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Wood products may help to avoid fossil emissions when they substitute for more fossil-intensive products. However, the estimates of avoided fossil emissions attributed to wood use tend to be based on incomplete market assumptions. Wood products are assumed to fully substitute for non-wood products, yet substitution rarely occurs 1:1 and wood products can also substitute for each other. This study outlines a systematic procedure grounded on economic theory for approximating the existence and rate of substitution between wood and non-wood products, and calculates the marginal avoided fossil emissions with both conventional assumptions and more realistic assumptions based on an expert survey, taking the case of textile markets. The results suggest that regenerated cellulosic fibers (RCFs) are not perfect substitutes for synthetic fibers, meaning that part of an additional RCF supply will replace established textile fibers while part of it merely adds to the overall textile supply, and thereby aggregate fossil emissions. Moreover, in the long term, RCFs are more likely to substitute for synthetics than for cotton, and in the short term, non-viscose RCFs are more likely to substitute for contemporary viscose than for polyester or cotton. In the specified case, the alteration of market assumptions leads to quadrupling the marginal substitution impacts of wood use. Besides the relatively high fossil intensity of contemporary viscose, this is partly explained by increased absolute aggregate fossil emissions. Producing a more realistic account of substitution processes in the forest products markets is central in directing investments that ensure a net reduction in fossil emissions.

Drained peatlands are a large emission source and a shift to paludiculture (rewetting and cultivation of wet-tolerant plants) is emerging as a potential emission reduction measure. Paludiculture can potentially results in emission savings from direct emissions, product substitution and carbon storage, but the whole life cycle climate impacts are rarely studied. In this study, we evaluated two paludiculture product systems (cattail (Typha) construction board and common reed (Phragmites) horticultural vermicompost) with cradle-to-grave life cycle assessment (LCA) applied global sensitivity analysis to identify, which parts of the product system would need more research and product development to ensure net emission savings. Based on the results, both product systems result in much lower emissions than current agricultural land use and may be net greenhouse gas sinks (average − 6.0 tCO2eq ha−1 for cattail board; −3.0 tCO2eq ha−1 for reed growing media). The uncertainty in the product life cycle is concentrated to a few key processes: the direct CO2 and CH4 emissions from paludiculture, construction board additives, and CH4 emissions from vermicomposting reed. Further research to these would minimize the uncertainty and help in maximizing the climate mitigation potential of paludiculture derived products. Highlights • Paludiculture reduces emissions from agricultural peatlands. • Paludiculture products can store carbon and substitute emission intensive products. • Benefits can be increased by identifying high emission process stages in production. • Life cycle assessment can help in guiding process development.

Small and medium-sized enterprises (SMEs) have a substantial role in the economy and job creation, but they are a remarkable source of environmental impacts. SMEs often lack skills and resources to...

BackgroundThe climate impacts of wood-based products can be measured by substitution impacts and changes in product carbon stocks. Cascade use of wood aims to increase resource efficiency and minimize the impact on the environment and climate, but it may lead to changes in the product portfolios of industries. Thus, measuring the overall impact is challenging. This study analyses the impact of wood cascading on the climate under varying market responses. Cascade use here refers to discarded sawnwood product utilisation in panel and wood-based composite production. The study utilises explorative scenarios where Finnish wood-based flows are modelled in an Excel-based material flow model, and discarded sawnwood flows are shifted from energy use to material use in the end-of-life stage. The Reference case represents the situation where discarded wood-based products are only used for energy. The scenarios portray plausible market responses to cascading, with cascade production either leading to additional wood-based panel and composite production, or substituting primary sawnwood products thus leading to lower overall harvest levels. ResultsThe results show that the cascading can result in 1.6%-5.4% more avoided C emissions compared to reference when considering the substitution impacts, the carbon stock changes in wood products, and the avoided carbon loss from roundwood harvest. Besides the market response, the results vary depending on the time-period selected for the estimation of the average annual carbon stock change of wood products and the emission profile of non-wood products. ConclusionsThe results of this study indicate that cascading can contribute to climate change mitigation regardless of the market response, but it depends on the market response whether the reduction potential origins from wood-based products or indirect changes in the harvest levels. There are less avoided C emission gains in the technosystem, if cascading production substitutes primary production and therefore reduces the wood harvest. However, the opposite holds, if the average substitution impacts are significantly reduced in the future due to decarbonization of non-wood sectors. Thus, in the long-term, extending the carbon residence in the technosystem or in the ecosystem may provide a larger climate change mitigation potential than increasing the substitution impacts. Keywords: carbon stock change, cascading, forest industries, greenhouse gas emissions, harvested wood products, substitution, substitution impact

