Die Kreislaufwirtschaft zielt unter anderem darauf ab, Abfall als Rohstoff für neue Produkte zu nutzen. Bei Ökobilanzen von Produkten stellt sich diesbezüglich die Frage, wie sich im offenen Kreislauf rezyklierter oder thermisch verwerteter Abfall bewerten lässt. Für die Bewertung von Produktsystemen sind zwei Allokationsmethoden üblich: Die Cut-Off Methode, welche den Einsatz von Recyclingmaterialien begünstigt und die Avoided Burden Methode, welche die Abgabe von recyclingfähigem Material begünstigt. Wir diskutieren diese beiden Methoden hinsichtlich ihrer Eignung zur Bewertung einer Kreislaufwirtschaft, gemessen an der europäischen Abfallhierarchie. Als Fallbeispiel dienen verschiedene End-of-Life-Szenarien für Glas und den Kunststoff Polypropylen, die wir mit Hilfe der Umweltindikatoren Material Footprint und Carbon Footprint bewertet haben. Als Ergebnis zeigt sich, dass die Anwendung von Avoided Burden im Fall einer thermischen Verwertung in einer Müllverbrennungsanlage problematisch ist. Zum einen ergibt sich in diesem Fall ein negativer Material Footprint, falls dadurch ein Steinkohlekraftwerk substituiert wird, zum anderen wird die Abfallhierarchie teilweise übergangen, da die thermische Verwertung günstiger erscheint als Recycling. Des Weiteren wurde herausgestellt, dass die oberste Priorität in der Abfallhierarchie, die Vermeidung, durch den Cut-Off Ansatz höher begünstigt wird, als durch die Avoided Burden Methode.
Biodiversity loss is widely recognized as a serious global environmental change process. While large-scale metal mining activities do not belong to the top drivers of such change, these operations exert or may intensify pressures on biodiversity by adversely changing habitats, directly and indirectly, at local and regional scales. So far, analyses of global spatial dynamics of mining and its burden on biodiversity focused on the overlap between mines and protected areas or areas of high value for conservation. However, it is less clear how operating metal mines are globally exerting pressure on zones of different biodiversity richness; a similar gap exists for unmined but known mineral deposits. By using vascular plants' diversity as a proxy to quantify overall biodiversity, this study provides a first examination of the global spatial distribution of mines and deposits for five key metals across different biodiversity zones. The results indicate that mines and deposits are not randomly distributed, but concentrated within intermediate and high diversity zones, especially bauxite and silver. In contrast, iron, gold, and copper mines and deposits are closer to a more proportional distribution while showing a high concentration in the intermediate biodiversity zone. Considering the five metals together, 63% and 61% of available mines and deposits, respectively, are located in intermediate diversity zones, comprising 52% of the global land terrestrial surface. 23% of mines and 20% of ore deposits are located in areas of high plant diversity, covering 17% of the land. 13% of mines and 19% of deposits are in areas of low plant diversity, comprising 31% of the land surface. Thus, there seems to be potential for opening new mines in areas of low biodiversity in the future.
Poor sustainability and increasing economic shortcomings in fossil raw material use besides further technical developments of substitutes lead to a growing potential for CO2-utilisation. Hence, we balanced CO2-based methane and methanol production in a life cycle assessment and identified CO2-utilisation as a greenhouse gas saving method. However, it requires a lot of renewable energy.
This review of sources has assessed existing evidence for economic benefits arising from activities fostering the use of vehicles that use electricity to power an electric motor. It is designed to support cities in their decision making and measure selection process. The article is one of 22 reviews published in this volume.
Cleaner vehicles
(2016)
This review of sources has assessed existing evidence for economic benefits arising from innovations or interventions that aim to improve the environmental performance of vehicles - such as enhancements to engine and vehicle technologies or improved fuels. It is designed to support cities in their decision making and measure selection process. The article is one of 22 reviews published in this volume.
In the future, the capacities of renewable SNG (synthetic natural gas) will expand significantly. Pilot plants are underway to use surplus renewable power, mainly from wind, for electrolysis and the production of hydrogen, which is methanated and fed into the existing gas pipeline grid. Pilot projects aim at the energetic use of SNG for households and transport in particular for gas fueled cars. Another option could be the use of SNG as feedstock in chemical industry.
