A circular economy has been suggested to be able to respond to environmental challenges caused by over-production and consumption of products. Reuse is a circularity measure ranked high in the waste management hierarchy and is especially relevant for passive durable products such as furniture. Reusing furniture has the potential to contribute to the decarbonization of companies. This thesis aimed to explore the potential of reuse contribution to climate change mitigation. An Excel model was developed to explore different reuse scenarios from a life cycle perspective, accounting for potential avoided emissions by selling second-hand furniture. The results indicated that reusing furniture resulted in about 42% reduced climate impacts, although it depended on the characteristics of second-hand trade. Furthermore, the second-hand furniture trade characteristics that influence the GHG emissions were identified, such as replacement rates, second-hand transport, and variability of items sold. An improved scenario by optimizing the furniture trade characteristics can save up to 80% of climate impact. The results indicated that reuse could significantly contribute to the climate commitments of companies, although it cannot be the only mitigation measure to reach carbon neutrality. / Att implementera en cirkulär ekonomi har föreslagits för att kunna adressera miljöutmaningar orsakade av överproduktion och konsumtion av produkter. Återanvändning är ett cirkulärt mått som rankas högt i avfallshanteringshierarkin och är särskilt relevant för passiva och slitstarka produkter som möbler. Återanvändning av möbler har potential att bidra till att minska koldioxidutsläppen hos företag. Denna avhandling syftade till att undersöka potentialen om återanvändning kan bidra till att minska klimatförändringen. En Excel-modell utvecklades för att utforska olika återanvändnings- scenarier ur ett livscykelperspektiv som räknar ut potentiella undvikna utsläpp genom att sälja begagnade möbler. Resultaten visade att återanvändning av möbler resulterade i cirka 40 % minskad klimatpåverkan, även om det berodde på second-handhandelns egenskaper. Vidare identifierades second-handmöbelhandelns egenskaper som påverkar utsläppen av växthusgaser, t.ex. som ersättningstaket, second-handtransport och variation av sålda varor. Ett förbättrat scenario genom att optimera möbelhandelns egenskaper kan spara upp till 80 % av klimatpåverkan. Resultaten visade att återanvändning avsevärt skulle kunna bidra till företagens klimatåtaganden, även om det inte kan vara den enda begränsningsåtgärden för att nå koldioxidneutralitet.

With global emissions of human activities that drive climate change on the rise, global institutions and authorities are trying to introduce new regulations in the industry, in order to accomplish a significant reduction of carbon emissions. In order for companies to be more effective in reducing carbon emissions, not only from their products but also along their value chains and product portfolios, it is of vital importance to understand and quantify them. Following that need, tools that can measure the carbon footprint of various corporate operations (carbon calculators) have risen in popularity in the latest years. A sector in which companies can significantly improve their environmental impact is their IT equipment portfolio. WeCycle, as developed by Greener Scandinavia AB (partner of this project), is a platform that facilitates reselling of old IT equipment, while aiming to reduce its environmental impacts. This project then, in cooperation with WeCycle, aims to develop a software tool that calculates the environmental benefits (kg of CO2 eq. avoided) when reusing old IT equipment. This can help clients estimate this benefit, while also providing a CSR incentive. The specific methodological steps needed in order to complete the project included literature review concerning the state of e-waste and initiatives to minimize its environmental impacts, guidelines, and procedures related to LCA of IT equipment and various other carbon calculators, developing calculation model and assumptions in order to compile the database, interface design, and finally using and testing the software tool against a real case scenario - case study provided by WeCycle. The results, and design process of the project, were enlightening in the matter of understanding potential benefits of reusing IT equipment, but also in identifying the “hotspot” stages of an electronic device’s lifecycle. Even though variations were noticed depending on the type of the device (e.g. smartphones vs desktop computers), it is evident that the emissions that occur during the production phase are considered of major importance (ranked either 1st or 2nd most important/emission heavy stage), and therefore the benefits of reusing are of a high relative magnitude. All in all, this project resulted in a useful tool for WeCycle to measure the benefits of their practices, as well as for any user or company that would like to measure the carbon emissions that can be avoided when they give their old IT equipment up for resell. Hopefully, by easily quantifying these benefits, this tool can motivate both a behavioral change in the industry, as well as researchers to expand it in order to cover all sectors of the industry and everyday life. / När globala utsläpp av mänskliga aktiviteter stiger, försöker globala institutioner och myndigheter att införa nya regler för att minska