Background Replacing non-renewable materials and energy with wood offers a potential strategy to mitigate climate change if the net emissions of ecosystem and technosystem are reduced in a considered time period. Displacement factors (DFs) describe an emission reduction for a wood-based product or fuel which is used in place of a non-wood alternative. The aims of this review were to map and assess DFs from scientific literature and to provide findings on how to harmonise practices behind them and to support coherent application. Results Most of the reviewed DFs were positive, implying decreasing fossil GHG emissions in the technosystem. The vast majority of the reviewed DFs describe avoided fossil emissions either both in processing and use of wood or only in the latter when wood processing emissions were considered separately. Some of the reviewed DFs included emissions avoided in post-use of harvested wood products (HWPs). Changes in forest and product carbon stocks were not included in DFs except in a few single cases. However, in most of the reviewed studies they were considered separately in a consistent way along with DFs. DFs for wood energy, construction and material substitution were widely available, whereas DFs for packaging products, chemicals and textiles were scarce. More than half of DFs were calculated by the authors of the reviewed articles while the rest of them were adopted from other articles. Conclusions Most of the reviewed DFs describe the avoided fossil GHG emissions. These DFs may provide insights on the wood-based products with a potential to replace emissions intensive alternatives but they do not reveal the actual climate change mitigation effects of wood use. The way DFs should be applied and interpreted depends on what has been included in them. If the aim of DFs is to describe the overall climate effects of wood use, DFs should include all the relevant GHG flows, including changes in forest and HWP carbon stock and post-use of HWPs, however, based on this literature review this is not a common practice. DFs including only fossil emissions should be applied together with a coherent assessment of changes in forest and HWP carbon stocks, as was the case in most of the reviewed studies. To increase robustness and transparency and to decrease misuse, we recommend that system boundaries and other assumptions behind DFs should be clearly documented.

Highlights • Wood-based substitution benefits are likely to decrease over time • Carbon residence has more importance in the future as an indicator • Energy use of wood should be reduced to increase climate benefits • Global agreement is needed to fund clean technologies and reduce fossil ones To obtain net climate benefits from intensified forest utilization in the short-term, the substitution impact of wood harvesting and increased carbon stocks of wood-based products should be higher than the forest carbon stock loss. However, the product specific substitution impacts change dynamically over time along with technological development, and long-term climate change mitigation strategies need to consider this, as well as the market forces. We identified future pathways enabling globally market viable environments for wood utilization scenarios in Finland resulting in net climate benefits in 2050. We I) indicated substitution impacts in 2050 applying future-oriented parameter modification based on LCA, and developed quantitative target scenarios by altering wood-based product portfolios to achieve required substitution, and II) identified pathways enabling scenarios by applying participatory backcasting. In the scenarios, a major shift from primary energy use to high added-value products including textiles, chemicals, composites and advanced biofuels, or long-lifetime construction products was needed and more lifecycles for wood products by recycling were required. The actions enabling market viable environment focused on the global level policies and consumer perceptions, while actions locally were limited and current production technology development oriented. We recommend multi-target backcasting together with LCA to analyse more synergies and trade-offs.

Forests and forest industries can contribute to climate change mitigation by sequestering carbon from the atmosphere, by storing it in biomass, and by fabricating products that substitute more greenhouse gas emission intensive materials and energy. The objectives of the study are to specify alternative scenarios for the diversification of wood product markets and to determine how an increasingly diversified market structure could impact the net carbon emissions (NCEs) of forestry in Finland. The NCEs of the Finnish forest sector were modelled for the period 2016-2056 by using a forest management simulation and optimization model for the standing forests and soil and separate models for product carbon storage and substitution impacts. The annual harvest was fixed at approximately 70 Mm(3), which was close to the level of roundwood removals for industry and energy in 2016. The results show that the substitution benefits for a reference scenario with the 2016 market structure account for 9.6 Mt C (35.2 Mt CO2 equivalent [CO2 eq]) in 2056, which could be further increased by 7.1 Mt C (26 Mt CO2 eq) by altering the market structure. As a key outcome, increasing the use of by-products for textiles and wood-plastic composites in place of kraft pulp and biofuel implies greater overall substitution credits compared to increasing the level of log harvest for construction. peerReviewed

