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  • 1.
    Penaloza, Diego
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Royne, Frida
    RISE Res Inst Sweden, Gothenburg, Sweden..
    Sandin, Gustav
    RISE Res Inst Sweden, Gothenburg, Sweden..
    Svanstrom, Magdalena
    Chalmers Univ Technol, Div Environm Syst Anal, Gothenburg, Sweden..
    Erlandsson, Martin
    IVL Swedish Environm Res Inst, Stockholm, Sweden..
    The influence of system boundaries and baseline in climate impact assessment of forest products2019Ingår i: The International Journal of Life Cycle Assessment, ISSN 0948-3349, E-ISSN 1614-7502, Vol. 24, nr 1, s. 160-176Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PurposeThis article aims to explore how different assumptions about system boundaries and setting of baselines for forest growth affect the outcome of climate impact assessments of forest products using life cycle assessment (LCA), regarding the potential for climate impact mitigation from replacing non-forest benchmarks. This article attempts to explore how several assumptions interact and influence results for different products with different service life lengths.MethodsFour products made from forest biomass were analysed and compared to non-forest benchmarks using dynamic LCA with time horizons between 0 and 300years. The studied products have different service lives: butanol automotive fuel (0years), viscose textile fibres (2years), a cross-laminated timber building structure (50years) and methanol used to produce short-lived (0years) and long-lived (20years) products. Five calculation setups were tested featuring different assumptions about how to account for the carbon uptake during forest growth or regrowth. These assumptions relate to the timing of the uptake (before or after harvest), the spatial system boundaries (national, landscape or single stand) and the land-use baseline (zero baseline or natural regeneration).Results and discussionThe implications of using different assumptions depend on the type of product. The choice of time horizon for dynamic LCA and the timing of forest carbon uptake are important for all products, especially long-lived ones where end-of-life biogenic emissions take place in the relatively distant future. The choice of time horizon is less influential when using landscape- or national-level system boundaries than when using stand-level system boundaries and has greater influence on the results for long-lived products. Short-lived products perform worse than their benchmarks with short time horizons whatever spatial system boundaries are chosen, while long-lived products outperform their benchmarks with all methods tested. The approach and data used to model the forest carbon uptake can significantly influence the outcome of the assessment for all products.ConclusionsThe choices of spatial system boundaries, temporal system boundaries and land-use baseline have a large influence on the results, and this influence decreases for longer time horizons. Short-lived products are more sensitive to the choice of time horizon than long-lived products. Recommendations are given for LCA practitioners: to be aware of the influence of method choice when carrying out studies, to use case-specific data (for the forest growth) and to communicate clearly how results can be used.

  • 2.
    Peñaloza, Diego
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Exploring climate impacts of timber buildings: The effects from including non-traditional aspects in life cycle impact assessment2015Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    There is an urgency within the building sector to reduce its greenhouse gas emissions and mitigate climate change. An increased proportion of biobased building materials in construction is a potential measure to reduce these emissions. Life cycle assessment (LCA) has often been applied to compare the climate impact from biobased materials with that from e.g. mineral based materials, mostly favouring biobased materials. Contradicting results have however been reported due to differences in methodology, as there is not yet consensus regarding certain aspects. The aim of this thesis is to study the implications from non-traditional practices in climate impact assessment of timber buildings, and to discuss the shortcomings of current practices when assessing such products and comparing them with non-renewable alternatives.

    The traditional practices for climate impact assessment of biobased materials have been identified, and then applied to a case study of a building with different timber frame designs and an alternative building with a concrete frame. Then, non-traditional practices were explored by calculating climate impact results using alternative methods to handle certain methodological aspects, which have been found relevant for forest products in previous research such as the timing of emissions, biogenic emissions, carbon storage in the products, end-of-life substitution credits, soil carbon disturbances and change in albedo. These alternative practices and their implications were also studied for low-carbon buildings.