koldioxidutsläppen. För att företagen ska vara mer effektiva när det gäller minskade koldioxidutsläpp, inte bara från sina produkter men också med sina värdekedjor och produktportföljer, är det viktigt att förstå och kvantifiera dem. För att uppnå detta, har verktyg som kan mäta koldioxidavtrycket av olika företagsverksamheter (kolkalkylatorer) ökat i popularitet de senaste åren. En sektor i vilken företag kan förbättra sin miljöpåverkan är deras IT-utrustning. WeCycle, ett projekt som utvecklats av Greener Scandinavia AB (partner för detta projekt), är en plattform som underlättar återförsäljning av gammal IT-utrustning medan den siktar på att minska miljöpåverkan. Projektet, i samarbete med WeCycle, syftar till att utveckla ett mjukvaruverktyg som beräknar miljöfördelar (kg CO2-ekv.) vid återanvändning av gammal IT-utrustning. Detta kan hjälpa kunder att uppskatta denna fördel, samtidigt som de ger ett CSR-incitament. Projektets resultat var till hjälp för att förstå de potentiella fördelarna med att återanvända IT-utrustning, men också för att identifiera "hotspot" -stadierna i en elektronisk apparats livscykel. Även om det märktes variationer beroende på enhetens typ (t.ex. smartphones jämfört med stationära datorer) är det uppenbart att utsläpp som uppstår under produktionsfasen är av stor betydelse (rankad antingen viktigaste eller näst viktigaste fasen) och därför ger återanvändning relativt stor miljönytta. Förhoppningsvis, genom att kvantifiera dessa fördelar med ett lättanvänt verktyg, kan detta projekt motivera både en beteendemässig förändring i branschen och forskare att vidareutveckla verktyget till att omfatta alla industrisektorer och hushållens konsumtion.

Stickstoffdüngung und Bodenbewirtschaftung sind die Hauptquellen für Treibhausgase aus Anbausystemen. Dennoch sind diese Maßnahmen in Ackerbaubetrieben unerlässlich. In Anbetracht der Notwendigkeit, rasch Maßnahmen gegen den Klimawandel zu ergreifen, ist es notwendig Minderungspotentiale und Kosten in diesen Betrieben zu ermitteln und vergleichen. Es wurden Fallstudien in den USA, in Brasilien und in Deutschland durchgeführt, wobei jeweils eine Kultur in jeder Region untersucht wurde. Wissenschaftliche Literatur und Fokusgruppen mit lokalen Experten wurden genutzt, um realistische Ergebnisse zu generieren, die den lokalen Kontext abbilden. Diese Arbeit zeigt, dass die Wirtschaftlichkeit der Minderungsstrategien von dem betrachteten Zeithorizont abhängt, der sich aus der Kohlenstoffdynamik im Boden ergibt. Kurzfristig bieten Strategien, die die Kohlenstoffbindung fördern, ein größeres Minderungspotenzial, was jedoch langfristig nicht zutrifft. Kurzfristig wurden in Brasilien und den USA die geringsten Minderungskosten durch die Optimierung der Stickstoffdüngung erreicht. Diese Kosten sind negativ, was bedeutet, dass die Anwendung dieser Strategien, nicht nur ihre Emissionen, sondern auch ihre Kosten senken würden. Weitere kosteneffiziente Strategien waren die Verringerung der Bodenbearbeitungsintensität und Zwischenfrüchte, die in allen Fällen mit vergleichbaren Minderungskosten durchführbar waren und die Kohlenstoffbindung fördern. Der Einsatz von Hemmstoffen schließlich, der in den USA und in Brasilien möglich war, hatte die höchsten Minderungskosten. Langfristig betrachtet stiegen die Minderungskosten von Strategien mit Kohlenstoffbindung an und waren ähnlich hoch oder höher als bei Strategien ohne Kohlenstoffbindung. Da in allen Fällen dieselbe Methodik angewandt wurde, sind die Ergebnisse vergleichbar. Darüber hinaus sind die Ergebnisse zwar spezifisch für den Kontext, in dem sie berechnet wurden, sie liefern jedoch Erkenntnisse für ähnliche Regionen. / Nitrogen fertilization and soil management are the main sources of greenhouse gases from cropping systems. Yet these operations are essential on arable farms. Considering the need to take quick action against climate change, it is necessary to understand which mitigation potentials and cost can be attained in these farms and how they compare. Case studies in the USA, Brazil and in Germany were conducted, assessing one crop in each region. Scientific literature and focus groups with local experts were used to generate realistic results which depict the local context. This thesis identified that the economics of the mitigation strategies depended on the time horizon considered, which results from the carbon dynamics in the soil. In the short term, strategies promoting carbon sequestration offer a larger mitigation potential, yet this is not valid in the long term. In the short term, the lowest mitigation costs were attained by optimizing the nitrogen rate, feasible in the USA and Brazil. These costs are indicated to be negative, implying that adopting the strategy would not only lower emissions, but also reduce their costs. The next most cost efficient strategies were the reduction of the tillage intensity and cover crops, which were feasible in all cases with comparable mitigation costs and promote carbon sequestration. Lastly, the adoption of inhibitors, feasible in the USA and in Brazil, had among the highest mitigation costs. Assuming the long term, the mitigation costs of strategies with carbon sequestration increased, becoming similar to or higher than strategies without carbon sequestration. By applying the same methodology in each case, the results are comparable. Moreover, while the findings are specific to the context in which they were calculated, they provide insights for similar regions.

