Dissertationen zum Thema „Climates changes“

Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007.<br>Committee Chair: Georgakakos, Aris; Committee Member: Fu, Rong; Committee Member: Peters-Lidard, Christa; Committee Member: Roberts, Phil; Committee Member: Sturm, Terry; Committee Member: Webster, Don.

University of Technology, Sydney. Faculty of Engineering.<br>This research has analysed the economy-wide impacts of carbon tax as a policy option to reduce the rate of growth of carbon-dioxide emissions from the electricity sector in Australia. These impacts are analysed for energy and non energy sectors of the economy. An energy-oriented Input–Output framework, with ‘flexible’ production functions, based on Translog and Cobb-Douglas formulations, is employed for the analysis of various impacts. Further, two alternative conceptions of carbon tax are considered in this research, namely, based on Polluter Pays Principle (PPP) and Shared Responsibility Principle (SRP). In the first instance, the impacts are analysed, for the period 2005–2020, for tax levels of $10 and $20 per tonne of CO2, in a situation of no a-priori limit on CO2 emissions. The analysis shows that CO2 emissions from the electricity sector, when carbon tax is based on PPP, would be 211 and 152 Mt, for tax levels of $10 and $20, respectively (as compared to 250 Mt in the Base Case scenario, that is, the business-as-usual-case). The net economic costs, corresponding with these tax levels, expressed in present value terms, would be $27 and $49 billion, respectively, over the period 2005-2020. These economic costs are equivalent to 0.43 and 0.78 per cent of the estimated GDP of Australia. Further, most of the economic burden, in this instance, would fall on the electricity sector, particularly coal-fired electricity generators – large consumers of direct fossil fuel. On the other hand, in the case of a carbon tax based on SRP, CO2 emissions would be 172 and 116 Mt, for tax levels of $10 and $20, respectively. The corresponding net economic costs would be $47 (0.74 per cent of GDP) and $84 (1.34 per cent of GDP) billion, respectively, with significant burden felt by the commercial sector – large consumers of indirect energy and materials whose production would contribute to CO2 emissions. Next, the impacts are analysed by placing an a-priori limit on CO2 emissions from the electricity sector – equivalent to 108 per cent of the 1990 level (that is, 138 Mt), by the year 2020. Two cases are analysed, namely, early action (carbon tax introduced in 2005) and deferred action (carbon tax introduced in 2010). In the case of early action, the analysis suggests, carbon tax of $25 and $15, based on PPP and SRP, respectively, would be required to achieve the above noted emissions target. The corresponding tax levels in the case of deferred action are $51 and $26, respectively. This research also shows that the net economic costs, in the case of early action, would be $32 billion (for PPP) and $18 billion (for SRP) higher than those in the case of deferred action. However, this research has demonstrated, that this inference is largely due to the selection of particular indicator (that is, present value) and the relatively short time frame (that is, 2005–2020) for analysis. By extending the time frame of the analysis to the year 2040, the case for an early introduction of carbon tax strengthens. Overall, the analysis in this research suggests that an immediate introduction of carbon tax, based on SRP, is the most attractive approach to reduce the rate of growth of CO2 emissions from the electricity sector and to simultaneously meet economic and social objectives. If the decision to introduce such a tax is deferred, it would be rather difficult to achieve not only environmental objectives but economic and social objectives as well.

