Resources, Conservation and Recycling

Islands are bounded systems, often plagued with several sustainability challenges of limited land and resource availability, as well as pressing waste management issues. Despite these known problems, research aiming to help develop proper e-waste management systems for small island nations is scarce. Focusing on five Caribbean island states, this study provides the first comprehensive view of e-waste generation trends in an island context and explores the factors driving those trends. The study estimates Electrical and Electronic Equipment (EEE) flows for the five island cases over a period of 60 years (1965–2025), including e-waste that these flows have and will generate. A dynamic material flow analysis (MFA) approach has been used to estimate these flows and stocks for 206 product types. The results show that the five Caribbean islands produced double the e-waste per capita per year, i.e., 13 kg/cap/year compared to global average of 6.1 kg/cap/year in 2016. The aggregated amount of e-waste generated per year on these five islands seems to significantly rise in future: from 27,500 tonnes in 2010 to an estimated amount of 59,000 tonnes in 2025. This considerable estimated e-waste generation rate, when not properly managed, is not only harmful for the local environment, but also translates into considerable health impacts and loss of valuable resources. From a sustainability perspective, small islands should consider moving away from a linear to a circular economy that will limit waste generation as well as reliance on the supply of virgin materials from outside.

Material Stock Assessments (MSA) form an essential component in our understanding of the functions of built infrastructure within the socioeconomic system and its environmental impacts. Scarce material stock data are a major impediment, and studies are often limited in scope, resolution, or both, and often employ ad-hoc methods hampering comparability between regions. In this study we describe the development of a method to estimate material stocks on a continental scale with a resolution of city districts and small settlements and its application to Europe. We use satellite-derived nighttime lights data to delineate distinct built-up areas. These areas’ radiance values serve as a proxy for built-up volume, estimated using cluster-based regressions with random resampling. Coupled with building intensities of different building materials, we derive a spatial MSA for Europe, presented in multiple levels of aggregation from city district to continental. The total material stocks of Europe are 109 billion tons, with an average of 37 thousand tons/km2. The results reveal multi-level spatial patterns of material stock densities, enabling comparisons between and within regions and countries. The model offers good agreement with previous studies, highlighting its advantage in data acquisition, spatial comparability, and benchmarking abilities. The used data can be updated regularly, offering the ability of future exploration into spatiotemporal dynamics of material stocks.

Replacing traditional fossil fuel with bioethanol has been adopted in many countries to reduce carbon emissions and achieve climate mitigation targets. However, the soaring global demand for food and bioethanol in the future may impose heavy environmental pressure on major sugar crops producing regions of Latin America and the Caribbean (LAC) through significant changes in land and water uses. Irrigation expansion in the rainfed dominant cropping areas would partially slow down the land use expansion by boosting yields, but require large-scale investments. This study assesses the future land and water demand triggered by sugar crops expansion from the food-energy-water/land nexus perspective through coupling the Global Agro-Ecological Zones model (GAEZ) with Multi-Regional Input-Output (MRIO) analysis. We further analyse the tradeoffs between water and land use under future scenarios of climate change and socio-economic development regarding to the expected goals of biofuel policies and irrigation expansion strategies in LAC countries due to sufficient local water resources. The results show that the projected water and land demand of sugar crops in LAC would increase by 198% and 205% from 2014 to 2040. Increasing the low- or non- irrigated area up to 50% would mitigate the yield loss and reduce the land demand by 10%, with limited impact on the local water resources in most LAC countries. Major bioethanol producers with limited water demand compared with available water resources, such as Brazil and Argentina, could further promote irrigation to avoid significant landuse change and benefit other countries’ land ecosystems via inter-regional bioethanol trade. While in potential higher water stress countries, including Dominican Republic, El Salvador, Guatemala and Mexico, under bioenergy orientated policy in 2040, reducing biofuel policy targets or importing bioethanol from resource rich countries would be a better option. These results could provide guidelines to balance sugar crops production and sustainable water and land use strategies across LAC.

