Impact of closed-loop network configurations on carbon footprints: A case study in copiers

Growing concerns about the environment make a supply chains’ eco-footprint increasingly important, presuming that footprints are a more effective (policy) instrument than those currently in use. The eco-footprint comprises all kinds of environmental impact, but often is narrowed down to one aspect; e.g. the carbon footprint, material footprint, the water footprint, and so on. Although returns give rise to an additional goods flow from customers back to producers, it usually improves the eco-footprint due to the substitution effect. The reverse channel supplies high quality (recovered) products, components and materials to the forward channel thereby reducing the need for virgin sourcing and production. We refer to this as closed-loop recovery, as opposed to recovery for cascade markets which lacks substitution. To maximize substitution, the recovered items must re-enter the original supply chain. The feasibility of closed-loop recovery depends partly on the geographical proximity of forward and reverse facilities. We develop a decision framework for optimizing closed loop network configurations, i.e. the combined disposition and location–transport decision. We apply the framework to a single case study concerning one type of footprint (namely the carbon footprint) of a copier (closed-loop) supply chain. The main implication is that a regional network, with combined forward and reverse facilities per continent, proves most efficient and most robust in view of uncertain exogenous variables, but only when a full set of closed-loop options is available (including closed-loop recycling). As an embedded case, main contribution value of it lies in the discovery of a new phenomenon with generic implications; namely that not only the closed-loop supply chains footprint strongly depends on the substitution effect, but that in turn the feasibility of closed-loop recovery options depends heavily on the network design. From delineations of the study we derive issues for further research.     

Assessment of the coherence of the Swiss waste wood management

Waste wood recovery by thermal treatment with energy recovery or by recycling allows the substitution and conservation of primary resources. Swiss government notes the potential presence of tensions between policies which simultaneously encourage the cascade use of wood, the recycling or the energy recovery by thermal treatment of waste wood. The aim of the present research is to assess the coherence of waste wood management in Switzerland by a quantitative and qualitative approach. First, a material flow analysis allows to model the wood resources and waste wood metabolism over one century. The simulation results of various scenarios of waste wood management establish that the additional impacts of the immediate thermal treatment are less significant for the reduction of CO₂eq emissions but more significant for the energy production than its cascade treatments on Swiss territory. Secondly, a documentary analysis examines the determinants of the current waste wood treatments prevailing in Switzerland. Thus, the causes of the strong presence on Swiss territory of the sector of thermal treatment, the export of almost half of waste wood generated and the sub-exploitation of Swiss forest act as barriers or drivers that result in introducing a crowding-out effect where no amount of waste wood is available for recycling in Switzerland. The comparison of the results of the two approaches leads to the conclusion that the current waste wood management is coherent in relation to the various goals of the Swiss federal policies but the waste wood potential for energy production is not fully exploited. The recommendations on the waste wood management and the possibilities to use the model for other case studies are given in the conclusion.     

Perceptions, attitudes and interest of Swedish architects towards the use of wood frames in multi-storey buildings

Use of wood frames from sustainable forestry instead of non-wood frames in multi-storey buildings can reduce primary energy use and carbon dioxide emissions in construction. However, construction actors might have different perceptions towards wood frames than towards steel and concrete frames. Such perceptions may influence the actors’ decision to adopt wood frames. In this study we use a web-based questionnaire to assess Swedish architects’ perceptions, attitudes and interest towards steel, concrete and wood frames in multi-storey buildings (n = 412). Results indicate that the responding architects find concrete the most suitable frame material in buildings of 3-8 storeys, mainly because of the performance of concrete with regards to the engineering aspects (e.g. stability and fire safety) that were considered important in the choice of frame material. Although wood is considered the least suitable frame material, the overall attitude towards, and interest in, using wood is positive and related to the perceived environmental benefits of wood. This may derive from an increased discussion of and information about the environmental impact of buildings. Wood may be perceived as new and innovative while not considered as adequately proven as steel and concrete with regards to engineering aspects.     

