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Assessing global resource use : a systems approach to resource efficiency and pollution reduction
(2017)
The growing demand for timber, in particular for renewable energy, increases pressures on global forests and requires a robust monitoring system to ensure sustainability. This article takes a first step toward more systemic monitoring by asking how the global use of forests by EU consumers can be accounted for. Specifically, this article builds on and develops the method of global land use accounting to account for the EU-27's consumption of primary timber between 2002 and 2011 in terms of both volume and forest area. It assesses international trade flows for around 100 commodities and converts them into a volume of primary raw timber based on conversion values. Results reveal that both imports and exports increased over the assessed time period, with primary EU-27 timber estimated to be around 1 m3/cap in 2011. Gaps, uncertainty and a lack of harmonization regarding especially trade data and conversion values are key challenges to further improving the robustness of the method and reliability of results. Future research may focus on improving the method to address in particular recycled and recovered flows as well as the question of whether area or volume is the most appropriate metric for further development of a forest footprint indicator.
The growing demand for wood to meet EU renewable energy targets has increasingly come under scrutiny for potentially increasing EU import dependence and inducing land use change abroad, with associated impacts on the climate and biodiversity. This article builds on research accounting for levels of primary timber consumption - e.g., toward forest footprints - and developing reference values for benchmarking sustainability - e.g., toward land use targets - in order to improve systemic monitoring of timber and forest use. Specifically, it looks at future trends to assess how current EU policy may impact forests at an EU and global scale. Future demand scenarios are based on projections derived and adapted from the literature to depict developments under different scenario assumptions. Results reveal that by 2030, EU consumption levels on a per capita basis are estimated to be increasingly disproportionate compared to the rest of the world. EU consumption scenarios based on meeting around a 40% share of the EU renewable energy targets with timber would overshoot both the EU and global reference value range for sustainable supply capacities in 2030. Overall, findings support literature pointing to an increased risk of problem shifting relating to both how much and where timber needed for meeting renewable energy targets is sourced. It is argued that a sustainable level of timber consumption should be characterized by balance between supply (what the forest can provide on a sustainable basis) and demand (how much is used on a per capita basis, considering the concept of fair shares). To this end, future research should close data gaps, increase methodological robustness and address the socio-political legitimacy of the safe operating space concept towards targets in the future. A re-use of timber within the economy should be supported to increase supply options.
Renewable energy targets in the European Union (EU) have raised the demand for timber and are expected to increase dependence on imports. However, EU timber consumption levels are already disproportionally high compared to the rest of the world. The question is, how much timber is available for the EU to sustainably harvest and import, in particular considering sustainable forest management practices, a safe operating space for land-system change, and the global distribution of "common good" resources. This article approaches this question from a supply angle to develop a reference value range for the current as well as future sustainable supply of timber at the EU-27 and global levels. For current supply estimates, national-level data on forest area available for wood supply, productivity in that area, as well as the rate available for harvest were collected and aggregated into three potential supply scenarios. For future supply estimates, a safe operating space scenario halting land use change, a sensitivity analysis, and a literature review were performed. To provide both a comparison of global versus EU sustainable supply capacities and to develop a benchmark toward evaluating and comparing levels of consumption to sustainable supply capacities, per capita calculations were made. Results revealed that the per capita sustainable supply potential of EU forests is estimated to be around three times higher than the global average in 2050. Whether a global or EU reference value is more appropriate for EU policy orientation, considering both strengthened economic and cultural ties to the forest in forest-rich countries as well as the need to prevent problem shifting associated with exporting land demands abroad, is discussed. Further research is needed to strengthen and harmonize data, improve methods for modeling future scenarios and incorporate interdisciplinary and multi-stakeholder perspectives toward the development of robust and politically relevant reference values for sustainable consumption levels.
