Thèses sur le sujet « Carbon dioxide – Environmental aspects – Europe »

To have better understandings of the partial pressure of carbon dioxide (pCO2)in northern South China Sea(NSCS), the pCO2readings from 1999-2012 were reviewed. Both the pCO2in NSCS and in the atmosphere also showed an increasing trends and the pCO2in NSCS varied across the seasons. There are many important processes that influenced the pCO2in NSCS, which were the rise of the temperature, biological production, seasonal upwelling, Pearl River discharge, increase in the concentration of atmospheric pCO2and the rate of calcification. These six mechanisms extend different strengths on the resultant sea surface pCO2in NSCS. The impact of induced sea water acidification on the marine phytoplankton by the high pCO2in NSCS would also be discussed. The drop of pH in the seawater would change the community of phytoplankton from diatom to dinoflagellate as a resistance to the change of pH of dinoflagellate that was better than the diatom. DMS, which was one of the climatically important gases, would also affected by the high pCO2induced seawater acidification. Hong Kong (HK) was studied as a case to estimate whether NSCS also faced the same impacts upon by the marine phytoplankton. The study showed that the diatom was relatively sensitive to the drop of pH in HK waters. The DMS producing marine phytoplankton was also affected by the drop of pH in HK waters. It was concluded that the NSCS might also face the same situation with HK. Finally, three instruments were recommended to have a better management in NSCS, namely, knowledge gaps and NSCS research priorities, valuing the NSCS as well as decision making team. Firstly, filling the knowledge gaps and NSCS research priorities aim to enhance the ability of the ocean sequestration to absorb and store the largest amount of anthropogenic CO2as possible. Afterwards, valuing the NSCS aims to protect the marine organisms, such as the phytoplankton, form the negative impacts of the decrease of ocean acidity. Last but not least, a good decision making team aims to balance the conflicts between those various options to reduce the anthropogenic CO2with ocean sequestration and impacts result from the ocean sequestration.
published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management

The negative consequences of sprawling metropolitan regions have attracted attention in both academia and in practice regarding how to better design settlements and alter travel behavior in a quest to curtail vehicle emissions. Studies that have attempted to understand the nexus between land use, travel and vehicle emissions have not been able to address the issue of self-selection in a satisfactory manner. Self-selection occurs when households choose their residential location based, in part, on expected travel behavior. This non-random experience makes the use of traditional regression frameworks that strongly rely on random sampling, unsuitable. This replication study's purpose was to examine the impact of land use and travel on CO2 emissions using the Heckman (1979) sample selection model in Portland Metropolitan Area. three research questions guided this study: (1) Does self-selection to drive a motor vehicle lead to reduction in CO2 emissions? (2) Does land use and automobile travel influence the decision to drive after controlling for self-selection? (3) What land use and travel factors determine CO2 emissions after controlling for self-selection? The findings suggest driving has a statistically significant negative effect on estimated CO2 and that most land use variables significantly affect driving behavior.

We have successfully investigated the use of CO2 as a miscibility switch to create an environment in which we can run a homogeneously catalyzed reaction while maintaining a heterogeneous separation. We explored the use of this technique with fluorous biphasic systems, a fluorous solid support, and aqueous biphasic systems. In the case of the fluorous systems, CO2 was added to induce solubility of the fluorous catalyst. When the reaction was completed, CO2 was vented and the system returned to a biphasic state, making the separation easy. For the aqueous biphasic systems, the organic phase is chosen such that it is fully miscible with water at ambient conditions. Examples include acetonitrile, THF, and dioxane. The addition of CO2 reduces the polarity of the solvent and causes a phase split. The recovery of the water-soluble catalyst is once again heterogeneous. The application to aqueous biphasic systems is the most exciting studied. Aqueous biphasic systems are used industrially in the hydroformylation of propylene. With our technique, these systems can be extended to more hydrophobic substrates. We have shown a rate increase of 65 fold and 99% product recovery at modest pressures for the hydroformylation of 1-octene. These aqueous biphasic systems also show much promise in the arena of enzyme catalyzed reactions. We can create an environment in which the enzyme kinetics will no longer be mass transfer limited.

The CO2 flux of two peatlands in northern Alberta was examind during the 2004 growing season using eddy covariance measurements of net ecosystem exchange (NEE), chamber measurements of total ecosystem respiration, and empirical models driven by meteorological inputs. The two ecosystems, a poor fen and an extreme-rich fen, differed significantly in plant species composition, leaf area index, aboveground biomass and surface water chemistry. The mean diurnal pattern of NEE at the peak of the season was similar between the sites, however, the extreme-rich fen had a higher photosynthetic and respiratory capacity than the poor fen. Over the 6 month study, the poor fen was shown to accumulate between 2 to 3 times more carbon than the extreme-rich fen despite having a lower photosynthetic capacity. The evergreen nature of the poor fen site allowed for a longer season of net CO2 uptake than the deciduous species that dominated the extreme-rich fen.
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We examined how fast- and slow-growing families (based on height at 10 years) of Pinus banksiana Lamb. are affected by a climate altered by CO$ sb2$ during their first growing season. Our primary objective was to evaluate the possibility that genotypes performing best under present conditions may not necessarily do best under projected warmer climate. Seedlings were grown for six months in two climatic environments (350 $ mu$L/L CO$ sb2$ x present temperatures and 700 $ mu$L/L CO$ sb2$ x 4$ sp circ$C warmer temperatures) and with 100 ppm and 5 ppm nitrogen.
The CO$ sb2$T$ sp circ$ environment had a significant effect on most biomass components of seedlings and water-use efficiency but not on height and other growth variables. The nitrogen fertilization was generally the most significant effect of the treatments for most growth variables.
All the families responded in a similar way to variations in the growing environments except for WUE. Family differences were more important for measurements of height and growth variables than for biomass components. The architecture of seedlings was also highly variable between families. Norm of reaction graphs were built for several growth variables to outline which families were overall most successful in an enriched CO$ sb2$T$ sp circ$ environment. Of the 15 families studied, four of them were classified as most successful in a projected high CO$ sb2$T$ sp circ$ climate.

The Quebec City - Windsor corridor is the busiest and most important trade and transportation corridor in Canada. The transportation sector is the second largest greenhouse gas (GHG) emission category in the country. Governments around the world, including Canada, are considering increased mode share by rail as a way to reduce transportation emissions. To understand whether freight mode shift is a realistic means to reduce transportation emissions, an analytical model is needed that can predict the effect of government policy on mode split.
This thesis provides background on the freight transportation-GHG nexus in Canada and describes the development, implementation, reasoning behind, and results of, a Stated Preference shipper carrier choice survey for the Quebec City - Windsor corridor conducted during the fall of 2005. It then describes how the resulting carrier choice models are used to estimate the potential to displace truck traffic to rail (premium-intermodal) under current conditions, as well as to test the effectiveness of different possible future policy or service offering scenarios.
The results show that premium-intermodal has the potential to capture a substantial share of traffic between the main destinations in the Quebec City - Windsor Corridor. However, its ability to contribute significantly to reducing CO2 emissions is limited. According to the analyses conducted, potential reductions are considered to be in the range of nil to 0.413 Mt---a fraction of what the federal government was hoping to be able to achieve through "further public-private collaboration to promote the use of intermodal freight opportunities and to increase the use of low-emission vehicles and modes" (Government of Canada 2002).
At the same time, these potential reductions are based on a small proportion of total truck-related emissions and a few city-pairs. Extension of the current analysis to more city-pairs separated by longer distances might arrive at different conclusions.

Recent studies of the environmental Kuznets curve raise questions regarding the relationship between environmental indicators and GDP and the fundamental reasons that explain this relationship. In response, this thesis presents one-sector and two-sector models to analyze the alternative causal relationships between an environmental indicator and GDP at different stages of economic development. These models analyze how economic scale, technology, preferences, and economic structure influence the causality and shape of the relationship. These theoretical studies are followed by two empirical studies. The first tests the causal relationship between CO2 emissions and GDP in Canadian manufacturing industries. The second explores several factors as the fundamental causes that influence the CO2 emissions in the same industries. Factors, such as economic scale, preferences, technological progress, structural change, and energy input, are found to be crucial in the determination of CO2 emissions. The empirical results are positive, but there are data limitations. The empirical studies can be re-evaluated as more data becomes available.

This study focused on the reproductive response to elevated CO2 of plants possessing below-ground storage. I tested the hypotheses that under elevated CO2: (1) Plants with greater non-foliar storage capacity win show more reproductive response and (2) The altered foliar physiology of carbon (C) and nitrogen (N) use will cause increases in seed number and quality. Carbon dioxide treatments of High (650 muL L-1) and Ambient (360 muL L-1) were used in a controlled environment, simulated growing season, and in a natural pasture community. Hypothesis 1 was tested experimentally using four Raphanus varieties that differed in hypocotyl and leaf sizes. N fertilization and harvest times were used to obtain a range of root:shoot ratios. Enhancements in vegetative leaf area rather than the hypocotyl predicted reproductive responsiveness to CO 2. However, after three years of CO2 exposure in the pasture, hypocotyl-storing Taraxacum officinale responded strongly in vegetative biomass which correlated with inflorescence size and number. Fitness was enhanced four-fold, while the leaf-storing Plantago major produced more ramets and had only a two-fold fitness increase. Hypothesis 2 was tested by examining the C and N physiology underlying the vegetative organs and seeds of the pasture plants. Under elevated CO2, photosynthesis increased two-fold and senescence was delayed. Total plant C:N ratio did not differ, suggesting N acquisition increased. N similarly limited seed number in all cases suggesting an unchanged Physiology of N use in reproduction. While morphology constrained total biomass response, provisioning to seeds increased as shown by higher seed mass and number and decreased variability in number and mass. In all cases, leaf mass increase under high CO2 corresponded with fitness increase. Phenology constrained response to CO 2 as there was no plasticity in flowering day in Raphanus and Plantago, while there were flowering delays but greater seed maturation rate in Tar