Circulation indices: new tools for analyzing the structure of material cascades

An improved understanding of the cascading structure of recycling is important for increasing resource productivity. The cascading theory, developed to analyze resource cascading, has two major dimensions; resource quality and resource lifetime. The latter is the only dimension for which a quantitative evaluation has been carried out in the previous research. In this study, we propose new tools to quantify both dimensions. These tools enable statistical estimation of the times of utilization of the material cascaded. The pre-circulation index (pre-CI) counts how many times the material has been utilized before consumption. For material in which quality deterioration is measurable largely on the basis of the number of utilization times, pre-CI can be an index of resource quality. The post-circulation index (post-CI) counts how many times the material will be utilized after consumption. The higher the number of utilization times, the longer the lifetime of the material. Thus, post-CI can be an index of resource lifetime. Total-circulation index (TCI) is the sum of pre- and post-CIs. This can be an overall index of resource productivity. We apply the method presented herein to an analysis of the paper recycling system in Japan. Some important features of the CIs are demonstrated by the results; certain potential remains for further improvements in paper recycling in Japan. In the case that two products have the same utilization rates, their pre-CIs can still differ according to the positions they occupy in the cascade. In the case that two recycling policies achieve the same size of primary raw material reduction, they can still differ in their impact to the whole cascade. By the method described herein, the CIs can represent the structure of a material cascade quantitatively and offer important knowledge by which to increase resource productivity.     

Long-term engineering properties of recycled plastic lumber used in pier construction

Plastic lumber manufactured using post consumer waste plastic has been proposed as an acceptable material for use in the construction of docks, piers and bulkheads and is touted to outlast conventional wood products due to its strength, durability and resistance to rot. This study examines the long-term engineering properties of plastic lumber manufactured using post consumer waste plastic (TRIMAX, Ronkonkoma, NY). Plastic lumber profiles were used in the decking of a pier built in West Meadow Creek, Old Field, NY during December 1995. Samples of plastic lumber were removed from the deck of the pier periodically over a two-year period and returned to the laboratory for testing. Results of engineering tests showed the in-plane compression modulus (260±30 MPa), dimensional stability and the Shore D surface hardness (60±2) of plastic lumber removed from the pier remained similar to or greater than their pre-placement values. In contrast, significant changes in the modulus of elasticity of plastic lumber were measured with prolonged weathering. The modulus of elasticity of plastic lumber initially decreased from 1370 Pa to 750 Pa following 12 months weathering, a decrease equal to 45% of its pre-placement value and then increased during the second year to close to its initial value. The high variability in the modulus of elasticity should restrict the use of plastic lumber profiles to non-load bearing structural applications.     

Carbon accounting rules and guidelines for the United States forest sector

The United States Climate Change Initiative includes improvements to the U.S. Department of Energy's Voluntary Greenhouse Gas Reporting Program. The program includes specific accounting rules and guidelines for reporting and registering forestry activities that reduce atmospheric CO2 by increasing carbon sequestration or reducing emissions. In the forestry sector, there is potential for the economic value of emissions credits to provide increased income for landowners, to support rural development, to facilitate the practice of sustainable forest management, and to support restoration of ecosystems. Forestry activities with potential for achieving substantial reductions include, but are not limited to: afforestation, mine land reclamation, forest restoration, agroforestry, forest management, short-rotation biomass energy plantations, forest protection, wood production, and urban forestry. To be eligible for registration, the reported reductions must use methods and meet standards contained in the guidelines. Forestry presents some unique challenges and opportunities because of the diversity of activities, the variety of practices that can affect greenhouse gases, year-to-year variability in emissions and sequestration, the effects of activities on different forest carbon pools, and accounting for the effects of natural disturbance.     

