In response to the ever-intensifying urgency for environmental preservation, the imperative for sectors with substantial carbon footprints to adapt and drive the transition to a low carbon economy is apparent. Sustainability transitions, signifying systemic changes towards sustainable socio-technical systems, emerge as critical in this context, especially within the banking sector. This industry, anchored by its pervasive Information Technology (IT) infrastructure, stands as a key actor in the paradigm shift towards global sustainability. This study investigates the implications of the global transition towards net-zero emissions by 2050 for the IT strategy of banks. This transition necessitates significant changes in the banking sector’s practices, with a particular focus on reducing energy consumption and promoting sustainable operations. The paper presents an in-depth investigation of the factors that banks need to address when adapting their IT strategy to align with these imminent changes. The research methodology followed a qualitative research design, with semi-structured interviews conducted among banking sector practitioners serving as the primary data collection method. Additionally, the study applied the Technological-Organizational-Environmental (TOE) framework to analyze the adoption of sustainable practices in the banking sector. This framework allowed for a comprehensive understanding of the multifaceted nature of the transition towards net-zero emissions, considering the intertwined aspects of technology, organization, and environment. The findings of this research reveal significant insights into the key drivers and strategies required for banks as they make decisions about their IT strategies, particularly in response to the transition towards net-zero emissions. The urgency of environmental sustainability and its integration into strategic planning have emerged as primary drivers, leading to the adoption of Green IT for balancing operational efficiency with environmental responsibility. This strategy has influenced banks’ responses and adaptation by prompting introspective resource management, integrating sustainability into organizational culture, and shaping an environmentally conscious workforce. In conclusion, despite facing various complexities, banks are demonstrating resilience and adaptability in their transition towards sustainability, indicating a future of continuous innovation and transformative practices firmly rooted in sustainability. The findings from this research significantly contribute to the existing body of knowledge, offering deeper insights into the interplay between banking practices and the urgent transition towards net-zero emissions. Future research could further enrich this understanding byassessing the effectiveness of banks’ sustainability initiatives, their achievements against set sustainability targets, and the evolving role of Green IT in driving sustainable banking. / Det växande behovet av miljömässig hållbarhet markerar tydligt nödvändigheten för sektorer med storakoldioxidavtryck att anpassa sig och driva övergången till en ekonomi med minskade koldioxidutsläpp. Övergången till hållbarhet, som innebär systematiska förändringar mot hållbara socio-tekniska system, framstår som avgörande i detta sammanhang, särskilt inom banksektorn. Denna bransch, förankrad av sin omfattande IT-infrastruktur, är en viktig aktör i det paradigmskifte som leder mot global hållbarhet. Denna studie undersöker vad den globala övergången mot nettonollutsläpp fram till 2050 innebär för bankernas IT-strategier. Denna övergång kräver omfattande anpassningar inom banksektorn, med särskild inriktning på att minska energiförbrukningen och främja hållbara verksamhetsmetoder. Rapporten presenterar en djupgående undersökning av de faktorer som banker behöver ta hänsyn till när de anpassar sin IT-strategi för att möta dessa förestående förändringar. Studiemetoden följde en kvalitativ forskningsdesign, med semistrukturerade intervjuer genomförda bland experter och yrkesverksamma inom banksektorn som den primära metoden för datainsamling. Studien applicerade dessutom ramverket Technological-Organizational-Environmental (TOE) för att analysera införandet av hållbara praxis i banksektorn. Detta ramverk möjliggjorde en omfattande förståelse för den flerdimensionella naturen av övergången mot nettonollutsläpp, med hänsyn till de sammankopplade aspekterna av teknik, organisation och externa faktorer. Studiens resultat ger värdefulla insikter om de huvudsakliga drivkrafterna och strategierna som bankerna behöver för att fatta beslut om sina IT-strategier, särskilt i samband med övergången till nettonollutsläpp. Det kritiska behovet av miljömässig hållbarhet och dess integrering i strategisk planering har vuxit fram som centrala drivkrafter, vilket har lett till att Grön IT har antagits för att balansera operativ effektivitet med miljömässigt ansvarstagande. Denna strategi har påverkat bankers respons och anpassning genom att stödja självgranskande resurshantering, integrera hållbarhet i organisationskulturen, och forma en miljömedveten arbetskraft. Sammanfattningsvis, trots mångfald av utmaningar, visar banker motståndskraft och anpassningsförmåga i sin övergång mot hållbarhet, vilket indikerar en framtid av kontinuerlig innovation och omformande metoder som är starkt förankrade i hållbarhet. Resultaten från denna studie bidrar till det befintliga kunskapsfältet, och erbjuder djupare insikter i samspelet mellan bankpraxis och den kritiska övergången mot nettonollutsläpp. Framtida studier kan ytterligare berika denna förståelse genom att utforska effektiviteten i bankers hållbarhetsinitiativ, deras framsteg mot uppsatta hållbarhetsmål, och den utvecklande rollen för Grön IT i att driva hållbar bankverksamhet.