The EU is aiming to increase the utilisation of renewable energy to 20% of the total energy consumption by 2020. For Finland, the target is 38%. Renewable energy sources are assumed to reduce greenhouse gas emissions when compared to fossil fuels. Yet not all environmental impacts of renewable energy use are thoroughly assessed, and there are no comprehensive assessments on the impacts and risks of renewable energy production that would take into account all possible environmental impacts. We applied qualitative expert knowledge to attain information on the impacts and risks of renewable energy in Finland. According to the expert panel, the overall impacts of renewable energy by 2020 are not significant. However, we found some hot spot areas, i.e. areas of the most concern related to particulate matter formation during regional wood combustion, climate impacts of forest energy, biodiversity impacts connected to several renewable energy sources, and eutrophication caused by utilisation of agricultural energy sources. There are currently no reliable and generally accepted methods to estimate the biodiversity impacts of renewable energy production, thus, this topic would require further studies. The climate change impacts of forest based energy sources are relatively well studied, but the results of these studies are highly variable because of different assumptions on spatial and time scale. A qualitative impact assessment framework, as described in this paper, can be used to assess the environmental impacts of renewable energy production and is a potential option to attain information on the renewable energy impacts as long as reliable and comparable quantitative datasets are not available. These kinds of qualitative assessments can also be applied to detect the areas that need further studies.

Highlights • Displacement factor (DF) describes the substitution climate impact of wood use. • We estimated required displacement factor (RDF) to achieve zero emissions. • RDF should be 2.0–2.4 tC tC−1 for increased wood use in 2017–2116 in Finland. • RDF appears greater than the estimated current average DF. • This is a threat for forest-based bioeconomy from the climate change viewpoint. A displacement factor (DF) may be used to describe the efficiency of using wood-based products or fuels instead of fossil-based ones to reduce net greenhouse gas (GHG) emissions. However, the DFs of individual products and their production volumes could not be used alone to evaluate the climate impacts of forest utilization. For this reason, in this study we have developed a methodology to assess a required displacement factor (RDF) for all wood products and bioenergy manufactured and harvested in a certain country in order to achieve zero CO2 equivalent emissions from increased forest utilization over time in comparison with a selected baseline harvesting scenario. Input data for calculations were produced with the simulation model, Monsu, capable of predicting the carbon stocks of forests and wood-based products. We tested the calculations in Finnish conditions in a 100-year time horizon and estimated the current average DF of manufactured wood-based products and fuels in Finland for the interpretation of RDF results. The results showed that if domestic wood harvesting will be increased by 17–33% compared to the basic scenario, the RDF will be 2.0 to 2.4 tC tC−1 for increased wood use in 2017–2116. However, the estimated average DF of manufactured wood-based products and fuels currently in Finland was less than 1.1 tC tC−1. The results indicate strongly that the increased harvesting intensity from the current situation would represent a challenge for the Finnish forest-based bioeconomy from the viewpoint of climate change mitigation. For this reason, there is an immediate need to improve reliability and applicability of the RDF approach by repeating corresponding calculations in different circumstances and by improving estimations of DFs on country levels.

A sustainable society index (SSI) has been designed to measure the sustainability of different countries in terms of economic, environmental and human well‐being dimensions. These areas were subdivided into eight categories and 24 indicators. The paper shows that the SSI could be considered as a decision‐making problem with multiple objectives. We propose a decision‐analysis approach for estimation of the weights of indicators, categories and dimensions of well‐being, with the target being a construction of overall scores for countries. A questionnaire was sent to experts from several countries, and the weights were estimated from their individual answers. The SSI 2010 results for different countries were recalculated through utilization of the estimated weights. There were some differences in the rankings compared with the earlier results with equal weights. Potential biases of the SSI approach used are critically evaluated, and opportunities to develop the SSI described. Copyright © 2016 John Wiley & Sons, Ltd and ERP Environment

Companies have a central role in the transition towards more sustainable economic systems, as they are one of the major sources of environmental impacts, economic activity and social development. Various tools are available to support sustainability assessments, but there is little information on how suitable they are for company-level assessments and how companies use them in real-life applications. The article examines some of the commonly used tools and the utilisation of these tools in Finnish companies. A sample of seven tools was compiled: multi-criteria decision analysis (MCDA), material flow analysis, life cycle assessment (LCA), input–output models, sustainability indicators and indices, cost–benefit analysis (CBA) and optimisation methods. MCDA, LCA, CBA and optimisation methods were found to be successful with respect to many of the criteria used in the evaluation, but none of them was comprehensive. The assessment indicates that MCDA has the greatest potential to be successfully applie...