Waste Management and Climate Change

Waste management has at least five types of impacts on climate change, attributable to: (1) landfill methane emissions; (2) reduction in industrial energy use and emissions due to recycling and waste reduction; (3) energy recovery from waste; (4) carbon sequestration in forests due to decreased demand for virgin paper; and (5) energy used in long-distance transport of waste: A recent USEPA study provides estimates of overall per-tonne greenhouse gas reductions due to recycling. Plausible calculations using these estimates suggest that countries such as the US or Australia could realise substantial greenhouse gas reductions through increased recycling, particularly of paper.     

One step forward toward characterization: some important material properties to distinguish biochars

Terra Preta research gave evidence for the positive influence of charred organic material (biochar) on infertile tropical soils. Facing global challenges such as land degradation, fossil energy decline, water shortage, and climate change, the use of biochar as a soil amendment embedded into regional matter cycles seems to provide an all-round solution. However, little is known about biochar effects on individual ecosystem processes. Besides, the term is used for a variety of charred products. Therefore, the aim of this study was to investigate principal material properties of different chars to establish a minimum set of analytical properties and thresholds for biochar identification. For this purpose, chars from different production processes (traditional charcoal stack, rotary kiln, Pyreg reactor, wood gasifier, and hydrothermal carbonization) were analyzed for physical and chemical properties such as surface area, black carbon, polycyclic aromatic hydrocarbons, and elemental composition. Our results showed a significant influence of production processes on biochar properties. Based on our results, to identify biochar suitable for soil amendment and carbon sequestration, we recommend using variables with the following thresholds: O/C ratio <0.4, H/C ratio <0.6, black carbon >15% C, polyaromatic hydrocarbons lower than soil background values, and a surface area >100 m g.     

Waste Management and Climate Change

Waste management has at least five types of impacts on climate change, attributable to: (1) landfill methane emissions; (2) reduction in industrial energy use and emissions due to recycling and waste reduction; (3) energy recovery from waste; (4) carbon sequestration in forests due to decreased demand for virgin paper; and (5) energy used in long-distance transport of waste: A recent USEPA study provides estimates of overall per-tonne greenhouse gas reductions due to recycling. Plausible calculations using these estimates suggest that countries such as the US or Australia could realise substantial greenhouse gas reductions through increased recycling, particularly of paper.     

Implications of Land Use Changes on Carbon Dynamics and Sequestration—Evaluation from Forestry Datasets, India

Forests and soils are a major sink of carbon, and land use changes can affect the magnitude of above ground and below ground carbon stores and the net flux of carbon between the land and the atmosphere. Studies on methods for examining the future consequences of changes in patterns of land use change and carbon flux gains importance, as they provide different options for CO₂ mitigation strategies. In this study, a simulation approach combining Markov chain processes and carbon pools for forests and soils has been implemented to study the carbon flows over a period of time. Markov chains have been computed by converting the land use change and forestry data of India from 1997 to 1999 into a matrix of conditional probabilities reflecting the changes from one class at time t to another class time t+1. Results from Markov modeling suggested Indian forests as a potential sink for 0.94 Gt carbon, with an increase in dense forest area of about 75.93 Mha and decrease of about 3.4 Mha and 5.0 Mha in open and scrub forests, if similar land use changes that occurred during 1997–1999 would continue. The limiting probabilities suggested 34.27 percent as dense forest, 6.90 as open forest, 0.4 percent mangrove forest, 0.1 percent scrub and 58 percent as non-forest area. Although Indian forests are found to be a potential carbon sink, analysis of results from transition probabilities for different years till 2050 suggests that, the forests will continue to be a source of about 20.59 MtC to the atmosphere. The implications of these results in the context of increasing anthropogenic pressure on open and scrub forests and their contribution to carbon source from land use change and forestry sector are discussed. Some of the mitigation aspects to reduce greenhouse gas emissions from land use change and forestry sector in India are also reviewed in the study.     