    The use of non-traditional practices can affect the climate impact assessment results of timber buildings, and to some extent the comparison with buildings with lower content of biobased building materials. This effect is especially evident for energy-efficient buildings. Current normal practices tend to account separately for forest-related carbon flows and aspects such as biogenic carbon emissions and sequestration or effects from carbon storage in the products, missing to capture the forest carbon cycle as a whole. Climate neutrality of wood-based construction materials seems like a valid assumption for studies which require methodological simplification, while other aspects such as end-of-life substitution credits, soil carbon disturbances or changes in albedo should be studied carefully due to their potentially high implications and the uncertainties around the methods used to account for them. If forest phenomena are to be included in LCA studies, a robust and complete model of the forest carbon cycle should be used. Another shortcoming is the lack of clear communication of the way some important aspects were handled.

    Ladda ner fulltext (pdf)
    Thesis
  • 3.
    Peñaloza, Diego
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial. RISE - Research Institutes of Sweden.
    Future scenarios for climate change mitigation of new building construction in Sweden: Effects of different technological pathwaysManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Climate mitigation strategies are required with urgency. The Swedish construction sector contributes to a significant share of the country’s yearly greenhouse gas (GHG) emissions. A variety of alternative climate mitigation strategies is available aimed to different processes and activities related to production and operation of buildings. Several studies evaluating the effectiveness of these strategies have been performed at the building stock level. These studies however do not consider the technological change in manufacturing of building materials. The objective of this study is to evaluate the climate change mitigation effects of increasing the use of biobased materials in the construction of new residential buildings in Sweden under different scenarios related to technological change in material manufacturing. For this, the climate impact from Swedish new buildings has been assessed for the coming one hundred years using a model that combines scenario analysis based on official statistics and life cycle assessment of seven different building typologies. Eight different scenarios for increased use of low-impact building typologies such as timber buildings and low-impact concrete are explored under different pathways for growth of their market share and changes in energy production. The results show that the benefits from an increased use of biobased materials are significant in all scenarios evaluated, but decrease if the use of low-impact concrete expands more rapidly or under optimistic scenarios for energy production. Results are also highly sensitive to the choice of climate impact metric. Results also show that the Swedish construction sector can only reach maximum climate change mitigation scenarios if all the low-impact typologies are implemented together and rapidly, including a rapid switch to cleaner energy.

  • 4.
    Peñaloza, Diego
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial. RISE - Research Institutes of Sweden.
    The influence of system boundaries and baseline in climate impact assessment of forest productsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Purpose

    This article aims to explore how different assumptions about system boundaries and setting of baselines for forest growth affect the outcome of climate impact assessments of forest products during life cycle assessment (LCA), including potential climate impact mitigation from replacing non-forest benchmarks. This article attempts to explore how several assumptions interact and influence results for different products with different service life lengths.

    Methods

    Four products made from forest biomass were analysed and compared to non-forest benchmarks using dynamic LCA with time horizons between 0 and 300 years. The studied products have different service lives: butanol automotive fuel (0 years), viscose textile fibres (2 years), a cross-laminated timber building structure (50 years) and methanol used to produce short-lived (0 years) and long-lived (20 years) products. Five calculation setups were tested featuring different assumptions about how to account for the carbon uptake during forest growth or regrowth. These assumptions relate to the timing of the uptake (before or after harvest), the spatial system boundaries (national, landscape and single stand approaches) and the land use baseline (zero baseline and natural regeneration).

    Results and discussion

    The implications of using different assumptions depend on the type of product. The choice of time horizon for dynamic LCA and the timing of forest carbon uptake are important for all products, especially long-lived ones where end-of-life biogenic emissions take place in the relatively distant future. The choice of time horizon is less influential when using landscape or national spatial boundaries than when using a stand approach, but has great influence on the results for long-lived products. The influence of the methodological choices studied in the comparison of the products with their benchmarks has divergent outcomes. Short-lived products perform worse than their benchmarks with short time horizons whatever spatial boundaries are chosen, while long-lived products outperform their benchmarks with all methods tested.

    Conclusions

    The choices of spatial boundaries, temporal boundaries and land use baseline have a large influence on the results, but this influence decreases for longer time horizons. Short-lived products are more sensitive to the choice of time horizon than long-lived products. Recommendations are given for LCA practitioners: to be aware of the influence of method choice when carrying out studies, to prioritise case-specific data for forest growth and to communicate clearly how results should be used and interpreted.

