Modelling the impact of climate change on the water from agricultural areas on a regional scale over a 40 year time period is the subject of this thesis. The Grand River watershed spans approximately 290 km with an area of approximately 6,800 km². Approximately 90% of the watershed is agricultural land some of which is tile drained. These tile drains, which cover approximately 15% of the total land of the watershed, are installed to augment field drainage. The tile drains usually outlet somewhere along the perimeter of a property; the discharge then typically moves along the surface until it discharges into a surface water body such as a river, pond, or lake. Investigating the impact of climate change on agricultural tile drainage at a watershed scale can be achieved using modelling. The tile drains can affect both the water quality and the water quantity of a watershed. With the potential climatic changes, the storm intensity, and growing season also could change. Spatial data for the Grand River watershed was gathered to allow for further simulation. The data for tile drained areas was added to land use/land class and soil data for the watershed to produce a map of tile drained agricultural areas. Climate change scenarios were then simulated for each cell. Three climate change scenarios were investigated to determine the impact on tile drain discharge and the hydrological process for the watershed. The climate change scenarios that were chosen were the A2, A1B, and the B1 scenario of the Intergovernmental Panel on Climate Change. After the simulations were completed for the tiled areas and the results collected, the simulations showed the greatest impact of tile drain discharge in the spring season as well as the fall season. For the tiled cells the annual average discharge was approximately 0.22 m3/ha for 1999. The average discharge was approximately 0.15 m3/ha for April of 1999. April accounted for approximately 65% of the annual tile drainage for 1999. The climate change scenarios were simulated and the average annual discharge increased approximately 0.023 m3/ha and 0.021 m3/ha for the A2 and A1B scenarios respectively. The B1 scenario had an average annual decrease of approximately 0.022 m3/ha.

Snow Albedo Feedback (SAF) in response to climate change is a process that can amplify the climate warming response to increases in anthropogenic atmospheric CO2 concentrations from the 20th to the 21st Century. Warmer surface air temperature may induce snowmelt and expose darker underlying surfaces which absorb more incoming solar radiation and further increase the ambient temperature. Springtime SAF in the fully Coupled Model Intercomparison Project Phase 3 (CMIP3) models is associated with summertime circulation. However, no clear physical mechanism explaining this link has been found. Furthermore, there is a large intermodel spread in the projection of SAF among the CMIP3 models which is primarily controlled through the parameterization of snow albedo in each model. Limited work was conducted on assessing the response of SAF to that of an isolated controlling parameter such as snow albedo. Here, the uncoupled Geophysical Fluid Dynamics Laboratory Atmospheric Model 2.1 (AM2.1) was used to diagnose SAF in the CMIP3 models by conducting a set of sensitivity experiments with perturbed snow albedo. This was performed to remove indirect external climate factors that may influence SAF and to use the simplified uncoupled model to understand the behaviours exhibited by the complex coupled models. Snow cover extent (SNC) and snow metamorphosis as a function of temperature (TEM) that influences SAF, as well as the knock-on effects of SAF on soil moisture, snow mass, snow melt and circulation were analyzed using both the CMIP3 and AM2.1 models. In addition, it was hypothesized that summertime Land Sea Contrast response to climate change (dLSC) is a physical mechanism that induces summertime circulation patterns in relation to springtime SAF. It is found that the AM2.1 can similarly reproduce SNC and TEM as well as the spread in SAF exhibited in the CMIP3 models. However, no robust link can be determined between SAF and its knock-on effects. Furthermore, the correlation between SAF and dLSC is not significant and thus dLSC is not a physical mechanism that influences the summertime circulation patterns in response to climate change. It is the expectation that these research results can provide an in-depth understanding of the role of SAF among fully coupled GCMs through tests performed by the uncoupled simulation.