The contribution of the EU bioeconomy to sustainable development depends on how it is implemented. A high innovation potential is accompanied by considerable risks, in particular regarding the exacerbation of global land use conflicts. This article argues that a systemic monitoring system capable of connecting human-environment interactions and multiple scales of analysis in a dynamic way is needed to ensure that the EU bioeconomy transition meets overarching goals, like the Sustainable Development Goals. The monitoring should be centered around a dashboard of key indicators and targets covering environmental, economic, and social aspects of the bioeconomy. With a focus on the land dimension, this article examines the strengths and weakness of different economic, environmental and integrated models and methods for monitoring and forecasting the development of the EU bioeconomy. The state of research on key indicators and targets, as well as research needs to integrate these aspects into existing modeling approaches, are assessed. The article concludes with key criteria for a systemic bioeconomy monitoring system.
Previous studies showed that using carbon dioxide (CO2) as a raw material for chemical syntheses may provide an opportunity for achieving greenhouse gas (GHG) savings and a low-carbon economy. Nevertheless, it is not clear whether carbon capture and utilization benefits the environment in terms of resource efficiency. We analyzed the production of methane, methanol, and synthesis gas as basic chemicals and derived polyoxymethylene, polyethylene, and polypropylene as polymers by calculating the output-oriented indicator global warming impact (GWI) and the resource-based indicators raw material input (RMI) and total material requirement (TMR) on a cradle-to-gate basis. As carbon source, we analyzed the capturing of CO2 from air, raw biogas, cement plants, lignite-fired power, and municipal waste incineration plants. Wind power serves as an energy source for hydrogen production. Our data were derived from both industrial processes and process simulations. The results demonstrate that the analyzed CO2-based process chains reduce the amount of GHG emissions in comparison to the conventional ones. At the same time, the CO2-based process chains require an increased amount of (abiotic) resources. This trade-off between decreased GHG emissions and increased resource use is assessed. The decision about whether or not to recycle CO2 into hydrocarbons depends largely on the source and amount of energy used to produce hydrogen.
The amount of land directly disturbed by mining is a key generic environmental pressure indicator. A novel method based on the measurement of the cumulative net area disturbances using Landsat satellite images and its correlation with the cumulative ore production at the mine site was applied. Weighted disturbance rates (WDRs) were calculated indicating the annual quantity of hectares newly disturbed per million metric tons of ore extracted. Results show that open pit (OP) have a smaller average WDR (5.05 ha/Mt) than underground (UG) mines (11.85 ha/Mt). This is explained by the relation between the annual amounts of new net area disturbed and of ore extracted which is larger for UG than for OP mines due to the annual extraction volume (lower for UG). Overall findings demonstrate that bauxite mining has the highest WDR (7.98 ha/Mt), followed by gold (6.70 ha/Mt), silver (5.53 ha/Mt), copper (4.5 ha/Mt) and iron (4.25 ha/Mt).
In a globalized economy, the use of natural resources is determined by the demand of modern production and consumption systems, and by infrastructure development. Sustainable natural resource use will require good governance and management based on sound scientific information, data and indicators. There is a rich literature on natural resource management, yet the national and global scale and macro-economic policy making has been underrepresented. We provide an overview of the scholarly literature on multi-scale governance of natural resources, focusing on the information required by relevant actors from local to global scale. Global natural resource use is largely determined by national, regional, and local policies. We observe that in recent decades, the development of public policies of natural resource use has been fostered by an "inspiration cycle" between the research, policy and statistics community, fostering social learning. Effective natural resource policies require adequate monitoring tools, in particular indicators for the use of materials, energy, land, and water as well as waste and GHG emissions of national economies. We summarize the state-of-the-art of the application of accounting methods and data sources for national material flow accounts and indicators, including territorial and product-life-cycle based approaches. We show how accounts on natural resource use can inform the Sustainable Development Goals (SDGs) and argue that information on natural resource use, and in particular footprint indicators, will be indispensable for a consistent implementation of the SDGs. We recognize that improving the knowledge base for global natural resource use will require further institutional development including at national and international levels, for which we outline options.
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.
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.
The CO2 utilisation is discussed as one of the future low-carbon technologies in order to accomplish a full decarbonisation in the energy intensive industry. CO2 is separated from the flue gas stream of power plants or industrial plants and is prepared for further processing as raw material. CO2 containing gas streams from industrial processes exhibit a higher concentration of CO2 than flue gases from power plants; consequentially, industrial CO2 sources are used as raw material for the chemical industry and for the synthesis of fuel on the output side. Additionally, fossil resources can be replaced by substitutes of reused CO2 on the input side. If set up in a right way, this step into a CO2-based circular flow economy could make a contribution to the decarbonisation of the industrial sector and according to the adjusted potential, even rudimentarily to the energy sector.