Afforestation projects in China have substantially contributed to national CO2 sequestration and play an important role in international climate change mitigation. However, these nation-wide afforestation projects are usually funded by the national government, with very large and unsustainable investments. It is important to find alternative sources of funding to finance afforestation, and convince poor farmers to become involved in afforestation projects. Carbon-subsidized afforestation could be the solution. The current study aims to find i) whether farmers need additional subsidies to reforest their marginal farmland; if so, ii) whether the value of carbon sequestration of afforestation can offset farmers' net costs. To do this, first I determine the amount of carbon sequestration though afforestation. Second, I assess the value of carbon sequestration, the costs and benefits of afforestation projects, and the costs and benefits of crop production. Third, I investigate the optimal rotation period of the plantations considering a joint production of timber and carbon, for different species. Results show that total carbon sequestration through tree biomass and soil carbon following afforestation differs among tree species and stand age as well as across regions. Economic trees sequester less carbon than ecological trees and bamboo. Among economic trees, nut trees with an inedible hard shell sequester more carbon than fruit trees. The regional context significantly influences the carbon sequestration potential, with more carbon sequestered in southern and eastern regions than in northern regions. Bamboo also shows a remarkable carbon sequestration potential, which is even greater than Chinese fir and Poplar in northern regions. Although afforestation programs have huge potential to store carbon, the voluntary acceptance by landowners crucially depends on their economic outcome. I found that usually carbon credits can compensate for the opportunity costs of alternative land uses, except i) when highly profitable croplands are afforested, in which case carbon credits are not sufficient, and ii) when croplands that generates low incomes are afforested, in which case carbon credits are not needed. Fruit trees are the most cost-effective option for afforestation. Bamboo afforestation is economically attractive if carbon revenues is included. The minimum price of carbon credit decreases with increasing project duration because more carbon is stored when time increases. This does not hold for fast-growing trees like Eucalyptus, for which the minimum price increases with extended project duration. Given the temporal variations of joint production of timber and carbon sequestration, the carbon accounting regimes (tCER, temporary Certified Emission Reductions and lCER, long-term Certified Emission Reductions) have a significant impact on the optimal rotation as well as on the revenue. Forest managers have an incentive to use tCER accounting to finance slow-growing plantations, and lCER for fast-growing ones. I perform a sensitivity analysis detects the changes of rotation period with different carbon prices and discount rates. While the optimal decision for slow-growing species (e.g. Chinese fir) is highly sensitive to changes in both variables under tCER accounting, the results concerning fast-growing species (e.g. Eucalyptus) are most sensitive under the lCER accounting regime. In contrast, carbon revenues have a minimal impact on the optimal rotation of Poplar plantations, no matter which regime is applied. I conclude that carbon-subsidized afforestation is a feasible way to offset the opportunity costs of retired farmland and support the livelihood of farmers. The findings can contribute to the efficient and sustainable management of forestry projects using carbon sequestration, while the methodology can also be applied to other regions in the world.

This study is aimed at developing policies for energy efficiency by observing the past changes of energy use in Indonesia???s manufacturing sector over the period 1980???2000, and to investigate mitigation options for energy-related CO2 emissions in the sector. The first part of the study uses decomposition analysis to assess the effect of the changes in energy consumption and the level of CO2 emissions, while the second part investigates energy efficiency improvement strategies and the use of economic instruments to mitigate CO2 emissions in the manufacturing sector. Economic activity was the dominant factor in increasing energy consumption over the whole period of analysis, followed by the energy intensity effect and then the structural effect. The increase in aggregate energy intensity over the period 1980-2000 was mainly driven by the energy intensity effect. In turn, the technical effect was the dominant contributor to changes in energy intensity effect, with the fuel-mix effect being of lesser importance. Changes in CO2 emissions were dominated by economic activity and structural change. Sub-sectors that would benefit from fuel switching and energy efficiency improvements are the textile, paper, and non-metal sub-sectors. Three main options for reducing CO2 emissions from the manufacturing sector were considered: the imposition of a carbon tax, energy efficiency initiatives, and other mitigation measures. A carbon tax was found to reduce sectoral emissions from the direct use of oil, gas and coal, but increased the demand for electricity. At the practical level, energy efficiency improvements can be implemented by adopting energy efficient technologies that can reduce aggregate energy intensity up to 37.1 per cent from the base-year level, estimated after imposition of a carbon tax at $30 per tonne of carbon. A major priority for energy efficiency improvements was found to be in the textile and the paper and chemical sub-sectors. A mitigation measure such as the Clean Development Mechanisms could be encouraged in order to reduce projected emission levels. The preferred option would be the adoption of energy efficient technologies in the textile, chemical, paper and non-metal sub-sectors.

I investigated the utility of Br- as a chemical ionization mass spectrometry (CIMS) reagent ion for the detection and measurement of both atmospheric trace gases and aerosol species. The primary goals of this study are to obtain fast, very sensitive measurements of nitrate and sulfate and to ascertain if gas phase PAN and HNO3 could be measured simultaneously with the same chemical ionization scheme. Gas-phase measurements of PAN and nitric acid were conducted and the sensitivities of these measurements to temperature and relative humidity were determined. The potential for measuring aerosol composition by CIMS was assessed by comparison with PILS (particle-into-liquid sampler) measurements.

This study has provided a landscape level estimate of leaf area index (LAI) and net primary productivity (NPP) for a temperate broadleaf forest ecosystem in south-central Indiana. The estimates were compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) biophysical products LAI and NPP from both spatial and temporal perspectives. The evidence suggests that field-based estimates were poorly correlated with global MODIS data due to the simplifying assumptions of the MODIS global applicability, saturation problems of the red reflectance in highly vegetated areas, homogeneous land cover types of the study area, and other design assumptions of the field-based estimates. To improve the localized applicability of MODIS product algorithms, an empirical and localized algorithm combining in-situ measurements, the buildup of a localized biophysical model, and remote sensing-derived data were suggested for each local-scaled ecosystem.
Department of Natural Resources and Environmental Management

Of all the strategies to reduce carbon emissions, carbon dioxide (CO₂) geological sequestration is an immediately available option for removing large amounts of the gas from the atmosphere. However, our understanding of the transition behavior between Forchheimer and Darcy flow through porous media during CO₂ injection is currently very limited. In addition, the kinetic mass transfer of SO₂ and CO₂ from CO₂ stream to the saline and the fully coupling between the changes of porosity and permeability and multiphase flow are two significant dimensions to investigate the brine acidification and the induced porosity and permeability changes due to SO₂ co-injection with CO₂. Therefore, this dissertation develops a multiphase flow, contaminant transport and geochemical model which includes the kinetic mass transfer of SO₂ into deep saline aquifers and obtains the critical Forchheimer number for both water and CO₂ by using the experimental data in the literature. The critical Forchheimer numbers and the multiphase flow model are first applied to analyze the application problem involving the injection of CO₂ into deep saline aquifers. The results show that the Forchheimer effect would result in higher displacement efficiency with a magnitude of more than 50% in the Forchheimer regime than that for Darcy flow, which could increase the storage capacity for the same injection rate and volume of a site. Another merit for the incorporation of Forchheimer effect is that more CO₂ would be accumulated in the lower half of the domain and lower pressure would be imposed on the lower boundary of the cap-rock. However, as a price for the advantages mentioned above, the injection pressure required in Forchheimer flow would be higher than that for Darcy flow. The fluid flow and contaminant transport and geochemical model is then applied to analyze the brine acidification and induced porosity and permeability changes due to SO₂ co-injection. The results show that the co-injection of SO₂ with CO₂ would lead to a substantially acid zone near the injecting well and it is important to include the kinetic dissolution of SO₂ from the CO₂ stream to the water phase into the simulation models, otherwise considerable errors would be introduced for the equilibrium assumption. This study provides a useful tool for future analysis and comprehension of multiphase Darcy-Forchheimer flow and brine acidification of CO₂ injection into deep saline aquifers. Results from this dissertation have practical use for scientists and engineers concerned with the description of flow behavior, and transport and fate of SO₂ during SO₂ co-injection with CO₂ in deep saline aquifers.

Thesis (MSc) -- Macquarie University, Division of Environmental and Life Sciences, Dept. of Chemistry and Biomolecular Sciences, 2008.
Bibliography: p. 120-124.
Introduction -- Environmental factors affecting the emission of biogenic Volatile organic compounds -- Materials and experimental procedures -- Quantification using sold-phase microextraction in a dynamic system: technique development -- The emission profile of Tristaniopsis laurina -- Study of the effect of elevated atmospheric CO₂ levels on the emission of BVOCS from Australian native plants -- Conclusions and future work.
Biogenic Volatile Organic Compounds (BVOCs) emitted by plants can affect the climate and play important roles in the chemistry of the troposphere. As ambient atmospheric carbon dioxide (CO₂) levels are rapidly increasing knowledge of the effect of elevated atmospheric CO₂ on plant BVOC emissions is necessary for the development of global climate models. -- During this study, the effect of elevated atmospheric CO2 mixing ratios on BVOC emissions from Corymbia citriodora (Lemon Scented Gum) and Tristaniopsis laurina (Water Gum) was determined for the first time through the combination of Solid-Phase Microextraction (SPME), Gas Chromatography-Flame Ionisation Detection (GC-FID), Gas Chromatography-Mass Spectrometry (GC-MS) and an environment chamber. For C. citriodora elevated atmospheric CO₂ led to a decrease in the emission rate of α-pinene, β-pinene, eucalyptol, citronellal and β-caryophyllene, however, elevated CO₂ had no effect on the emission rate of citronellol. The emission profile of T. laurina has been determined for the first time. For T. laurina elevated CO₂ led to a decrease in the emission rate of α-pinene but the emission rates of β-pinene, limonene, eucalyptol and citronellol were unaffected. The results obtained in this work confirm that the effect of elevated atmospheric CO₂ on plant BVOC emissions is species-specific.
Mode of access: World Wide Web.
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Large areas of northern peatlands have been drained and afforested in the second half of the 20th century with significant impacts on important ecosystem services, including loss of biodiversity and potential changes in C storage. A considerable effort is currently invested into restoring original peatland function and ecosystem services, with an increasing area of newly restored peatland areas over recent years. However, the effect of restoration on the greenhouse gas (GHG) budget is unknown. This study is the first quantification of CO2, CH4 and N2O fluxes from forest-to-bog restoration sites spanning 0 to 17 years in age. Further, the impact of afforestation on peat decomposition is measured in situ, and the impact of afforestation on the biochemical composition of the peat in relation to CO2 and CH4 fluxes is investigated. Results show that forest-to-bog restoration is successful from a GHG perspective, since all three major GHG fluxes of the restoration sites are changing along the chronosequence towards the fluxes from near pristine bog sites. The peat decomposition rate under the forest plantations is a big part of the total soil respiration at 126.8 ± 14.7 g C m-2 y-1 (44% of total soil CO2 efflux) and our results indicate a slowing down of peat decomposition towards the near pristine bog. CH4 fluxes increase with restoration age, whilst all sites remain a small sink for N2O. I observed changes in peat quality and nutrient availability in the pore water under forests. Different CO2 fluxes between vegetation-free peat cores from different sites for the same temperature and water level show that these differences in peat quality and nutrient availability shape the biogeochemical processes in the peatlands. However only small differences in CH4 fluxes between sites were evident, suggesting that on its own (and in absence of biotic interactions under field conditions), forestry effects on CH4 flux are limited.