It is known that the decarbonization of our economy is crucial for our quest to mitigate climate change and build a sustainable society. Governments are reviewing strategies to eliminate, or at least minimize, the release of carbon emissions into the atmosphere. These efforts are not limited to national energy networks, but also extended to industry and other carbon-intensive sectors. In general, the Pulp & Paper industry is regarded as bio-based and relatively sustainable since most of its raw materials are recycled or come from biogenic sources. However, this is an energy-intensive industry, and even though bioenergy covers most of the energy needs at pulp plants, recycled paper mills do not count on the same resources and rely heavily on fossil fuels to power their operations. This study was performed to assess and compare different decarbonization pathways available for a recycled paper mill. For this, operational data was gathered to characterize the thermal and electric demands and assess locally available resources. Simultaneously, scientific literature was consulted to assemble a technology portfolio, from which the most suitable technologies were selected. Carbon capture and storage, electrification, and hydrogen were chosen to be tested, under different scenarios, using an energy modelling software. Finally, the combinations were evaluated and compared. It was found that under ideal conditions it is possible to achieve an emissions reduction of almost 100% via electrification and hydrogen-based options. However, this would represent a significant increase in the operating cost of the energy system and would depend on the development of the necessary infrastructure. The most promising alternative for this site was a combination of electrification and green electricity purchase agreements. However, further work is needed to improve the efficiency of the energy use and generation, to achieve a carbon-neutral operation without incurring elevated costs. / Det är känt att avkarboniseringen av vår ekonomi är avgörande för vår strävan att mildra klimatförändringarna och bygga ett hållbart samhälle. Regeringar ser över strategier för att eliminera, eller åtminstone minimera, utsläpp av koldioxid i atmosfären. Dessa ansträngningar är inte begränsade till nationella energinät, utan sträcker sig även till industrin och andra kolintensiva sektorer. Massa- och pappersindustrin är biobaserad och relativt hållbar eftersom de flesta av dess råvaror återvinns eller kommer från biogena källor. Detta är dock en energiintensiv industri, och även om bioenergin täcker det mesta av energibehovet vid massafabrikerna, räknar inte återvunnet pappersbruk med samma resurser som är starkt beroende av fossila bränslen för att driva sin verksamhet. Denna studie utfördes för att bedöma och jämföra olika avkolningsvägar tillgängliga för ett återvunnet pappersbruk. För detta samlades operativa data in för att karakterisera de termiska och elektriska kraven och bedöma lokalt tillgängliga resurser. Samtidigt konsulterades vetenskaplig litteratur för att sammanställa en teknologiportfölj, från vilken de mest lämpliga teknologierna valdes ut. Kolavskiljning och lagring, elektrifiering och väte valdes ut för att testas, under olika scenarier, med hjälp av en mjukvara för energimodellering. Slutligen utvärderades och jämfördes kombinationerna. Man, fann att det under ideala förhållanden är möjligt att uppnå en utsläppsminskning på nästan 100 % via elektrifiering och vätebaserade alternativ. Detta skulle dock innebära en betydande ökning av driftskostnaden för energisystemet och skulle bero på utvecklingen av den nödvändiga infrastrukturen. Det mest lovande alternativet för denna plats var en kombination av elektrifiering och köp av grön el. Det krävs dock ytterligare arbete för att effektivisera energianvändningen och energiproduktionen, för att uppnå en koldioxidneutral drift utan förhöjda kostnader.

