Cette recherche ambitionne d'analyser d'un point de vue socioépistémique les controverses climatiques. Elle s'est structurée autour de deux objectifs principaux : (1) Elaborer et tester un outil d'analyse résolument réflexif construit au fur et à mesure de l'enquête articulant des cadres préexistants et parfois controversés. (2) Analyser les jeux d'acteurs et d'arguments dans les différents espaces de médiation des savoirs controversés concernant la compréhension du système climatique afin de démêler leurs dimensions épistémologique et axiologique. Pour cela cette recherche propose à partir d'un travail bibliométrique, une reconstruction sociohistorique des principaux éléments controversés depuis le XVIIIe siècle jusqu'à nos jours. De plus elle articule : une analyse des discours de chercheurs climatologues ou non suivant différentes situations de communications, une enquête fondée sur des entretiens individuels et collectif et une analyse sociologique pragmatico-linguistique. Cette radiographie des controverses climatiques permet de décrire « le mille-feuille discursif », restituant le In (la partie visible depuis l'espace public) et le Off (la partie relevant de l'activité de la recherche), en démêlant les dimensions ontologique, épistémologique et axiologique. / This PhD dissertation sets out to analyze, in a socioepistemic way, the various controversies relating to global warming. This work is based on two objectives: (1) to develop and test a reflective analysis tool developed as an ongoing investigation in a single analytical framework articulating existing and occasionally controversial frameworks. (2) To analyze actors' strategies and arguments in the different areas of mediation concerning controversial climate system of knowledge, regarding the understanding to disentangle epistemological and axiological dimensions. This thesis is based on a bibliometric work to build a socio-historical reconstruction of the main controversial elements from the eighteenth century to the present time. Following this epistemological basis the analysis progresses in three steps. The first is an analysis based on a researcher's corpus (climatologists or otherwise) in various situation of communication, secondly completed by inquiry detailed survey with individual and collective interviews and finally a sociolinguistic analysis. Only then does it become possible to provide a radiography of global warming controversies restoring the part we can see, the In and the Off, to unravel the ontological, epistemological and axiological dimensions.

Esta pesquisa procura reunir provas e evidências científicas contrárias à hipótese do aquecimento global antropogênico e elucidar seu significado na atualidade. Argumentamos que o clima está em permanente transformação, não podendo ser reduzido a um produto de variações das concentrações atmosféricas de dióxido de carbono e que a preocupação com mudanças climáticas não é uma novidade histórica mas, apesar disso, nosso desconhecimento sobre o funcionamento do sistema climático é ainda desafiador. Concluímos que a hipótese do aquecimento global antropogênico não é consensual e exerce hoje a função de ideologia legitimadora do capitalismo tardio, perpetuando a exclusão social travestindo-se de compromisso com as gerações futuras. / This research aims to gather scientific proofs and evidences against anthropogenic global warming hypothesis and to elucidate its meaning in the present. We argue that climate is in a permanent transformation, not resuming itself to a product of atmospheric carbon dioxide concentration variations and that worries about climatic changes are not new but, despite this, our ignorance on the functioning of the climate system is still challenging. We conclude that anthropogenic global warming hypothesis is not consensual and exerts nowadays the function of late capitalism legitimating ideology, perpetuating social exclusion transvestiting itself as a commitment to future generations.