Questa tesi di dottorato analizza l’utilizzo del sorgo (Sorghum bicolour (L.) Moench) al fine di produrre energia elettrica, tramite combustione diretta della biomassa. Il focus della tesi è stato quello di sottolineare i benefici ed i rischi associati all’uso di tre genotipi di sorgo caratterizzati da diversa lunghezza del ciclo culturale (precoce, medio-tardivo e tardivo). La dinamica e la durata del processo di essicazione in campo sono state simulate attraverso un modello ad hoc (“sorghum haying model”), il quale integrato a CropSyst, è stato utilizzato per realizzare un’analisi del rischio produttivo stimando le perdite di biomassa (respirazione e meccanizzazione), ed i mancati affienamenti. Nell’analisi del rischio vengono stimati il numero di ettari necessari e la probabilità di eccedere la soglia di 64.000 ton ss anno-1 necessari per l’alimentazione di una centrale nell’Oltrepò pavese . Inoltre uno studio di Life Cycle Assessment è stato condotto per la valutazione dell’impatto ambientale dell’utilizzo del sorgo integrato a quello della paglia per il completamento del fabbisogno totale della centrale 94.000 ton ss anno-1. Particolare attenzione inoltre è stata data alla variazione del contenuto di C organico del suolo dovuto alla rimozione della paglia ed all’interramento dei mancati affienamenti di sorgo. Il genotipo precoce mostra le migliori performance produttive ed energetiche oltre che la più alta probabilità di eccedere la soglia di 64.000 ton ss anno-1. Lo studio di LCA non ha mostrato differenze significative tra i genotipi anche se il minor impatto ambientale, è stato evidenziato dal genotipo tardivo conseguenza dell’interramento della più alta quantità di mancati affienamenti. / This PhD thesis explores the use of sorghum (Sorghum bicolour (L.) Moench) as a dedicated bio-energy crop and highlights the benefits and risks associated with the use of early, medium-late and late sorghum genotypes to generate electricity by direct combustion in a biomass power plant. The dynamics and duration of the field drying process were simulated through the development of a specific model ("sorghum haying model"), which integrated with CropSyst, was used to perform a production risk assessment analysis estimating the biomass losses (respiration and mechanical), the haymaking failures and consequently to quantify the amount of dry baled biomass available for the power plant. In addition, the number of hectares needed to plant sorghum and the probability to exceed the threshold of 64000 Mg DM y-1, necessary to feed a biomass power plant in Oltrepò Pavese, were estimated. A complete Life Cycle Assessment (LCA) study was carried out in order to evaluate the environmental impact of the three sorghum genotypes involved in this study. The LCA study takes into consideration the use of winter wheat straw as an additional biomass source to satisfy the total biomass power plant needs (94000 Mg DM y-1). Particular attention was given to the soil organic C change (ΔSOC) due to straw removal and haymaking failures soil incorporation. Early genotype showed the best biomass production and energy performance as well as the highest probability to exceed the threshold of 64000 Mg DM y-1. The LCA results did not show significant differences between genotypes although the lower environmental impact, has been achieved by the late genotype due to the highest amount of haymaking failures incorporated in the soil.