<p dir="ltr">The chemical industry faces unprecedented pressure to reduce its carbon footprint while meeting growing global demand. As a major contributor to greenhouse gas emissions, accounting for approximately 7% of global carbon release, the sector plays a crucial role in achieving net-zero goals. This challenge is further compounded by projections suggesting that demand for chemicals could increase up to four-fold by 2050, and by the sector's role in producing several raw materials for other industries.</p><p dir="ltr">Within this context, endothermic reactors are of particular concern. The production of ethylene, propylene, and hydrogen alone accounts for around 3.6% of global CO2 emissions, representing over half of the chemical industry's total release. This situation underscores the need for alternatives in reactor design and operation.</p><p dir="ltr">To address these challenges, we introduce novel decarbonized process schemes and unit operations. The research centers around the development of Electric Reaction Towers (ERTs), a novel reactor configuration designed to ensure consistent product composition despite intense process fluctuations, such as those associated with Variable Renewable Energy (VRE). This is achieved by creating Custom Non-linear Heat Profiles (CNHPs) that maintain the key dimensionless groups of the system under dynamic conditions.</p><p dir="ltr">We present the concept of ERTs, explore their key principles, and the intuition behind their design. Additionally, we introduce Modular Reaction Towers (MRTs), which retain the benefits of handling fluctuations while addressing the investment and logistical challenges of adopting electric reactors.</p><p dir="ltr">The research employs a combination of Dimensional Analysis, Process Simulations, and Computational Fluid Dynamics (CFD) to evaluate these novel designs. Using ethylene production as a case study, we demonstrate that ERTs can enhance output by up to 4.2 times compared to state-of-the-art industrial designs.</p><p dir="ltr">The study further explores several additional concepts: Intermediate Cooling Zones (ICZs) and their potential to optimize complex reaction systems; the application of MRTs in the decentralized production of liquid hydrocarbons from shale gas to reduce flaring; and TurboQuenching, a novel approach to rapidly cool reaction products without a cooling agent while co-producing power. Finally, we discuss the broader implications of these innovations for the chemical industry's transition to more sustainable and efficient production methods.</p><p dir="ltr">By fundamentally re-thinking reactor design, this research contributes to the development of more efficient and sustainable production methods in the chemical industry, supporting the transition to a Net-Zero future.</p><p><br></p>

La conception des bâtiments à consommation énergétique nette zéro (BCENN) a été introduite pour limiter la consommation d'énergie et les émissions polluantes dans les bâtiments. Le défi dans la conception de BCENN est de trouver la meilleure combinaison de stratégies de conception qui feront face aux problèmes de performance énergétique d'un bâtiment particulier. Cette thèse présente une méthodologie pour l'optimisation multicritères basée sur la simulation des BCENN. La méthodologie proposée est un outil utile pour améliorer la conception des BCENN et faciliter la prise de décision dans les premières phases de la conception des bâtiments. L’amélioration des bâtiments en matière d'efficacité énergétique nécessite une optimisation des paramètres passifs. Une étude complète sur la conception passive optimale pour les bâtiments résidentiels est présentée. Le confort thermique adaptatif des occupants est également amélioré en mettant en œuvre les stratégies de refroidissement passif appropriées telles que les dispositifs d’occultation et la ventilation naturelle. Les caractéristiques des systèmes de conditionnement de l’air et de production d’énergie mis en œuvre dans les BCENN doivent être sélectionnées avec soin pour garantir l'objectif de performance prévu. Dans cette thèse, six ensembles de systèmes énergétiques sont comparés et optimisés, pour la conception de BCENN dans des climats représentatifs