Effects of increased wood energy consumption on carbon storage in forests of the United States

Large but feasible increases that have been projected for the production of wood energy in the United States can be expected to significantly alter the current carbon storage patterns in US forest vegetation. The 1976 net wood increment left after forest cutting equals about 136 × 10⁶ tons of carbon/year, with about 60% of the increment found in merchantable trees, and the remainder in nonmerchantable components.Achieving 5–10 quads of wood energy beyond 1976 levels by the year 2010 can significantly change current carbon storage patterns with the magnitude of change dependent on the extent of residue harvest to meet energy goals, and the rate of future forest growth. Complete loss of the apparent net wood increment is a possible outcome.Although the future growth and harvest situation cannot be known now, a range of possible scenarios suggests that US forests in the year 2010 will store much less carbon than today, thus significantly changing their role in the global carbon cycle.     

Environmental impact of meat meal fertilizer vs. chemical fertilizer

Animal by-products (ABP) are rich in nutrients and energy. This LCA study assessed and compared the environmental impact of using meat meal as fertilizer with that of using chemical fertilizer. In one system the nutrient content of ABP Category 2 was recovered and used as a meat meal fertilizer on arable land, replacing chemical fertilizers. In the other system a chemical fertilizer was used and the energy content of the ABP material recovered. The functional unit consisted of one kg of harvested spring wheat and treatment of 0.59 kg of ABP Category 2. The system for nutrient recovery and chemical fertilizer replacement had lower emissions of greenhouse gases and acidification than the energy recovery system, but had higher total use of energy and eutrophying emissions. Overall, the results of the study greatly depended on the fuels replaced.     

Land use change effects on forest carbon cycling throughout the southern United States

We modeled the effects of afforestation and deforestation on carbon cycling in forest floor and soil from 1900 to 2050 throughout 13 states in the southern United States. The model uses historical data on gross (two-way) transitions between forest, pasture, plowed agriculture, and urban lands along with equations describing changes in carbon over many decades for each type of land use change. Use of gross rather than net land use transition data is important because afforestation causes a gradual gain in carbon stocks for many decades, while deforestation causes a much more rapid loss in carbon stocks. In the South-Central region (Texas to Kentucky) land use changes caused a net emission of carbon before the 1980s, followed by a net sequestration of carbon subsequently. In the Southeast region (Florida to Virginia), there was net emission of carbon until the 1940s, again followed by net sequestration of carbon. These results could improve greenhouse gas inventories produced to meet reporting requirements under the United Nations Framework Convention on Climate Change. Specifically, from 1990 to 2004 for the entire 13-state study area, afforestation caused sequestration of 88 Tg C, and deforestation caused emission of 49 Tg C. However, the net effect of land use change on carbon stocks in soil and forest floor from 1990 to 2004 was about sixfold smaller than the net change in carbon stocks in trees on all forestland. Thus land use change effects and forest carbon cycling during this period are dominated by changes in tree carbon stocks.     

Silvicultural management in maintaining biodiversity and resistance of forests in Europe-the Mediterranean region

Outstanding features of Mediterranean forest area are highlighted with a special reference to biodiversity and connections with forest management. The naturally originated and anthropogenic progress of the mosaic-like evolution, as well as the man-induced factors and natural constraints are described. The past and present close linkages between management and biodiversity are then analysed by means of a few, outstanding cases typical of the geographical region. The management shift on increasing economically marginal forest area (abandonment) appears to be the major force currently driving connections with inherent and associated biodiversity. The goals following the new-established environmental roles of forests have shifted towards adaptive management, namely the implementation of locally tailored rules in accordance with prominent forest functions. Key priorities to face up to the new scenarios are then discussed.Economic and policy implications are addressed with reference to multipurpose forestry and the related annual flow of outputs. It is shown the role of water-related services, as well the provision of various non-wood forest products and public goods in addition to wood and other traditional forest outputs. Reference is also made to the dualism between the Northern and the South-Eastern Mediterranean countries due to different level of economic development (and pressure of forest resources) together with very different institutional structures, i.e. public ownership in Southern and South-Eastern Mediterranean countries. Nevertheless, the situation is going to become more harmonious in the medium run by growing economic development, the affirmation of local rights on forest resources, globalisation and, above all, rural out migration and exchanges of peoples confirming the traditional role of the Mediterranean Region at cross road of South-North and Eastern-Western cultures.     