Climate Change has been related to GHG emissions, of both natural and anthropogenic origin. Agricultural management practices like reduced tillage and intensive cropping systems have a significant impact on the flow of C among its sources and sinks. These management practices involve complex biophysical interactions resulting in a range of impacts on farm income and GHG abatement. The focus of this study was on the impact of alternative annual crop tillage systems on GHG emissions and income to better inform climate change mitigation policy in agriculture. Besides tillage intensity, cropping intensity and crop mix and the interaction of these characteristics with the biological and physical attributes, the emission and income effects are a function of factor inputs, factor costs and commodity prices. Therefpre, the analysis was multi-disciplinary in nature and the tool of choice that depicts impacts on individual indicators is Trade-off Analysis (TOA). A component of risk analysis was also included. The analysis focused on short and long-term performance, the uncertainty of soil N2O emission coefficients as well as changes in weather patterns. As the adoption of reduced till has been a relatively recent development and as such, there is not a lot of long-term biophysical and economic data, which limits the effectiveness of econometric analysis. The different scenarios of uncertainty and long-term impacts were analysed by use of a simulation model. The model was parameterised with Intergovernmental Panel on Climate Change (IPCC) 1996 coefficients, a farmer survey, and cost data from Saskatchewan Agriculture Agri-Food and Rural Revitalization (SAFRR) for 2004. Results indicated that net GHG emissions were relatively lower for reduced tillage management while conventional tillage may be relatively more attractive from an economic perspective. However, results indicated that such economic factors as risk and economies of size may have a significant influence on this latter result. The study also highlighted the need to evaluate the GHG abatement potential of reduced tillage while simultaneously considering the abatement capability of the farm.

This project involves studying the connection between climate change and large scale conflict within Darfur. This has been accomplished by initially giving a summary of the history of Sudan and Darfur Sudan, while ending with a chronology of events leading up to 2002/3 when large scale conflict between ethnic groups and the state occured in Darfur. This is followed by an analysis of the events leading up to conflict, focusing on the group vs. group and group vs. state interacton over resources in the area which climate change brought about. Following this  is a discussion section in which relevant connections between the conflict in Dafur and outside forces are discussed. The conclusion lends to the fact that the confllict in Dafur is related to flow policies of managing confclit emitted from Khartoum.

The variation of El Nino Southern Oscillation (ENSO) events from the mid-nineteenth century until the beginning of the twenty-first century is explored using an ocean reanalysis. Decadal variability and trends in the strength, frequency, duration, and propagation direction of ENSO events is investigated. The hypothesis that there are different types of ENSO and that the location of ENSO is shifting to the west Pacific is also studied. The study uses the latest version of an ocean reanalysis, called SODA 2.2.4 (Simple Ocean Data Assimilation), which covers the period from 1871 through 2008. The reanalysis uses an eddy-permitting resolution model of the ocean forced with boundary conditions available from an atmospheric reanalysis that covers the same period. SODA 2.2.4 assimilates all available hydrographic and surface marine observations of temperature and salinity to produce a "best estimate" of the ocean state in terms of temperature, current, salinity, and sea surface height. A new index based on the first moment of anomalous sea surface temperature over the equatorial Pacific is used to describe the location and strength of warm and cold events. The results show strong decadal variability in the strength of El Nino events but little trend during the period of 1871-2008. The strength of La Nina events has neither prominent decadal variation nor a trend. The index also documents changes in frequency, duration, and location of ENSO events. The study shows that the frequency of El Nino varies considerably over the record. Given the large variance in the period of ENSO it is difficult to reliably determine if there has been a change in the period of El Nino events. The location of warming during El Nino can be described by a normal distribution centered at about 140 degrees W. The strength and frequency of ENSO events have very little trend indicating negligible impact from global warming.

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Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2010.