  • 5.
    Peñaloza, Diego
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial. RISE - Research Institutes of Sweden.
    The role of biobased building materials in the climate impacts of construction: Effects of increased use of biobased materials in the Swedish building sector2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Irreversibel global påverkan på klimat och miljö måste undvikas och olika strategier som begränsar klimatförändringarna kan utnyttjas för att hantera denna utmaning. En betydande andel av de globala utsläppen av växthusgaser kan hänföras till byggsektorn i allmänhet och cementproduktion i synnerhet, och begränsningsstrategier söker alternativ till fossil- och mineralbaserade resurser, med mindre påverkan, som exempelvis en ökad användning av biobaserade material i byggandet. Livscykelanalys (LCA) har använts för att demonstrera klimatnyttan av denna ökning, men skogens komplexiteter i samband med biogent koldioxid skapar osäkerhet i resultaten då de som genomför LCA-studier traditionellt utelämnar viktiga nyckelaspekter.

    Denna avhandling syftar till att öka förståelsen för effekterna av en ökad användning av biobaserade material för begränsning av byggandets klimatpåverkan i ett livscykelperspektiv. Forskningsfrågorna formulerades med fokus på att identifiera icke-traditionell LCA-metodik, samt att bedöma miljöeffekterna av en ökad användning av biobaserade material med redovisning av dessa aspekter på olika nivåer, gällande enstaka konstruktioner och byggnadsbeståndet som helhet. Den metodik som används är dynamisk LCA i kombination med data om skogskolbalans, med analyser av flera scenarier med olika metodologiska antaganden. Fallstudier med olika kännetecken användes, nämligen en byggnad, en bilvägsbro och en uppskattning av det svenska byggnadsbeståndet på lång sikt.

    Resultaten bekräftar att en ökad användning av biobaserade material minskar klimatpåverkan av byggandet – en tydlig majoritet av de scenarier som analyserats för alla fallstudier resulterar i sänkt klimatpåverkan. Införandet av icke-traditionella LCA-aspekter påverkar resultatet, men förändrar inte att en ökad användning av biobaserade material resulterar i lägre långsiktig och kumulativ klimatpåverkan. Resultaten visar också att den maximala klimatbegränsningspotentialen endast nås genom att samtidigt införa andra tekniska lösningar med lägre klimatpåverkan. När det gäller LCA-metodik visar resultaten att antagandet att biobaserade byggnadsmaterial är klimatneutrala är en överförenkling eftersom deras klimatpåverkan beror på fallspecifika faktorer och därför bör inga generaliseringar göras. Några av dessa klimatpåverkande faktorer beror på modellering av skogssystemet i en dynamisk LCA; såsom när skogstillväxten antas börja i förhållande till avverkningen, den geografiska upplösningen för att analysera de biogena kolflödena dvs. som ett avverkningsbestånd eller på landskapsnivå och vad utgångsläget sätts till vid analys av skogens markanvändning. Andra faktorer beror på LCA-modellering, nämligen valet av integrerad tidshorisont för beräkning av klimatpåverkan, det antagna scenariot för avfallshantering och lagringsperioden för det biogena kolet i tillverkade produkter.

    För att minska osäkerheten i bedömning av klimatpåverkan av biobaserade byggmaterial rekommenderas användning av minst en mätmetod som gör det möjligt att bedöma koldioxidutsläppen baserat på tidpunkten på dessa, samt att tillämpa mätvärden med långa tidsperspektiv. Redovisning av icke-traditionella aspekter har en betydande effekt på klimatpåverkan av biobaserade byggmaterial. Utförare av analyser rekommenderas därför även att redovisa hur dessa aspekter hanteras och att ställa upp flera olika scenarier och analysera dessa med flera olika metodologiska inställningar. Slutligen rekommenderas att ta hänsyn till den tekniska utvecklingen vid analyser av långsiktig klimatpåverkan av byggnadsbeståndet som genomförs med dynamiska värden för processer som äger rum i framtiden.