Graduation date: 2000

Human activities have contributed to the increase in atmospheric greenhouse gases such as carbon dioxide (CO2). This anthropogenic gas emission has led to a rise in the average Earth temperature. Moreover, the ocean constitutes the major sink for anthropogenic CO2 and its dissolution in surface waters has already resulted in an increase of seawater acidity since the beginning of the industrial revolution. This is commonly called ocean acidification. The increase in water temperature could induce modifications of the physical and chemical characteristics of the ocean. Also, the structure and the functioning of marine ecosystems may be altered as a result of ocean acidification. Phytoplankton productivity is one of the primary controls in regulating our climate, for instance via impact on atmospheric CO2 levels. Coccolithophores, of which Emiliania huxleyi is the most abundant species, are considered to be the most important pelagic calcifying organisms on Earth. Coccolithophores are characterized by calcium carbonate platelets (coccoliths) covering the exterior of the cells. They form massive blooms in temperate and sub-polar oceans and in particular along continental margin and in shelf seas. The intrinsic coupling of organic matter production and calcification in coccolithophores underlines their biogeochemical importance in the marine carbon cycle. Both processes are susceptible to change with ocean acidification and warming. Coccolithophores are further known to produce transparent exopolymer particles (TEP) that promote particle aggregation and related processes such as marine snow formation and sinking. Thus, the impact of ocean warming and acidification on coccolithophores needs to be studied and this can be carried out through a transdisciplinary approach. The first part of this thesis consisted of laboratory experiments on E. huxleyi under controlled conditions. The aim was to estimate the effect of increasing water temperature and acidity on E. huxleyi and especially on the calcification. Cultures were conducted at different partial pressures of CO2 (pCO2); the values considered were 180, 380 and 750 ppm corresponding to past, present and future (year 2100) atmospheric pCO2. These experiments were conducted at 13°C and 18°C. The cellular calcite concentration decreases with increasing pCO2. In addition, it decreases by 34 % at 380 ppm and by 7 % at 750 ppm with an increase in temperature of 5°C. Changes in calcite production at future pCO2 values are reflected in deteriorated coccolith morphology, while temperature does not affect coccolith morphology. Our findings suggest that the sole future increase of pCO2 may have a larger negative impact on calcification than its interacting effect with temperature or the increase in temperature alone. The evolution of culture experiments allows a better comprehension of the development of a bloom in natural environments. Indeed, in order to predict the future evolution of calcifying organisms, it is required to better understand the present-day biogeochemistry and ecology of pelagic calcifying communities under field conditions. The second part of this dissertation was dedicated to results obtained during field investigations in the northern Bay of Biscay, where frequent and recurrent coccolithophorid blooms were observed. Cruises, assisted by remote sensing, were carried out along the continental margin in 2006 (29 May – 10 June), 2007 (7 May – 24 May) and 2008 (5 May – 23 May). Relevant biogeochemical parameters were measured in the water column (temperature, salinity, dissolved oxygen, Chlorophyll-a and nutrient concentrations) in order to determine the status of the bloom at the time of the different campaigns. Calcification has been shown to be extremely important in the study area. In addition, TEP production was significant at some stations, suggesting that the northern Bay of Biscay could constitute an area of important carbon export. Mortality factors for coccolithophores were studied and the first results of lysis rates measured in this region were presented. Results obtained during culture experiments and comparison with data reported in the literature help to better understand and to predict the future of coccolithophores in a context of climate change. Data obtained during either culture experiments or field investigations allowed a better understanding of the TEP dynamics. Finally, the high lysis rates obtained demonstrate the importance of this process in bloom decline. Nevertheless, it is clear that we only begin to understand the effects of global change on marine biogeochemistry, carbon cycling and potential feedbacks on increasing atmospheric CO2. Thus, further research with a combination of laboratory experiments, field measurements and modelling are encouraged.

