Climate change has exacerbated environmental degradation processes, causing an imbalance in the natural concentrations in atmospheric greenhouse gases. This has resulted in a myriad of socio–economic effects which have focused global attention on methodologies to reduce these effects, such as carbon sequestration. To achieve long term sustainability and success, community involvement in the technical and social aspects of carbon sequestration projects is necessary and must be acknowledged. One such mitigation methodology which incorporates the ideals of community proactive participation is carbon sink reforestation projects. This study is based on a community perspective of a carbon sink reforestation project, carried out in KwaZulu-Natal, South Africa. The study provides a holistic perspective of the concept of carbon sequestration drawing together technical aspects of carbon sequestration reforestation projects and the inclusion of the role of communities. The methodology comprised of questionnaires with industry experts and a local community, following a thematic data analysis. The current perception from industry is that the South African government lacks significant technology, capacity and finance to effectively manage national forest carbon sequestration regimes. Project participants expressed the view that these types of projects provided a sense of belonging and hope and articulated their gratitude for the environmental knowledge they gained from the project experience. Technical and social aspects of such projects such as carbon calculations and participatory rural appraisal techniques enhance a country’s ability for successful implementation of such projects. Findings reveal a need for technology, capacity building and finance; and the effects participation in these projects has on individuals. This is followed by recommendations and a ‘How To Guide’ developed by the researcher. This guide intends to enhance the collaboration of the technical aspects and involvement of communities throughout the project implementation process. Carbon regimes in this century will continue to grow in size and complexity. Stakeholder participation will be a strong factor in the success or failure of carbon sequestration reforestation projects. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Carbon sequestration, or carbon capture and storage (CCS), is the process of capturing anthropogenically generated CO2, transporting the CO2 to an injection site, and then injecting the CO2 into suitable reservoirs for long-term storage, or sequestration. Integral to the successful sequestration of CO2 is an understanding of the confining intervals (seals) above potential reservoirs. The purpose of this thesis research was to perform a detailed geological study of the Eau Claire Formation and equivalent parts of the Conasauga Group in part of the Ohio River Valley region in order to better evaluate its suitability as a confining interval for the underlying Mount Simon Sandstone and basal sandstone equivalents. Detailed correlations of subsurface data using available geophysical logs, cores, and cuttings are used to correlate facies between the Eau Claire Formation in western and central Kentucky and the Conasauga Group in eastern Kentucky and neighboring areas. Additional information on the confining potential of the Eau Claire and Conasauga formations were obtained through porosity evaluation and XRF analyses in combination with available geochemical and permeability data, which are keyed to the correlations.

Internalizing carbon value for forest landowners has the potential to increase carbon supply in forest and mitigate CO2 in the atmosphere. In this study, we developed a modified Hartman model to investigate how payments of carbon offsets impact the optimal management of hardwood forests in Kentucky under condition of catastrophic events. Different carbon markets were modeled and several sensitivity analyses were performed to examine varied management strategies to achieve maximized financial return or highest environmental benefits. Furthermore, another model was developed to incorporate the impact of risk aversion to price uncertainty using E-V model. We were able to identify the most favorable scenarios for landowners and society in the face of price variability and catastrophic risk.