    Ladda ner fulltext (pdf)
    fulltext
  • 6.
    Peñaloza, Diego
    et al.
    KTH. RISE Res Inst Sweden, Eklandagatan 86, S-41261 Gothenburg, Sweden.
    Erlandsson, Martin
    IVL Swedish Environm Res Inst, Valhallavagen 8, S-11427 Stockholm, Sweden..
    Berlin, Johanna
    RISE Res Inst Sweden, Eklandagatan 86, S-41261 Gothenburg, Sweden..
    Wålinder, Magnus
    KTH.
    Falk, Andreas
    KTH.
    Future scenarios for climate mitigation of new construction in Sweden: Effects of different technological pathways2018Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 187, s. 1025-1035Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A variety of climate mitigation strategies is available to mitigate climate impacts of buildings. Several studies evaluating the effectiveness of these strategies have been performed at the building stock level, but do not consider the technological change in building material manufacturing. The objective of this study is to evaluate the climate mitigation effects of increasing the use of biobased materials in the construction of new residential dwellings in Sweden under future scenarios related to technological change. A model to estimate the climate impact from Swedish new dwellings has been proposed combining official statistics and life cycle assessment data of seven different dwelling typologies. Eight future scenarios for increased use of harvested wood products are explored under different pathways for changes in the market share of typologies and in energy generation. The results show that an increased use of harvested wood products results in lower climate impacts in all scenarios evaluated, but reductions decrease if the use of low-impact concrete expands more rapidly or under optimistic energy scenarios. Results are highly sensitive to the choice of climate impact metric. The Swedish construction sector can only reach maximum climate change mitigation scenarios if the low-impact building typologies are implemented together and rapidly.

  • 7.
    Peñaloza, Diego
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Erlandsson, Martin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Falk, Andreas
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Exploring the climate impact effects of increased use of bio-based materials in buildings2016Ingår i: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 125, s. 219-226Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Whenever Life Cycle Assessment (LCA) is used to assess the climate impact of buildings, those with high content of biobased materials result with the lowest impact. Traditional approaches to LCA fail to capture aspects such as biogenic carbon exchanges, their timing and the effects from carbon storage. This paper explores a prospective increase of biobased materials in Swedish buildings, using traditional and dynamic LCA to assess the climate impact effects of this increase. Three alternative designs are analysed; one without biobased material content, a CLT building and an alternative timber design with “increased bio”. Different scenario setups explore the sensitivity to key assumptions such as the building's service life, end-of-life scenario, setting of forest sequestration before (growth) or after (regrowth) harvesting and time horizon of the dynamic LCA. Results show that increasing the biobased material content in a building reduces its climate impact when biogenic sequestration and emissions are accounted for using traditional or dynamic LCA in all the scenarios explored. The extent of these reductions is significantly sensitive to the end-of-life scenario assumed, the timing of the forest growth or regrowth and the time horizon of the integrated global warming impact in a dynamic LCA. A time horizon longer than one hundred years is necessary if biogenic flows from forest carbon sequestration and the building's life cycle are accounted for. Further climate impact reductions can be obtained by keeping the biogenic carbon dioxide stored after end-of-life or by extending the building's service life, but the time horizon and impact allocation among different life cycles must be properly addressed.

  • 8.
    Peñaloza, Diego
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial. RISE - Research Institutes of Sweden.
    Erlandsson, Martin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Pousette, Anna
    Climate impacts from road bridges: effects of introducing concrete carbonation and biogenic carbon storage in wood2018Ingår i: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 14, nr 1, s. 56-67Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The construction sector faces the challenge of mitigating climate change with urgency. Life cycle assessment(LCA), a widely used tool to assess the climate impacts of buildings, is seldom used for bridges. Materialspecificphenomena such as concrete carbonation and biogenic carbon storage are usually unaccountedfor when assessing the climate impacts from infrastructure. The purpose of this article is to explore theeffects these phenomena could have on climate impact assessment of road bridges and comparisonsbetween bridge designs. For this, a case study is used of two functionally equivalent design alternativesfor a small road bridge in Sweden. Dynamic LCA is used to calculate the effects of biogenic carbon storage,while the Lagerblad method and literature values are used to estimate concrete carbonation. The resultsshow that the climate impact of the bridge is influenced by both phenomena, and that the gap betweenthe impacts from both designs increases if the phenomena are accounted for. The outcome is influencedby the time occurrence assumed for the forest carbon uptake and the end-of-life scenario for the concrete.An equilibrium or 50/50 approach for accounting for the forest carbon uptake is proposed as a middlevalue compromise to handle this issue.