Despite the spatial significance of Canadas boreal forest, there is very little known about greenhouse gas emissions within it. The primary objective of this project was to study the atmosphere-soil exchange of CH4 and N2O in the boreal forest of central Saskatchewan. In the summers of 2006 and 2007, greenhouse gas emissions were measured along transects in three different mature forest stands (trembling aspen, black spruce and jack pine) using a sealed chamber method. In addition, the gross rates of mineralization and nitrification, and the relative contribution of nitrification and denitrification to N2O emissions, were measured at the trembling aspen site using a stable isotope technique in which 15N-enriched nitrate and ammonium were injected into intact soil cores. The amount of 14N found in the labeled pools was used to measure the gross rates, and the amount of 15N found in the emitted N2O was used to determine the relative contribution of the different N pathways to total N2O emissions. Results indicated that the jack pine and black spruce sites were slight sinks of CH4 (-1.23 kg CH4-C ha-1 yr-1and -0.17 kg CH4-C ha-1 yr-1 respectively in 2006 and -0.95 kg CH4-C ha-1 yr-1and 0.45 kg CH4-C ha-1 yr-1 respectively in 2007), whereas the trembling aspen site was a net source (46.7 kg CH4-C ha-1 yr-1 in 2006 and 196.0 kg CH4-C ha-1 yr-1 in 2007). All three sites had very low cumulative N2O emissions, ranging from -0.02 to 0.14 kg N2O-N ha-1 yr-1 in both years. Of the environmental controls examined for CH4, consumption at the jack pine site was correlated positively with organic carbon and negatively with water-filled pore space. Black spruce CH4 emissions were correlated negatively with both organic carbon and clay content, and emissions at the trembling aspen site were positively correlated with soil temperature and organic carbon, while also related to the presence of standing water (2006 and 2007 had very high precipitation, causing a high water table and ponding in depressions). The N2O emissions were not correlated with any of the environmental parameters measured at the jack pine or black spruce sites, but clay content was positively related to emissions at the trembling aspen site. The 15N results indicated that N cycling at the trembling aspen site was very rapid, allowing little N to escape the system as N2O; the majority of emissions that did occur were due to a nitrification-related process.

Despite the spatial significance of Canadas boreal forest, there is very little known about greenhouse gas emissions within it. The primary objective of this project was to study the atmosphere-soil exchange of CH4 and N2O in the boreal forest of central Saskatchewan. In the summers of 2006 and 2007, greenhouse gas emissions were measured along transects in three different mature forest stands (trembling aspen, black spruce and jack pine) using a sealed chamber method. In addition, the gross rates of mineralization and nitrification, and the relative contribution of nitrification and denitrification to N2O emissions, were measured at the trembling aspen site using a stable isotope technique in which 15N-enriched nitrate and ammonium were injected into intact soil cores. The amount of 14N found in the labeled pools was used to measure the gross rates, and the amount of 15N found in the emitted N2O was used to determine the relative contribution of the different N pathways to total N2O emissions. Results indicated that the jack pine and black spruce sites were slight sinks of CH4 (-1.23 kg CH4-C ha-1 yr-1and -0.17 kg CH4-C ha-1 yr-1 respectively in 2006 and -0.95 kg CH4-C ha-1 yr-1and 0.45 kg CH4-C ha-1 yr-1 respectively in 2007), whereas the trembling aspen site was a net source (46.7 kg CH4-C ha-1 yr-1 in 2006 and 196.0 kg CH4-C ha-1 yr-1 in 2007). All three sites had very low cumulative N2O emissions, ranging from -0.02 to 0.14 kg N2O-N ha-1 yr-1 in both years. Of the environmental controls examined for CH4, consumption at the jack pine site was correlated positively with organic carbon and negatively with water-filled pore space. Black spruce CH4 emissions were correlated negatively with both organic carbon and clay content, and emissions at the trembling aspen site were positively correlated with soil temperature and organic carbon, while also related to the presence of standing water (2006 and 2007 had very high precipitation, causing a high water table and ponding in depressions). The N2O emissions were not correlated with any of the environmental parameters measured at the jack pine or black spruce sites, but clay content was positively related to emissions at the trembling aspen site. The 15N results indicated that N cycling at the trembling aspen site was very rapid, allowing little N to escape the system as N2O; the majority of emissions that did occur were due to a nitrification-related process.