In this study, the authors analyse potential CO2 sources, the potential demand and the range of applications of CO2. In the last chapter of the final report, they give recommendations for research, development, politics and economics for an appropriate future designing of CO2 utilisation options based upon their previous analysis.
The paper reflects the hypothesis that those technological and institutional innovations survive which extend the safe operating range (SOR) of the Humans-Technologies-Institutions (HTI) system (e.g. companies, cities, regions and countries). The multidimensional SOR of a country comprises in particular safe livelihood, quality of life, security, monetary stability, supply security and quality of the environment. A "mechanism of progress" is described involving the search for higher safety and independence of constraints. With innovation and learning in a key role, the mechanism leads to a relative decoupling of resource use and economic value added and a growing share of knowledge generation in the economy. Competition of HTI systems for scarce resources may lead to independence strategies such as enhanced resource efficiency. It may also lead to cooperation of competing HTI systems facilitated by new institutions thus forming an HTI system at higher level of complexity. While the consortium could coordinate their resource consumption within the boundaries of safe operating space, the partner HTI systems would further expand their SOR. Data is provided that net resource importing countries have developed higher material productivity thus increasing their independence from resource supply, and countries with such capability have gained higher innovation capacity.
The bioeconomy is gaining growing attention as a perceived win-win strategy for environment and economy in the EU. However, the EU already has a disproportionately high global cropland footprint compared to the world average, and uses more cropland than domestically available to supply its demand for agricultural products. There is a risk that uncontrolled growth of the bioeconomy will increase land use pressures abroad. For that reason, a monitoring system is needed to account for the global land use of European consumption. The aim of this paper is to take a closer look at the tools needed to monitor global cropland footprints, as well as the targets needed to benchmark development. This paper reviews recent developments in land footprint accounting approaches and applies the method of global land use accounting to calculate the global cropland footprint of the EU-27 for the years between 2000 and 2011. It finds a slight decrease in per capita cropland footprints over the past decade (of around 1% annually, reaching 0.29 ha/cap in 2011) and advocates promoting a further decrease in per capita cropland requirements (of around 2% annually) to reach global land use targets for keeping consumption within the safe operating space of planetary boundaries by 2030. It argues that strategic land reduction targets may still go hand in hand with the growth of a smart, innovative and sustainable bioeconomy by reinforcing the need for policies that support greater efficiency across the life-cycle and reduce wasteful and excessive consumption practices. Recommendations for further improving land footprint accounting are given.
Many countries have started to develop policy programs for the sustainable use of natural resources. Indicators and targets can cover both a territorial and a life-cycle-wide global perspective. This article focuses on how a safe operating space for global material resource use can be outlined based on existing economy-wide material flow indicators. It reflects on issues such as scale and systems perspective, as the choice of indicators determines the target "valves" of the socio-industrial metabolism. It considers environmental pressures and social aspects of safe and fair resource use. Existing proposals for resource consumption targets are reviewed, partially revisited, and taken as a basis to outline potential target values for a safe operating space for the extraction and use of minerals and biomass by final consumption. A potential sustainability corridor is derived with the Total Material Consumption of abiotic resources ranging from 6 to 12 t/person, the Total Material Consumption of biotic resources not exceeding 2 t/person, and the Raw Material Consumption of used biotic and abiotic materials ranging from 3 to 6 t/person until 2050. For policy, a "10-2-5 target triplet" can provide orientation, when the three indicators are assigned values of 10, 2, and 5 t/person, respectively.
