials is analysed with respect to specific system boundaries, and averages are proposed (Sections 5.1–5.6). The materials for which data is considered useful and of adequate quality for the project were glass, aluminium, steel, plastic, paper and organic waste (see Section 3 for selection criteria). Data for secondary and primary production, and the calculated difference between them, are presented for all materials (cf. Figure 2). For plastic, paper and organic waste, incineration data is also included, and to be able to compare systems for material recycling and incineration, data for separate energy supply is added. This amount of energy supplied is the same as supplied from incineration (cf. Figure 3). Finally, the proposed averages for all materials analysed are presented and the collected results described (5.7).

The discussion is divided into five parts that require separate elaboration: Comparison with previous recommendations (6.1), Impact of energy use and energy mix (6.2), Geographical differences (6.3), Quality of materials for secondary production (6.4), and Data availability and uncertainty (6.5).

This project emanates from a perceived need for environmental data that can be used for communication in the recycling industry active in Norway, Denmark and Sweden. Its purpose is to compare material recycling with virgin material production, thus involving both material supply and recycling systems in the analysis.

Given the results presented in this report and the limitations of this kind of study, there are several possibilities for further study concerning the environmental benefits of material recycling. When considering possible continuation it should be acknowledged that potential climate impact is only one of several environmental indicators, though one that has been given much attention in recent years. However, there are other issues that are important in relation to recycling systems, such as resource depletion, energy use, eutrophication and toxicity. The alternative paths are briefly described below.

The studies that include other impact categories than global warming potential are marked with colours in the table below. Red colour indicates that indicators for energy and/or water use are included, while green colour indicates the inclusion of one or several other LCA impact categories (“LCA” or “Full LCA” indicates that many impact categories are included). For convenience, studies not containing relevant data and studies of informal character are not included in the list.