Impacts of bioeconomy on climate have been much discussed, but less attention has been given to biodiversity deterioration. One approach to assess biodiversity impacts is Life Cycle Assessment (LCA). Finland is a forested country with intensive forest industries, but only coarse biodiversity LCA methods are available. The aim of this study was to further develop and apply approaches to assess the biodiversity impacts of wood use in Finland. With the species richness approach (all taxons included), biodiversity impacts were higher in Southern than in Northern Finland but impacts in Southern and Northern Finland were lower when mammals, birds and molluscs were included. With the ecosystem indicators approach, if the reference situation were forest in its natural state, biodiversity impacts were higher than in the case where the initial state of forest before final felling was used to derive biodiversity loss. In both cases, the biodiversity impacts were higher in Northern Finland. These results were not coherent as the model applying species richness data assesses biodiversity loss based on all species, whereas the ecosystem indicators approach considers vulnerable species. One limitation of the species richness approach was that there were no reliable datasets available. In the ecosystem indicators approach, it was noticed that the biodiversity of managed Finnish forests is substantially lower than in natural forests. Biodiversity LCA approaches are highly sensitive to reference states, applied model and data. It is essential to develop approaches capable of comparing biodiversity impacts of forest management practices, or when looking at multiple environmental impacts simultaneously with the LCA framework.

Bioenergy production is considered the single most significant contributor to the climate change mitigation within the forest sector. In addition, the production of forest-based bioenergy may also positively affect social welfare, local development and forest economy. In environmental markets the role of forests and the challenge of combining international, national and local needs related to their sustainable use for bioenergy and social livelihood is increasing. These global ecological and socio-economic changes pose new challenges for ecologically, economically, socially and culturally sustainable utilization of forest resources. The purpose of this literature review is to map the existing indicator sets introduced in scientific literature suitable for evaluating the sustainability of forest-based bioenergy production systems from a local perspective. In addition, also the challenges in assessing ecological, economic, social and cultural sustainability by using different types of indicators are discussed. According to the results of this study, there are plenty of indicators suitable for assessing either the ecological, economic, social and cultural sustainability of forest-based bioenergy production at a local level. In contrast, information on appropriate procedures for taking into account local development goals abreast with the objectives of sustainable development at general global level are lacking. Additionally, in order to analyze trade-offs in different sustainability dimensions caused by optional decisions regarding forest-based energy production, methodological development would be required. The comprehensive indicators lists presented in this study can employed as background information to define the measures that are especially relevant in enhancing the local sustainability goals from the perspective of different stakeholders in specific localities.

The sustainability of the utilization of wood biomass for energy and other purposes has been widely assessed in different studies. Especially discrete methods from the family of Multi-Criteria Decision Analysis (MCDA), such as Outranking methods, Multi-Attribute Utility Theory, and Analytic Hierarchy Process (AHP) are often applied. AHP is considered one of the most promising options to be used in sustainability assessments, because it is comprehensible to apply and it incorporates the preferences of decision-makers in an advanced manner. In this study, we present a theoretical multi-dimensional framework based on a modified version of AHP for assessing sustainability and apply it in a case of wood-based bioenergy production in eastern Finland. The framework includes four dimensions of sustainability and life cycle phases from the acquisition of raw material to manufacturing the final product. The production systems used in the empirical sustainability assessments are a local heat production plant, a combined heat and power production plant, and a wood pellet processing plant. Local sustainability experts identified indicators relevant at the regional scale. The impact assessment data were obtained from literature, by interviewing the managers of the bioenergy plants, and from a postal survey administered to local people. The local heat provider received the highest sustainability index; however, there were no considerable differences between the sustainability indexes. None of the bioenergy production systems can be considered the most sustainable regardless of the assumptions employed in the framework. The framework provided the basis for a quantitative, interdisciplinary approach to assess sustainability.

Multi-objective forest planning is a multi-methodological endeavor whose success largely depends on how well the combined use of different methods contributes to the goals of the planning. This review assessed the benefits of mixing methods in natural resources planning. A sample of 30 peer-reviewed research articles was analyzed using an evaluation framework, designed based on democracy and planning theories, and participatory planning literature, including four dimensions: transparency, flexibility, consensus building, and operability. According to analyses, mixing different types (i.e. qualitative and quantitative) of methods generally yields greater benefits than the combination of similar methods. The subsample of 12 planning cases that utilized simulation-optimization software (SOS) appeared operable and moderately transparent, whereas flexibility and consensus building were often lacking. In comparison to the wide scholarly discussion on multi-methodology and mixing methods, it was observed that su...