The early stage of development raises the question of whether SNG should be better used for mobility or the production of chemicals. This study compares the global warming potential (GWP) of the production of fossil natural gas (NG) and carbon-dioxide (CO2)-based SNG and its use for car transport versus chemical use in the form of synthesis gas. Since the potential of wind energy for SNG production is mainly located in northern Germany, the consequences by a growing distance between production in the North and transport to the South of Germany are also examined.
The results indicate that CO2-based SNG produced with wind power would lead to lower GWP when substituting NG for both uses in either transport or chemical production. Differences of the savings potential occur in short-distance pipeline transport. The critical factor is the energy required for compression along the process chain.
Distributed cogeneration units are flexible and suited to providing balancing power, thereby contributing to the integration of renewable electricity. Against this background, we analysed the technical potential and ecological impact of CHP (combined heat and power) systems on the German minutes reserve market for 2010, 2020 and 2030. Typical CHP plants (from 1 to 2800 kWel) were evaluated in relation to typical buildings or supply cases in different sectors. The minutes reserve potential was determined by an optimisation model with a temporal resolution of 15 min. The results were scaled up to national level using a scenario analysis for the future development of CHP. Additionally, the extent to which three different flexibility measures (double plant size/fourfold storage volume/emergency cooler) increase the potential provision of balancing power was examined. Key findings demonstrate that distributed CHP could contribute significantly to the provision of minutes reserve in future decades. Flexibility options would further enhance the theoretical potential. The grid-orientated operating mode slightly increases CO2 emissions compared to the heat-orientated mode, but it is still preferable to the separate generation of heat and power. However, the impacts of a flexible mode depend greatly on the application and power-to-heat ratio of the individual CHP system.
The so-called "Semesterticket" is a special tariff for university students in Germany which enables them to use public transport in the area of their university. Semester tickets are financed in solidarity by the students: If a university runs a semester ticket, all students automatically have to buy a ticket for one semester (6 months), regardless of whether they want to use public transport or not. In return, the students can use public transport in the area of their university for a very low semester contribution as much as they want without purchasing any extra tickets. In Germany, the first semester ticket was introduced 25 years ago in Darmstadt (1991) as a result of student initiatives. Today, most German universities run a semester ticket.
This article describes the concept of semester tickets in Germany, their development over the time and presents empirical research data on student acceptance and the effects of semester tickets on mode shift to public transport and the reduction of car ownership.
Stockholm, Hamburg, Vitoria-Gasteiz, Nantes, Kopenhagen, Bristol, Ljubljana, Essen - das sind die Europäischen Umwelthauptstädte der Jahre 2010 bis 2017. Sie wurden in einem jährlichen europaweiten Wettbewerb von der Europäischen Kommission als Vorbildstädte ausgewählt. Sie zeigen aus Sicht der Europäischen Kommission, wie eine zukunftsfähige, umweltorientierte Stadtentwicklung im 21. Jahrhundert aussehen kann. Welchen EU-Benchmark markieren diese acht Städte für die Gestaltung eines klimaschonenden Personenverkehrs in der Stadt?
This article analyses drivers and barriers to returning and recycling mobile phones and their consideration in existing communication and collection campaigns.
This is an important issue based on the fact that the mobile phone market is growing rapidly. In 2015 there are nearly 7 billion global mobile cellular subscriptions. This means that, at least theoretically, everyone in the world has access to mobile communication services (ITU 2015). However, the production of mobile phones is linked to an increasing use of natural resources: the "ecological rucksack" of a mobile phone is equal to about 75 kg of resources (Nordmann et al. 2015); while the global recycling rate of mobile phones is under 10 per cent (Nokia 2008, Tanskanen 2012).
In order to adress this issue, the main factors that influence return and recycling behaviour (focussing on mobile phones) will be discussed in chapter 2 of this article. The theoretical analysis is based on the norm activation model by Ellen Matthies (2005). This analysis will be complemented by empirical data and findings generated in the research project "Return and use of old mobile phones", funded by the German Ministry of Education and Research (Wuppertal Institute for Climate, Environment, Energy/Institute for Advanced Sustainability Studies, 2012-2014). To conclude, we will identify and operationalise essential components of mobile phone communication and collection campaigns, based on the theoretical approach of Matthies, literature and empirical studies, in order to develop a set of criteria for analysing and rating such communication and collection campaigns.
The results show that economic incentives as well as education and communication play a very important role in initiating more sustainable behavioural patterns in the ICT sector. The role of emotional factors is often underestimated in the development of communication activities. In summary, successful mobile phone communication and collection campaigns require a combination of several institutional, economic, social and emotional factors.