Moss dominated ecosystems are an important part of the global terrestrial carbon cycle. Over large areas, remote sensing can be useful to provide an improved understanding of these ecosystems. Two boreal mossess (Pleurozium and Sphagnum) were assessed using remote sensing based spectral vegetation indices for estimating biochemical capacity and photosynthetic efficiency by varying net photosynthesis rate via changes in water content. In the laboratory, changes in the normalized difference vegetation index (NDVI) and chlorophyll index coincided with declining photosynthetic capacity due to desiccation. This effect was more dramatic in Sphagnum. The photochemical reflectance index (PRI) did not vary with changes in CO2 supply as anticipated, possibly due to overriding effects of changing water content. The water band index (WBI) was strongly related to water content but this relationship showed an uncoupling in the field. Bi-directional reflectance measurements indicated what WBI was sensitive to sensor, sun, and moss surface slope angles.
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Thesis (MDF)--Stellenbosch University, 2012.
In recent years there has been a growth in literature from multiple disciplines on the potential effects of climate change and a corresponding growth in literature on potential mitigation and adaptation response strategies, including multiple means of shifting to a low-carbon future. Multiple assessment techniques have been developed to understand the potential vulnerability to, and impacts of climate change. At the same time, there is a lack of methodology to understand the potential vulnerability to, and impacts of, responses to climate change on a micro level. This research report describes the development of a reference framework to be used to monitor the vulnerability of the Cape Town International Airport to changes in carbon pricing and/or a shift to a low-carbon future. A theoretical approach was taken, which reviews existing techniques and proposes an integrated framework approach which was then applied to the case study of Cape Town International Airport. Existing literature on what is understood by a low carbon future shows that there is uncertainty about what mitigation and adaptation approaches will be adopted on various scales, and, similarly, uncertainty on what this means for a low carbon economy. Existing scenario development, vulnerability assessment, risk assessment and impact assessment methodologies were then reviewed, revealing a dearth of integrated approaches and an emphasis on the direct impacts of climate change, with a lack of attention to the impacts of responses to climate change. Finally, an overview of what are considered key driving forces in airport feasibility is provided in order to identify potential areas of vulnerability that require attention in any assessment of an airports’ vulnerability to different futures. Building on the various methodologies reviewed, and the understanding of key airport drivers, a reference framework is developed with special focus on the Cape Town International Airport and its current financial structure and planning framework. The final section of the paper discusses preliminary findings as illustrative of the approach, concluding that the framework can be applied via multidisciplinary collaboration, but that further work would be required both internally and externally in order to better manage uncertainties.

The potential for an adaptive response to global climatic change was evaluated for an annual C$ sb3$ weed, Brassica juncea, by performing a selection on fecundity for eight generations. During the selection, atmospheric carbon dioxide and temperature were gradually increased from current levels (370 $ rm mu L cdot L sp{-1}$ CO$ sb2$, 20$ sp circ$C) to conditions predicted during the next century by climate models (650 $ rm mu L cdot L sp{-1}$ CO$ sb2$, 23.6$ sp circ$C) including heat stress events at 32$ sp circ$C/26$ sp circ$C day/night), At the end of the selection, a reciprocal transplant experiment was conducted to identify genetic differences between control selection lines of plants and those selected under increasing CO$ sb2$ and temperature. I observed a genetic adaptation of early vegetative growth elevated CO$ sb2$ and temperature, which resulted in to 63% more biomass and 11% higher photosynthetic rates. Reproductive biomass, however, was decreased during the selection, mainly due to temperature stress, which disrupted flower development and induced strong maternal effects, counteracting the selection on fecundity.

The increasing threat of C02 to the global warming has prompted many governments to implement strategies to reduce the emission of C02 and other greenhouse gases into the atmosphere. The sequestering of C02 collected from power stations into the ocean is one of the promising strategies which can be used to achieve this goal. The east coast of Australia is identified as a favourable location for the C02 dumping scheme. The location of power stations along the east coast, with its narrow continental shelf, has provided favourable conditions for both the economical construction and running costs, of the ocean C02 disposal scheme. Compared to other oceans in the world, the Tasman Sea, and South Pacific Ocean in general, because of its high concentration of carbonate ions in the water column and sedimentary CaCO3, provides one of the best regions in which neutralisation of C02 can take place. The uncertainties of the fate of C02 after it has been released into the ocean and of its environmental impact are investigated. The current knowledge of C02 dumping schemes are reviewed to identify the most suitable scheme that can be adopted for Australia. It is proposed that an injection of liquid C02 at a depth of 1,000 m would be sufficient to ensure the long-term aim of sequestering the C02 produced in Australia into the ocean as well as minimising the environmental impact to the marine environment. A special release nozzle is needed to allow maximum mixing between the liquid C02 and seawater. The creation of denser COz-enriched plume will allow the anthropogenic C02 collected to sink to greater depths. The aims of creating the sinking current are two. One is to ensure the C02 reaches a greater depth and thus increases the resident time of C02 in the ocean. The other is to allow the C02 to react with sediment CaCO3, which in general is in abundance in the Tasman Sea and the South Pacific Ocean. This neutralisation process will not only reduce the impact of C02 on the environment but also provide a permanent sequestration of C02.

Plants emit a diverse range of biogenic volatile organic compounds (BVOCs) into the atmosphere, of which isoprene is the most abundantly emitted. Isoprene significantly affects biological and atmospheric processes, but the range of isoprene and BVOCs present in bamboos has not been well characterized. In this thesis I explore the range of isoprene emission found in bamboos and relate it to plant morphological and physiological characteristics. In addition, I measure and relate the entire suite of BVOCs present in the bamboos to their fundamental isoprene emission rate. Interspecific variation in isoprene emission documented in a comprehensive survey of bamboos. Two groups of bamboo species were measured in the greenhouse and the field. Elevated photosynthetic rate was significantly correlated with isoprene emission. In the field, dark respiration rate was highest in bamboos that made the least amount of isoprene. The total BVOC suite was significantly influenced by whether or not leaf-level isoprene emission was present. I conclude that bamboos vary with regard to physiology, morphology, and total BVOC suite and that isoprene emission is correlated with these changes, and introduce the bamboos as a novel system for studying the impacts of isoprene emission.

In my thesis, I address two important issues: (i) the creation of a price signal through the use of carbon markets (or cap-and-trade schemes) and (ii) the necessity to reach a global agreement on greenhouse gas emission reduction policies. It consists of three separate papers. Chapters 2 and 3 of this thesis emphasize theoretically and empirically the fact that achieving international cooperation on climate change is very difficult. Chapter 3 suggests that the global nature of the climate change problem and the design of climate agreements (i.e. the means available to reduce CO2 emissions) may explain this failure. Chapter 2 shows theoretically that asymmetric information between countries may exacerbate the free-rider problem. These two chapters also provide some possible solutions to the lack of international cooperation. To address the issue of information asymmetry, chapter 2 proposes the creation of institutions in charge of gathering and certifying countries' private information before environmental negotiations. If achieving international cooperation is still not possible, chapter 3 suggests that regional cooperation may supplement global treaties. Chapter 1 presents an example of such a regional agreement to reduce CO2 emissions. The EU emissions trading system is a cornerstone of the European Union's policy to combat climate change. However, as it is highlighted in chapter 1, the design of such regional carbon markets really matters for their success in reducing carbon emissions. This chapter shows the interactions between intertemporal permit trading and the incentives of firms to undertake long-term investments in abatement technologies.
Doctorat en Sciences économiques et de gestion
info:eu-repo/semantics/nonPublished

This thesis estimates the impacts of rooftop photovoltaic (PV) capacity on electricity generation and CO2 emissions in America's Pacific Northwest. The region's demand for electricity is increasing at the same time that it is attempting to reduce its greenhouse gas emissions. The electricity generated by rooftop PV capacity is expected to displace electricity from fossil fueled electricity generators and reduce CO2 emissions, but when and how much? And how can this region maximize and focus the impacts of additional rooftop PV capacity on CO2 emissions? To answer these questions, an hourly urban rooftop PV generation profile for 2009 was created from estimates of regional rooftop PV capacity and solar resource data. That profile was compared with the region's hourly fossil fuel generation profile for 2009 to determine how much urban rooftop PV generation reduced annual fossil fuel electricity generation and CO2 emissions. Those reductions were then projected for a range of additional multiples of rooftop PV capacity. The conclusions indicate that additional rooftop PV capacity in the region primarily displaces electricity from natural gas generators, and shows that the timing of rooftop PV generation corresponds with the use of fossil fuel generators. Each additional Wp/ capita of rooftop PV capacity reduces CO2 emissions by 9,600 to 7,300 tons/ year. The final discussion proposes some methods to maximize and focus rooftop PV impacts on CO2 emissions, and also suggests some questions for further research.

According to the United States Department of Energy, fossil-fueled power plants account for 78% of stationary source CO2 emission in the United States and Canada. This has led electric utilities across the globe to research different alternatives for energy. Carbon sequestration has been identified as a bridge between fossil fuels and clean energy. This thesis will present research results regarding the transportation costs of CO2 and the suitability of geology in the Florida Pan-Handle for sequestration infrastructure. The thesis will utilize various evaluation tools including GIS, numerical models, and optimization models. Analysis performed for this thesis and review of published literature produced estimated carbon storage capacities for two areas in and near the Florida Pan-Handle. These areas were labeled Disposal Area 1 and Disposal Area 3. Disposal Area 1 was estimated to contain capacity for the storage of 5.58 gigatonnes of CO2. Disposal Area 3 was estimated to contain capacity for the storage of 2.02 gigatonnes of CO2. Transportation scenarios were analyzed over a 25 year period and the capacities above are sufficient to store the CO2 emissions from the Pan-Handle network of power plants for the study period. Four transportation routing scenarios were investigated using transportation costs from the Poiencot and Brown CO2 pipeline capital cost model. The scenarios (models) consisted of the Right-Of-Way, Solo-Funded, Piece-Wise, and Authority models. Each presents a different method for the overall funding of the Florida Pan-Handle CO2 network and produced different total levelized and mean unit costs. The cheapest network on a mean unit cost basis was the network for Disposal Area 1 in the Authority Model, producing a mean unit cost of $0.64 per tonne of CO2.

Detta examensarbete syftar till att utveckla ett nytt sätt att använda betong för inredningsändamål. Betong har alltid använts i större byggnader, infrastruktur och andra kategorier. Nyligen började den moderna inredningen använda betong inomhus, till exempel som bänkskiva eller som en hylla. Arbetet fokuserar på en huvudfråga: Är betong ett bra materialval för inredning? För att besvara denna fråga bestämdes några punkter för att komma till huvudfrågan. Följande punkter behövde testat och analyserad för att komma till svaren:    - Beräkna och testa betongens hållfasthet    - Testa slagtålighet    - Analysera hur betong reagerar med kemikalier med olika pH-värde    - Förhållandet mellan miljö och betong    - Studera produktionen av betong Laborationstest, litteraturskällor och fältstudier användes som metoder för att få ett resultat av ovan nämnda punkter. Resultaten visar att betong kan användas som inredningsändamål och kan användas i större utsträckning än vad som är fallet idag. Sammanfattningsvis är betong ett bra material som används för inredningsändamål och den framtida tekniken kommer att minska koldioxidutsläppen som följer med produktionen av betongen. Det kommer att göra betong ännu bättre som material att använda i framtiden.
The following thesis aims to develop a new way to use concrete as interior material. Concrete has always been used in larger scale buildings, infrastructure and in other categories. Recently the modern interior design started to use concrete indoors for example as countertop or as a shelf. This thesis focuses on one main question: is concrete a good material choice for interior use. To answer that question, we decided to have sub questions to help to get to the main question. The following questions needed test and analysis methods to get to the answers:    - Calculate and test the strength of concrete    - Test impact resistance    - Analyze how concrete reacts with chemicals with different PH-values    - Study the production of concrete    - Relation between environment and concrete Lab tests, literature sources, and field studies was used as methods to answer those questions. The results shows that concrete can be utilized as interior material and can be used to a greater extent than is the case today. In conclusion concrete is a good material as used for interior purposes and the future technology will decrease carbon dioxide emissions that comes with production of the concrete. That will make concrete even better as material to use in the future.