  • 9.
    Peñaloza, Diego
    et al.
    SP Technical Research Institute of Sweden.
    Norén, Joakim
    SP Technical Research Institute of Sweden.
    Eriksson, Per-Erik
    SP Technical Research Institute of Sweden.
    Decreasing the carbon footprint of energy efficientbuildings, what comes next?2013Ingår i: Passivhus Norden 2013, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    A full LCA was conducted to explore the contribution from each life cycle stage to the carbonfootprint of energy efficient buildings, and the role of bio-based materials as future potentialalternatives to decrease further carbon emissions in the building sector. Eight different designalternatives with comparable functionality were evaluated for Wälluden, a four-storey multi-familybuilding in Växjö, Sweden. The designs include three different building systems; volumetric modules,massive timber structural elements and a column-beam structure as well as the original design of thebuilding from 1995 both with wood and concrete frame structures. The three new designs weremodelled under conventional and passive house energy efficiency categories. A square meter ofliving area was used as the functional unit, and a service life of one hundred years was assumed. Theanalysis includes processes from raw material extraction, manufacturing of building materials,construction, energy generation for the use phase, selected maintenance activities, demolition anddisposal of the building waste. Concrete carbonation phenomena, carbon storage and end-usebenefits from substituting fossil energy effects with wood material waste were also explored. Theresults show that the benefits of more use phase energy efficient designs are significant, but as theuse-phase impact lowers and there is less improvement potential; both the production and end-usephase become more relevant. Indeed, for the passive house design, the production phase carbonfootprint is of the same order as for a one hundred years use phase. For the production phase,increasing the share of bio-based products can decrease significantly the carbon footprint of theproduction phase of a building, no matter which building system is chosen. Bio-based materials havehigher potential environmental benefits for the end-use phase, even as there are uncertainties overthe fate of materials in future waste management systems.

  • 10. Royne, Frida
    et al.
    Penaloza, Diego
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial. SP Technical Research Institute of Sweden, Sweden.
    Sandin, Gustav
    Berlin, Johanna
    Svanström, Magdalena
    Climate impact assessment in life cycle assessments of forest products: implications of method choice for results and decision making2016Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 116, s. 90-99Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As life cycle assessments are often conducted to provide decision support, it is important that impact assessment methodology is consistent with the intended decision context. The currently most used climate impact assessment metric, the global warming potential, and how it is applied in life cycle assessments, has for example been criticised for insufficiently accounting for carbon sequestration, carbon stored in long-lived products and timing of emission. The aim of this study is to evaluate how practitioners assess the climate impact of forest products and the implications of method choice for results and decision-making. To identify current common practices, we reviewed climate impact assessment practices in 101 life cycle assessments of forest products. We then applied identified common practices in case studies comparing the climate impact of a forest-based and a non-forest-based fuel and building, respectively, and compared the outcomes with outcomes of applying alternative, non-established practices. Results indicate that current common practices exclude most of the dynamic features of carbon uptake and storage as well as the climate impact from indirect land use change, aerosols and changed albedo. The case studies demonstrate that the inclusion of such aspects could influence results considerably, both positively and negatively. Ignoring aspects could thus have important implications for the decision support. The product life cycle stages with greatest climate impact reduction potential might not be identified, product comparisons might favour the less preferable product and policy instruments might support the development and use of inefficient climate impact reduction strategies.

  • 11.
    Røyne, Frida
    et al.
    SP Technical Research Institute of Sweden.
    Peñaloza, Diego
    SP Technical Research Institute of Sweden.
    Sadin, Gustav
    SP Technical Research Institute of Sweden.
    Berlin, Johanna
    SP Technical Research Institute of Sweden.
    Svanström, Magdalena
    Chalmers, Sweden.
    Climate impact assessment in LCAs of forest products: Implications of method choice for results and decision-makingManuskript (preprint) (Övrigt vetenskapligt)
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