Executive summary Background The European Commission is preparing a "Thematic Strategy for the Sustainable Use of Natural Resources", the so-called "resources strategy". A first Communication on this was adopted by the Commission in October 2003 (COM 527, 2003), and the strategy is planned to be completed in 2005. The general aim of the resources strategy is "to develop a framework and measures that allow resources to be used in a sustainable way without further harming the environment". Objectives and scope The present report aims to support the development of the resources strategy by extracting and assessing the science-based evidence from eight recent studies that have been identified as relevant for understanding the environmental implications of resource use: * Labouze E, Monier V, Puyou J-B (2003). Study on external environmental effects related to the life cycle of products and services. BIO Intelligence Service and O2 France for the European Commission, Directorate General Environment. * Moll S, Acosta J, Villanueva A (2004). Environmental implications of resource use - insights from input-output analyses. Copenhagen: European Topic Centre on Waste and Material Flows. Draft manuscript, January 2004. * van der Voet E, van Oers L, Nikolic I (2004). Dematerialisation: not just a matter of weight - Development and application of a methodology to rank materials based on their environmental impacts. Leiden: Centre for Environmental Studies at Leiden University. CML report no. 160. * Phylipsen D, Kerssemeeckers M, Blok K, Patel M, de Beer J (2002). Assessing the environmental potential of clean material technologies. Institute for Prospective Technological Studies, Joint Research Centre (DG JRC), European Commission. Report EUR 20515 EN. * Nemry F, Thollier K, Jansen B, Theunis J (2002). Identifying key products for the federal product and environment policy. Final report. Institut Wallon de développement économique et social et d'aménagement du territoire ASBL and Vlaamse Instelling voor Technologisch Onderzoek (VITO) for the Belgian Federal Services of Environment, Department on Product Policy. * Dall O, Toft J, Andersen TT (2002). Danske husholdningers miljøbelastning (Environmental impacts of Danish households). Danish Environmental Protection Agency. (Arbejdsrappport 13). In Danish. * Nijdam DS, Wilting H (2003). Milieudruk consumptie in beeld (A view on environmental pressure on consumption) RIVM report 7714040004). In Dutch. * Rixt K, Falkena H-J, Benders R, Moll HC, Noorman KJ (2003). Household metabolism in European countries and cities - Comparing and evaluating the results of the cities Fredrikstad (Norway), Groningen (The Netherlands), Guildford (UK), and Stockholm (Sweden). Toolsust Deliverable No. 9. Groningen: Center for Energy and Environmental Studies, University of Groningen. The objectives of the present study were to analyse and evaluate this existing body of research with a view to identifying those materials and resources whose use has the greatest environmental impacts. This should result in * Conclusions on the present state of knowledge about the relationships between resource use, material flows and environmental impacts; and * Proposals on how to approach future research in support of developing the environmental aspects of an EU resources strategy. Nature of the studies The common feature of the eight considered studies is that they aim at determining the driving forces behind environmental impacts and resource consumption in the European Union or parts of it. The considered studies cover a range of methodological approaches, ranging from "top-down-approaches" where impacts are determined from National Accounts Matrix extended by Environmental Accounts (NAMEA) to "bottom-up-approaches" where environmental impacts are determined from Life Cycle Assessments (LCAs). While all studies have been made with other purposes than supporting the EU's resources strategy, it has been analysed in the present study to what extent the results of the studies can be applied in the EU's resources strategy. It turns out that all of the considered studies do contribute to our understanding of what are the environmentally most relevant types of resource use, through identifying relationships between environmental impacts and specific material flows or product groups within the production and consumption realms. The immediate possibilities the studies offer to establish direct links between indicators of resource use and indicators of environmental impact are more limited and additional research would be required to explore such links. Types of environmental impacts considered Environmental impacts are typically classified in a number of impact categories of which the following are covered by most of the considered studies: * Acidification * Climate change (global warming) * Ecotoxicity * Human toxicity * Nutrient enrichment (eutrophication) * Photochemical ozone formation (smog) * Stratospheric ozone depletion This set of well-established impact categories is commonly used and spans the main part of the environmental concerns that are presently generally considered important. Core activities at the origin of environmental impacts From analysing the data and models applied in the considered studies, it has been found that the by far largest share of the major environmental pressures affecting those environmental impact categories originate from a limited number of human activities referred to as "core activities": * Combustion processes * Solvent use * Agriculture * Metal extraction and refining * Dissipative uses of heavy metals * Housing and infrastructure * Marine activities * Chemical industry Second order driving forces of environmental impacts The core activities can be seen as first order driving forces for the environmental impacts, themselves driven by second order driving forces largely in the form of market forces, ultimately