Este trabalho objetiva contribuir com o planejamento da geração de energia elétrica por meio da utilização de geração fotovoltaica de forma distribuída, ou seja, instalada e em operação em paralelo junto com a rede de distribuição de energia elétrica. Utiliza-se uma abordagem hipotético-dedutiva, buscando hipóteses, na forma de questões orientadoras, que serão testadas por meio do tratamento dos dados coletados e sua posterior análise e interpretação. O método de procedimento é o estudo de caso, sendo escolhida a cidade de Curitiba e o restante dos municípios compreendendo sua Região Metropolitana. A partir da elaboração da revisão na literatura, visando constituir a fundamentação teórica desta pesquisa, é elaborado um breve inventário estatístico e do aspecto de geração de energia elétrica da cidade de Curitiba, no contexto do estado do Paraná. Os procedimentos metodológicos envolvem a simulação de cenários de inserção de geração fotovoltaica distribuída, considerando diferentes níveis de penetração, e seus efeitos sobre curvas de carga reais para a cidade de Curitiba. Foram selecionados 12 dias, considerados críticos, para a análise que contemplou a contribuição fotovoltaica em termos da redução do consumo de energia elétrica, redução de emissões de CO2 e, por fim, capacidade do sistema fotovoltaico em reduzir a demanda máxima do sistema elétrico. Constatou-se que o intervalo de capacidade instalada em energia solar fotovoltaica situa-se entre 40,80 MWp e 55,68 MWp, desconsiderando exceções, e remete a valores de máximo Fator Efetivo de Capacidade de Carga (FECC), para condição de irradiação máxima e irradiação típica, no inverno e verão. Dessa forma, este intervalo é considerado apropriado do ponto de vista do aumento da capacidade do sistema elétrico, devido à presença de geradores fotovoltaicos distribuídos. Além disso, o referido intervalo além de aumentar em mais de 50% a capacidade do sistema elétrico, acarreta em redução anual do consumo de energia elétrica entre 50,8 GWh e 69,4 GWh, além de evitar a emissão de 18.501 toneladas de CO2-eq a 25.251 toneladas de CO2-eq, sendo, portanto, um importante vetor para o aumento da oferta de energia elétrica, aumento da capacidade do sistema elétrico e, por fim, redução de emissões de Gases do Efeito Estufa, principalmente o CO2.
This study aims to deepen knowledge in the item electricity generation planning through the use of distributed generation using solar photovoltaic energy, which means that photovoltaic systems are able to operate in parallel with the electricity distribution network. A hypothetical-deductive approach was developed, seeking hypotheses in the form of guiding questions, which will be tested by treatment of the collected data and their analysis and interpretation. The method of procedure is the case study, being applied to the Metropolitan Region of Curitiba. The literature review aims to be the theoretical basis of this research, therefore it mainly consists of a brief statistical and electrical energy inventory of the city of Curitiba in Paraná state. The methodological procedures involve the simulation of different scenarios for distributed PV generators by varying their Penetration Level, so that the effects on actual load curves for the region analyzed were quantified. 12 critical days were selected to the analysis that included the photovoltaic contribution in terms of reducing electrical energy consumption, reducing CO2 emissions and, finally, the capacity of the photovoltaic systems to reduce the maximum demand of the electrical system of the city. It was concluded that the most appropriate PV Penetration Level, in terms of power, regards with 40,80 MWp up to 55,68 MWp, disconsidering exceptions. This result leads to maximum values of Effective Load Carrying Capacity (ELCC), for maximum and typical solar radiation, during the seasons of winter and summer. In result, this proposed interval represents the better peak shaving capability of PV, because of its higher ELCC parameter. Furthermore, in addition to increase more than 50% in the capacity of the electrical system, there is an annual amount of energy generated about 50.8 GWh and 69.4 GWh, which represents 18,501 to 25,251 tons of CO2-eq avoided. For this reason, solar PV energy is an extremely important and feasible strategy to enhance the electricity generation, the capacity of the electrical system and to reduce greenhouse gases emission, especially CO2.

The full text available is only the introduction of the thesis.
Defence date: 15 June 2009
Supervisor: Giovanni Federico External supervisor: Timo Myllyntaus Examining Board: Giovanni Federico Bartolomé Yun Casalilla Magnus Lindmark Jan Luiten van Zanden
This thesis examines Finland‘s transition from a solar based energy system to a fossil fuel based one, and the environmental consequences of this transition. The period under examination is from the beginning of the 19th century to the present, covering Finland's transition from a proto-industrial agricultural society to a --post- industrial| society. The theoretical starting point has been the environmental Kuznets curve hypothesis, which proposes that some pollution or measures of environmental degradation would follow an inverted U-curve related to incomes, increasing at low income levels and decreasing at high income levels. Based on the historical approach used in this thesis, two new explanations for the existence of an environmental Kuznets curve are added: 1) The severity of environmental degradation might itself create a turning point for the emissions, or in some cases fear of severe effects. 2) What at a first glance seems to be a genuine environmental improvement might just be a transformation of one environmental problem into another. Some proponents of economic growth go as far as claiming that economic growth is a necessary condition for proper protection of the environment. This thesis turns the argument around, claiming that the causal connection goes in an opposite direction: proper environmental standards and conservation comprise a necessary condition for economic growth in the long run. Finland industrialized by means of renewable, indigenous energy sources. The switch to imported fossil fuels in the 1960s led to exceptionally fast growth of carbon and sulphur dioxide emissions. The emissions of sulphur dioxide started to decline in the 1970s while the emission growth of carbon dioxide only slowed down. The initial decline of sulphur dioxide emissions was mainly a side-effect of changes in industrial processes rather than an outcome of a deliberate policy. Furthermore, anxiety about large and widespread damage to the forests was a major reason for active measures to decrease sulphur dioxide emissions since the mid- 1980s. Thus the emissions themselves provoked their downturn. Quantitative calculations on the use of natural resources provide valuable tools, which can give new insights to old questions and raise new questions. Burning cultivation of peatlands, which has been neglected in historical research, was found to be the greatest source of carbon dioxide in Finland during the whole of the nineteenth century and at the beginning of the twentieth century. Another neglected occupation, the production of potash might have consumed as much wood during the 19th century as the production of tar.

