quired and consent identification. One main characteristic of the database is its transparency in reporting to enable individual assessment of data appropriateness and to support the plurality in methodological approaches. Outlook. Further work on the ecoinvent database may comprise work on the database content (new or more detailed datasets covering existing or new economic sectors), LCI (modelling) methodology, the structure and features of the database system (e.g. extension of Monte Carlo simulation to the impact assessment phase) or improvements in ecoinvent data supply and data query. Furthermore, the deepening and building up of international co-operations in LCI data collection and supply is in the focus of future activities.

In many regions and at the planetary scale, human pressures on the environment exceed levels that natural systems can sustain. These pressures are caused by networks of human activities, which often extend across countries and continents due to global trade. This has led to an increasing requirement for methods that enable absolute environmental sustainability assessment (AESA) of anthropogenic systems and which have a basis in life cycle assessment (LCA). Such methods enable the comparison of environmental impacts of products, companies, nations, etc, with an assigned share of environmental carrying capacity for various impact categories. This study is the first systematic review of LCA-based AESA methods and their applications. After developing a framework for LCA-based AESA methods, we identified 45 relevant studies through an initial survey, database searches and citation analysis. We characterized these studies according to their intended application, impact categories, basis of carrying capacity estimates, spatial differentiation of environmental model and principles for assigning carrying capacity. We then characterized all method applications and synthesized their results. Based on this assessment, we present recommendations to practitioners on the selection and use of existing LCA-based AESA methods, as well as ways to perform assessments and communicate results to decision-makers. Furthermore, we identify future research priorities intended to extend coverage of all components of the proposed method framework, improve modeling and increase the applicability of methods.

No abstract

Conclusion.The disposal phase should by default be included in LCA studies. The use of a material not only necessitates its production, but also requires its disposal. The created inventories and user tools facilitate heeding the disposal phase with a similar level of detail as production processes. The risk of LCA-based decisions shifting burdens from the production or use phase to the disposal phase because of data gaps can therefore be diminished. Recommendation and Perspective.Future improvements should include the modelling of metal ore refining waste (tailings) which is currently neglected in ecoinvent, but is likely to be relevant for metals production. The disposal technologies considered here are those of developed Western countries. Disposal in other parts of the World can differ distinctly, for logistic, climatic and economic reasons. The cross-examination of landfill models to LCIA soil fate models could be advantageous. Currently only chemical elements, like copper, zinc, nitrogen etc. are heeded by the disposal models. A possible extension could be the modelling of the behaviour of chemical compounds, like dioxins or other hydrocarbons.

Summary The concept of eco‐efficiency is increasingly being applied to judge the combined environmental and economic performance of product systems, processes, and/or companies. Ecoefficiency is often defined as the ratio of economic value added to environmental impact added. This definition is not appropriate for end‐of‐pipe treatment technologies because these technologies aim at improving the environmental performance of technical processes at the cost of financial expense. Therefore, an indicator for the assessment of end‐of‐pipe technologies has been proposed. This indicator, called environmental cost efficiency (ECE), is defined as the ratio of net environmental benefits to the difference in costs. ECE is applied to four end‐of‐pipe technologies for the treatment of municipal solid waste: sanitary landfill, mechanical‐biological treatment, modern grate incineration, and a staged thermal process (pyrolysis and gasification). A life‐cycle assessment was performed on these processes to quantify the net environmental benefit. Moreover, the approximate net costs (costs minus benefits) were quantified. The results show that, relative to grate incineration, sanitary landfills and mechanical‐biological treatment are less costly but environmentally more harmful. We calculated the ECE for all combinations of technologies. The results indicate that the staged thermal process may be the most environmentally cost‐efficient alternative to all other treatment technologies in the long run, followed by mechanical‐biological treatment and grate incineration.