<p> Pacific Small Island States (PSIS) are in the precarious position as some of the first jurisdictions to grapple with the current and forecasted effects of climate change, such as forced migrations and loss of culture. Yet, islanders' viewpoints are neither often fully understood nor heeded by those at the international decision making levels. Therefore, how and to what extent are PSIS successfully preparing for climate change? </p><p> This completed study used a mixed methods approach that examines nissology &mdash; how islanders view and understand themselves &mdash; and its relationship with successful (discussed and defined within the study) adaptation planning. The study also used a mixed methods approach to juxtapose the findings of the nissological and success analyses with a second research question: an in-depth study and analysis of regional and global policymaking entities, and the degrees to which they may influence islanders' preparation for climate change. </p><p> The study examined 18 PSIS and their Climate Change Adaptation Plans (CCAPs) and then interviewed PSIS' representatives at their respective Missions to the United Nations in New York City to evaluate how PSIS view and foresee current and future policies regarding climate change at the global, regional, and local levels. Then, fieldwork was performed within the United States Territories in the Pacific: American Samoa, Guam, and the Northern Mariana Islands to obtain on-the-ground information regarding implementation of plans, policies, and projects. </p><p> The study attempted to address two specific gaps in the literature via the triangulation of methods and data: the relationship between an island-centric viewpoint of CCAPs and successful climate change as well as how policymaking in the Pacific at the local, regional, and global levels either assisted or hindered successful climate change adaptation policy. </p><p> The results suggested answers to these two key questions as well as several unexpected or emergent findings. Regarding the two principal research questions, PSIS that crafted their CCAPs in a more nissological or island-centric manner were indicative of states that were foreseen to be more successful in adapting to current and future climate change effects. Next, PSIS that were part of AOSIS, the various regional associations, and those PSIS that had complete sovereignty (independent) were indicative of those PSIS expressing greater overall success at preparing for climate change than those PSIS not meeting these criteria. However, not all PSIS had the opportunity to become members of AOSIS or certain regional organizations for various reasons. </p><p> Finally, a policy document was created at the end of the study to illustrate some of the best practices based upon this study's findings. Immediately preceding the policy document are other emergent findings indicative of future areas of research and exploration within the realms of nissology, regional associations and partnerships, and successful climate change adaptation.</p>

Soil microbes influence the global carbon cycle via their role in the decomposition and formation of soil organic matter. Thus, rates of ecosystem processes such as primary production, soil respiration, and pedogenesis are sensitive to changes in the aggregate functional traits of the entire microbial community. To predict the magnitude and direction of microbial feedbacks on climate change, it is necessary to identify the physiological, ecological, and evolutionary mechanisms that underlie microbes’ responses to altered temperature and rainfall. Therefore, I examined microbial community composition and function in relation to manipulations of resource availability and precipitation in two contrasting ecosystems: a tropical rainforest at La Selva Biological Station, Costa Rica, and a semi-arid grassland in central Texas. I conducted a leaf litter decomposition experiment at La Selva to identify the physiological constraints on microbial allocation to extracellular enzymes, which degrade organic matter. I found strong evidence that microbial enzyme production is decoupled from foliar stoichiometry, consistent with weak links between leaf litter nutrients and decomposition rates at the pan-tropical scale. Next, to examine whether ecological trade-offs within microbial communities may drive shifts in carbon cycling at local spatial scales, I quantified changes in soil fungal and bacterial community composition in response to an in situ precipitation exclusion experiment I established at La Selva. Although drought-induced shifts in community structure were small, large increases in biomass-specific respiration rates were observed under dry conditions. These findings suggest that physiological adjustments to drought may constitute an important feedback on climate change in wet tropical forests. Finally, I focused on microbial community responses to climate change within a meta-community framework, using a reciprocal transplant experiment to investigate how dispersal shapes bacterial community structure along a natural rainfall gradient in central Texas. I found that soils from the wet end of the precipitation gradient exhibited more plastic functional responses to altered water availability. However, soil bacterial community composition was resistant to changes in rainfall and dispersal, preventing functional acclimatization to precipitation regime. Together, the results of these experiments emphasize the potential for physiological plasticity or microevolutionary shifts within microbial populations to drive ecosystem carbon cycling under climate change. / text

This PhD project explores the political influence of four sets of non-governmental actors upon the international politics of global warming. The forms of influence attributable to Working Group 1 of the Intergovernmental Panel on Climate Change (the body set up to advise governments on the science of climate change), the mass media's coverage of global warming, and the political involvement of both the fossil fuel lobbies and environmental groups in the policy debate on climate change, are understood via use of literatures on the dimensions of power appropriate to understanding the significance of non-state actors. The project stems from a widely acknowledged absence of a detailed understanding of the role of non-governmental organisations in international environmental politics, which extends to the international politics of global warming. The influence of each group of actors is conceptualised in different ways, so that the forms of power used to describe the various groups are not compared. Rather, the aim of the thesis is to assess what a less state-centred reading of the international politics of global warming, derived from a discussion of the role of the above actors, has to offer existing explanations. The analysis of these groups of actors sheds light on different aspects of the way the issue of climate change has been addressed at the international level. The conclusions drawn about the influence of these actors are used to critique the popular use of Regime accounts in international environmental politics that focus upon the process of institutional bargaining between states, which are argued to provide an inadequate basis for explanation of the global politics of climate change.