大量學術文獻指出氣候變化是毫不含糊地由持續增加的人為溫室氣體排放所造成。其中，二氧化碳排放（碳排放）是最為重要的溫室氣體排放。碳排放和經濟發展之間的密切關係亦受到廣泛肯定。碳排放和收入之間的關係引起了研究人員的極大興趣。學者們對該關係的環境庫茲涅茨曲線（一個倒U形曲線）的有效性持有不同的觀點，該曲線之有效性的討論可以分為兩部分，即時間和空間（國家）的尺度。
在這項研究中，首先以描述性統計研究碳排放量的變化，其中包括排放總量，人均排放量和碳強度三個指標。然後，透過雙對數和二次雙對數回歸模型進一步研究這三項指標和各經濟發展指標的關係（經濟發展指標包括總量和人均國內生產總值，貿易值和產業值）。結果指出國內生產總值可以很好地解釋碳排放之變化。根據1970年到2007年的數據，排放總量和國內生產總值總量在雙對數回歸模型中呈現顯著的線性關係。同樣在雙對數回歸模型中，人均排放量和人均國內生產總值之間的關係則從顯著線性變成顯著二次（倒U形曲線），從而支持環境庫茲涅茨曲線理論。碳強度和人均國內生產總值之間的關係是顯著的倒U形曲線。所有研究國家的回歸結果指出，發達國家在經濟增長的同時，已經減少排放總量及人均量，而發展中國家沒有減少。大多數發達國家在碳強度和人均國內生產總值的關係上呈現顯著的負相關，而發展中國家在碳強度和人均國內生產總值之間的關係上比例平均。在一般情況下，其他因素如貿易值和產業值解釋碳排放變化之能力較國內生產總值差。較特別的結果是由於製造、礦業和公用事業產業值屬於高碳密集性，該產業能很好地解釋碳排放的變化，所以為該產業的度身訂造之減排控制是必要的。
進一步說，發展中國家之間的差異仍然很大。透過層次聚類法，所有國家基於排放水平可分成11個類。其中，第11類主要包括發達國家，擁有極高的排放總量，非常高的人均排放量和中等的碳強度。與此同時，第4類主要包括發展中國家，亦有非常高的總排放量，中等的人均排放量和極高的碳強度。美國和中國，分別為第11類和第4類的案例研究，這兩國能有效地幫助了解碳排放和經濟發展之相互關係。其他集群則代表不同的經濟發展階段。聚類分析的結果可作為未來國際氣候變化政策建設的參考。
Wealth of scholarly reviewed literatures indicates that climate change is unequivocally caused by the continual increase in anthropogenic greenhouse gases (GHGs) emissions. Carbon dioxide emissions remain to be of upmost importance among all GHGs emissions. It is widely accepted that close relationship between carbon dioxide emissions and economic development exists. The relationship between carbon dioxide emissions and income, in particular, has aroused much research interests. Researchers have polarizing views on the validity of Environmental Kuznets Curve (EKC), an inverted U-shaped curve of that relationship. The ground of argumentation for the validity of EKC can be also divided into two parts, namely temporal and spatial (national) extents.
In this research, variations in three indicators of carbon dioxide emissions, including total emissions, per capita emissions and carbon intensity (CI), are firstly examined by descriptive statistics. Next, double-log and quadratic double-log regression models are employed to study the relationship between these three indicators and indicators of economic development (including the total and per capita GDP, trade values and sectoral values). Results show that GDP has high explanatory power for the large variation of emissions. By using the data from 1970 to 2007, the relationship between total emissions and total GDP is significantly linear in double-log regression models. The relationship between per capita emissions and per capita GDP has changed from linear to quadratic (inverted U-shaped), which supports the EKC. The relationship between CI and per capita GDP is significant in an inverted U-shaped curve. Regression results in each country indicate that developed countries have reduced total and per capita emissions in parallel with economic growth while developing countries have not. Majority of developed countries have negative relationship between CI and per capita GDP; whereas their counterparts have even proportion in the relationships. Other explanatory factors, like trade values and sectoral values, in general, have lower explanatory power than GDP. Surprisingly, results indicated that manufacturing, mining and utility (MMU) sector yields very high explanatory power for the variation of carbon dioxide emissions due to the sector’s high carbon-intensive nature. Tailor-made control on this sector is necessary for emissions abatement.
Furthermore, as the variation within developing countries is still large, countries are classified into clusters on the basis of their levels of emissions by Hierarchical Cluster Analysis. Eleven clusters are formed. Among all, cluster 11, comprised of mostly developed countries, yields extremely high total emissions, very high per capita emissions and medium CI. Meanwhile, cluster 4, made of mostly developing countries, have very high total emissions, medium per capita emissions and extremely high CI. The USA and China, case studies of clusters 11 and 4 respectively, have provided insight for the interactive relationship between emissions and economic development. Remaining clusters represent different stages of economic development. The results of the clustering can serve as a reference for the construction of future climate change policy.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Detailed summary in vernacular field only.
Wong, Wai Fung.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2012.
Includes bibliographical references (leaves 273-280).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts also in Chinese.
ABSTRACT --- p.i
摘錄 --- p.iii
ACKNOWLEDGEMENTS --- p.iv
TABLE OF CONTENTS --- p.v
LIST OF TABLES --- p.x
LIST OF FIGURES --- p.xix
LIST OF ABBREVIATIONS --- p.xxiv
Chapter CHAPTER ONE: --- INTRODUCTION --- p.1
Chapter 1.1 --- EFFECTS OF CARBON DIOXIDE EMISSIONS ON CLIMATE CHANGE --- p.1
Chapter 1.2 --- VARIATION IN CARBON DIOXIDE EMISSIONS AMONG COUNTRIES IN TERMS OF THREE INDICATORS: TOTAL AMOUNT, PER CAPITA AMOUNT AND CARBON INTENSITY (CI) --- p.3
Chapter 1.3 --- RELATIONSHIP BETWEEN CARBON DIOXIDE EMISSIONS AND ECONOMIC DEVELOPMENT --- p.6
Chapter 1.4 --- RESEARCH QUESTIONS --- p.8
Chapter 1.5 --- RESEARCH OBJECTIVES --- p.8
Chapter 1.6 --- SIGNIFICANCE OF THE STUDY --- p.9
Chapter 1.7 --- ORGANIZATION OF THE THESIS --- p.10
Chapter CHAPTER TWO: --- LITERATURE REVIEW --- p.12
Chapter 2.1 --- CARBON DIOXIDE EMISSIONS --- p.12
Chapter 2.1.1 --- Definitions of carbon dioxide emissions --- p.12
Chapter 2.1.2 --- Estimation of carbon dioxide emissions --- p.13
Chapter 2.1.3 --- Importance of carbon dioxide emissions in the context of climate change --- p.15
Chapter 2.2 --- ECONOMIC DEVELOPMENT --- p.19
Chapter 2.2.1 --- Concept and different stages of economic development --- p.19
Chapter 2.2.2 --- Indicators of economic development among all countries --- p.20
Chapter 2.2.3 --- Economic development since 1970 in major countries --- p.23
Chapter 2.3 --- PAST STUDIES ON THE RELATIONSHIP BETWEEN CARBON DIOXIDE EMISSIONS AND ECONOMIC DEVELOPMENT --- p.30
Chapter 2.3.1 --- Relationship between emissions and income expressed by GDP --- p.30
Chapter 2.3.2 --- Relationship between emissions and international trade expressed by export and import values --- p.38
Chapter 2.3.3 --- Relationship between emissions and sectoral composition expressed by sectoral values --- p.43
Chapter 2.4 --- RESEARCH GAPS IN THE RELATIONSHIP BETWEEN CARBON DIOXIDE EMISSIONS AND ECONOMIC DEVELOPMENT --- p.44
Chapter 2.4.1 --- Identification of relationship between emissions and economic development --- p.44
Chapter 2.4.2 --- Classification of countries based on the amount of carbon dioxide emissions --- p.46
Chapter 2.4.3 --- Research plan for this study --- p.47
Chapter 2.5 --- SUMMARY OF THE LITERATURE REVIEW --- p.48
Chapter CHAPTER THREE: --- CONCEPTUAL FRAMEWORK, DATA SOURCE AND METHODOLOGY --- p.49
Chapter 3.1 --- INTRODUCTION OF THE CONCEPTUAL FRAMEWORK --- p.49
Chapter 3.2 --- RELATIONSHIP BETWEEN ECONOMIC DEVELOPMENT AND CARBON DIOXIDE EMISSIONS UNDER THE CONCEPTUAL FRAMEWORK --- p.50
Chapter 3.3 --- INTRODUCTION TO THE INDICATORS OF THE CONCEPTUAL FRAMEWORK --- p.51
Chapter 3.4 --- RELATIONSHIPS AMONG THE COMPONENTS --- p.53
Chapter 3.4.1 --- Relationship between income and carbon dioxide emissions --- p.53
Chapter 3.4.2 --- Relationship between international trade and carbon dioxide emissions --- p.54
Chapter 3.4.3 --- Relationship between sectoral composition and carbon dioxide emissions --- p.54
Chapter 3.5 --- EXAMINATION OF THE RELATIONSHIP IN SPATIAL AND TEMPORAL EXTENT --- p.54
Chapter 3.6 --- DATA SOURCE --- p.57
Chapter 3.6.1 --- Data source for the indicators of economic development and population --- p.57
Chapter 3.6.2 --- Data source for the indicators of carbon dioxide emissions --- p.58
Chapter 3.7 --- METHODOLOGY --- p.59
Chapter 3.7.1 --- Variables used in the research --- p.59
Chapter 3.7.2 --- Methodology used in the research --- p.60
Chapter 3.8 --- SUMMURY OF THE CONCEPTUAL FRAMEWORK, DATA SOURCE AND METHODOLOGY --- p.63
Chapter CHAPTER FOUR: --- VARIATIONS IN THE LEVELS OF INDICATORS OF CARBON DIOXIDE EMISSIONS AND INDICATORS OF ECONOMIC DEVELOPMENT --- p.65
Chapter 4.1 --- VARIATIONS IN CARBON DIOXIDE EMISSIONS, POPULATION AND GDP --- p.65
Chapter 4.1.1 --- Variation in total carbon dioxide emissions --- p.65
Chapter 4.1.2 --- Variation in total population --- p.72
Chapter 4.1.3 --- Variation in total GDP --- p.75
Chapter 4.1.4 --- Variation in per capita carbon dioxide emissions --- p.79
Chapter 4.1.5 --- Variation in per capita GDP --- p.83
Chapter 4.1.6 --- Variation in CI --- p.87
Chapter 4.2 --- VARIATIONS IN INTERNATIONAL TRADE VALUES AND SECTORAL VALUES --- p.91
Chapter 4.2.1 --- Variation in total export values --- p.91
Chapter 4.2.2 --- Variation in total import values --- p.94
Chapter 4.2.3 --- Variation in per capita export values --- p.96
Chapter 4.2.4 --- Variation in per capita import values --- p.99
Chapter 4.2.5 --- Variation in trade balance --- p.102
Chapter 4.2.6 --- Variation in total sectoral values --- p.104
Chapter 4.2.7 --- Variation in per capita sectoral values --- p.106
Chapter 4.2.8 --- Variation in sectoral composition --- p.107
Chapter 4.3 --- SUMMARY ON THE VARIATIONS IN THE LEVELS OF INDICATORS OF CARBON DIOXIDE EMISSIONS AND INDICATORS OF ECONOMIC DEVELOPMENT --- p.109
Chapter CHAPTER FIVE: --- RELATIONSHIPS BETWEEN INDICATORS OF CARBON DIOXIDE EMISSIONS AND INDICATORS OF ECONOMIC DEVELOPMENT --- p.112
Chapter 5.1 --- RELATIONSHIPS BETWEEN CARBON DIOXIDE EMISSIONS AND INCOME IN TERMS OF TOTAL AMOUNT, PER CAPITA AMOUNT AND CARBON INTENSITY --- p.112
Chapter 5.1.1 --- Relationship between total carbon dioxide emissions and total GDP --- p.112
Chapter 5.1.2 --- Relationship between per capita carbon dioxide emissions and per capita GDP --- p.123
Chapter 5.1.3 --- Relationship between CI and per capita GDP --- p.133
Chapter 5.2 --- RELATIONSHIPS BETWEEN CARBON DIOXIDE EMISSIONS AND INTERNATIONAL TRADE IN TERMS OF TOTAL AMOUNT, PER CAPITA AMOUNT AND CARBON INTENSITY --- p.142
Chapter 5.2.1 --- Relationship between total carbon dioxide emissions and total values of exports and imports --- p.142
Chapter 5.2.2 --- Relationship between per capita carbon dioxide emissions and per capita values of exports and imports --- p.146
Chapter 5.2.3 --- Relationship between CI and per capita values of exports and imports . --- p.151
Chapter 5.3 --- RELATIONSHIP BETWEEN CARBON DIOXIDE EMISSIONS AND SECTORAL COMPOSITION IN TERMS OF TOTAL AMOUNT, PER CAPITA AMOUNT AND CARBON INTENSITY --- p.157
Chapter 5.3.1 --- Relationship between of total carbon dioxide emissions and total values of six sectors --- p.157
Chapter 5.3.2 --- Relationship between per capita carbon dioxide emissions and per capita values of six sectors --- p.160
Chapter 5.3.3 --- Relationship between CI and per capita values of six sectors --- p.163
Chapter 5.3.4 --- Relationship between indicators of carbon dioxide emissions and ratios of sectoral values to the sum of all sectors --- p.165
Chapter 5.4 --- SUMMARY ON THE RELATIONSHIPS BETWEEN INDICATORS OF CARBON DIOXIDE EMISSIONS AND INDICATORS OF ECONOMIC DEVELOPMENT --- p.168
Chapter CHAPTER SIX: --- CLASSIFICATION OF COUNTRIES BASED ON THE LEVELS OF TOTAL CARBON DIOXIDE EMISSIONS, PER CAPITA CARBON DIOXIDE EMISSIONS AND CARBON INTENSITY --- p.171
Chapter 6.1 --- CORRELATION ANALYSIS BETWEEN TOTAL EMISSIONS, PER CAPITA EMISSIONS AND CARBON INTENSITY --- p.171
Chapter 6.2 --- MEMBERSHIP OF COUNTRIES AND BASIC CHARACTERISTICS OF EACH CLUSTER --- p.173
Chapter 6.2.1 --- Result of Hierarchical Cluster Analysis and membership of countries --- p.173
Chapter 6.2.2 --- Characteristics of each cluster in terms of carbon dioxide emissions --- p.176
Chapter 6.2.3 --- Characteristics of each cluster in terms of GDP (indicator of economic development) --- p.180
Chapter 6.3 --- IN-DEPTH EXAMINATION OF THE CHARACTERISTICS OF EACH CLUSTER --- p.184
Chapter 6.3.1 --- Clusters with extremely high to very high total emissions: clusters 11 and 4 --- p.185
Chapter 6.3.2 --- Clusters with high total emissions: clusters 8, 10 and 3 --- p.211
Chapter 6.3.3 --- Clusters with medium to low total emissions: clusters 9, 2 and 1 --- p.230
Chapter 6.3.4 --- Clusters with very low to extremely low total emissions: clusters 5, 6 and 7 --- p.247
Chapter 6.4 --- SUMMARY OF THE RESULTS --- p.263
Chapter CHAPTER SEVEN: --- CONCLUSION --- p.267
Chapter 7.1 --- MAJOR FINDINGS OF THE RESEARCH --- p.267
Chapter 7.2 --- IMPLICATIONS OF THE RESEARCH --- p.270
Chapter 7.3 --- LIMITATIONS OF THE RESEACH --- p.271
Chapter 7.4 --- RECOMMENDATION FOR FUTURE RESEARCH --- p.272
REFERENCES --- p.273
APPENDICES --- p.281