Can a small island state be sustainable? Small islands often suffer from a myriad of sustainability challenges owing to their remoteness, size, dependency on imports, and limited waste absorption capacity. Most imports end up as waste accumulation in dumpsites at the end of their life-cycle, representing a one-way material flow. The concept of the “circular economy” (CE) is a promising resource management strategy for island nations to improve solid waste management. In a CE, waste is a resource to be continually circulated within the economy. This study uses material flow accounting (MFA) to quantify waste deposits in Grenada, a tri-island, Caribbean state (population: 110,874). Like many Caribbean islands, Grenada has waste challenges as a result of accumulation of materials in open dumpsites and the persistence of illegal dumping. We estimated that Grenada generated 46,097 tonnes or 1.14 kgs per capita per day of waste in 2017. Leveraging disaggregated trade and waste data, we quantified three problematic waste streams: plastics, tyres, and motor oil and demonstrate an approach for conducting MFA in data-poor environments. Based on the results, Grenada has opportunities to decrease waste production by implementing circularity measures. We recommend improving data collection, implementation of the polluter pays principle, banning substitutable, problematic materials, and developing waste management plans for problematic materials. It is critically important that Grenada transition to a more sustainable waste management system in order to realize the vision of sustainable development. The results of this study make an important contribution to island industrial ecology and sustainable development.

This research employed a spatially explicit analysis to calculate the total material stock and demolition waste flows for Padua, a medium sized Italian city, for the period 1902–2007. The analysis of maps and aerial photographs allowed for the calculation of building lifespan, which grew until the second half of the twentieth century, but had a sharp decline during the 1990’s caused by a wave of urban renewal triggered by policies to improve the energy efficiency and remove asbestos from buildings. A detailed investigation of historical construction technologies allowed for the creation of a material inventory database by building typology and construction period, which was then used to calculate the total stock of buildings of Padua. Our results show that the historical city centre remained practically unaltered over the past century, and that most of the expansion happened at the city periphery. From 1902 to 2007 the stock of building materials grew from 134 to 209 tonnes per capita, and is expected to further increase to 222 tonnes per capita by 2030. We also implemented a model to estimate the waste potential from demolition activities using the total stock and expected lifespan as input parameters. We estimate that waste flows accounted for 985 kg per capita in 2007 and are expected to raise to 1.9 tonnes per capita in 2030. These results are informative for urban planners, especially those involved in fast urbanising regions (e.g. China, India), who can use these results as a benchmark of future stocks and waste flows.

Can material flow analysis (MFA) support strategic decisions necessary for the development of circular economy (CE) in a developing country? MFA can be an essential tool in providing necessary data inputs for decisions related to the development of CE. Data-poor environments in developing economies, however, e.g. lack of data on physical flows in manufacturing, pose challenges to doing MFA. Other data however, in particular trade statistics accounting for shipment mass, are often available. We undertake a case study to characterize plastic flows in Trinidad and Tobago (T&T) for 2016, demonstrating how leveraging such data enables MFA. A notable result from the MFA is that much (48%) of the landfilled plastic in T&T comes from plastic packaging for imported products rather than intentional domestic use. This is an example of what is probably a typical CE challenge for island nations: Importing materials with limited domestic demand at end-of-life. We use the MFA results to propose suggestions for a more circular flow of plastics in T&T. First, there is potential to divert plastic waste (including packaging plastic) for use as feedstock in a local cement plant. Second, the scale of PET plastic flows is of sufficient scale (26,000 metric tons annually) to make domestic recycle feasible. Techno-economic studies are needed to properly develop and evaluate these proposals, the role of the MFA here is to identify promising directions.

