Open Access

The material stocks in the anthroposphere are growing faster than ever due to urbanization and growing per capita use. Owing to the growing potential insecurity of raw material supply the evaluation of resources gains increasing attention. Despite growing utilization of anthropogenic deposits, ‘urban mining’ has not yet sufficiently been supported by specific exploration methods. An exploration method for anthropogenic deposits is proposed and described by application to the copper stocks of Switzerland. The method combines material flow analysis with a bottom‐up analysis of material stocks. The stock composition and temporal characteristics are analysed by surveys and literature analysis. The stock amounts to 269±31 kg capita -1 for the year 2000. The retrospective data are used as parameters to construct a dynamic stock model, which is calibrated by historical trade statistics. The potential for drafting scenarios is discussed. The stock situation in Switzerland is reviewed and compared with that of other regions.

In this study, the relevance of psychological variables as predictors of the ecological impact of mobility behavior was investigated in relation to infrastructural and sociodemographic variables. The database consisted of a survey of 1991 inhabitants of three large German cities. In standardized interviews attitudinal factors based on the theory of planned behavior, further mobility-related attitude dimensions, sociodemographic and infrastructural characteristics as well as mobility behavior were measured. Based on the behavior measurement the ecological impact of mobility behavior was individually assessed for all participants of the study. In a regression analysis with ecological impact as dependent variable, sociodemographic and psychological variables were the strongest predictors, whereas infrastructural variables were of minor relevance. This result puts findings of other environmental studies into question which indicate that psychological variables only influence intent-oriented behavior, whereas impact-oriented behavior is mainly determined by sociodemographic and household variables. The design of effective intervention programs to reduce the ecological impact of mobility behavior requires knowledge about the determinants of mobility-related ecological impact, which are primarily the use of private motorized modes and the traveled distances. Separate regression analyses for these two variables provided detailed information about starting points to reduce the ecological impact of mobility behavior.

Scenarios for the future of renewable energy through 2050 are reviewed to explore how much renewable energy is considered possible or desirable and to inform policymaking. Existing policy targets for 2010 and 2020 are also reviewed for comparison. Common indicators are shares of primary energy, electricity, heat, and transport fuels from renewables. Global, Europe-wide, and country-specific scenarios show 10% to 50% shares of primary energy from renewables by 2050. By 2020, many targets and scenarios show 20% to 35% share of electricity from renewables, increasing to the range 50% to 80% by 2050 under the highest scenarios. Carbon-constrained scenarios for stabilization of emissions or atmospheric concentration depict trade-offs between renewables, nuclear power, and carbon capture and storage (CCS) from coal, most with high energy efficiency. Scenario outcomes differ depending on degree of future policy action, fuel prices, carbon prices, technology cost reductions, and aggregate energy demand, with resource constraints mainly for biomass and biofuels.

The enhanced use of biomass for the production of energy, fuels, and materials is one of the key strategies towards sustainable production and consumption. Various life cycle assessment (LCA) studies demonstrate the great potential of bio-based products to reduce both the consumption of non-renewable energy resources and greenhouse gas emissions. However, the production of biomass requires agricultural land and is often associated with adverse environmental effects such as eutrophication of surface and ground water. Decision making in favor of or against bio-based and conventional fossil product alternatives therefore often requires weighing of environmental impacts. In this article, we apply distance-to-target weighing methodology to aggregate LCA results obtained in four different environmental impact categories (i.e., non-renewable energy consumption, global warming potential, eutrophication potential, and acidification potential) to one environmental index. We include 45 bio- and fossil-based product pairs in our analysis, which we conduct for Germany. The resulting environmental indices for all product pairs analyzed range from -19.7 to +0.2 with negative values indicating overall environmental benefits of bio-based products. Except for three options of packaging materials made from wheat and cornstarch, all bio-based products (including energy, fuels, and materials) score better than their fossil counterparts. Comparing the median values for the three options of biomass utilization reveals that bio-energy (-1.2) and bio-materials (-1.0) offer significantly higher environmental benefits than bio-fuels (-0.3). The results of this study reflect, however, subjective value judgments due to the weighing methodology applied. Given the uncertainties and controversies associated not only with distance-to-target methodologies in particular but also with weighing approaches in general, the authors strongly recommend using weighing for decision finding only as a supplementary tool separately from standardized LCA methodology.