High atmospheric concentrations of CO2 contribute to adverse effects that impact human health and the climate. The need to reduce CO2 is evident, and climate stabilization will require a combination of mitigation, utilization, and even negative emission technologies. Thus, one key approach will be to transform abundant CO2 into a useful feedstock for processes that not only produce value-added products but also match the scale necessary to impact anthropogenic emissions. The tandem CO2 reduction and light alkane transformation reactions over specialized bifunctional catalysts have the potential to produce olefins or synthesis gas by efficiently utilizing the C2-C4 components in shale gas while reducing a greenhouse gas. The reactions of CO2 with light alkanes may occur through two distinct pathways, oxidative dehydrogenation (CO2 + CnH2n+2 → CnH2n + CO + H2O, CO2-ODH) and dry reforming (nCO2 + CnH2n+2 → 2nCO + (n+1)H2, DR). The two reactions can occur simultaneously at temperatures ≥823 K with considerable conversions. Until recently, there has been little understanding regarding the identification of bimetallic catalytic systems that either selectively cleave the C-H bonds to produce olefins or effectively break all the C-C and C-H bonds to produce dry reforming products. In this work, we discuss a combined approach of flow reactor experiments, in situ characterization, and density functional theory (DFT) calculations to help create a design platform for catalysts that are inherently active and selective for the reactions of CO2 and light alkanes. Particularly, it was of interest to use propane as CO2 reduction feedstock due to its increasing abundance and highly marketable respective olefin. Through the combined approach, non-precious Fe3Ni1 and precious Ni3Pt1 supported on CeO2 were identified as promising catalysts for the CO2-ODH and DR of propane, respectively. In situ X-ray absorption spectroscopy measurements revealed the oxidation states of metals under reaction conditions and DFT calculations were utilized to identify the most favorable reaction pathways over the two types of catalysts. While both the CO2-ODH and DR reactions of alkanes produce valuable molecules, the separation of gas phase products is challenging. Therefore, it was highly desirable to develop a tandem reaction scheme in which the reaction of CO2 and alkanes can produce liquid products. Another potential chemistry with increased similarity to the operating conditions of CO2-ODH, is the tandem reactions of CO2-assisted oxidative dehydrogenation and aromatization of light alkanes (CO2-ODA). In this process, alkanes are transformed directly into aromatics without the need for expensive naphtha while increasing the consumption of CO2 per mol of value-added product and facilitating downstream separation because of the production of liquid aromatics. One critical change upon the introduction of CO2 to the dehydrogenation/aromatization pathway is the formation of water. The presence of water under reaction conditions has been shown to be problematic for zeolites as it causes changes in the framework. Phosphorous modification at an optimal loading improved the hydrothermal stability of Ga/ZSM-5, reduced coke formation on the catalyst surface, and allowed for the formation of more liquid aromatics through the CO2-ODAE reaction pathway compared to the direct dehydrogenation and aromatization reaction. With the aid of DFT calculations, the mechanisms for the production of aromatics from ethane were identified, providing insight on the effect of Ga modification on ethylene formation over ZSM-5 as well as the role of CO2 on the aromatization of ethylene. Future efforts should be geared toward enhancing aromatics yield through the design of hydrothermal stable zeolite-based materials with bimetallic active centers that are capable of activating CO2.

The ocean is the only cumulative sink of atmospheric CO2. It has absorbed approximately 40% of the CO2 from fossil fuel burning and cement production, lowering atmospheric CO2 and limiting climate change. Here we will examine the regional and global mechanisms controlling the evolution of ocean uptake of this additional carbon from human activities (anthropogenic carbon, Cant) using ocean models and observations. Cant is rapidly injected into the deep ocean, sequestering it from the atmosphere for centuries. It is currently uncertain whether any of this sequestered Cant was absorbed from the atmosphere in the subpolar North Atlantic. Here we present evidence that the upper limb of the ocean’s overturning circulation supplies the subpolar North Atlantic with capacity to absorb Cant from the atmosphere. Using a coupled ocean model, we find that surface freshening of the subpolar North Atlantic reduces the volume available for Cant storage. We also investigate whether global ocean Cant uptake is reduced due to changing ocean circulation, this time across multiple emission scenarios, including scenarios with aggressive emission mitigation. Though it is clear that emission mitigation will reduce the magnitude of the ocean carbon sink, the mechanisms governing the decline in uptake have not been studied in detail. We find that the ocean sink becomes less efficient due to kinematic effects wherein Cant escapes from the surface ocean as atmospheric CO2 plateaus and then declines. In emission scenarios ranging from high to low emissions, projected changes in global Cant uptake due to ocean circulation are small. This is in contrast with the subpolar North Atlantic, where future circulation change plays a important role in the declining Cant uptake.

Thesis (M.A. (Anthropology))--University of the Witwatersrand, Faculty of Humanities, School of Social Sciences, 2016.
Governments, like South Africa, are implementing carbon tax and carbon credit programs to incent businesses to lower their GHG emissions. That is not to say there are not loftier motivations in the wider world, but in this study we have mostly encountered Homo Economicus. Our observations have noted that people either want to make money or save money by way of participating in the green economy. Earth’s threatening posture is yet to change our “habitus”. The changes so far are from economic coercion and not ecological conviction. And it’s primarily prompted through the scientific community, who are understandably, the first responders to a threat with slow and mostly imperceptible reverberations. The responses of those trying to make money, involve participating in the process of carbon commodification. CERs are a new form of currency available to those able to deploy labor and capital in efforts to capture carbon molecules and prevent their creation. The looming South African carbon tax has spurred organizations to lower their emissions so as not to effect bottom-line profitability. [Taken from the conclusion. No abstract provided]
MT2017

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library.
This study area for this research is characterised by a regional anticline plunging to the east-south-east with large-scale internal architecture comprising transgressive, retrogradationally stacked stratigraphy that dips gently landward and is unconformably truncated by overlying sealing units. The primary reservoir/aquifer targets for CO₂ injection are palaeo-shoreline parallel nearshore sandstone bodies characterised by high porosity and permeability and good interconnectivity. The key regional sealing unit is the Lakes Entrance Formation, which consists of mudstone and marl capable of sealing large columns of CO₂. The proposed stategy for CO₂ geosequestration is to inject CO₂ outside four-way structural closure to allow up-dip fluid migration to the north then west governed by the structure of regional sealing units. Probabilistic estimates of CO₂ capacity utilising the proposed strategy indicate that 1395-2575 Mtonnes could be sequestered.
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Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2007