Cyclones distribution and intensities impact directly on human activities, mainly due to their associated intense precipitation and winds. The main aim of this thesis is to understand changes in the cyclones originated in the South Atlantic focusing on their genesis and intensifying mechanisms. Cyclones are identified and tracked based on the relative vorticity field at 850 hPa computed from the winds. The characteristics of the cyclones are obtained by diagnostic variables sampled within a radial distance from each cyclone center and to produce a spatial distribution of the cyclone properties at the time of genesis. Also, cyclone centered composites are used to analyze the cyclone structure and the evolution of cyclones during their genesis. The climatology of cyclones was done using NCEP-CFSR and shows four main cyclogenesis regions in the South Atlantic Ocean: on the Southern Brazilian coast (SE-BR, 30°S), over the continent near the La Plata river discharge region (LA PLATA, 35°S), on the southeastern coast of Argentina (ARG, 40°S-55°S) and on the Southeastern Atlantic (SE-SAO, centered at 55°S and 10°W). To access changes in cyclone development, we used the CMIP5 HadGEM2-ES historical experiment (1980-2005) and RCP8.5 future projection (2074-2099). The HadGEM2-ES can represent the main South Atlantic characteristics of cyclones according to NCEP-CFSR climatology. However, there is an underestimation in cyclone frequency in the equatorward side of the storm track, particularly in the LA PLATA region. The HadGEM2-ES RCP8.5 future projection shows a general decrease of approximately 10% of cyclogenesis in the South Atlantic domain, which is mainly related to the poleward shift of the storm track. However, LA PLATA region presents a slight increase in its cyclogenetic activity (6.1 and 3.6%), in the summer and winter, respectively). The increase in genesis at 30°S over the continent is associated with the strengthening of the upper-level jet and the increase of warm and moisture advections at the same location. The enhance in the moisture transport from the tropics is also related to the intensification of the cyclone in the domain, mainly northward of 35°S. Finally, a downscaling using WRF was performed in an attempt to improve the climate model resolution. However the downscaling produces less and weaker cyclones in the NCEP-CFSR and HadGEM2-ES runs. The only region that presented an improvement was LA PLATA, due to the better representation of local features related to orography and moisture processes. The downscaled HadGEM2-ES RCP8.5 also shows an increase in cyclogenesis in the LA PLATA region and other locations. The HadGEM2-ES RCP8.5 projection and its downscaling shows that the cyclogenesis in some locations of South America is increasing, mainly due to the increase in the low-level moisture content and the strengthening of the equatorward flank of the upper-level jet. The cyclones in this locations will be slightly intense (between 20°S and 30°S) and will affect a narrow area close to the South American coast.<br>A distribuição e intensidade dos ciclones afeta diretamente as atividades humanas devido a precipitação e fortes ventos associados a esses sistemas. O objetivo principal deste trabalho é entender as mudanças nos ciclones gerados no Atlântico Sul devido às mudanças climáticas, focando em seus mecanismos geradores e intensificadores. Os ciclones foram identificados e rastreados utilizando a vorticidade relativa em 850hPa, calculada a partir do campo de ventos horizontal. Também foram usadas composições centradas para a análise da estrutura e evolução dos ciclones durante seu desenvolvimento. A climatologia de ciclones feita com o NCEP-CFSR mostra quatro regiões ciclogenéticas principais no Oceano Atlântico Sul: na costa sul do Brasil (SE-BR, 30°S), sobre o continente próximo da desembocadura do Rio da Prata (LA PLATA, 35°S), na costa sudeste da Argentina (ARG, 40°S-55°S) e no Sudeste do Atlântico (SE-SAO, centrada em 55°S, 10°W). Para analisar as mudanças no desenvolvimento dos ciclones, nós utilizamos os experimentos histórico (1980-2005) e RCP8.5 (2074-2099) do HadGEM2-ES (CMIP5). O HadGEM2-ES é capaz de reapresentar as principais características dos ciclones do Atlântico Sul, quando comparado à climatologia. No entanto, existe uma subestimativa do número de ciclones no lado equatorial da região de máxima atividade ciclônica, principalmente na região LA PLATA. A projeção futura HadGEM2-ES no cenário RCP8.5 mostra uma redução de aproximadamente 10% na ciclogêneses no domínio do Atlântico Sul, principalmente associada ao deslocamento em direção ao polo da região de máxima atividade ciclônica. Porém, a região LA PLATA apresenta um pequeno aumento em sua atividade ciclogenética (6.1 e 3.6%), no verão e inverno, respectivamente). O aumento na ciclogênese em 30°S está associada ao fortalecimento do jato de altos níveis e ao aumento da advecção quente e de umidade nessa localidade. O aumento do transporte de umidade dos trópicos está associado também à intensificação dos ciclones observada na projeção futura, principalmente ao norte de 35°S. Por fim, uma regionalização com o modelo WRF foi usada para melhorar a resolução do modelo climático. Porém, as simulações regionais subestimaram os ciclones em número e intensidade. A única região que em as regionalizações apresentaram melhor desempenho foi a LA PLATA, devido a uma melhor representação de feições locais associadas a orografia e processos úmidos. A regionalização do cenário futuro RCP8.5 também apresentou aumento da ciclogênese do LA PLATA, mas para o inverno. Tanto a projeção RCP8.5 do HadGEM2-ES quanto sua regionalização mostram que a ciclogênese em algumas regiões da América do Sul está aumentando, principalmente devido ao aumento de umidade em baixos níveis da atmosfera e fortalecimento do lado ramo equatorial do jato de altos níveis. Os ciclones nessas localidades serão intensos (entre 20°S e 30°S) e tendem a afetar uma região mais próxima à costa.