The environmental history of Chatthin Wildlife Sanctuary, a protected area in Myanmar (Burma)

We reconstructed the history of Chatthin Wildlife Sanctuary (CWS) to understand how social and economic events, and policy changes affected the sanctuary's condition. We surveyed 25 villages surrounding CWS to evaluate past and present ecological conditions, compare the results with historical accounts and identify causal relationships. During the first half of the 20th century, the primary threat was the government's reduction of old growth forest to supply fuel wood for the British-built railway. The railroad opened the area to colonization, but the villagers' impact on timber and wildlife was low. From 1945 to 1988, villagers became the primary force of landscape degradation. The post-war windfall of firearms increased hunting pressure, and populations of large mammal started to decline. With the economic decline of the 1970s and 1980s, the community's demand for game and forest products intensified, and the large mammal fauna was reduced from eleven to four species. From 1988-2003, the forests surrounding the sanctuary were fragmented and degraded. The absence of large predators rendered the park safe for livestock, and the combined effects of grazing and removal of forest products seriously degraded habitat within CWS. Major threats to CWS during the past two decades have resulted from land use decisions in which government-planned economic enterprises caused encroachment by villagers. Stabilization and recovery of this sanctuary will require management compatible with human needs, including expanded buffer zones, better core area protection, community forestry projects, and probably relocation of villages within the park.     

Energy planning and wood balances

Woodfuel balances are commonly used by energy planners in developing countries to determine the adequacy of woodfuel resources. Recently, critics have argued that wood balances are misleading in their simplicity, exaggerating both the severity of the woodfuel shortage and the need for planned interventions to solve that problem. This paper examines four different wood balances developed for Tanzania. While the four studies all indicate that areas with miombo woodlands are in the greatest wood surplus, the specific estimates for any given region may differ widely. Despite their shortcomings, energy planners need woodfuel balances to give an impression of the adequacy of woodfuel resources. However, if energy planning is to have any effect, these balances must represent the beginning, and not the end result, of the planning process. Planners must follow the wood-energy balance analysis with work utilizing local people to solve local problems.     

Understanding and Integrating Local Perceptions of Trees and Forests into Incentives for Sustainable Landscape Management

We examine five forested landscapes in Africa (Cameroon, Madagascar, and Tanzania) and Asia (Indonesia and Laos) at different stages of landscape change. In all five areas, forest cover (outside of protected areas) continues to decrease despite local people's recognition of the importance of forest products and services. After forest conversion, agroforestry systems and fallows provide multiple functions and valued products, and retain significant biodiversity. But there are indications that such land use is transitory, with gradual simplification and loss of complex agroforests and fallows as land use becomes increasingly individualistic and profit driven. In Indonesia and Tanzania, farmers favor monocultures (rubber and oil palm, and sugarcane, respectively) for their high financial returns, with these systems replacing existing complex agroforests. In the study sites in Madagascar and Laos, investments in agroforests and new crops remain rare, despite government attempts to eradicate swidden systems and their multifunctional fallows. We discuss approaches to assessing local values related to landscape cover and associated goods and services. We highlight discrepancies between individual and collective responses in characterizing land use tendencies, and discuss the effects of accessibility on land management. We conclude that a combination of social, economic, and spatially explicit assessment methods is necessary to inform land use planning. Furthermore, any efforts to modify current trends will require clear incentives, such as through carbon finance. We speculate on the nature of such incentive schemes and the possibility of rewarding the provision of ecosystem services at a landscape scale and in a socially equitable manner.     