Symbiotic nitrogen fixation is the greatest potential input of nitrogen into terrestrial ecosystems. As a result, nitrogen fixation is critical to the functioning of the land carbon sink and its capacity to offset anthropogenic CO2 emissions and climate change. However, our understanding of the controls over nitrogen fixation rates and nitrogen fixing tree abundance is limited, resulting in paradoxes such as the relative absence of nitrogen fixing trees at high latitudes (where nitrogen is most limiting and it seems that nitrogen fixation should be most beneficial) and tropical forest nitrogen saturation, a mechanistically poor representation of nitrogen fixation in terrestrial biosphere models, and incomplete theory for variation in the successional trajectories of nitrogen fixing trees. This dissertation consists of four chapters that examine the drivers of symbiotic nitrogen fixation rates and the abundance of nitrogen fixing trees as they pertain to latitude, climate, and nitrogen fixation strategies. In chapter 1, I develop a method to measure coupled nitrogen fixation and plant carbon exchange in real-time, non-destructively, continuously, and at the whole plant scale. This permits a study of the controls of nitrogen fixation rates over timescales that range from seconds to months. In chapter 2 and 3, I apply the method developed in chapter 1 to determine the temperature response of nitrogen fixation rates and the timescales over which nitrogen fixation is regulated. For chapter 2 and 3, I grew nitrogen fixing tree species of tropical and temperate origin and representing the two types of nitrogen fixing symbioses (rhizobial and actinorhizal) across a 10 °C gradient of growing temperatures. In chapter 2, I show that nitrogen fixation depends on growing temperature and geographic origin and peaks at 30-38 °C, which is 5-13 °C higher than previous estimates based on other nitrogen fixing symbioses and 3-7 °C higher than net photosynthesis. These findings have direct implications for how nitrogen fixation is represented in terrestrial biosphere models and are in direct contrast to terrestrial biosphere model predictions of a decline in tropical nitrogen fixation with warming associated with climate change. In chapter 3, I show that nitrogen fixation takes 1-3 weeks to be down-regulated by 50% following an alleviation of nitrogen limitation, 1-5 weeks to be up-regulated by 50% following the initiation of nitrogen fixation when nitrogen becomes limiting, and up to 4 months for nitrogen fixation to start following a drastic reduction in soil nitrogen supply. Theory says that time-lags in regulating nitrogen fixation start becoming important for plant competition and losses of available nitrogen from ecosystems if they are between 1 day and 1 week. Thus, time-lags on the order of multiple weeks are a significant cost of a facultative nitrogen fixation strategy and resolve the tropical nitrogen forest nitrogen paradox characterized by high losses of available nitrogen at the ecosystem scale in spite of down-regulation of nitrogen fixation at the individual scale. In chapter 4, I show that nitrogen fixing tree abundance is bimodal in all regions of the contiguous United States except the Northeast and that founder effects can explain this pattern and the persistence of nitrogen fixing trees in old forests. Using theory, I show that founder effects are most probable at intermediate soil nitrogen supply, when nitrogen fixers have a high relative capacity to uptake available nitrogen, and when nitrogen fixing trees are facultative in their nitrogen fixation strategy. These chapters provide a new tool for studying nitrogen fixation, critical data for improving terrestrial biosphere models and our understanding of how nitrogen fixation and nitrogen cycling varies across latitude and how it will change with climate change, and new theory for the successional trajectories of nitrogen fixers.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering. 10 February, 2017.
Climate change due to the ever-increasing emission of anthropogenic greenhouse gases arising from the use of fossil fuels for power generation and most industrial processes is now a global challenge. It is therefore imperative to develop strategies or modern technologies that could mitigate the effect of global warming due to the emission of CO2. Carbon capture and storage (CCS) is a viable option that could ensure the sustainable use of cheap fossil fuels for energy generation with less CO2 emission. Amongst existing CCS technologies, absorption technology using monoethanolamine (MEA) is very mature and widely embraced globally. However, the absorption technology has a lot of challenges such as, low CO2 loading, high energy requirement for solvent regeneration, corrosive nature etc. On this note, the adsorption technology using solid sorbents is being considered for CO2 capture due to its competitive advantages such as flexibility, low energy requirement for sorbent regeneration, non-corrosive nature etc. On the other hand, adsorbents have a very vital role to play in adsorption technology and there is need to understand the behaviour of adsorbents for CO2 capture under different operating conditions in order to adapt them for wider applications. On this note, the study contained in this dissertation investigated the adsorption behaviour of a novel polymer-based adsorbent (polyaspartamide) during post-combustion CO2 capture using experimental study and mathematical modelling approach. Polyaspartamide is an amine-rich polymer widely used in drug delivery. In addition, its rich amine content increases its affinity for CO2. Its porosity, thermal stability and large surface area make it a promising material for CO2 capture. In view of this, polyaspartamide was used as the adsorbent for post-combustion CO2 capture in this study. This dissertation investigated the kinetic behaviour, the diffusion mechanism and rate limiting steps (mass transfer limitation) controlling the CO2 adsorption behaviour of this adsorbent. Furthermore, effect of impurities such as moisture and other operating variables such as temperature, pressure, inlet gas flow rate etc. on the CO2 adsorption behaviour of polyaspartamide was also investigated. Existing mathematical models were used to understand the kinetics and diffusion limitation of this adsorbent during CO2 capture. Popularly used gas-solid adsorption models namely; Bohart- Adams and Thomas model were applied in describing the breakthrough curves in order to ascertain the equilibrium concentration and breakthrough time for CO2 to be adsorbed onto polyaspartamide. Lagergren’s pseudo 1st and 2nd order models as well as the Avrami kinetic models were used to describe the kinetic behaviour of polyaspartamide during post-combustion CO2 capture. Parameter estimations needed for the design and optimization of a CO2 adsorption system using polyaspartamide were obtained and presented in this study. The Boyd’s film diffusion model comprising of the interparticle and intra-particle diffusion models were used to investigate the effect of mass transfer limitations during the adsorption of CO2 onto polyaspartamide. Data obtained from continuous CO2 adsorption experiments were used to validate the models in this study. The experiments were conducted using a laboratory-sized packed-bed adsorption column at isothermal conditions. The packed bed was attached to an ABB CO2 analyser (model: ABB-AO2020) where concentrations of CO2 at various operating conditions were obtained. The results obtained in this study show that temperature, pressure and gas flow rate had an effect on the adsorption behaviour of polyaspartamide (PAA) during CO2 capture. Polyaspartamide exhibited a CO2 capture efficiency of 97.62 % at the lowest temperature of 303 K and pressure of 2 bar. The amount of CO2 adsorbed on polyaspartamide increased as the operating pressure increased and a decrease in the adsorption temperature resulted in increased amount of CO2 adsorbed by polyaspartamide. The amounts of CO2 adsorbed on polyaspartamide were 5.9, 4.8 and 4.1 mol CO2/kg adsorbent for adsorption temperatures of 303, 318 and 333 K, respectively. The maximum amount of CO2 adsorbed by polyaspartamide at different flow rates of 1.0, 1.5 and 2.5 ml/s of the feed gas were 7.84, 6.5 and 5.9 mmol CO2/g of adsorbent. This shows that higher flow rates resulted in decreased amount of CO2 adsorbed by polyaspartamide because of low residence time which eventually resulted in poor mass transfer between the adsorbent and adsorbate. Under dry conditions, the adsorption capacity of polyaspartamide was 365.4 mg CO2/g adsorbent and 354.1 mgCO2/g adsorbent under wet conditions. Therefore, the presence of moisture had a negligible effect on the adsorption behaviour of polyaspartamide. This is very common with most amine-rich polymer-based adsorbents. This could be attributed to the fact that CO2 reacts with moisture to form carbonic acid, thereby enhancing the CO2 adsorption capacity of the material. In conclusion, this study confirmed that the adsorption of CO2 onto polyaspartamide is favoured at low temperatures and high operating pressures. The adsorption of CO2 onto polyaspartamide was governed by film diffusion according to the outcome of the Boyd’s film diffusion model. It was also confirmed that intra-particle diffusion was the rate-limiting step controlling the adsorption of CO2 onto polyaspartamide. According to the results from the kinetic study, it can be inferred that lower temperatures had an incremental effect on the kinetic behaviour of polyaspartamide, external mass transfer governed the CO2 adsorption process and the adsorption of CO2 onto polyaspartamide was confirmed to be a physicochemical process (both physisorption and chemisorption).
MT2017

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2016
Global climate change is among the major challenges the world is facing today, and can be attributed to enhanced concentrations of Greenhouse Gases (GHG), such as carbon dioxide (CO2), in the atmosphere. Therefore, there is an urgent need to mitigate CO2 emissions, and carbon capture and storage (CCS) is amongst the possible options to reduce CO2 emissions. Against this background, this work investigated the synthesis and performance evaluation of Polyaspartamide (PAA) adsorbent for CO2 capture. In particular, the effect of the presence of water-soluble amines in the amine-grafted poly-succinimide (PSI) (referred to as Polyaspartamide (PAA) adsorbent), was investigated. Methyl Amine (MA) and Mono-Ethanol Amine (MEA) were employed as water-soluble amines and the effect of changes in their concentration on CO2 adsorption capacity was investigated as well. Water-soluble amines were incorporated to allow water solubility of the adsorbent paving the way for freeze-drying to improve the geometric structure (surface area, pore volume and pore size) of the adsorbent. Initially, the PSI was loaded with Ethylenediamine (EDA), forming PSI-EDA. The water-soluble amines were grafted to PSI-EDA, with the EDA added to improve the chemical surface of the adsorbent for CO2 capture. NMR and FTIR analyses were performed and confirmed the presence of MA and MEA amine groups in the PAA, thereby indicating the presence of the grafted amines on the backbone polymer. BET analysis was performed and reported the pore volume, pore size and surface area of the freeze-dried material. It was observed that the physical properties did not change significantly after the freeze-drying compared to literature where freeze-drying was not employed. An increase in adsorption capacity with an increase in MA and MEA concentrations in MA-PAA and MEA-PAA samples was observed. At low amine concentrations (20% amine and 80% EDA grafted), MEA-PAA was observed to exhibit higher adsorption capacity compared to the MA-PAA samples. At high amine (100% amine grafted) concentrations, MA-PAA samples displayed higher adsorption capacity. Three runs were performed on each sample and the results obtained were reproducible. The best adsorption capacity obtained was 44.5 g CO2/kg Ads. Further work was then performed to understand the effects of operating variables on CO2 adsorption as well as the interactive effect using the Response Surface Methodology approach. The experiments were done by use of CO2 adsorption equipment attached to an ABB gas analyzer. A central composite design of experiment method with a total of 20 experiments was employed to investigate three factors, namely, temperature, pressure and gas flow rate. Six regression models were drawn up and mean error values computed by use of Matlab, followed by response surfaces as well as contours, showing the influence of the operating variables on the adsorption capacity as well as interaction of the factors were then drawn up. The results obtained displayed that each of the factors investigated, temperature, pressure and gas flowrate had an incremental effect on the adsorption capacity of PAA, that is, as each factor was increased, the adsorption capacity increased up to a point where no more increase occurred. Adsorption was seen to increase for both an increase in gas flowrate and adsorption pressure to a maximum, thereafter it starts to decrease. A similar trend was observed for the interaction between temperature and pressure. However, the interaction between gas flowrate and temperature was such that, initially as the temperature and the gas flowrate increase, the adsorption capacity increases to a maximum, thereafter, the temperature seizes to have an effect on the adsorption capacity with a combined effect of decreasing temperature and increasing gas flowrate resulting in a further increase in adsorption capacity. It was confirmed that the operating variables as well as the flow regime have an effect on the CO2 adsorption capacity of the novel material. The highest adsorption capacity was obtained in the pressure range 0.5 bar to 1.7 bar coinciding with the temperature range of 10 oC to 45 oC. The interaction of gas flowrate and adsorption pressure was such that the highest adsorption capacity is in the range 0.8 bar to 1.5 bar which coincides with the gas flowrate range from 35 ml / min to 60 ml / min. In conclusion, the best adsorption capacity of 44.5 g / kg via the TGA and 70.4 g / kg via the CO2 adsorption equipment was obtained from 100 % MA grafted PSI.
GR2016

Earth’s climate is intricately linked to the carbon cycle through the radiative effect of atmospheric carbon dioxide. The ocean plays a central role in this climate-carbon system; as oceans store ∼50 times more carbon than the atmosphere, even small changes in ocean chemistry could greatly affect global climate. Understanding how the oceanic carbon reservoir has evolved across changing climates is thus critical for both constraining mechanisms of climate change and predicting impacts from anthropogenic carbon addition. This dissertation contributes to knowledge of the ocean carbon reservoir’s evolution across the last 1.5 million years of Earth’s history, with a particular focus on two key intervals of climatic change: 1) Present day, when a large, human-sourced perturbation to the carbon cycle is underway, the effects of which are not yet fully realized; and 2) The mid-Pleistocene transition (MPT; ∼900,000 years ago), when natural cycles of global warming and cooling increased in intensity and duration. Without direct observations for both these time intervals, I focus on documenting changes to ocean carbon chemistry using proxies for seawater composition. The primary tools for this purpose are boron concentrations (B/Ca ratios) and the boron isotopic composition (δ11B) of carbonate skeletons produced by marine organisms. These tools are rooted in the aqueous chemistry of boron, in which the speciation and isotopic composition of boron compounds change with seawater pH. To test present-day changes in the oceanic carbon reservoir, I measured δ11B on the calcitic skeletons of deep-sea corals (genus Keratoisis). Results show that while coral δ11B does correlate with deep ocean pH, δ11B variations within coral skeletons are too large to be explained by changes in deep ocean pH over the corals’ lifespan. These variations most likely reflect the biology of the coral organism, suggesting that δ11B measurements in Keraotisis cannot be utilized to track ocean pH until coral growth mechanisms are better understood. To complement these δ11B data, I measured the radiocarbon (14C) content of Keratoisis skeletons. Results show that coral skeletal 14C tightly correlates to the 14C content of the deep ocean, and that bamboo corals live for 50 to 300 years with radial growth rates of 10 to 80 μm per year. This supports the use of 14C for generating bamboo coral ages and growth rates, and for tracking perturbations to the 14C content of the deep ocean. Through my deep-sea coral study, I learned the importance of accurate and precise δ11B measurements for sound interpretations of ocean carbon chemistry. These interpretations necessitate highly specialized analysis protocols. While two protocols are commonly applied for δ11B measurements, existing comparisons found relatively large offsets between both protocols. To trace the cause and implications of this offset, I established a new δ11B measurement protocol and performed an internal comparison between the new and existing measurement protocols. Results confirm that carbonate δ11B values are significantly offset between techniques. Although the nature of this offset remains enigmatic, I show that both techniques show the same δ11B-to-pH sensitivity, and consistent pH estimates are obtained when a protocol-specific constant offset is applied. This suggests that both δ11B analysis protocols can be applied for reconstructing pH with equal confidence. To test for changes in the ocean carbon reservoir across the MPT, I investigated the B/Ca and Cd/Ca composition of the benthic foraminifer Cibicidoides wuellerstorfi to track deep ocean carbonate saturation state (∆[CO32−]) and nutrient inventories. At 4.3 km water depth in the South Atlantic Ocean, B/Ca abruptly decreased by 20% and Cd/Ca increased by 40% between 950 and 900 ka, equivalent to a 60 μmol/kg increase in abyssal ocean carbon storage. Coincident shifts in deep ocean circulation and atmospheric pCO2 around 900 ka suggest that a new regime of deep ocean carbon sequestration developed during the MPT. I argue that this regime was intricately linked with the increased magnitude and duration of glacial cycles following the MPT.