Regulating carbon markets in order to fight the effects of climate change has in recent years become an integral part of many economies around the world. Ensuring that policymakers implement market-based climate change legislation according to international best practice is an essential part to guarantee that a carbon market system operates smoothly within a country’s economy. There are many opportunities that exist in South Africa towards developing a lucrative carbon market; however, the information to implement such a system is hard to come by and complex to analyse. This dissertation will aim to shed some light on this relatively new field of the law as it will provide an overview of international best practice within the carbon market sphere. Furthermore, this dissertation will examine the legal nature of a carbon credit; analyse international instruments regulating carbon markets and discuss existing South African policies and legislation related to climate change and carbon markets. This will lead to the ultimate objective of this dissertation: to propose a possible framework for the regulation of a South African carbon market based upon international best practice. This dissertation revealed the imperative need for South African policymakers to implement legislation to conform to international best practice within carbon markets. In this regard the dissertation also revealed that the infrastructure to regulate such a market already exists within South Africa. Only subtle changes to these infrastructure systems will be required in order for to accommodate a functioning carbon market. The study revealed that the only way to convince entities around the world to emit fewer emissions and to contribute towards the fight against climate change is to attach a monetary value to emissions. Associating a price to carbon is the only way to sanction entities that produce emissions and compensate entities that mitigate emissions. A carbon tax coupled with a carbon offset mechanism, as opposed to a emissions trading scheme, would be the best option with regards to establishing a South African carbon policy. This will ensure a fair playing field, as carbon tax liable entities would be held responsible to pay the same fixed price per ton of carbon that they emit. Coupling the carbon tax with a carbon offset mechanism, trading with carbon credits, will incentivise companies to invest in “greener” technologies and to emit fewer emissions. This dissertation revealed that international best practice in the carbon market sphere, still poses significant difficulties such as price volatility associated with carbon credits; validation and verification inconsistencies within the different carbon standards; and supply and demand fluctuations. These difficulties where highlighted in this dissertation and solutions relating to these difficulties were discussed. The time has come for South Africa to enter the carbon market sphere, whether it be through the introduction of a carbon tax or otherwise. This dissertation illustrates that the infrastructure and stakeholders associated to a South African carbon market needs to be developed. If, when and how the government will actually implement such a carbon market system, remains a question to be answered.

Thesis (Ph.D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.<br>Committee Chair: Armistead G. Russell; Committee Member: Athanasios Nenes; Committee Member: M. Talat Odman; Committee Member: Michael Bergin; Committee Member: Yuhang Wang.