Weighting in Life Cycle Assessment (LCA) is a much-debated topic. Various tools have been used for weighting in LCA, Multi-Criteria Decision Analysis (MCDA) being one of the most common. However, it has not been thoroughly assessed how weight elicitation techniques of MCDA with different scales (interval and ratio) along with external and internal normalisation affect weighting and subsequent results. The aim of this survey is to compare different techniques in an illustrative example in the building sector. A panel of Nordic LCA experts accomplished six weighting exercises. The different weight elicitation techniques are SWING which is based on the interval scale; Simple Multi-Attribute Rating Technique (SMART) and Analytic Hierarchy Process (AHP) which is based on the ratio scale. Information on the case study was provided for the panellists, along with characterised or normalised impact assessment scores. However, in the first weighting exercise, the panellists were not provided with any scores or background information, but they had to complete the weighting at a more general level. With the weights provided by the panel, the environmental impacts of three alternative house types were aggregated. The calculations were based on three well-grounded aggregation rules, which are commonly used in the field of LCA or decision analysis. In the illustrative construction example, the different aggregation rules had the biggest impact on the results. The results were different in the six calculation methods: when externally normalised scores were applied, house type A was superior in most of the calculations, but when internal normalisation was accomplished, house type C was superior. By using equal weights, similar results were obtained. None of the panellists intuitively considered A as the superior house type, but in some of the calculations, this was indeed the case. Furthermore, the results refer to the fact that the panellists completed the weighting on the basis of their general knowledge, without taking the features of different weight elicitation techniques into account. External normalisation provides information on a magnitude of impacts, and in some cases, external normalisation may be a more influential factor than weighting. Based on the results, it cannot be stated which different weight elicitation technique is the most suitable for LCA. However, the method should be selected based on the aims and purpose of the study. Moreover, the elicitation questions should be explained with care to experts so that they interpret the questions as intended.

Cultural sustainability has become a much discussed topic in the forestry and bioenergy sectors. However, there are not many indicators available for measuring cultural sustainability. In order to identify indicators for the assessment of the cultural sustainability impacts of wood-based bioenergy in eastern Finland, two-phased expert interviews were conducted. The process was supported by a hybrid approach: A qualitative mapping technique was applied when the indicators were identified, and weights for the indicators were set using a quantitative rating technique. The experts identified 49 indicators of cultural sustainability. Most of the generated indicators were relevant for local uses and highlighted the perceptions of the general public. Furthermore, most of the indicators were relevant from the perspective of raw material acquisition. Applying methods of differing backgrounds enabled advanced problem structuring, which allowed the identification of indicators suitable for assessing cultural sustainability of wood-based bioenergy in Eastern Finland. The quantitative rating technique enabled the determination of the importance of the indicators generated. Nevertheless, it seems that the hybrid approaches have many challenges related to the quantitative measuring of the participants’ perceptions. Cultural sustainability indicators should be identified within a case study, since it seems that most of the cultural sustainability indicators are case specific. The process introduced here offers steps for identifying case-specific cultural sustainability indicators; however, the concept of cultural sustainability cannot be strictly defined.

A commonly agreed methodology for weighting the relative importance of different environmental impacts in Life Cycle Assessment (LCA) is lacking, although it is becoming a typical phase in LCA. Multi-Criteria Decision Analysis (MCDA) provides an avenue to develop weighting tools applicable in LCA. The purpose of this paper is to describe a process of assessing environmental impacts of two alternative raw materials and to present the problems related to it. A panel which includes experts in measuring the environmental impacts of biomass production was requested to identify and weight impact categories to assess environmental impacts of biomass production. The panelists identified new environmental impacts (such as biodiversity) not included to the standard LCA. The highest weights were given by the panelists to climate change, natural land use change and biodiversity. The environmental impacts were analyzed for four case biomass production chains producing biodiesel and pulp in Finland. In case chains, the raw material for biodiesel is Asian palm oil or Finnish rapeseed oil, while the raw material for pulp is South American eucalyptus or Finnish birch. The calculations of the LCA impacts were limited to the impact categories for which inventory data were available. In calculations, different types of normalization procedures were tested to receive information on their effects on the LCA results. According to the results, in some cases normalization have considerable impact on the magnitude of the results. In general, the results imply that biomass imported from developing countries has less environmental impacts compared to the local forest and field biomass produced in Finland. However, due to the several sources of uncertainties included in the results, they are only to be used for illustrative purposes. In the future, applying the MCDA in LCA may deepen the applicability of the analyses, if valid and reliable data is available.