choisis, à savoir Indore (besoin de froid dominant), Tromso (besoin de chaud dominant) et Beijing (climat mixte). / The conception of net zero energy buildings (NZEB) has been introduced to limit energy consumption, global warming potentials, and pollution emissions in buildings. The challenge in NZEB design is to find the best combination of design strategies that will enhance the energy performance of a particular building. The aim of this thesis is to develop an understanding of NZEBs design concepts. Besides, it aims to assist NZEB designers to select the suitable design options of passive and RE systems based on a systemic evaluation in different climates. This thesis presents a methodology for the simulation-based multi-criteria optimization of NZEBs. The methodology is applied to investigate the cost-effectiveness potential for optimizing the design of NZEBs in different case studies taken as diverse climatic zones. The proposed methodology is a useful tool to enhance NZEBs design and to facilitate decision making in early phases of building design. A comprehensive study on optimal passive design for residential buildings is presented. The occupants’ adaptive thermal comfort is also improved by implementing the appropriate passive cooling strategies such as blinds and natural ventilation. The configurations and capacities of the implemented RE systems in NZEBs must be appropriately selected to ensure the intended performance objective. In the thesis, investigation, optimization and comparison of six RE solution sets for designing NZEBs is carried out in three typical climates: Indore (cooling dominant), Tromso (heating dominant) and Beijing (mixed climate).

Countries' long-term climate targets are described by different concepts who, over time, have become increasingly dependent on negative emissions technologies (NETs) in order for the targets to be reached. This thesis is a cross country comparison, examining similarities and differences in the concepts used by seven countries to express their long-term climate targets, focusing on their plans for implementing NETs. The empirical material was collected from interviews with experts from each country. Concepts in long-term climate targets can have various interpretations and there are uncertainties about what emissions that are covered within the different concepts. NETs are crucial for achieving any type of net-zero target however they are in nascent stages, except for forest management, and there are several factors affecting the possibilities to implement NETs. It is important not to focus too much on NETs to comply with the long-term climate targets, NETs should function as a complement to emissions reduction and target the unavoidable emissions. We recommend that countries clarify what emissions are included within their concept, set out specific targets for NETs and lastly put a great effort into clarifying policy instruments related to NETs. / Ländernas långsiktiga klimatmål beskrivs av olika begrepp som är beroende av negativa utsläppstekniker för att målen ska nås. Denna avhandling är en jämförelse mellan sju länder där ländernas likheter och skillnader undersöks genom deras val av begrepp och även deras planer för att implementera tekniker för att nå negativa utsläpp. Det empiriska materialet samlades in från intervjuer med experter från varje land. Begrepp i de långsiktiga klimatmålen kan ha olika tolkningar och det råder osäkerhet om vilka utsläpp som täcks upp inom de olika begreppen. Negativa utsläppstekniker är avgörande för att uppnå alla typer av netto-nollmål men de befinner sig i väldigt tidiga faser av utveckling, förutom skog som redan finns på plats och det finns flera faktorer som påverkar möjligheterna att implementera negativa utsläppstekniker. Det är viktigt att inte fokusera för mycket på negativa utsläppstekniker för att uppfylla de långsiktiga klimatmålen, de bör fungera som ett komplement till utsläppsminskning och rikta in sig på de oundvikliga utsläppen. Vi rekommenderar att länder klargör vilka utsläpp som ingår i begreppen, fastställer specifika mål för negativa utsläppstekniker och slutligen satsar mycket på att klargöra policyinstrument relaterade till negativa utsläppstekniker.