Connectivity and affluence provide communities on small islands with opportunities and challenges. Both factors drive the expansion of material stocks which in turn determines future waste generation. For islands with limited waste treatment options an effective waste management strategy is inevitable. For the Greek island of Samothraki, construction and demolition waste (CDW) represents a new phenomenon. The advent of tourism, EU funding, labor migration and the construction of a new port in the 1960s led to an expansion of the built environment unprecedented on the island. As a consequence, new types and expanding quantities of CDW put the island community increasingly in the need for action. The European Waste Framework Directive, reinforced in 2018 with the Circular Economy Package, demands from EU member states at least 70% recycling and recovery rate of CDW until 2020. In this study, a mixed methods approach enabled the integration of data from official statistics, field surveys and interviews into a dynamic stock-driven model for different infrastructure and buildings types on Samothraki from 1971 to 2016. Our results show that the material stock expanded from 175 t/cap to 350 t/cap in the given period, leading to a 15-fold increase of annual CDW generation. With a recycling rate of only 14%, the island is currently far away from meeting the recycling and recovery targets of the EU-WFD. This study provides a systematic and dynamic analysis for developing policy and management options on reducing, re-using and recycling of CDW on islands where waste treatment options are limited.

Connectivity and affluence provide communities on small islands with opportunities and challenges. Both factors drive the expansion of material stocks which in turn determines future waste generation. For islands with limited waste treatment options an effective waste management strategy is inevitable. For the Greek island of Samothraki, construction and demolition waste (CDW) represents a new phenomenon. The advent of tourism, EU funding, labor migration and the construction of a new port in the 1960s led to an expansion of the built environment unprecedented on the island. As a consequence, new types and expanding quantities of CDW put the island community increasingly in the need for action. The European Waste Framework Directive, reinforced in 2018 with the Circular Economy Package, demands from EU member states at least 70% recycling and recovery rate of CDW until 2020. In this study, a mixed methods approach enabled the integration of data from official statistics, field surveys and interviews into a dynamic stock-driven model for different infrastructure and buildings types on Samothraki from 1971 to 2016. Our results show that the material stock expanded from 175 t/cap to 350 t/cap in the given period, leading to a 15-fold increase of annual CDW generation. With a recycling rate of only 14%, the island is currently far away from meeting the recycling and recovery targets of the EU-WFD. This study provides a systematic and dynamic analysis for developing policy and management options on reducing, re-using and recycling of CDW on islands where waste treatment options are limited.

The discussion on urban metabolism has been long dominated by natural scientists focussing on natural forces shaping the energy and material flows in urban systems. However, in the anthropocene human forces such as industrialization and urbanization are mobilizing people, goods and information at an increasing pace and as such have a large impact on urban energy and material flows. In this white paper, we develop a combined natural and social science perspective on urban metabolism. More specifically, innovative conceptual and methodological interdisciplinary approaches are identified and discussed to enhance the understanding of the forces that shape urban metabolism, and how these forces affect urban living and the environment. A challenging research agenda on urban metabolism is also presented.

This study estimates the amount of urban ores in Taipei City between 1965 and 2014 by analyzing data of the buildings through statistics and geographical information systems (GIS). Hot spot analysis (HSA) is introduced to assess the location of resources. Our results show that up to the year 2014, 186 Mton of construction materials were accumulated in Taipei, and the per capita total building material stock was 68 ton. In the short term, the hot spots with development potential are Da’an (Zone I) and Zhongshan (Zone II) Districts in Taipei City. Zone I (0.1 km2) stored 180 kton of materials; while Zone II (0.6 km2) stored 119 kton of materials. This study provides quantitative data on urban ores with high spatial and temporal resolution for enhancing material recycling planning and management. Material stocks could then combine with the material flow to build a dynamic material flow model for assessing the quantity of extractable urban ores, and the feasibility of exploitation in the future.