The Gulf Coast Carbon Center (GCCC), a branch of the Bureau of Economic Geology of the University of Texas at Austin, conducted a pilot CO2 sequestration experiment in the Oligocene, Frio Formation at the South Liberty Oil Field, Dayton, Texas. Petrographic examination of core samples from the Frio “C” sandstone, ranging in depth from 1500m-1657m, classifies the sandstone as a poorly cemented, subangular to subrounded, subarkose with mean composition of Q70F24L6. Detrital grains are dominated by quartz, plagioclase, K-feldspar, and volcanic rock fragments. Matrix increases with depth. Measured core plug mean porosity is 32% (±3) and mean permeability is 1513md (±872). Point count porosity, dominated by primary intergranular porosity, is 24% (±10). Formation waters, sampled during the sequestration experiment, exhibited a rapid decrease in pH and increases in alkalinity and dissolved metals (Ca, Fe, Mn, Zn, Pb, & Mo). In an effort to identify the source of ions in solution, XRD and SEM analyses were completed. XRD and SEM analyses identify illite/smectite clay coats with rare amounts of kaolinite. SEM with EDAX analyses identified authigenic pyrite, occurring as framboids and euhedral crystals, and lesser amounts of quartz and feldspar overgrowths, and barite. Secondary porosity, through the dissolution of feldspar, is also observed (1% ±1). EDAX analysis of clay grain coats identifies Fe, Si, O, Al, K, Na, and Mg and BSE identifies pyrites (≤ 1μm) intergrown with the clays. Electron microprobe analyses of euhedral and framboidal pyrite were conducted to quantify trace element concentrations. Microprobe analyses identified Mn as the dominant trace element associated with these upper Frio Formation pyrites, indicating that pyrite serves as the source for Fe and Mn ions identified in the formation waters. Alteration mechanisms of the pyrite, allowing the release of Fe and Mn into solution, are still unknown though may result from surface complexes created when the pyrite is exposed to increasing HCO3- concentrations- a by-product of CO2 injection. These data are essential in understanding the chemical changes occurring in the formation and assisting in a model simulation of the Frio sandstone’s chemical reactive properties, all in response to increased CO2 concentrations. This research supports the GCCC’s CO2 sequestration efforts, assessing the Frio Formation as a repository for anthropogenic CO2, and ultimately, atmospheric CO2 reduction / Department of Geology

Global energy consumption will increase in the next decades and it is expected to largely rely on fossil fuels. The use of fossil fuels is intimately related to CO₂ emissions and the potential for global warming. Geological CO₂ storage aims to mitigate the global warming problem by sequestering CO₂ underground. Coupled hydro-chemo-mechanical phenomena determine the successful operation and long term stability of CO₂ geological storage. This research explores various coupled phenomena, identifies different zones in the storage reservoir, and investigates their implications in CO₂ geological storage. Spatial patterns in mineral dissolution and precipitation are examined based on a comprehensive mass balance formulation. CO₂-dissolved fluid flow is modeled using a novel technique that couples laminar flow, advective and diffusive mass transport of species, mineral dissolution, and consequent pore changes to study the reactive fluid transport at the scale of a single rock fracture. The methodology is extended to the scale of a porous medium using pore network simulations to study both CO₂ reservoirs and caprocks. The two-phase flow problem between immiscible CO₂ and the formation fluid (water or brine) is investigated experimentally. Plug tests on shale and cement specimens are used to investigate CO₂ breakthrough pressure. Sealing strategies are explored to plug existing cracks and increase the CO₂ breakthrough pressure. Finally, CO₂-water-surfactant mixtures are evaluated to reduce the CO₂-water interfacial tension in view of enhanced sweep efficiency. Results can be used to identify optimal CO₂ injection and remediation strategies to maximize the efficiency of CO₂ injection and to attain long-term storage.