<p dir="ltr">Smart windows, dynamically adjusting optical transmittance, face global adoption challenges due to climatic and economic variability. Aiming these issues, we synthesized a methyl cellulose (MC) salt system with high tunability for intrinsic optical transmittance (89.3%), which can be applied globally to various locations. Specifically, the MC window has superior heat shielding potential below transition temperatures while turning opaque at temperatures above the Lower Critical Solution Temperature (LCST), reducing the solar heat gain by 55%. Such optical tunability is attributable to the particle size change triggered by the temperature-induced reversible coil-to-globular transition. This leads to effective refractive index and scattering modulation, making them prospective solutions for light management systems, an application ahead of intelligent fenestration systems. MC-based windows demonstrated a 9°C temperature decrease compared to double-pane windows on sunny days and a 5°C increase during winters in field tests, while simulations predict an 11% energy savings.</p><p dir="ltr">Incorporating MC-based phase change materials in passive solar panels indicated optimized energy efficiency, offering a sustainable alternative. Real-time simulations validate practical applicability in large-scale solar panels. Furthermore, a temperature-responsive sorbent with a dark layer demonstrates an optimal optical and water uptake performance. Transitioning between radiative cooling and solar heating, the sorbent exhibits high water harvesting efficiency in lab and field tests. With an adjustable LCST at 38 ℃, the cellulose-based sorbent presents a potential solution for atmospheric water harvesting, combining optical switching and temperature responsiveness for sustainable water access. Furthermore, the ubiquitous availability of materials, low cost, and ease-of-manufacturing will provide technological equity and foster our ambition towards net-zero buildings and sustainable future.</p>

‘Nature-positive’ (NP) is emerging as an increasingly used term, intended to encompass goals aimed at reversing the global decline in biodiversity and the incessant destruction of ecosystems. The 1.5-degree goal of the Paris agreement has become a unifying target in the climate discourse, accompanied by the guiding concept of ‘net-zero’ emissions. Anequivalent, widely accepted target for biodiversity has been called for, with NP being named a contender to take this position. However, the concept NP, and net-zero alike, have been subject to criticism. Building on an extensive literature search, this study seeks to identify and analyse the most frequently employed definitions of NP, and who promotes them. It also aims to draw conclusions from a comparative analysis where definitions of NP are mapped onto the IPBES- promoted Nature Futures Framework (NFF). For this purpose, an assessment tool (‘the NFF Mixing Triangle’) is presented. The study finds that NP is frequently used without specifying its meaning, in scientific and non-scientific literature alike. While existing dominant definitions are largely aligned on the conceptual level, there is a lack of consensus on a common definition among stakeholders. The Global Goal for Nature (GG4N) stands out as the most referenced source for defining NP, and is found to have the strongest alignment with NFF. While problematising and discussing criticism, the study suggests a number of focus areas that could serve the future potential of NP. This includes converging NP definitions, balancing definitions across the NFF value dimensions, and considering applicability across multiple scales. An aspiration to consolidate guiding frameworks, use of the Mitigation Hierarchy to strengthen the robustness of NP, and focus on stewardship inside corporations as well as across sectors and value chains, is proposed. Meanwhile, the study suggests that the external drivers of legislation and regulation, and the current growth paradigm and consumption patterns, need to be addressed in concert if NP is to have a real contribution to sustainability transformation.