Quantifying the changing patterns and determinants of material stocks (MS) is important for understanding the interplay between socioeconomic development and environment conservation, and for addressing the challenges in sustainable development. This paper conducts a MS accounting for 10 materials in 6 major infrastructures in Beijing, Tianjin and Shanghai, and probes into the driving factors behind the change within the 1978–2013 period through a logarithmic mean divisia index decomposition method. The results suggest that MS changes through a rapid enhancement in the 1980s, a steadily growth in the 1990s, and an acceleration after the 2000s. A relative decoupling phenomenon was detected in the development of economy and MS, which was largely caused by the decline of MS intensity. The policy implications include paying more attentions to the improvement of MS efficiency especially in buildings, substituting for less energy-intensive construction materials, controlling the extensive urban sprawl, and raising the population density.

Demolition waste represents a significant portion of the total generated waste and has a high importance from both a waste management and a resource efficiency perspective. The urban context is highly relevant to assess the environmental impact of the end-of-life stage of buildings and potential for future reduction to properly design corresponding demolition waste management strategies. The goal of this paper is the development of a framework for the characterization of building material stocks and the assessment of the potential environmental impact associated with the end-of-life of buildings at the urban scale to support decision on waste management strategies. The methodology combines a bottom-up material stock model based on geographical information systems (GIS) and a spatial–temporal database with life cycle assessment (LCA) for the evaluation of end-of-life scenarios. The approach was tested for the city of Esch-sur-Alzette (Luxembourg) and provided significant results on the quantity and the composition of the housing material stock. Two alternative scenarios involving recycling rates of respectively 50% and 70% for inert materials were assessed and an average reduction potential of 25.6% on abiotic depletion potential and 9.2% on global warming potential was estimated.

The world’s industrialised nations have accumulated a wealth of assets in the form of buildings, infrastructure and other durable goods. These assets constitute a valuable reservoir of secondary raw materials. This “anthropogenic material stock” should be understood as a future capital stock that must be systematically managed and exploited. Yet this capital stock has hitherto been largely ignored in discussions on resource efficiency, which instead have focused on inputs of primary raw materials. This is partly due to insufficient knowledge of the size and constitution of this material stock as well as its dynamics. Therefore, a project was set up by Germany’s Federal Environment Agency to provide the missing information. Project results offer a comprehensive view of material stocks, inflows and outflows connected to durable goods. Thus we note an annual per capita growth in Germany’s anthropogenic material stock of 10t. In the last 50 years an estimated 42 billion tons of material has been added to the anthropogenic stock. Not all of this can be classified to primary groups of goods. Around 28 million tons of material has been consumed by buildings, infrastructure, building services as well as durable consumer goods. Of this figure, over 99% can be located in the built environment. This mass is approximately 79 times larger than the material mass currently consumed every year by these sectors. Annual outflow from the stock is around 0.8%. The annual rate of growth of the observed stock of goods is 0.5%. The various figures can be further broken down according to individual groups of goods and material groups. This knowledge provides the necessary foundation for the long-term monitoring of the anthropogenic stock and, moreover, is an important step in the evidence-based development of a model to incorporate and to improve closed-loop material flows as well as to support politics of securing supply of raw materials.

The building sector is known to have the largest inventories of materials in industrialized societies. In comparison to residential buildings, non-residential buildings (NRBs) are much more diverse in function, components and their respective materials. In order to provide insights in material stocks of the non-residential area, this study focused on the case of the Rhine-Main area, a metropolitan region holding extensive stocks of office buildings as well as factory, logistic and other NRBs. The investigation covered analysis of spatial data and examination of single buildings. The structure of the NRB sector was comprehensively characterized in a case-study area as to function and age-classes of existing buildings in terms of building gross volume. The two types “factory” and “commercial/retail and services buildings” accounted for about half of the existing buildings. As to age, about one third of the buildings was found to originate before 1948. This indicates the high importance of renovation activities as a prerequisite for the continuous use of NRBs. Specific material contents of buildings were assessed, showing a large variety. Combining spatial and building related information, a methodological approach was developed which provides area-wide information on material stocks incorporating the allocation to function and age-class of NRBs. This approach may be used for regional estimation of potentials of secondary resources and for Material Flow Analysis in order to estimate potentials and flows of secondary resource.

