A change in the atmospheric inventory of a greenhouse gas produces a radiative forcing on the atmosphere which results in climatic change. Thus to understand climate change resulting from perturbations to atmospheric greenhouse gas concentrations it is necessary to quantify the radiative forcing. Here, radiative forcings are presented for large changes in atmospheric CO2, CH4, and N2O in the modern atmosphere and large changes in atmospheric CO2, CH4 and 18 other gases for the Archean atmosphere. For the modern Earth, I present new calculations of radiative forcing at very high concentrations of CO2, CH4, and N2O, relevant to extreme anthropogenic climate change and paleoclimate studies. CO2 forcing is calculated over the range 100 ppmv to 50,000 ppmv. CH4, and N2O forcings are calculated over the range 100 ppbv to 100 ppmv. The sensitivity of these calculations to spatial averaging and tropopause definition are examined. I compare our results with the ``simplified expressions'' reported by IPCC, and find significant differences at high greenhouse gas concentrations. I provide new simplified expressions which agree much better with the calculated forcings, and suggest that these expressions be used in place of the IPCC expressions. Additionally, I provide meridionally resolved forcings which may be used to force simple and intermediate complexity climate models. For the Archean Earth, I present new calculations of radiative forcing for CO2 (10^-6 - 1 bar), CH4 (500 ppbv - 10,000 ppmv) and 18 other gases (10 ppbv - 10 ppmv). I aim to provide a set of radiative forcing and overlap calculations which can be used as a standard for comparisons. Radiative forcings are calculated for atmospheres with various N2 inventories (0.5, 1, and 2 bar). The effect of overlap and atmospheric pressure on radiative forcing are examined. The CO2 radiative forcings are consistent with previous work, however, I find significantly more shortwave absorption by CH4 than previously reported which may limit warming above 100 ppmv. For the 18 other gases, I find that significant radiative forcings result from low concentrations (<1 ppmv). These forcings are compared to those given in the literature. / Graduate / 0756 / 0608 / 0725 / bbyrne@uvic.ca

Global warming, associated with elevated levels of greenhouse gases is expected to alter hydrologic regimes, permafrost extent and vegetation composition in the Hudson Bay Lowlands (HBL). Greenhouse gas (respiration, CH4 and N2O; GHG) emissions and soil gas concentrations were determined over the growing seasons of 2005 and 2006 from numerous habitats within three dominate ecosystems within the HBL, a polygonized-peat plateau, northern fringe boreal forest and palsa fen, near Churchill, Manitoba. Nitrous oxide emissions and soil concentrations were near zero however, a trend for very slight production of N2O was observed at dry aerobic sample positions while very slight consumption occurred at very wet sample locations. “Hot-spots” of intense CH4 emissions and soil concentrations occurred in the sedge-dominated areas of high moisture and plant productivity, whereas areas of low moisture and plant productivity resulted in slight CH4 consumption. Of all the ecosystems studied, the palsa fen had the greatest CH4 production, with carbon losses from CH4 occurring at rates of approximately 50 g C m-2 during the growing season. A peat plateau ecosystem site was also used to compare GHG emissions using a similar vegetation type (Cladina stellaris) and under differing soil conditions. Based on the results, slight gradients in soil conditions such as moisture content, peat accumulation and active layer depths altered respiration emissions but did not significantly affect CH4 and N2O fluxes. The differences in GHG emissions were not as great as those between different plant community types, which suggest plant community types could be used to predict GHG emissions in similar environments.