Human large-scale use of coal, oil, natural gas and other fossil fuels, which emit large quantities of energy use is caused by the greenhouse effect of greenhouse gases, including carbon dioxide increases rapidly, is the culprit of global warming. Man type and species of global warming has brought the threat of the living environment, how to effectively slow down global warming has become the man to face critical issues. According to Taiwan's greenhouse gas emissions from all sectors data show that the transport sector with a significant contribution to greenhouse gas emissions, developed with the vehicle industry, motor vehicles have become the main transport means of transport to daily life, but also resulted in major metropolitan areas and air pollution from carbon dioxide, improve air quality and reduce carbon emissions, should have to be propaganda vehicle maintenance and regular inspection of work, vehicle maintenance facilities for the engine than coke will effectively reduce unnecessary vehicle emissions and pollution, with a view to sustainable human development. This study to collect relevant information through expert interviews, sorting out the market viability of the Automotive engine carbon removal methods are "bubble-type engine than coke," the "trickle engine program than coke" and "In addition to product hydrogen aircraft engine Carbon Programme "of three. And to identify factors that impact assessment, "the cost of implementation", "when applied to pollution assessment," "clear the effect of coke", "engine damage effects" and "ease of handling," and five. Main and analytic theory, experts in the field to conduct the carbon removal of the vehicle engine is assessed for the valid questionnaires, the use of AHP Analysis Method Comparison of the order of priority or importance, to find consistency through the whole management of the common point of view. Comprehensive management and access to the whole study found that industry, government, science and other 12 experts were assessing the overall level of the importance of the five ranking for the "impact of engine damage," the most important, were "clear the effect of coke," " when applied to pollution assessment, "" implementation costs "," easy operation "of the last. The engine in the current market feasible than carbon technology, the experts unanimously agree that the "hydrogen aircraft engine program than coke," the most advantage of the actual promotion of environmental protection that, the Government Ying Ying Zao Leung good conduct political Peihehuanjing, provide economic incentives to encourage people to Automotive engine carbon removal and counseling industry to promote environmental protection measures. The research results could serve as references for the Government's future vehicles and the carbon reduction policies.

Jellyfish blooms create problems worldwide, which may increase with global warming, water pollution, and over-fishing. Benthic polyps (scyphistomae) asexually produce buds and small jellyfish (ephyrae), and this process may determine the population size of the large, swimming scyphomedusae. Environmental factors that affect the asexual reproduction rates include food, temperature, salinity, and light. In the present study, polyps of Aurelia aurita (L.), originated from Tapong Bay, southwest Taiwan, were studied in different combinations of temperatures (T), light intensities (L), and salinities (S). In the T (20, 25, 30¢XC) ¡Ñ L (372, 56, and 0 lux) experiment which was with a 12 h light-12 h dark photoperiod, production of new buds decreased with warmer temperatures and stronger light intensity. Warm temperatures accelerated strobilation and increased the daily production of ephyrae. The proportion of ephyrae to total asexual reproduction (new buds + ephyrae) increased dramatically in warmer temperatures and stronger light. Survival period was reduced at the highest temperature. Strobilation did not occur at the lowest temperature in darkness. All measures of total asexual reproduction indicated that medium to high temperatures would lead to faster production of more jellyfish; however, continuous high temperatures might result in high polyp mortality. Light intensity affected asexual reproduction less than did temperature, only significantly accelerating the strobilation rate. Because the interactive effects of light and temperature were significant for polyp survival time and the production of jellyfish per polyp, combined light and temperature effects are likely important for strobilation in situ. In the T (27, 31, 35¢XC) ¡Ñ S (25, 30, and 35) experiment which was in dark environment, production of new buds decreased with higher temperatures and salinity. The proportion of ephyrae to total asexual reproduction (new buds + ephyrae) increased with warmer temperatures, but survival period was reduced at the highest salinity, and strobilation was substantially reduced, even though the temperature was warmer compared to the T ¡Ñ L experiment. Salinity affected asexual reproduction less than did temperature, only significantly affecting production of new buds, and slightly affecting survival period and the proportion of ephyrae to total asexual reproduction. According to these two experiments, warmer temperature may accelerate strobilation in light condition and lead to better yield of swimming jellyfish, however continuously warm temperature would reduce the yield by decreasing budding and higher mortality. Complete dark led to much less strobilation, especially at low temperatures, suggesting that the existence of light might be more important than light intensity. The effects of salinity on asexual reproduction were not as conspicuous as that of temperature and light.

Thesis (Masters) -- University of Ballarat, 2008. / Submitted in partial fulfillment of the requirements for the degree of Master of Arts (Visual Arts), Arts Academy. Bibliography: leaves 56-58.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Environmental Sciences." Includes bibliographical references (p. 103-106).