The current flow of carbon for the production, use, and waste management of polymer-based products is still mostly linear from the lithosphere to the atmosphere with rather low rates of material recycling. In view of a limited future supply of biomass, this article outlines the options to further develop carbon recycling (C-REC). The focus is on carbon dioxide (CO2) capture and use for synthesis of platform chemicals to produce polymers. CO2 may be captured from exhaust gases after combustion or fermentation of waste in order to establish a C-REC system within the technosphere. As a long-term option, an external C-REC system can be developed by capturing atmospheric CO2. A central role may be expected from renewable methane (or synthetic natural gas), which is increasingly being used for storage and transport of energy, but may also be used for renewable carbon supply for chemistry. The energy input for the C-REC processes can come from wind and solar systems, in particular, power for the production of hydrogen, which is combined with CO2 to produce various hydrocarbons. Most of the technological components for the system already exist, and, first modules for renewable fuel and polymer production systems are underway in Germany. This article outlines how the system may further develop over the medium to long term, from a piggy-back add-on flow system toward a self-carrying recycling system, which has the potential to provide the material and energy backbone of future societies. A critical bottleneck seems to be the capacity and costs of renewable energy supply, rather than the costs of carbon capture.
Global warming, the overall extraction of minerals and the expansion of cultivated land for biomass harvest are growing globally. These "Big Three" represent key environmental pressures which may lead to a continuous degradation of the living environment, if not controlled at levels with acceptable low risk. The situation is complex, because countries and regions consume products which require resources such as minerals and land in various parts of the world. Nevertheless, it is possible to measure the global resource use which is associated with the domestic consumption. In order to inform policies at the national and supranational level whether it may be necessary to adjust the incentive framework for industry and households, reference data are needed to compare the status quo of their countries with what may be deemed acceptable at a global level. This chapter outlines a rationale for the derivation of possible long-term targets for total material consumption of abiotic materials (TMCabiot) and global land use for crops (GLUcropland). The indicated targets are expressed in tentative per capita values which may serve as a first orientation and basis for further debate and research.
Carbon recycling, in which organic waste is recycled into chemical feedstock for material production, may provide benefits in resource efficiency and a more cyclical economy - but may also create "trade-offs" in increased impacts elsewhere. We investigate the system-wide environmental burdens and cost associated with carbon recycling routes capable of converting municipal solid waste (MSW) by gasification and Fischer-Tropsch synthesis into ethylene. Results are compared to business-as-usual (BAU) cases in which ethylene is derived from fossil resources and waste is either landfilled with methane and energy recovery (BAU#1) or incinerated (BAU#2) with energy recovery. Monte Carlo and sensitivity analysis is used to assess uncertainties of the results. Results indicate that carbon recycling may lead to a reduction in cumulative energy demand (CED), total material requirement (TMR), and acidification, when compared to BAU#1. Global warming potential is found to be similar or slightly lower than BAU#1 and BAU#2. In comparison to BAU#2, carbon recycling results in higher CED, TMR, acidification, and smog potential, mainly as a result of larger (fossil-based) energy offsets from energy recovery. However, if a renewable power mix (envisioned for the future) is assumed to be offset, BAU#2 impacts may be similar or higher than carbon recycling routes. Production cost per kilogram (kg) MSW-derived ethylene range between US$1.85 and US$2.06 (Jan 2011 US$). This compares to US$1.17 per kg for fossil-based ethylene. Waste-derived ethylene breaks even with its fossil-based counterpart at a tipping fee of roughly US$42 per metric ton of waste feedstock.
This article presents the accounts of China's Total Material Requirement (TMR) during 1995–2008, which were compiled under the guidelines of Eurostat (2009) and with the Hidden Flow (HF) coefficients developed by the Wuppertal Institute. Subsequently, comparisons with previous studies are conducted. Using decomposition, we finally examine the influential factors that have changed the TMR of China. The main findings are the following: (1) During 1995–2008 China's TMR increased from 32.7 Gt to 57.0 Gt. Domestic extraction dominated China’s TMR, but a continuous decrease of its shares can be observed. In terms of material types, excavation constituted the biggest component of China's TMR, and a shift from biomass to metallic minerals is apparent; (2) Compared with two previous studies on China's TMR, the amounts of TMR in this study are similar to the others, whereas the amounts of the used part of TMR (Direct Material Input, DMI) are quite different as a result of following different guidelines; (3) Compared with developed countries, China's TMR per capita was much lower, but a continuous increase of this indicator can be observed; (4) Factors of Affluence (A) and Material Intensity (T), respectively, contributed the most to the increase and decrease of TMR, but the overall decrease effect is limited.