Predicting how increasing atmospheric carbon dioxide concentration will affect the hydrologic cycle is of utmost importance for water resource management, ecological systems and for human life and activities. A typical perspective is that the water cycle will mostly be altered by atmospheric effects of climate change, precipitation and radiation, and that the land surface will adjust accordingly. Terrestrial processes can however feedback significantly on the hydrologic changes themselves. Vegetation is indeed at the center of the carbon, water and energy nexus. This work investigates the processes, the timing and the geography of these feedbacks. Using Earth System Models simulations from the Coupled Model Intercomparison Project, Phase 5 (CMIP5), with decoupled surface (vegetation physiology) and atmospheric (radiative) responses to increased atmospheric carbon dioxide concentration, we first evaluate the individual contribution of precipitation, radiation and physiological forcings for several key hydrological variables. Over the largest fraction of the globe the physiological response indeed not only impacts, but also dominates the change in the continental hydrologic cycle compared to either radiative or precipitation changes due to increased atmospheric carbon dioxide concentration. It is however complicated to draw any conclusion for the soil moisture as it exhibits a particularly nonlinear response. The physiological feedbacks are especially important for extreme temperature events. The 2003 European heat wave is an interesting and crucial case study, as extreme heat waves are anticipated to become more frequent and more severe with increasing atmospheric carbon dioxide concentration. The soil moisture and land-atmosphere feedbacks were responsible for the severity of this episode unique for this region. Instead of focusing on statistical change, we use the framework of Regional Climate Modeling to simulate this specific event under higher levels of surface atmospheric carbon dioxide concentration and to assess how this heat wave could be altered by land-atmosphere interactions in the future. Increased atmospheric carbon dioxide concentration modifies the seasonality of the water cycle through stomatal regulation and increased leaf area. As a result, the water saved during the growing season through higher water use efficiency mitigates summer dryness and the heat wave impact. Land-atmosphere interactions and carbon dioxide fertilization together synergistically contribute to increased summer transpiration if rainfall does not change. This, in turn, alters the surface energy budget and decreases sensible heat flux, mitigating air temperature rise during extreme heat periods. This soil moisture feedback, which is mediated and enabled by the vegetation on a seasonal scale is a European example of the impacts the vegetation could have in an atmosphere enriched in carbon dioxide. We again use Earth System Models to systematically and statistically investigate the influence of the vegetation feedbacks on the global and regional changes of extreme temperatures. Physiological effects typically contribute to the increase of the annual daily maximum temperature with increasing atmospheric carbon dioxide concentration, accounting for around 15% of the full trend by the end of the XXIth Century. Except in Northern latitudes, the annual daily maximum temperature increases at a faster pace than the mean temperature, which is reinforced by vegetation feedbacks in Europe but reduced in North America. This work highlights the key role of vegetation in influencing future terrestrial hydrologic responses. Accurate representation of the response to higher atmospheric carbon dioxide concentration levels, and of the coupling between the carbon and water cycles are therefore critical to forecasting seasonal climate, water cycle dynamics and to enhance the accuracy of extreme event prediction under future climates in various regions of the globe.

The venting of anthropogenic CO₂ emissions into the atmosphere at increasing rates is probably influencing global warming and climate change. The Tangguh LNG development project in Papua, Indonesia will produce significant volumes of CO₂, which might be vented into the atmosphere. The LNG process will necessitate the separation of CO₂, estimated at 2.4 trillion cubic feet (TCF sc), from the natural gas reserves prior to liquefaction and shipping. This study screens and assesses the possible alternatives to atmospheric venting, and recommends subsurface CO₂ injection and sequestration/storage in saline aquifers. The study identifies specific subsurface locations for several Environmentally-Sustainable Sites for CO₂ Injection (ESSCI) in Bintuni Basin, where the Tangguh production fields are located. Alternatives to atmospheric venting of the estimated CO₂ volume at Tangguh include both non-geologic and geologic disposal options. Non-geologic options such as biosphere sinks (enhanced forest or agricultural growth), deep-ocean sinks (subsea dispersal), and direct commercial usage (e.g. use in beverage or fertilizer production, fire-retardant manufacturing) are impractical and of questionable impact in remote Papua, Indonesia. Several subsurface geological disposal options were investigated, but the most viable geologic disposal option for Tangguh CO₂ is injection into the downdip aquifer leg of the Roabiba Sandstone Formation hydrocarbon reservoir. Injected CO₂, at supercritical phase, is expected to migrate updip into the sealed structural traps at Vorwata or Wiriagar Deep, as the natural gas reserves are produced. A probabilistic ranking of data quality and quantity for five potential ESSCI reservoirs determined that the Middle Jurassic Roabiba Sandstone Formation has the highest likelihood of viable ESSCI sequestration/storage. A probabilistic ranking of data quality and quantity for eight ESSCI structural traps within the western flank of Bintuni Basin, determined that Vorwata, followed by Wiriagar Deep, are the most viable ESSCI structural traps at the Middle Jurassic reservoir level. Five potential ESSCI seals were evaluated and it was determined the best seal potential occurs in the Pre-Ayot Shales, directly overlying the Middle Jurassic reservoir at Vorwata. This unit is capable of holding a 3300 to 4660 foot (1006 to 1420 meter) CO₂_column. Seal integrity of the Pre-Ayot is very good because it is a relatively homogeneous deep-water shale that is composed primarily of ductile illite and kaolinite clays with a minor quartz and feldspar content. Sequence stratigraphy analysis suggests that the zone extends over the entire Vorwata three-way dip closure, with thickness between 17 feet (5 m) and 233 (71 m) feet. The maximum effective storage capacity of the Middle Jurassic reservoirs for each structure was calculated, taking into account irreducible water, trapped water, and trapped residual gas pore volumes. The Vorwata structure is capable of storing 19.3 TCFsc supercritical CO₂ at reservoir temperature and pressure. The Wiriagar Deep structure has potential storage capacity of 3.5 TCFsc, and Ubadari 2.8 TCFsc, at their respective reservoir temperatures and pressures. A ‘Rating Product Ranking’ was developed to quantify the results of the quality and quantity of four factors: Reservoir Data, Structure Data, Seal Data, and Storage Ratio. Each structure, and the respective top and lateral seal overlying the Middle Jurassic reservoirs, was evaluated. The net result was that Vorwata rated a 0.88 on a scale of zero to one, where 1.0 represents 100% confidence in ESSCI potential. Ubadari and Wiriagar Deep scored, respectively, 0.52 and a 0.45. Finally, the structures were evaluated for relative proximity to the proposed CO₂_source (i.e. the LNG plant location). With a weighted distance factor calculated with the Rating product for each potential injection site, Vorwata rated 0.88 on a scale of zero to one, Wiriagar scored 0.24, and Ubadari scored only 0.09. The Middle Jurassic ‘Roabiba Sandstone Formation reservoir’ at the Vorwata structure has the greatest potential as an ESSCI storage site. The Middle Jurassic ‘Aalenian Sandstone Formation reservoir’ at the Wiriagar Deep is the second-best potential ESSCI storage site. The subsurface ESSCI injection location proposed for the ‘Roabiba Sandstone Formation’ aquifer, 10 km southeast and down-dip from the known gas-water contact (GWC), is on the southeast Vorwata plunging anticlinal nose. An alternate potential ESSCI injection location proposed for the ‘Roabiba Sandstone Formation’ aquifer is 6 km south of and down-dip from the known gaswater contact (GWC) on Vorwata structure southern flank. A key issue was to determine the possible risk of fault re-activation from CO₂_ injection. NE-SW striking vertical faults have the highest risk of re-activation requiring an increase of over ~1460 psi (103 kg/cc) over hydrostatic at 14,000 ft TVDss (4267 m), for slippage to occur. The closest fault with a high risk of re- activation is 5 km northwest of the recommended ESSCI site location. Supercritical CO₂_ pressure is not expected to exceed the estimated pressure determined to cause fault re-activation. A 3D geological model of the Mesozoic interval was constructed over a large area of western Bintuni Basin. The model was constructed so as to preserve as much geological heterogeneity as possible yet still have a manageable number of active cells. Faults were incorporated into the model as strike-slip vertical fault surfaces (or indexed fault polygons) as a separate attribute. The geo-cellular model was built suitable for importation into a reservoir simulator (VIP), and a 25-year simulation run for natural gas production from the Vorwata Middle Jurassic reservoir, with concurrent CO₂ injection downdip into the Vorwata Middle Jurassic aquifer at the primary recommended ESSCI site location. The simulation verified the recommended location with the CO₂ slowly migrating into the Vorwata structural trap within the Middle Jurassic reservoir, and not compromising the hydrocarbon reserves or production. It is recommended that additional data be acquired such as conventional core, formation water samples, and specific logs such as dipole-sonic, multi-chambered dynamic formation testers (MDT), and mechanical rotary sidewall coring tools (MSCT). Lastly, several CO₂ monitoring methods and techniques are recommended for Tangguh to monitor CO₂ migration, pressures, and potential leakages. One such method is a vertical monitoring well at the recommended injection site. Other monitoring techniques include smart well completions, detection monitors at production wells with tracers injected prior to CO₂ injection. In addition, crosswell seismic surveys, electromagnetic methods, and electrical-resistance tomography techniques are suggested during the injection phase.
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Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2005