reflecting human demands. The second order driving forces are the main focus of the considered studies, which look at products or product groups, sometimes aggregated in need groups, or material flows induced by these products. Due to the great variation in applied methods and scopes, the results show a complex picture at the detailed level. However, at the more general level the studies reinforce each other in pointing to housing (construction and temperature regulation), transportation and food consumption as covering a large part of the most important consumption domains driving the environmental impacts and resource use in Europe. Correlation and causal relationships between resource use and environmental impacts With the exception of Moll et al. (2004), the considered studies do not analyse explicitly the correlation or causal relationships between indicators of resource use and indicators of environmental impact. However, from the underlying data and models it appears that, apart from environmental impacts directly related to resource extraction, there are only few instances where the relationship between resource use and environmental impacts are straightforward, and thus a more obvious target for policies aiming to reduce the environmental impacts from resource use: * The use of fossil fuels and "global warming potential" and "potential acidifying effect". * Use of specific metals, where there is a clear and linear relationship to environmental impacts from metal extraction and refining. A reduction in use of these metals will lead to a direct reduction in the associated impacts. * Area occupation, where it is the resource use itself that is of environmental concern. A reduction in area occupation will reduce the pressure on biodiversity. * Construction materials, where the resource use drives the waste stream, albeit mostly with a significant delay corresponding to the lifetime of the constructions. This list is, however, only indicative at this stage, and further systematic analysis would be needed to consolidate it (see below). It should be noted, furthermore, that even in those cases where causal relationships may be established it is unlikely that these relationships will be linear, especially at the aggregated level. Methodological alternatives Two main approaches have been applied in the studies considered: "bottom-up" and "top-down", each with specific advantages and disadvantages. The main advantage of the process-based "bottom-up" approach is its ability to treat each product or material separately in great detail. However, at the same time, it is notoriously incomplete when it comes to covering all activities involved in the production processes. In contrast, the main advantage of the input-output based "top-down" approach is its completeness. Since it takes its starting point in the national accounting matrices, it includes by definition all activities, materials and products in the economy. Its main disadvantage is the implicit assumption of homogeneity of the industries, i.e. that all products from an industry are assigned the same environmental impact per monetary unit. Methodological aspects are addressed in further detail in a following ESTO project: Evaluation of the Environmental Impact of Products (EIPRO). Knowledge gaps Based on the information and experience gathered from the eight studies and the critical assessment hereof, the following knowledge gaps with respect to development of the resources strategy have been identified: * Lack of systematic insights into the causal relationships between resource use and environmental impacts, and therefore of possibilities to give consolidated advice on priority needs in policy development. * Persisting weaknesses in environmental impact assessment models. Proposals to develop further the scientific input concerning the environmental aspects of the resources strategy Three different strategies for closing the knowledge gaps and developing further the scientific input to the resources strategy are proposed. 1. Exploit more thoroughly the models behind the existing studies with a focus on the relation between resources and environmental impacts. 2. Make a selection of the resources a priori seen as most relevant, and perform for each of them Substance Flow Analyses or other adequate resource-specific analyses. 3. Set up and use for the analysis a detailed European NAMEA (National Accounts Matrix extended by Environmental Accounts), specified from the outset in a way that takes into account the information needs of the EU's resources strategy (European top-down approach). The first strategy can probably be realised for a limited investment of 100.000+ Euros. It gives, however, not a structural information basis that can be easily updated. The investment in the last two strategies is probably of a similar order of magnitude (some two million Euros each alternative). Strategy 3 actually covers similar research as Strategy 2, but it is more systematic with the advantage that a structure is built that lasts and allows for regular and relatively cost-effective upgrading and updating. If a major investment will be made, the authors express a clear preference for Strategy 3. Improved and more comprehensive scientific input to the resources strategy following such lines is clearly recommended, but for effective policy development, it should be provided in close relation to parallel research and dialogue on: * A precaution-based approach to a resources strategy building on existing knowledge. * An approach based on the scarcity of resources in Europe and globally. * An approach building on equality among the different parts of the world. * The requirements of different methods of linking the state of the environment to resource consumption (through materials, product groups, consumption areas etc.). * The abatement strategies used in cases of resources where policies are already in place.