Global trade is increasingly being challenged by observations of growing burden shifting, in particular of environmental problems. This paper presents the first worldwide calculations of shifted burden based on material flow indicators, in particular direct and indirect physical trade balances. This study covers the period between 1962 and 2005 and includes between 82 and 173 countries per year. The results show that indirect trade flow volumes have increased to around 41 billion tonnes in 2005. The traded resources with the highest share of associated indirect flows are iron, hard coal, copper, tin and increasingly palm oil. Regarding the burden balance between regions, Europe is the biggest shifter whereas Australia and Latin America are the largest takers of environmental burden due to resource extraction. To evaluate the findings from a global perspective, the results are analysed in terms of resource flow induced environmental pressure related to a country's land area in terms of total and per capita area. Resource endowment and population density seem to be more relevant in determining the physical trade balance, including indirect flows, than income level.
Concerns over climate change and the security of industrial feedstock supplies have been opening a growing market for biobased materials. This development, however, also presents a challenge to scientists, policy makers, and industry because the production of biobased materials requires land and is typically associated with adverse environmental effects. This article addresses the environmental impacts of biobased materials in a meta-analysis of 44 life cycle assessment (LCA) studies. The reviewed literature suggests that one metric ton (t) of biobased materials saves, relative to conventional materials, 55 ± 34 gigajoules of primary energy and 3 ± 1 t carbon dioxide equivalents of greenhouse gases. However, biobased materials may increase eutrophication by 5 ± 7 kilograms (kg) phosphate equivalents/t and stratospheric ozone depletion by 1.9 ± 1.8 kg nitrous oxide equivalents/t. Our findings are inconclusive with regard to acidification (savings of 2 ± 20 kg sulfur dioxide equivalents/t) and photochemical ozone formation (savings of 0.3 ± 2.4 kg ethene equivalents/t). The variability in the results of life cycle assessment studies highlights the difficulties in drawing general conclusions. Still, common to most biobased materials are impacts caused by the application of fertilizers and pesticides during industrial biomass cultivation. Additional land use impacts, such as the potential loss of biodiversity, soil carbon depletion, soil erosion, deforestation, as well as greenhouse gas emissions from indirect land use change are not quantified in this review. Clearly these impacts should be considered when evaluating the environmental performance of biobased materials.
Resource-efficient construction : the role of eco-innovation for the construction sector in Europe
(2011)
Development of scientific and technical foundations for a national waste prevention programme
(2010)
In a new waste hierarchy the amended EU Waste Framework Directive (WFD) (2008/98/EG) confirmed the prevention of waste as a priority measure to protect the environment with regard to the production and handling of waste. Amongst others the Member States are requested to promote waste prevention. According to article 29 par. 1 WFD the prevention measures have to be planned in terms of waste prevention programmes to be created by the Member States until December 12th 2013. These prevention programmes are to describe existing waste prevention measures and set waste prevention goals. The progress is to be monitored and assessed by targeting appropriate, specific qualitative or quantitative benchmarks for adopted waste prevention measures. The programmes may be included in waste management plans or other environmental programmes. By the objectives and measures of prevention programmes the environmental impacts associated with generation of waste shall be decoupled from economic growth.
Managing solid waste is one of the biggest challenges in urban areas around the world. Technologically advanced economies generate vast amounts of organic waste materials, many of which are disposed to landfills. In the future, efficient use of carbon containing waste and all other waste materials has to be increased to reduce the need for virgin raw materials acquisition, including biomass, and reduce carbon being emitted to the atmosphere therefore mitigating climate change. At end-of-life, carbon-containing waste should not only be treated for energy recovery (e.g. via incineration) but technologies should be applied to recycle the carbon for use as material feedstocks. Thermochemical and biochemical conversion technologies offer the option to utilize organic waste for the production of chemical feedstock and subsequent polymers. The routes towards synthetic materials allow a more closed cycle of materials and can help to reduce dependence on either fossil or biobased raw materials. This chapter summarizes carbon-recycling routes available and investigates how in the long-term they could be applied to enhance waste management in both industrial countries as well as developing and emerging economies. We conclude with a case study looking at the system-wide global warming potential (GWP) and cumulative energy demand (CED) of producing high-density polyethylene (HDPE) from organic waste feedstock via gasification followed by Fischer–Tropsch synthesis (FTS). Results of the analysis indicate that the use of organic waste feedstock is beneficial if greenhouse gas (GHG) emissions associated with landfill diversion are considered.