A change in the atmospheric inventory of a greenhouse gas produces a radiative forcing on the atmosphere which results in climatic change. Thus to understand climate change resulting from perturbations to atmospheric greenhouse gas concentrations it is necessary to quantify the radiative forcing. Here, radiative forcings are presented for large changes in atmospheric CO2, CH4, and N2O in the modern atmosphere and large changes in atmospheric CO2, CH4 and 18 other gases for the Archean atmosphere. For the modern Earth, I present new calculations of radiative forcing at very high concentrations of CO2, CH4, and N2O, relevant to extreme anthropogenic climate change and paleoclimate studies. CO2 forcing is calculated over the range 100 ppmv to 50,000 ppmv. CH4, and N2O forcings are calculated over the range 100 ppbv to 100 ppmv. The sensitivity of these calculations to spatial averaging and tropopause definition are examined. I compare our results with the ``simplified expressions'' reported by IPCC, and find significant differences at high greenhouse gas concentrations. I provide new simplified expressions which agree much better with the calculated forcings, and suggest that these expressions be used in place of the IPCC expressions. Additionally, I provide meridionally resolved forcings which may be used to force simple and intermediate complexity climate models. For the Archean Earth, I present new calculations of radiative forcing for CO2 (10^-6 - 1 bar), CH4 (500 ppbv - 10,000 ppmv) and 18 other gases (10 ppbv - 10 ppmv). I aim to provide a set of radiative forcing and overlap calculations which can be used as a standard for comparisons. Radiative forcings are calculated for atmospheres with various N2 inventories (0.5, 1, and 2 bar). The effect of overlap and atmospheric pressure on radiative forcing are examined. The CO2 radiative forcings are consistent with previous work, however, I find significantly more shortwave absorption by CH4 than previously reported which may limit warming above 100 ppmv. For the 18 other gases, I find that significant radiative forcings result from low concentrations (<1 ppmv). These forcings are compared to those given in the literature. / Graduate / 0756 / 0608 / 0725 / bbyrne@uvic.ca

Alberta is the third largest economy in Canada and is expected to grow significantly in the coming decade. The energy sector plays a major role in Albertas economy. The objective of this research is to develop various greenhouse gas (GHG) mitigations scenarios in the energy demand and supply sectors for the Province of Alberta. This is done through an energy-environment planning and forecasting tool called Long Range Energy Alternative Planning system model (LEAP). By using LEAP, a sankey diagram for energy and emission flows for the Province of Alberta has been developed. A reference case also called as business-as-usual scenario was developed for a study period of 25 years (2005-2030). The GHG mitigation scenarios encompassed various demand and supply side scenarios. In the energy conversion sector, mitigation scenarios for renewable power generation and inclusion of supercritical, ultra-supercritical and integrated gasification combined cycle (IGCC) plants were investigated. In the oil and gas sector, GHG mitigation scenarios with carbon capture and sequestration (CCS) option were considered. In Albertas residential and commercial sector 4-6 MT of CO2 equivalents per year of GHG mitigation could be achieved with efficiency improvement. In the industrial sector up to 40 MT of CO2 equivalents per year of GHG reduction could be achieved with efficiency improvement. In the energy conversion sector large GHG mitigation potential lies in the oil and gas sector and also in power plants with carbon capture and storage (CCS) option. The total GHG mitigation possible in the supply side option is between 20 70 MT CO2 equivalents per year. / Engineering Management

