As the anthropogenic emissions of greenhouse gases (GHGs) have increased and received moreattention, the need for climate mitigation solutions has become more urgent. Today, several methodologies for carbon accounting exists, as well as the possibility to offset emissions by buying carbon offsets. All these methodologies directly or indirectly spring from LCA but have developed to metrics considering only climate and with a dissatisfying sustainability performance in other aspects. Four carbon accounting methodologies (VCS, Gold Standard, GHG Protocol, XPRIZE Carbon Removal) have been examined and compared, showing differences in the approach to quantification and to more holistic sustainability aspects. They have also been analysed in comparison to the QU.A.L.ITY framework proposed by the European Commission, which aims to ensure the quality of carbon removals and prevent greenwashing. The results showed a lack of coherence between the carbon offset standards as well as a low coherence with the criteria in the proposed framework and lack of holistic sustainability perspectives. Algae are photosynthesizing organisms fixating CO2 in the same process as terrestrial plants. They are fast growing and does not require land or much maintenance, which is why seaweed aquaculture has been suggested as a method for carbon removals. This have given birth to a plethora of start-ups aiming to sell carbon offsets from systems based on macroalgae, here called “seaweed offsets”. Nine companies/projects were identified and examined. The results showed that most of the companies used systems involving cultivation, while one company use wild seaweed. The two largest techniques for sequestration of the carbon fixated in the biomass were 1) sinking the seaweed into the deep sea and 2) making biochar from the biomass. However, there are not yet any standards covering this type of carbon offset methodologies and these offsets are thus not certified and the results also show that the efficiency of these activities is highly unreliable. Large uncertainties remain regarding the net carbon removal, sequestration, and potential ecological impacts. These uncertainties and knowledge gaps also cause the suggested methods for seaweed offsetting to clash with the QU.A.L.ITY framework. / I takt med att de antropogena utsläppen av växthusgaser har ökat och fått mer uppmärksamhet har behovet av lösningar för att begränsa klimatförändringarna blivit mer brådskande. Idag finns flera metoder för koldioxidredovisning och -beräkning, liksom möjligheten att klimatkompensera genom att köpa klimatkompensation. Alla dessa metoder här rör direkt ellerindirekt från LCA men har utvecklats till mått som endast tar hänsyn till klimat, och med en otillfredsställande hållbarhetsprestanda i andra aspekter. Fyra metoder förkoldioxidredovisning (VCS, Gold Standard, GHG Protocol, XPRIZE Carbon Removal) har undersökts och jämförts, vilket visar skillnader i tillvägagångssättet för kvantifiering och förmer holistiska hållbarhetsaspekter. De har också analyserats i jämförelse med ”QU.A.L.ITY”-ramverket som föreslagits av Europeiska kommissionen, vilket syftar till att säkerställa kvaliteten på lösningar som skall ta bort CO2 ur atmosfären och förhindra greenwashing. Resultaten visar på bristande samstämmighet mellan klimatkompensationsstandarderna samt låg överensstämmelse med kriterierna i det föreslagna ramverket och brist på holistiskahållbarhetsperspektiv. Alger är fotosyntetiserande organismer som fixerar CO2 i samma process som markväxter. De växer snabbt och kräver inte mark eller mycket underhåll, vilket är varför algodling har föreslagits som en metod för att minska halten CO2 i atmosfären. Detta har gett upphov till en uppsjö av nystartade företag som syftar till att sälja koldioxidkompensation från system baserade på makroalger, här kallade "tångkompensationer" (seaweed offsets). Nio företag/projekt identifierades och granskades. Resultaten visar att de flesta av företagen använder system som involverar odling, medan ett företag använder vild tång. De två största teknikerna för att binda kolet fixerat i biomassan var 1) sänka tången i djuphavet och 2) göra biokol av biomassan. Det finns dock ännu inga standarder som täcker denna typ av klimatkompenseringsmetoder och dessa kompensationer är därför inte certifierade. Resultaten visar också att effektiviteten i dessa system är mycket otillförlitlig. Storaosäkerheter kvarstår när det gäller netto upptag av CO2, lagring och potentiella ekologiska effekter. Dessa osäkerheter och kunskapsluckor gör också att de föreslagna metoderna för tångkompensation kolliderar med QU.A.L.ITY-ramverket.

Climate change is a collective action problem that has been seen as something that needs a global solution. This has resulted in multilateral agreements, such as the Paris Agreement, which can largely be said to have been unsuccessful so far. This has led to an increased awareness of the potential of cities as being part of the solution. Cities are often seen as key sources of climate change, but also as key sites for climate action. The Paris Agreement needs to be implemented on all political levels to be effective. This makes cities an important site for climate policy implementation. Some scholars of urban climate governance have looked at ways to evaluate climate policies in cities as a way to improve these processes. This study means to contribute to that field. The aim of the study is to evaluate climate policies in the city plans of Stockholm and Dublin. This has been done by testing an analytical framework which made it possible to shed light on the strengths and weaknesses of the climate policies and the governance structures in the plans. By doing this it was also possible to identify challenges in using the framework and give suggestions on how the framework can be improved. The study takes the form of a comparative case study of the two cities. Document analysis was used as a method to select and analyse the data and the empirical material consisted of the city plans of Stockholm and Dublin. These are policy documents containing general development plans of the cities. It was concluded that both plans contain both strengths and weaknesses. Examples of strengths are that both plans are well-integrated with activities on the regional and national level, that responsibility for implementation is centralised on the local level, that the plans promote innovation and that the plans are connected to long-term goals and visions. Examples of weaknesses are that neither plan makes use of more hard methods such as regulation, that the Dublin City Plan is not integrated with policy on the global level and that the Stockholm City Plan lacks monitoring systems. Regarding the analytical framework it was concluded that it can be used to analyse city plans rather than metropolitan plans. By testing the framework it was also possible to identify challenges in using the framework and give suggestions on how to improve it, such as by making some of the key attributes of the plan more widely applicable.

<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>