Consumption of natural resources should not exceed sustainable levels. The increasing use of biofuels and to some extent biomaterials, on top of rising food and feed demands, is causing countries to use a growing amount of global land, which may lead to land use conflicts and the expansion of cropland and intensive cultivation at the expense of natural ecosystems. Selective product certification cannot control the land use change triggered by growing overall biomass consumption. We propose a comprehensive approach to account for the global land use of countries for their domestic consumption, and assess this level with regard to globally acceptable levels of resource use, based on the concept of safe operating space. It is shown that the European Union currently uses one-third more cropland than globally available on a per capita basis and that with constant consumption levels it would exceed its fair share of acceptable resource use in 2030. As the use of global forests to meet renewable energy targets is becoming a concern, an approach to account for sustainable levels of timber flows is also proposed, based on the use of net annual increment, exemplified with preliminary data for Switzerland. Altogether, our approach would integrate the concept of sustainable consumption into national resource management plans; offering a conceptual basis and concrete reference values for informed policy making and urging countries to monitor and adjust their levels of resource consumption in a comprehensive way, respectful of the limits of sustainable supply.
As illustrated by the case studies of end-of-life vehicles and waste electric and electronic equipment, the approach of an extended producer responsibility is undermined by the exports of used and waste products. This fact causes severe deficits regarding circular flows, especially of critical raw materials such as platinum group metals. With regard to global recycling there seems to be a responsibility gap which leads somehow to open ends of waste flows and a loss or down-cycling of potential secondary resources. Existing product-orientated extended producer responsibility (EPR) approaches with mass-based recycling quotas do not create adequate incentives to supply waste materials containing precious metals to a high-quality recycling and should be amended by aspects of a material stewardship. The paper analyses incentive effects on EPR for the mentioned product groups and metals, resulting from existing regulations in Germany. It develops a proposal for an international covenant on metal recycling as a policy instrument for a governance-oriented framework to initiate systemic innovations along the complete value chain taking into account product group- and resource group-specific aspects on different spatial levels. It aims at the effective implementation of a central idea of EPR, the transition of a waste regime still focusing on safe disposal towards a sustainable management of resources for the complete lifecycle of products.
This contribution presents the state of the art of economy-wide material flow accounting. Starting from a brief recollection of the intellectual and policy history of this approach, we outline system definition, key methodological assumptions, and derived indicators. The next section makes an effort to establish data reliability and uncertainty for a number of existing multinational (European and global) material flow accounting (MFA) data compilations and discusses sources of inconsistencies and variations for some indicators and trends. The results show that the methodology has reached a certain maturity: Coefficients of variation between databases lie in the range of 10% to 20%, and correlations between databases across countries amount to an average R2 of 0.95. After discussing some of the research frontiers for further methodological development, we conclude that the material flow accounting framework and the data generated have reached a maturity that warrants material flow indicators to complement traditional economic and demographic information in providing a sound basis for discussing national and international policies for sustainable resource use.