<h2><br></h2> <p>This dissertation consists of distinct but related essays that delve into the impacts of changing economic conditions and climate mitigation policies on household consumption, health, and welfare outcomes. The first essay examines the effect of variations in economic factors, such as home values, on unhealthy consumption behaviors in the U.S. The second essay examines the distributional effects and possible health advantages of climate mitigation policies in India. The findings in this dissertation have significant implications for preventive health and environmental justice policies, particularly concerning vulnerable populations. </p> <p>The first essay of this dissertation investigates the impact of home value fluctuations on household tobacco and alcohol consumption in the U.S., specifically focusing on consumption based on homeownership status. First, we utilize high-frequency household transaction panel data and ZIP code-level home values to estimate the causal effect of home value fluctuations (or the housing wealth effect) on household tobacco and alcohol consumption for all U.S. households. Second, we predict household homeownership status by supplementing our primary household panel transaction data with a secondary household survey dataset; this allowed us to estimate the housing wealth effect separately for homeowners and renters. Home values are a leading economic indicator and effectively represent variation in housing wealth, whereas prior literature mainly focuses on lagging economic indicators, such as the unemployment rate. Housing wealth is a significant component of household net worth in the U.S. We leverage temporal and geographic fluctuations in household transactions and local home values to show that changes in housing wealth have a causal effect on household tobacco and alcohol consumption. Our findings show that declining home values increase tobacco and alcohol consumption among homeowners, with no effect on renters. Beer and cigarettes mainly drive this effect. Declining home values substantially increase annual consumption of nicotine, tar, carbon monoxide, and alcohol by volume, exacerbating public health concerns. In contrast, unemployment shocks increase tobacco and alcohol consumption among homeowners and decrease it among renters. The housing wealth effect is most pronounced among bubble states households, heavy-use consumers, low-income, and white households. The study emphasizes the importance of targeted policy interventions to mitigate the negative effects of fluctuations in housing wealth on unhealthy consumption, especially amid the current unpredictable economic environment and volatile real estate market. </p> <p>The second essay of this dissertation analyzes the distributional impacts of climate mitigation policies consistent with India’s 2030 Nationally Determined Contribution and 2070 net-zero target, using a dynamic global computable general equilibrium (CGE) model with heterogeneous Indian households. Specifically, we expand the CGE model to incorporate ten rural and ten urban household income deciles. Additionally, we link the CGE model with a global atmospheric source-receptor model to derive health co-benefits from reduced premature mortality due to lower air pollution. Several policy levers are considered in this study, including carbon pricing, enhanced coal consumption tax (or coal cess), and fossil subsidies phaseout. These are further combined with five alternative revenue recycling options. Our results suggest the potential welfare costs of such mitigation policies are rather moderate and do not exceed 0.5% over 2023-2050, not accounting for health and environmental co-benefits and damages avoided by successfully limiting global temperature rise to well below 2°C. However, health co-benefits from lower air pollution can potentially outweigh the mitigation costs. Combining carbon pricing and fossil subsidy removal is more efficient than carbon pricing alone, generating progressive medium-term welfare gains due to reduced market distortions. Raising coal cess rates is the least efficient policy. Inequality and distributional impacts vary significantly based on the chosen revenue recycling approach. Equal transfer of tax revenue across households proves to be the most efficient and equitable, followed by labor tax subsidies, leading to a Gini index and S20/S80 ratio reduction of 0.01%-1.7% and 0.1%-7%, respectively. Recycling revenues to stimulate green energy investments yields the least favorable distributional impacts and worsens inequality. Trade-offs exist between reducing inequality and fostering investment-driven economic growth when choosing revenue recycling options. Policymakers should prioritize policy mixes and revenue-recycling methods based on their objectives to effectively combat climate change while promoting sustainable growth and reducing income inequality in India. </p>

To strengthen support for climate action initiatives, this study analyzes how municipalities manage their stakeholders as part of the NetZeroCities mission, which is an initiative targeting selected European cities aiming to achieve net zero greenhouse gas emissions by 2030. This research utilizes the method of a case study, focussing on the process of a major city in Sweden, transitioning to net zero by 2030. Through the lens of Stakeholder and Network Theory it discovers how collaboration and networks within the city are established and maintained. The study uses a qualitative approach and utilizes three types of data collection methods: semi-structured Interviews with members of the municipality as well as stakeholders; Document Analysis of the NetZeroCities Contract of the municipality; a group Interview with local politicians. To analyze the empirical data we used the process of coding and a further categorization, which built the base for data analysis. The research highlights the importance of inclusive engagement, education, and awareness in promoting collaborative sustainability efforts. It underscores the value of sufficient communication channels, broad participation, strong networks and creative problem-solving. It also reveals gaps in the municipality's performance: a lack of communication strategies targeting the general public, limited networking opportunities for businesses, and a lack of unified management across departments and organizations, highlighting the need for unified leadership to integrate climate goals into daily practice. The study advocates for a closer, more structured collaboration between municipalities and stakeholders and stresses the need for strong interdisciplinary networks. It also emphasizes the necessity for education and communication efforts aimed at the general public in order to increase awareness and a sense of ownership of climate actions.