Various decision support methods are used to support the sustainable use of natural resources, but there is little evidence about these methods' actual performances. In this study, 35 carefully selected papers assessing the sustainable use of natural resources were evaluated. The evaluated papers utilized one of the following methods: optimization, cost- benefit analysis (CBA) and monetary valuation methods, multi-criteria decision analysis (MCDA) or hybrid approaches. Each method supported sustainability in a different manner. Optimization and CBA case studies rarely involved stakeholders and social sustainability was less processed. Monetary valuation case studies showed a regular participation of the general public, but in a passive role. Experts and stakeholders with an active role were typical participants in MCDA and hybrid case studies. Internationally and nationally defined indicators of sustainability were scarcely used because indicators were frequently defined by stakeholders or the authors of the studied papers. It was presumed that international and national indicators were unsuitable for local use. Sustainability indicators typically took both the quantitative and qualitative form, including gaps and uncertainties. MCDA could be a suitable method for assessing sustainability because it has no strict requirements on the form of the data, and the participation of stakeholders is comprehensive. For the problem structuring phase, however, MCDA might not provide efficient tools. The ideal method for assessing the sustainable use of natural resources could be a hybrid of two methods with different approaches: qualitative methods could be used in the problem structuring process, whereas quantitative methods could be used when priorities and thresholds are assessed.

There is a long tradition of sustainable forest policy in Finland. Today, forests should be managed on the basis of the principles of sustainable forestry. However, economics have driven such forestry practices, resulting in dramatic changes to the natural structure and dynamics of Finnish forests. Commercial forests should, however, also provide habitats for various organisms, and forestry activities should not reduce forest biodiversity. Indicators can provide useful information on the ecological status and trends in sustainable forestry, such information can then be used by decision-makers. In attempts to develop accurate and reliable indicators, it has been suggested that statistical data, inventory data and data on many taxa may prove useful. The richness of game species and the abundance of the Siberian flying squirrel have been considered as candidate indicators for sustainable forestry. Indicators of sustainable forestry are commonly used separately and the interrelations between the ecological, economic and social dimensions of forestry have rarely been studied. In this paper we examine associations between the abundance of animal species (16 game species and Siberian flying squirrels) and their co-occurrence with forest structural characteristics that are considered to be indicators of sustainable forestry. We were also interested in examining regional patterns of the variables, and determining which socio-economic indicators and land-use factors were associated (positively or negatively) with areas of forest for which there were indicators suggesting a good ecological condition. The study area consisted of 39 observation units. Based on our exploratory and descriptive analyses we suggest that using indices for different wildlife species groups and relative abundances of the Siberian flying squirrel together with forest structural characteristics and adequate socio-cultural variables could provide relevant information about trends in sustainable forestry. The application of indicators always depends on socio-cultural contexts and biogeographical factors, and these must be taken into consideration when making predictions or comparing different regions.

Various methods and tools have been applied to assess the sustainable use of forests and other natural resources. However, interpretation of generated results is demanding, often leading to misleading conclusions. One solution to more advanced and transparent sustainability assessments is to combine quantitative and qualitative methodologies (hybrid approach). Qualitative methods could be used to structure the problem, whereas quantitative tools could be assigned to attain numerical information on the rankings of the alternatives. As a result of sub-study I, it could be stated that hybrid approaches appear to be the most suitable methods to assess sustainability. In sub-study II, qualitative mapping technique and Multi-criteria analysis (MCA) were applied to identify and to rate cultural sustainability indicators for comparing four alternative wood-based bioenergy systems. The interviewed experts identified 49 indicators, but the transition phase between methods should be more coherent. In sub-study III, MCA and Life cycle assessment (LCA) were applied for comparing raw materials of pulp and biodiesel. The global biomasses received smaller environmental impact scores than local biomasses. However, it is possible that if biodiversity impacts could be included, the results would favour locally produced raw materials. In sub-study IV, different weighting techniques commonly used in MCA were applied for assessing the environmental impacts of alternative house types. The ranking of houses was highly dependent on the weighting technique and aggregation rules behind them. The main result of this thesis is that sustainability can be assessed with various tools, but there are several methodological and behavioural challenges. There was some evidence of benefits of mixing quantitative and qualitative methods, but more attention should be focused on how the methods are tied together. A more problem-orientated approach for sustainability assessments, with active involvement of stakeholders, would alleviate the process in terms of transparency, operability and acceptability.