Overviewing the European carbon (C), greenhouse gas (GHG), and non-GHG fluxes, gross primary productivity (GPP) is about 9.3 Pg yr-1, and fossil fuel imports are 1.6 Pg yr-1. GPP is about 1.25% of solar radiation, containing about 360 × 1018 J energy - five times the energy content of annual fossil fuel use. Net primary production (NPP) is 50%, terrestrial net biome productivity, NBP, 3%, and the net GHG balance, NGB, 0.3% of GPP. Human harvest uses 20% of NPP or 10% of GPP, or alternatively 1‰ of solar radiation after accounting for the inherent cost of agriculture and forestry, for production of pesticides and fertilizer, the return of organic fertilizer, and for the C equivalent cost of GHG emissions. C equivalents are defined on a global warming potential with a 100-year time horizon. The equivalent of about 2.4% of the mineral fertilizer input is emitted as N2O. Agricultural emissions to the atmosphere are about 40% of total methane, 60% of total NO-N, 70% of total N2O-N, and 95% of total NH3-N emissions of Europe. European soils are a net C sink (114 Tg yr−1), but considering the emissions of GHGs, soils are a source of about 26 Tg CO2 C-equivalent yr-1. Forest, grassland and sediment C sinks are offset by GHG emissions from croplands, peatlands and inland waters. Non-GHGs (NH3, NOx) interact significantly with the GHG and the C cycle through ammonium nitrate aerosols and dry deposition. Wet deposition of nitrogen (N) supports about 50% of forest timber growth. Land use change is regionally important. The absolute flux values total about 50 Tg C yr-1. Nevertheless, for the European trace-gas balance, land-use intensity is more important than land-use change. This study shows that emissions of GHGs and non-GHGs significantly distort the C cycle and eliminate apparent C sinks.
The physical dimension of international trade. Part 1: Direct global flows between 1962 and 2005
(2010)
The physical dimension of international trade is attaining increased importance. This article describes a method to calculate complete physical trade flows for all countries which report their trade to the UN. The method is based on the UN Comtrade database and it was used to calculate world-wide physical trade flows for all reporting countries in nine selected years between 1962 and 2005. The results show increasing global trade with global direct material trade flows reaching about 10 billion tonnes in 2005, corresponding to a physical trade volume of about 20 billion tonnes (adding both total imports and total exports). The share from European countries is declining, mainly in favour of Asian countries. The dominant traded commodity in physical units was fossil fuels, mainly oil. Physical trade balances were used to identify the dominant resource suppliers and demanders. Australia was the principal resource supplier over the period with a diverse material export structure. It was followed by mainly oil-exporting countries with varying volumes. As regards to regions, Latin America, south-east Asian islands and central Asia were big resource exporters, mostly with increasing absolute amounts of net exports. The largest net importers were Japan, the United States and single European countries. Emerging countries like the "Asian Tigers" with major industrial productive sectors are growing net importers, some of them to an even higher degree than European countries. Altogether, with the major exception of Australia and Canada, industrialized countries are net importers and developing countries and transition countries are net exporters, but there are important differences within these groups.
Comparative analysis of environmental impacts of maize-biogas and photovoltaics on a land use basis
(2010)
This study aims to stimulate the discussion on how to optimize a sustainable energy mix from an environmental perspective and how to apply existing renewable energy sources in the most efficient way. Ground-mounted photovoltaics (PV) and the maize-biogas-electricity route are compared with regard to their potential to mitigate environmental pressure, assuming that a given agricultural area is available for energy production. Existing life cycle assessment (LCA) studies are taken as abasis to analyse environmental impacts of those technologies in relation to conventional technology for power and heat generation. The life-cycle-wide mitigation potential per area used is calculated for the impact categories non-renewable energy input, green house gas (GHG) emissions, acidification and eutrophication. The environmental performance of each system depends on the scenario that is assumed for end energy use (electricity and heat supply have been contemplated). In all scenarios under consideration, PV turns out to be superior to biogas in almost all studied impact categories. Even when maize is used for electricity production in connection with very efficient heat usage, and reduced PV performance is assumed to account for intermittence, PV can still mitigate about four times the amount of green house gas emissions and non-renewable energy input compared to maize-biogas. Soil erosion, which can be entirely avoided with PV, exceeds soil renewal rates roughly 20-fold on maize fields. Regarding the overall Eco-indicator 99 (H) score under most favourable assumptions for the maize–biogas route, PV has still a more than 100% higher potential to mitigate environmental burden. At present, the key advantages of biogas are its price and its availability without intermittence. In the long run, and with respect to more efficient land use, biogas might preferably be produced from organic waste or manure, whereas PV should be integrated into buildings and infrastructures.