Key factors that influence households’ tree planting behaviour

Despite a decrease in indigenous forests and a growing demand for tree products in developing countries, tree planting activities are not considerably expanding in Tanzania. In this paper, we analyse factors that influence households’ tree planting behaviour, as well as the number of trees planted. Coast and Morogoro regions in the east of Tanzania were selected as the case, and data was gathered from 202 households in 11 villages in these regions where tree planting programmes have been or still are active. A Heckman model is used to analyse the factors that drive tree planting behaviour. Results indicate that households get wood energy from forest reserves (57%), in addition to their own planted trees (9.1%). Emperical findings show that the most important factors have significantly positive effects on households’ tree planting behaviour, as well as the extent to which it was implemented. These factors include households’ land sizes, households’ awareness of tree planting programmes, tree planting for wood energy, and the age of the head of the household. The right/freedom to harvest and transport tree products, households’ attitudes towards tree planting, and family size have significantly negative effects on households’ tree planting behaviour. This paper is perhaps the first comprehensive study to analyse the factors that influence households’ tree planting behaviour in Tanzania, and it uncovers results that are useful, even for other developing countries with similar conditions.     

Economics and GHG emission reduction of a PLA bio-refinery system—Combining bottom-up analysis with price elasticity effects

This paper analyses energy savings, GHG emission reductions and costs of bio-refinery systems for polylactic acid (PLA) production. The systems comprise ‘multi-functional’ uses of biomass resources, i.e. use of agricultural residues for energy consumption, use of by-products, and recycling and waste-to-energy recovery of materials. We evaluate the performance of these systems per kg of bio-based polymer produced and per ha of biomass production. The evaluation is done using data of Poland assuming that biomass and PLA production is embedded in a European energy and material market. First, the performance of different bio-refinery systems is investigated by means of a bottom-up chain analysis. Second, an analysis is applied that derives market prices of products and land depending on the own-price elasticity of demand. Thus, the costs of bio-refinery systems depending on the demand of land and material are determined. It is found that all PLA bio-refinery systems considered lead to net savings of non-renewable energy consumption of 70–220 GJ/(ha yr) and net GHG emission reductions of 3–17 Mg CO_2eq/(ha yr). Most of these PLA bio-refinery systems lead to net costs for the overall system of up to 4600 €/(ha yr). PLA production from short rotation wood leads to net benefits of about 1100 €/(ha yr) if a high amount of a high value product, i.e. fibres, is produced. Multi-functionality is necessary to ensure the viability of PLA bio-refinery systems from biomass with regard to energy savings and GHG emission reduction. However, the multi-functional use of biomass does not contribute much to overall incomes. Multifunctional biomass use – especially the use of biomass residues for energy consumption – contributes significantly to savings of non-renewable energy sources. Own-price elasticity of the demand for materials influences the overall costs of the bio-refinery system strongly. The own-price elasticity of land demand markets could become important if bio-refineries are introduced on a large scale.     

Trade-Offs Between Forest Protection and Wood Supply in Europe

Forest protection is one of the main measures to prevent loss of biological and landscape diversity. This study aimed to assess to what extent forests are currently protected and how felling restrictions affect the potential annual wood supply within 27 European Union member states, Norway, and Switzerland and to discuss trade-offs between intensified use of forest biomass and forest protection efforts. Protected forests covered 33 million ha (20 % of total forest area) in 2005, of which 16 million ha was protected for biodiversity and the remaining area for landscape diversity. Within the protected areas, on average 48 % of the volume cannot be harvested in forests protected for biodiversity and 40 % in forests protected for landscapes. Consequently, 73 million m³ (10 % of the annual theoretical potential supply from the total forest area) of wood cannot be felled from the protected forests in Europe. Protected forests do not necessarily affect wood supply given the current demand for wood in Europe. However, if demand for wood from European forests for material and energy use significantly increases, the impact of existing protected forest networks may become significant after all. On the other hand, wood harvesting is allowed to a fair extent in many protected areas. Hence, the question could be raised whether biodiversity and landscape diversity within designated areas are sufficiently protected. Careful planning is required to accommodate both the protection of biological and landscape diversity and demand for wood, while not forgetting all other services that forests provide.