Thesis (PhD)--University of South Australia, 2000

[Abstract]:Land use change from forest to non-forest use is a major source of greenhouse gases in Australia. From 1996, the Queensland Government provided incentives for landholders to plant ex-pasture and cropping areas with hardwood plantations through the Southeast Queensland Regional Forest Agreement program. Spotted gum (Corymbia citriodora subspecies Variegata) was a target hardwood species for Southeast Queensland (SEQ); however, the long-term viability of timber-alone plantations relative to cropping and livestock production, in the medium to low rainfall areas of SEQ, and elsewhere in Australia, is questionable. Carbon credits resulting from additional carbon sequestration may change the relative profitability of these land uses. The aim of this research was to compare spotted gum plantations with peanut-maize cultivation and beef pasture in low rainfall areas, incorporating carbon values.This study covers all variable costs and benefits, and different sources and sinks of three major greenhouse gases: carbon dioxide, methane and nitrous oxide. For the case study of three land use systems (maize-peanut cropping, pasture, and spotted gum plantations in the Kingaroy district of SEQ), production, carbon sequestration and emissions data were supplemented by formal and informal interviews with landholders, agronomists, sawmill staff and government extension personnel. Forest inventory, biomass and soil sampling, and stakeholder interviews were used as sources of primary data. The costs and benefits of all land use systems were converted into monetary terms and discounted to produce net present values. If the comparison of net present values is limited to traditional benefits (i.e. income from crops and hay in cultivation, beef in pasture and timber in plantation), cultivation is the most profitable option, followed by pasture and plantations. Even after the inclusion of beef value, plantations could not compete with other land use systems. After the inclusion of greenhouse gas value, plantations were the most profitable option, followed by pasture and cultivation. However, if the carbon price was reduced from the price assumed in this thesis of $10.5 t-1CO2e to $4.3 t-1CO2e, cultivation would remain the most profitable option. If the currently used nominal (pre-text) discount rate (six percent) increased to seven or eight percent, the optimal rotation of plantation would reduce from 34 to 31 years and 29 years, respectively. At a seven percent discount rate, plantations would be a less profitable than pasture, but marginally more profitable than cultivation. If the discount rate were eight percent, plantations would be less profitable than both pasture and cultivation.These findings have some implications for attempts to increase the plantation estate to three million hectares by 2020, through policy frameworks such as the Australian Government’s ‘Vision 2020’. Therefore, this study has recommended several measures to increase the benefits from plantations.

Fossil fuel–intensive companies are coming under increasing pressure to reduce their greenhouse gas emissions (GHGs). The political environment surrounding climate change and the evolution of the carbon market are complex and in a fluid state of play. Uncertainty exists with respect to government policy, greenhouse (GH) accounting standards, interaction with stakeholders and the capacity to ‘commoditise’ carbon emissions, making it difficult for companies to determine exactly how to build their internal capacity to deal with a shifting external situation. In Australia and the United States in particular, companies are receiving mixed messages from government about the necessity of reducing GHGs and the role of emissions trading. While market-based approaches to GHG reduction are being promoted, the governments of both countries have refused to ratify the Kyoto Protocol and failed to establish domestic emissions trading schemes. Finally, few companies have substantial experience in managing GHGs or in market-based approaches to GHG abatement, such as emissions trading. This research aims to provide guidance for industry capacity building with respect to market-based approaches to GHG reduction, recognising that generally this would require significant organisational learning and change to corporate systems. The proposed Framework facilitates organisational learning that goes beyond the detection and correction of errors to questioning and modifying existing norms and procedures and, further, to reflecting on past experience and creating new strategies. The research included participants as integral to the study, giving their ‘emic’ (insider) viewpoints centrality while allowing ‘etic’ (outsider / researcher) interpretation. Within the organisational learning literature, the approach that best describes this research is that of Action Research and Appreciative Inquiry. The principles of environmental management, cleaner production, corporate social responsibility and sustainable development inform the research. Surveys, focus groups and a literature review are employed as the data collection methods, which are compared and contrasted. The data suggest that a ‘one size fits all’ approach to industry capacity building with respect to market-based approaches to GHG reduction is not optimal or possible. This is due to the differing strategic objectives, varying assessment of risk and disparate circumstances and starting points of the companies involved. Thus, rather than a prescriptive model, this research has identified and prioritised the key themes and issues that currently influence corporate capacity building. Precursors to action have been specified and a ‘menu’ of choices provided. Lastly, a step-by-step Framework has been proposed to build companies’ capacity to participate in GHG emissions trading. It was also observed that the majority of the key themes and issues that influence companies and the preparatory actions they need to take are the same, whether a market-based system or a command-and-control system of GHG reduction is introduced. The thesis includes some suggestions for further research in the application and evaluation of this approach with companies in the field.

Thesis (Ph. D.)--Washington State University, December 2007. / Includes bibliographical references.

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.

Thesis (Ph.D.) -- University of Western Sydney, Hawkesbury, 2000. / A thesis presented in fulfilment of the requirement for the degree of Doctor of Philosophy, Centre for Horticulture and Plant Sciences, University of Western Sydney, Hawkesbury, 2000. Bibliography : leaves 178-207.