Earthquakes are natural phenomena that can cause severe damage to housing infrastructure and prolonged disruption to society. Depending on their magnitude, epicenter location, local construction characteristics, and many other features, earthquakes may generate large amounts of debris and waste. The large amounts of debris generated after the disaster become one of the main problems for a population facing health issues and the need to reconstruct the city. Proper characterization and quantification of debris, subsequent waste management and reconstruction planning are essential for the restoration of an area affected by an earthquake. This study presents a methodological approach to characterize, quantify and forecast the debris produced as a consequence of earthquakes, as well as the flow of materials required for the reconstruction of the area affected. The proposed methodology includes a residential infrastructure characterization stage, a probabilistic estimation of damage by characterizing the vulnerability functions using CAPRA-GIS tool, and material flow analyses (MFA) for the characterization and quantification of debris associated with the event of an earthquake and for new materials for the reconstruction stage. A case study was developed to test this methodological approach. The residential sector of Tacna, a city with high seismic risk located on the southern coast of Peru, was selected. Moreover, five different construction systems (i.e., reinforced masonry-bearing walls with concrete diaphragms, adobe, wood, concrete shear walls, and straw) used in the residential sector of Tacna were characterized. Also, three possible earthquake scenarios (i.e., 8.6Mw, 7.5Mw and 6.2Mw) were analyzed, each one with three different material end-of-life management situations. Simultaneously, the origin and quantities of new materials needed for the reconstruction of housing infrastructure were determined. The flow of new materials considered productivity rates in the construction and manufacturing sectors. The results show that in the presence of the greatest earthquake (8.6Mw), adobe and straw homes suffered greatest damage, with damage proportions of 63% and 48%, yielding 27,000 and 1390tonnes of debris, respectively. Also, 204,000tonnes of concrete, 7400tonnes of steel and 461,400tonnes of clay brick were included as debris generated in this scenario. Furthermore, for all scenarios, the MFA provides an estimate of regional import of materials (e.g., cement, steel, brick and wood) for the reconstruction phase. Finally, the methodology is applicable to developed and undeveloped countries with different housing types, their respective vulnerability functions and constant earthquake recurrence.

Recent years have seen a growing interest in the potential for a more circular economy and the application of material flow accounting to increase kno…

Garbage is the waste and discarded items of society. Archeologists obsessively dig up is historic or prehistoric garbage – the useless, broken, and unwanted. Yet, these digs tell us a great deal about the society in which the items were used. Countless inferences can be made from what is discarded, how it is discarded, where it is discarded, and why. Was it broken, used, consumed, or unwanted? These same questions and answers have as much to tell us about modern societies. What is discarded and thrown away? Is it broken, or merely unwanted? Has it been consumed, or was it past it's “shelf-life”? Along with this archaeological inferability goes the notion of the society in which it is discarded. Is it a modern “developed” society? Using datasets available from the United Nations and World Bank detailing waste generation, economic development, population, and land area, this paper will argue that waste generation is not only a product of the society in which it is based, but also profoundly affected by the rate and the way at which the society has approached modernity. Countries will likely always produce waste, but what becomes waste, and how much, is a product of the particular society and the technology they have to eliminate it.

For most materials used to provide buildings, infrastructure, equipment and products, global stocks are still sufficient to meet anticipated demand, but the environmental impacts of materials production and processing, particularly those related to energy, are rapidly becoming critical. These impacts can be ameliorated to some extent by the ongoing pursuit of efficiencies within existing processes, but demand is anticipated to double in the next 40 years, and this will lead to an unacceptable increase in overall impacts unless the total requirement for material production and processing is reduced. This is the goal of material efficiency, and this paper aims to stimulate interest in the area. Four major strategies for reducing material demand through material efficiency are discussed: longer-lasting products; modularisation and remanufacturing; component re-use; designing products with less material. In industrialised nations, these strategies have had little attention, because of economic, regulatory and social barriers, which are each examined. However, evidence from waste management and the pursuit of energy efficiency suggests that these barriers might be overcome, and an outline of potential mechanisms for change is given. In bringing together insights into material efficiency from a wide range of disciplines, the paper presents a set of 20 open questions for future work.

