Residential buildings and service sector buildings have an important contribution to climate change, directly via energy use in these buildings and indirectly through construction activities and... Show moreResidential buildings and service sector buildings have an important contribution to climate change, directly via energy use in these buildings and indirectly through construction activities and the production and disposal of buildings materials. In this paper, we introduce a model that looks at total global building stock for 26 regions between 1970 and 2050 and calculates the floor space and building materials both in new buildings and in demolished buildings. For residential buildings, we build upon the work of Marinova et al. (2019, this issue), who used a building material database to come up with scenarios for materials in the residential building stock. This paper adds two things. First, we introduce a new regression-based model for service building floor space, recognizing 4 different types of service-related buildings. Secondly, we use a dynamic stock model, based on lifetime distributions found in literature, to calculate the construction (inflow) and demolition (outflow) of building floor space for both residential and service-related purposes. We combine this with data from the building material database to come up with scenarios for the annual demand for construction materials worldwide as well as an estimation of the availability of waste materials after building demolition towards 2050. The model can thus be used to assess the potential for closing the material cycles in the construction sector, while distinguishing urban and rural areas explicitly. The results show that demand for construction materials will continue to increase in most regions, even in developed countries. Global demand for steel and cement for the building sector is estimated to be 769 Mt/yr and 11.9 Gt/yr respectively, by the end of the modelling period. This represents a respective growth of 31% and 14% compared to today. Drivers behind this are an expected growth of global residential building stock of about 50%, and a growth of about 150% in the building stock for services. Our model projects that by 2050, only 55% of construction-related demand for copper, wood and steel could potentially be covered by recycled building materials. For other materials the availability of scrap may be higher, reaching up to 71% of new demand in the case of aluminium. This means that in most regions urban mining cannot cover the growing demand for construction materials. (C) 2019 Published by Elsevier Ltd. Show less
Schipper, B.W.; Lin, H.C.; Meloni, M.A.; Wansleeben, K.; Heijungs, R.; Voet, E. van der 2018
Future global copper demand is expected to keep rising due to copper's indispensable role in modem technologies. Unfortunately, increasing copper extraction and decreasing ore grades intensify... Show moreFuture global copper demand is expected to keep rising due to copper's indispensable role in modem technologies. Unfortunately, increasing copper extraction and decreasing ore grades intensify energy use and generate higher environmental impact. A potential solution would be reaching a circular economy of copper, in which secondary production provides a large part of the demand. A necessary first step in this direction is to understand future copper demand. In this study, we estimated the copper demand until 2100 under different scenarios with regression and stock dynamics methods. For the stock dynamics method, a strong growth of copper demand is found in the scenarios with a high share of renewable energy, in which a much higher copper intensity for the electricity system and the transport sector is seen. The regression predicts a wider range of copper demand depending on the scenario. The regression method requires less data but lacks the ability to incorporate the expected decoupling of material use and GDP when the stock saturates, limiting its applicability for long-term estimations. Under all considered scenarios, the projected increase in demand for copper results in the exhaustion of the identified copper resources, unless high end-of-life recovery rates are achieved. These results highlight the urgency for a transition towards the circular economy of copper. Show less
Zijp, M.C.; Heijungs, R.; Voet, E. van der; Meent, D. van der; Huijbregts, M.A.J.; Hollander, A.; Posthuma, L. 2015
Sustainability assessments can play an important role in decision making. This role starts with selecting appropriate methods for a given situation. We observed that scientists, consultants, and... Show moreSustainability assessments can play an important role in decision making. This role starts with selecting appropriate methods for a given situation. We observed that scientists, consultants, and decision-makers often do not systematically perform a problem analyses that guides the choice of the method, partly related to a lack of systematic, though sufficiently versatile approaches to do so. Therefore, we developed and propose a new step towards method selection on the basis of question articulation: the Sustainability Assessment Identification Key. The identification key was designed to lead its user through all important choices needed for comprehensive question articulation. Subsequently, methods that fit the resulting specific questions are suggested by the key. The key consists of five domains, of which three determine method selection and two the design or use of the method. Each domain consists of four or more criteria that need specification. For example in the domain "system boundaries", amongst others, the spatial and temporal scales are specified. The key was tested (retrospectively) on a set of thirty case studies. Using the key appeared to contribute to improved: (i) transparency in the link between the question and method selection; (ii) consistency between questions asked and answers provided; and (iii) internal consistency in methodological design. There is latitude to develop the current initial key further, not only for selecting methods pertinent to a problem definition, but also as a principle for associated opportunities such as stakeholder identification. Show less
Font Vivanco, D.; Kemp, R.; Voet, E. van der; Heijungs, R. 2014
This article presents a general framework for macroenvironmental assessment, combining life cycle assessment (LCA) with the IPAT equation, and explores its combination with decomposition analysis... Show moreThis article presents a general framework for macroenvironmental assessment, combining life cycle assessment (LCA) with the IPAT equation, and explores its combination with decomposition analysis to assess the multidimensional contribution of technological innovation to environmental pressures. This approach is illustrated with a case study in which carbon dioxide (CO2) and nitrogen oxides (NOx) air emissions from diesel passenger cars in Europe during the period 1990-2005 are first decomposed using index decomposition analysis into technology, consumption activity, and population growth effects. By a second decomposition, the contribution of a specific innovation (diesel engine) is calculated on the basis of the technology and consumption activity effects, through a technological comparison with a relevant alternative and the calculation of the rebound effect, respectively. The empirical analysis for diesel passenger cars highlights the discrepancies between the micro (LCA) and macro (IPAT-LCA) analytical approaches. Thus, whereas diesel engines present a relatively less-pollutant environmental product profile than their gasoline counterparts, total CO2 and NOx emissions would have increased partly as a consequence of their introduction, mainly driven by the increase in travel demand caused by the induced direct price rebound effect from fuel savings and fuel price differences. The counterintuitive result shows the need for such an analysis. Show less