Bygg- och fastighetssektorn stod för 22% av Sveriges totala växthusgasutsläpp år 2021 vilket är en ökning med 1,9 % jämfört med föregående år. Det tydliggör behovet av ett mer hållbart byggande för att uppnå Sveriges klimatmål att uppnå noll nettoutsläpp senast år 2045. Det krävs en branschomställning där traditionella byggmetoder byts ut mot mer klimatneutrala arbetsprocesser, något som är utmanande idag. För att möta utmaningar har Bygg- och anläggningsföretagen antagit en färdplan 2045 som presenterar nio åtgärder för byggsektorn för att uppnå klimatneutralitet. Syftet med denna studie är att undersöka tillvägagångssätt och nya arbetsprocesser för en byggentreprenör i enlighet med åtgärderna i Färdplan 2045. För att möjliggöra studien har sex projekt och konsult intervjuats med hjälp av semi-strukturerad intervjuteknik för att få en djupare inblick i projektet. De djupare inblicken kan bidra till en ökad förståelse kring vilka hinder och klimatneutrala åtgärder som en byggentreprenör använder sig av. Resultatet presenteras i tabeller för att skapa en överblick kring återkommande klimateffektiva arbetsprocesser och eventuella hinder som hämmar klimatneutrala byggprojekt i enlighet med Färdplan 2045.Studien har identifierat flera klimatneutrala arbetsprocesser som använts i fallstudierna i olika omfattningar. Anpassning av arbetsprocesser utgör till stor del av beställarkraven och hållbarhetsambitionerna i projektet. Varsamma renoveringar har varit centrala, i synnerhet för kulturminnesmärkta byggnader men även i fallstudier som har höga hållbarhetsambitioner. Mängdningsprocesser har använts för beräkna materialåtgången där ett identifierat hinder är stora säkerhetspåslag som inneburit en suboptimering. Byggvarubedömningen har använts i alla fallstudier som bidragit till en förenklad process att välja material med låg klimatpåverkan. Internt inom byggentreprenörens verksamhet förekommer återbruk internt tillsammans med prefabricering och måttbeställningar för minimering av avfall. Det har genomförts projektering för främja flexibla och demonterbara planlösningar som ökar nyttjandegraden i fastigheten kombinerat med främja framtida återbruk. Det har genomförts omfattande åtgärder för att minimera byggarbetsplatsens klimatpåverkan med hjälp av en intern framtagen mall för resursoptimering. Miljövänlig etablering har genomförts tillsammans med att byggarbetsplatsens hålls elektrifierad och energisnål belysning som är hållbara tillvägagångssätt. Hinder för transportoptimeringar har identifierats med hänsyn till bristande planering och låg prioriteringsgrads om kräver vidare utveckling. Ett återkommande hinder är tids- och resursbrist att arbeta med hållbarhetsfrågor. För att möjliggöra minskad klimatpåverkan i byggprojekt krävs en tidig involvering av byggentreprenören för att skapa enhetliga mål och hållbarhetsambitioner. En tidig integrering bidrar till hållbara processer som sprids genom hela värdekedjan med hjälp av ett tydligt ledarskap och agerande som tar hållbarhet i beaktande.  Hinder har identifierats i form av brist i förståelse och kompetens som berör hållbart byggande. Stora byggnadskomplex byggs idag med korta tidsplaner, något som gör att traditionella byggmetoder används i större utsträckning. Det har bidragit till utvecklingen av byggkompetens hämmats när av traditionella arbetsprocesser används i större utsträckning. För framtida studier rekommenderas att genomföra en identisk studie hos en annan byggentreprenör för att bedöma likheter i arbetsprocesser och hinder som uppstår. Det rekommenderas även att genomföra en identisk studie hos beställare för att framhäva problematik och arbetsprocesser ur ett beställarperspektiv. En likadan studie rekommenderas att genomföras i framtiden hos byggentreprenören för att identifiera nya arbetsprocesser och dess effekter för att bedöma ifall byggentreprenören är i linje med klimatmålen. Det rekommenderas att ta fram standardiserade säkerhetspåslag vid mängdningar för att skapa en balans mellan minskad materialåtgång och undvika produktionsstopp. Slutligen rekommenderas det att undersöka färdplanens nio åtgärder mer ingående. / The Construction- and Real Estate sector was accountable for 22 % of Sweden’s total emissions in 2021, which marks a 1.9 % increase compared to the previous year. This highlights the urgent for a sustainable construction and