In Anbetracht des Kompromisses zwischen der Erzielung des höchsten Gewinns und der geringsten Umweltbelastung ist ein tiefes Verständnis der ökonomischen Folgen der Stickstoff (N) Düngung erforderlich. Die vorliegende Doktorarbeit liefert umfassende Einblicke in (i) die Auswirkungen des standortspezifischen N-Managements (SSNM) auf die Rentabilität und Risikominderung, (ii) die Auswirkungen von Unsicherheiten und Risikoeinflüssen auf optimale N-Düngergaben und (iii) das Potenzial und die Kosten der Vermeidung von Treibhausgas (THG) Emissionen durch N-Düngereduktion. Ein Modellierungsansatz wurde entwickelt, um die Wirkung von Ertrag und Proteingehalt, Wirtschafts- und Risikoauswirkungen sowie THG-Emissionen auf die N-Düngung zu simulieren. Die Ergebnisse der Arbeit zeigen, dass SSNM die Wirtschaftlichkeit verbessert, indem es eine höhere Weizenqualität und damit Preisprämien erzielt. SSNM reduziert das Risiko, die Backqualität nicht zu erreichen, und es gibt keine wesentlichen Nachteile beim Verlustrisikomanagement im Vergleich zum einheitlichen Management. Preisprämien für eine höhere Weizenqualität bieten Anreize für höhere N-Düngergaben. Prämien verflachen die Gewinnfunktion weiter, was unzureichende Argumente für eine Absenkung des N-Inputs aus der Wirtschaftlichkeitssicht liefert, selbst bei einer hohen Risikoaversion der Landwirte. Eine moderate Reduzierung der mineralischen N-Düngung kann die THG-Emissionen bei moderaten Opportunitätskosten mindern. Die THG-Vermeidung durch N-Düngereduktion in einer bestimmten Region kann unter Berücksichtigung kultur- und ertragszonenspezifischer Ertragswirkungen optimiert werden. Insgesamt liefert diese Arbeit wichtige Erkenntnisse über die Chancen und Nachteile der Anpassung der N-Düngergaben. Darüber hinaus leistet sie einen direkten Beitrag zur Identifizierung von kosten- und risikoeffizienten N-Managementoptionen und bildet die Grundlage für effektive politische Ansätze zur THG-Vermeidung durch selektive N-Düngereduktion. / Considering the tradeoff between achieving the highest profit and causing the lowest environmental impact, there is a need for a profound understanding of the economic consequences of nitrogen (N) fertilizer application. The present doctoral research provides comprehensive insights into (i) effects of site-specific N management (SSNM) on profitability and risk mitigation; (ii) impacts of uncertainties and risk implications on optimal N fertilizer rates; and (iii) potential and costs of mitigating greenhouse gas (GHG) emissions by N fertilizer reduction. A modelling approach was developed to simulate the response of yield, protein, economic and risk implications, and GHG emissions to N fertilizer application. Findings of the thesis show that SSNM improves profitability by achieving higher grain quality, thus, price premiums. SSNM reduces the risk of not reaching the baking grain quality and poses no considerable disadvantage on downside risk management compared to uniform management. Price premiums for higher wheat quality provide incentives for higher N input rates. Premiums further flatten the profit function, giving insufficient arguments for lowering N input from a farm profitability perspective, even in presence of high risk aversion of farmers. Moderate reduction of mineral N fertilizer can mitigate GHG emissions at moderate opportunity costs. GHG mitigation by N fertilizer reduction in a given region can be optimized considering crop and yield-zone-specific yield responses. Overall, this thesis provides important insights on chances and drawbacks of adjusting N fertilizer rates. Moreover, it makes a direct contribution in identifying cost- and risk-efficient N management options and provides a basis for effective policy approaches to reduce GHG emissions by selective N fertilizer reduction.

Le changement climatique est devenu aujourd’hui le fléau environnemental qui préoccupe etmobilise le plus la communauté internationale. L’aboutissement de cette mobilisation générale reste sansdoute la mise en place du régime international de lutte contre le changement climatique dont la Conventioncadredes Nations Unies sur le changement climatique et le Protocole de Kyoto constituent les basesjuridiques. Ce régime innove en ce qu’il fixe des engagements quantifiés de réduction des émissions de gaz àeffet de serre pour les États pollueurs, mais aussi en ce qu’il instaure des mécanismes dits de « flexibilité »dont la mise en oeuvre est assortie d’un contrôle original basé sur un Comité dit de « l’observance ». Mais, endépit de toute cette production normative, il est regrettable de constater aujourd’hui que le régimeinternational du climat est un véritable échec. En effet, si la mobilisation des États ne fait aucun doute, enrevanche, les mêmes États qui ont volontairement accepté de s’engager refusent délibérément d’honorer leursengagements pour des raisons essentiellement politiques, économiques et stratégiques. Ce travail ambitionnedonc de lever le voile sur les causes de cet échec en dressant un bilan mitigé de la première périoded’engagement de Kyoto qui a pris fin en 2012, et propose des perspectives pour un régime juridique duclimat post-Kyoto efficient et efficace, en mesure d’être à la hauteur des enjeux. / Climate change has become the scourge environmental concern and mobilizes more theinternational community. The outcome of this mobilization remains probably the implementation ofinternational climate change regime for which the Climate Convention and the Kyoto Protocol are the legalbases. This system is innovative in that it sets quantified emission reduction commitments for greenhouse gasemissions (GHG) for polluters States, but also in that it establishes mechanisms known as of “flexibility”whose implementation is accompanied by a control based on a Committee known as of “compliance”. Butdespite all this normative production, it is regrettable that today the international climate regime is a realfailure. Indeed, if the mobilization of states is no doubt, however, the same states that have voluntarily agreedto engage deliberately refuse to honour their commitments for essentially political, economic and strategicreasons. This work therefore aims to shed light on the causes of this failure by developing a mixed record ofthe first Kyoto commitment ended period in 2012, and offers prospects for a legal regime of the post-Kyotoclimate and efficient, able to be up to the challenges.