In Mauritius, solid waste disposal has been a cause for concern since the 1980s. Currently, there is no segregation of waste and some 1200tonnes of solid waste are generated daily by the 1.24 million inhabitants of the island. As processes such as recycling and composting are still in their infancy stage, most of the waste generated have to be disposed of at the sole landfill. The solid waste management practices of 1980s and early 1990s are no longer compatible with the changing composition and quantity of wastes now generated. As a result, there is an urgency to review the whole waste management system and come forward with sustainable solutions. This paper presents an overview of the disposal of non-hazardous solid waste in Mauritius and provides recommendations for improving the current disposal system.

Urban residential buildings are formed, maintained and reformed by different external material and energy flows, and their behaviors of input, accumulation and output are characterized by their architectural factors and modes of use that usually determine the consumption of material and energy of a building at its overall life cycle. In this research, we took Beijing city, a rapid developing city as a case study, and examined material flows of urban residential building system based on a survey of typical residential buildings in the urban areas of Beijing city. The quantitative analysis were made to describe the input, transformation/accumulation, and output of building materials from the year 1949 to 2008, and a comparative analysis was done to identify the differences of material uses among the buildings with different architectural structures as masonry–concrete, and steel–concrete. During the period from 1949 to 2008, there were six main materials of cement, sand, gravel, steel, bricks and timber used in urban residential building system in Beijing. The total amount of material imported into the system was 5.1×108t, among which the accumulated amount was 4.7×108t, an accumulation rate of 92.5%, and the total of building wastes reached 3.9×107t. Among the buildings with two architectural structures, the total amount of material use for buildings with steel–concrete structure was larger than masonry–concrete. It was found that the buildings with steel–concrete structure experienced a rapid increase since the year 1979 in Beijing. As a result of rapid urban development, the large-scale reformation and demolishment of urban old buildings also led to a rapid growth of the amount of building wastes. And the building wastes generated in the process of reformation and demolition began to exceed that produced in the process of new buildings construction. The amount of building wastes generated from 2004 to 2008 accounted for 52.2% of the total that generated from 1949 to 2008. From this research, the rapid development of Beijing's residential building system in the past 60 years became a big ecological pressure for urban sustainable building development. It is important to change the traditional model of urban construction, and develop some sustainable or ecologically friendly construction technologies to enhance the capacity of recycling and reuse of residential building wastes for realizing a sustainable urban building construction and management in Beijing.

This paper presents a system's engineering model for the strategic planning of an integrated solid waste management at local level and more specifically in an island with touristic development. The model was developed for the island of Corfu, but it can also be implemented in other touristic islands all over the world. It combines the worth benefit utility analysis (WBU) with the life cycle analysis (LCA), taking into account environmental, financial, technological and social criteria. The model's implementation in the island of Corfu demonstrates that the most efficient method for the waste disposal in Corfu is the combination of the material sorting at the waste source and the production of compost from the organic fraction. ?? 2004 Elsevier B.V. All rights reserved.

In order to develop a sustainable society, tools are needed to analyze the relationships between human activities and ecosystems and to estimate the carrying capacity of the natural resource base. In this paper, energy analysis is applied in a study of the small island society Nämdö in the Stockholm archipelago, Sweden. Nämdö has a permanent population of 41 persons and ca. 1000 summer residents. We estimated the energy and material flows on the island, including the primary and secondary production in natural and cultivated ecosystems, human production and consumption of food, and production of waste. Our results show that the island society's consumption exceeds the natural carrying capacity of the island. A great deal of food and energy is imported while only a minor amount of local resources are utilized. The island society is, at present, not constrained by the local resource base, but instead depends heavily on functioning transport communications with the mainland. Based on our findings we make recommendations for greater self-sufficiency, including use of locally available renewable resources and increased recycling.