<p>In this dissertation, I explored the effects of vegetation type on ecosystem services, focusing on services with significant potential to mitigate global environmental challenges: carbon sequestration and groundwater recharge. I analyzed >600 estimates of groundwater recharge to obtain the first global combined analysis of groundwater recharge and vegetation type. Using a regression model, I found that vegetation was the second best predictor of recharge after precipitation. Recharge rates were lowest under forests, intermediate in grasslands, and highest under croplands. The differences between vegetation types were higher in more humid climates and sandy soils but proportionately, the differences between vegetation types were higher in more arid climates and clayey soils. My extensive field estimates of recharge under paired vegetation types in central Argentina and southwestern United States provided a more direct test of the relationships between vegetation and recharge. The field data confirmed the strong influences of vegetation and its interactions with abiotic factors on recharge observed in the synthesis. The results indicate that vegetation shifts have a proportionately larger potential to affect recharge in more arid climates and clayey soils.</p><p>At the same study systems, I compared my field estimates of recharge to organic carbon stocks (in biomass, litter and soil) under the different vegetation types to evaluate tradeoffs between carbon sequestration and groundwater recharge as affected by vegetation shifts. To determine net values of vegetation shifts, I combined the changes in carbon and water with reported economic values of the ecosystem services. Based on physiological tradeoffs between photosynthesis and transpiration in plants, I hypothesized that vegetation promoting carbon storage would reduce recharge and vice versa. Changes in water and carbon services were inversely proportional, with rain-fed cultivation increasing groundwater recharge but decreasing carbon storage compared to the grasslands they replaced whereas woody encroachment did the opposite. In contrast, cultivated plots irrigated with ground water decreased both ecosystem services. Higher precipitation and clay content both exacerbated changes in carbon storage with grassland conversions, whereas higher precipitation accentuated, but higher clay content diminished, those in recharge. Regardless of the nature of vegetation shift, most of the net values of grassland conversions were negative, with the shifts representing increasing costs in the following order: woody encroachment, rain-fed cultivation and irrigated cultivation. Values of changes in carbon were greater in magnitude than those of recharge, indicating that establishment of carbon markets may drive land-use changes in grasslands over water markets.</p><p>Lastly, I examined the effects of changes in subsurface hydrology resulting from grassland conversion to croplands on soil inorganic carbon stocks in the same U.S. study system. I observed significantly lower inorganic carbon stocks under both rain-fed and irrigated croplands compared to the grasslands they replaced. The losses were visible to past 6 m depth in the soil profile and were uncharacteristically rapid for the carbon pool that is considered to be relatively inert. Based on the negative relationship between the inorganic carbon stocks and recharge rates and higher estimated exports of bicarbonates in recharge under croplands, I concluded that increased recharge with cultivation resulted in dissolution and leaching of grassland soil carbonates. Ecosystem services and their relationships to biotic and abiotic factors quantified here will further our understanding of the tradeoffs and interactions between the two services through vegetation shifts.</p> / Dissertation

The economic impacts of a government-funded, forest-based sequestration program were analyzed under two different payment schemes. The impacts were obtained by developing a regional, static CGE model built to accommodate a modified IMPLAN SAM for a determined region in the United States for 2008. The IMPLAN SAM was modified to accommodate the more conventional factors of production (labor, capital and land) and to account for land heterogeneity using the Major Land Resource Areas (MLRA). The regional aggregation considered included the Southern, Northeastern, Southwestern and Midwestern regions. The two policy scenarios considered consisted of two CO2-offset payment schemes: 1) the government compensates the generation of CO2-offsets only by the land converted to a carbon graveyard and 2) the government additionally compensates the CO2 offsets generated as a by-product by the existing commercial logging activity. By doing an analysis of the model with different budget magnitudes under the two scenarios, two different CO2-offset supply schedules were obtained with their respective CO2-offset price and quantity sets. For a budget allocation of $6.9 billion, approximately 1 billion metric tons of CO2 offsets (15% of U.S. 2008 total GHG emissions) were produced in the first scenario versus 0.8 billion metric tons (11% of U.S. 2008 GHG net emissions) in the second one. Fifty million acres were diverted out of agriculture and commercial forestry land to the carbon graveyard mainly in the Northern, Western and Central Great Plains in the first scenario. Twenty two million acres were diverted out of agricultural land to the carbon graveyard and commercial logging mainly in the Northern and Western Great Plains; and the Eastern and Western boundaries of the Appalachian Mountains in the second scenario. Both scenarios resulted in higher land and agricultural commodity prices, lower consumption of agricultural commodities by households, lower agricultural exports and higher imports. The payment structure of the second scenario benefited the commercial logging industry, increasing its production and exports, and decreasing its imports. The non-agricultural sectors mostly impacted by the two policy scenarios were the manufacturing, construction and government employment sectors.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 70-74). Also available on the World Wide Web.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: A, page: 4805. Adviser: Madhu Khanna. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Wyoming, 2007. / Title from PDF title page (viewed on June 16, 2009). Includes bibliographical references (p. 81-84).