The United Nations climate change conference in Nairobi came at the end of a year where public awareness of climate change had reached unprecedented heights. Nonetheless, the conference proceeded with its usual diplomatic ritual, apparently unaffected by time pressure. While it did see some progress on important issues for developing countries such as the Adaptation Fund, the Nairobi Work Programme on Impacts, Vulnerability, and Adaptation to Climate Change, and the Clean Development Mechanism (CDM), on questions regarding the future of the regime it proved to be at best a confidence-building session that served to hear further views. More serious work on the future of the regime must therefore be expected of the next Conferences of the Parties. This article by Wolfgang Sterk, Hermann E. Ott, Rie Watanabe and Bettina Wittneben summarises the results of the conference.

For the option of “carbon capture and storage”, an integrated assessment in the form of a life cycle analysis and a cost assessment combined with a systematic comparison with renewable energies regarding future conditions in the power plant market for the situation in Germany is done. The calculations along the whole process chain show that CCS technologies emit per kWh more than generally assumed in clean-coal concepts (total CO2 reduction by 72-90% and total greenhouse gas reduction by 65-79%) and considerable more if compared with renewable electricity. Nevertheless, CCS could lead to a significant absolute reduction of GHG-emissions within the electricity supply system. Furthermore, depending on the growth rates and the market development, renewables could develop faster and could be in the long term cheaper than CCS based plants. Especially, in Germany, CCS as a climate protection option is phasing a specific problem as a huge amount of fossil power plant has to be substituted in the next 15 years where CCS technologies might be not yet available. For a considerable contribution of CCS to climate protection, the energy structure in Germany requires the integration of capture ready plants into the current renewal programs. If CCS retrofit technologies could be applied at least from 2020, this would strongly decrease the expected CO2 emissions and would give a chance to reach the climate protection goal of minus 80% including the renewed fossil-fired power plants.

Stabilizing the concentration of greenhouse gases (GHGs) in the atmosphere at levels compatible with sustainable development is the objective of the United Nations Framework Convention on Climate Change (UNFCCC) and an imperative for the global community. This is a daunting task, and its magnitude and costs are debated among scientists as well as policy-makers [Stern, 2006]. While most GHGs in the past have been emitted by developed countries and they are called upon to reduce their emissions and take responsibility for past mistakes, the contribution of developing countries in the future will reach similar magnitudes and is equally threatening for life on this planet. While developing countries have no commitments under the UNFCCC, they can still contribute voluntarily to climate change mitigation. The Global Environment Facility (GEF), as the financial mechanism of the UNFCCC and the leading multilateral entity promoting energy efficiency and renewable energy in developing countries and countries in transition, needs to provide significant support to these countries with respect to reaching a path of sustainable energy supply and sustainable economic and social development. Since 1992, the GEF has provided around US$ 2 billion in grants to support projects in the climate change focal area, leveraging over US$ 10 billion in total investments. Most of these funds have been spent on climate change mitigation projects. The GEF's mandate with respect to mitigation is to develop, expand, and transform markets for energy and mobility in developing countries, enabling them to grow toward and efficiently operate on a less carbon-intensive path. In doing so, the GEF applies the incremental cost principle and is restricted in the selection of technologies by a number of factors. Developing markets for sustainable energy technologies and sustainable framework conditions is a long-term effort, and it is hard to understand how effective the GEF is or can be in fulfilling this mission. This paper discusses the magnitude of the challenge, and demonstrates that this challenge is too big for the GEF's limited funds, and provides some suggestions for the GEF's programming for maximizing its impact on global GHG emissions by seeking out the most rewarding opportunities and maximizing replication of successful project examples by effective outreach and knowledge management.