implement more sustainable building methods to achieve Sweden’s climate goals to achieve net-zero emissions by 2045. To address these challenges, the Construction and Civil Engineering Companies have adopted the Roadmap 2045, which presents nine measures with associated recommendations for achieving climate neutrality in the construction sector.The purpose of this study is to explore new approaches for a construction contractor that is in alignment with the measures outlined in Roadmap 2045. Semi-structured interviews have been held with six project representatives and one external consultant to gain a deeper insight into the climate-neutral measures and obstacles encountered in these projects. These deeper insights can contribute to understanding of climate-neutral measures and obstacles that a construction contractor is facing. The results are presented in tables to provide an overview of climate-efficient methods and obstacles that inhibits climate-neutrality in building projects in line with Roadmap 2045. The study has identified several work methods in various extents that contribute to lower emissions in the building projects. The adaption of work processes is dependent on the client’s sustainability ambitions in the construction project and requirements. Careful renovations have been central, particularly for building that have a high cultural heritage where demolitions are not an option but also in construction projects with high sustainability ambitions. Workprocess have been used to calculate material consumption in the building projects where an identified obstacle is large margins to the calculations which is a sub optimization. Assessments for building materials have been used in the building projects for contributing of an easier process of selecting materials with a low impact on the climate. Reuse of material is common, especially internally withing the contractor’s building projects which minimizes waste where also prefabrication and custom orders also plays a big role. There has been a planning to build demountable and flexible layouts which increase the buildings utilization rate combined with promoting future reuse. Big measurements have been taken to minimize the climate impact at the contractors building site with the help of a template that takes resource optimization into account. Environmentally friendly site has been implemented along with using energy-efficient light and using electrified machinery as sustainable approaches. Transport optimization is an obstacle that have been identified due to poor planning and low priority which requires further development of its working methods. A recurring obstacle is lack of resources and time to work further on the sustainability issues. To be able to reduce climate impact in the construction project, early involvement of the construction contractor is necessary to create the same sustainability ambitions and unified goal. Early integration does contribute to a sustainable approach that spread throughout the value chain with a clear leadership that takes sustainability into account. Obstacles have been identified where a lack of understanding and knowledge that relates to sustainability construction. Large building structures are being built with tight schedules today which promotes traditional construction processes and methods to a greater extent. This is a main reason why development of sustainable competence in constructions is being hindered when traditional processer is used more regularly rather than testing out new sustainable process. For future studies, its recommended to conduct an identical study with another construction contractor to identify similar if the obstacles and work processes are similar. It is also recommended to conduct an identical study with clients to highlight the problem from a client perspective and introducing new sustainable work methods for clients.  A similar study is recommended to conducted in the future at the same construction contractor do identify potential new work methods and processed and identify if the contractor is in line with Sweden climate goals. It is also recommended to develop standardized safety margins for building materials to creating a balance between avoiding production stoppages and reduced material consumption. Lastly, its recommended to examine roadmaps nine measures in more detail.