With climate change arising as an important issue in the 21th century, many states have been working diligently to develop climate action plans with the hopes of reducing greenhouse gas emissions and stop climate change from occurring. According to scientists' theories, however, many places across the globe are already feeling the effects of a changing climate and must therefore switch their focus from mitigation to adaptation. In the United States, there has been a focus on how climate change will impact one of the most vulnerable parts of the country, the transportation infrastructure. Many countries have already begun adapting their transportation infrastructure to climate change including the United States. This thesis focuses on how states are adapting to climate change by analyzing strategies, frameworks, and reports released by these states in order to document where they stand in regards to adaptation of the transportation network. The states that are adapting their transportation infrastructure are Washington, Oregon, California, Hawaii, Alaska, Florida, North Carolina, Maryland, Delaware, Pennsylvania, Michigan, Connecticut, Massachusetts, Vermont, and Maine. There is also a brief summary of how Canada and the United Kingdom are preparing for climate change with an analysis of frameworks and strategies used to adapt their transportation infrastructure. The ultimate goal of this thesis is to provide engineers and policymakers with evidence that several states are implementing adaptation into transportation projects and provide a variety of strategies for them to use in their own state. Specifically, this report provides applications of adaptation for Georgia to use, so that they can begin the lengthy process of adapting their transportation infrastructure to climate change.

Climate change emerged as a topic of public and political concern in the 1980s alongside the discovery of the ‘Antarctic Ozone Hole.’ The issue was raised up the political agenda in the latter half of the 1980s by scientists and international administrators operating in a transnational setting –culminating in the eventual formation of the Intergovernmental Panel on Climate Change (IPCC) in 1988. Created to produce a comprehensive assessment of the science, impacts and possible response strategies to climate change, the Panel managed to bridge to the two worlds of science and politics as a hybrid science-policy organisation, meeting the divergent needs of a variety of groups, specifically in the US Government. This thesis will provide an analysis of the negotiations that resulted in the formation of the IPCC in 1988. In particular, I examine the power politics of knowledge production in the relationship between a transnational set of scientists engaged in assessments of climate change and national policymakers. I argue that the IPCC was established as a means of controlling who could speak for the climate, when and how, and as such the Panel legitimised and privileged certain voices at the expense of others. In addition to tracing and examining the history of international climate change assessments in the 1980s, I will scrutinise how the issue became a topic of international political concern. Focusing on the negotiations between the World Meteorological Organization (WMO), United Nations Environment Programme (UNEP) and the United States of America in the formation of the IPCC, I will argue against the received view that the U.S. has consistently been in a battle with climate science and the IPCC. As I will show that the U.S. government was both integral to the decision to establish the IPCC and also one of its strongest backers. Following the formation of the Panel I examine the ad hoc decisions taken and processes adopted during the First Assessment (AR1) that contributed to the anchoring of the IPCC as the central authority on climate related knowledge. As such I show that in the absence of any formal procedural guidance there was considerable leeway for the scientists and Working Group Chairs to control and shape the content of the assessment. Finally, I analyse the ways in which U.S. and UK policymakers strategically engaged with the Panel. Significantly, I show that the ways in which the U.S. pushed all political debates to the heart of the scientific assessment imparted a linear approach to policymaking –assessment precedes and leads the policymaking –contributing to the increasing entanglement of the science and politics of climate change. Moreover, the narrow technical framing of the issue and the largely tokenistic attempts to involve participants from developing countries in the IPCC resulted in the UN resolutions (backed by developing countries) establishing the Intergovernmental Negotiating Committee/United Nations Framework Convention on Climate Change (INC/UNFCC) contrary to the wishes of U.S. policymakers.

Thesis (M. S.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2009.<br>Committee Chair: Rong Fu; Committee Member: Robert Dickinson; Committee Member: Robert X. Black. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Abstract The main objective of this research was to develop practical tools with which it is possible to improve the environment, micro-climate and energy economy of buildings and plans in different climate zones, and take the climate change into account. The parts of the study are: – State of art study into existing know-how about climate and planning. – Study of the effects of climate change on the built environment. – Development of simple micro-climate, nature and built environment analysis methods. – Defining the criteria of an acceptable micro-climatic environment. – Development of the wind test blower. – Presenting ways to interpret test results and draw conclusions. – Development of planning and design guidelines for different climate zones. An important part of the research is the development of the CASE wind test instrument, different wind simulation techniques, and the methods of observing the results. Bioclimatic planning and architectural design guidelines for different climate zones are produced. The analyse tools developed give a qualitative overall view, which can be deepened towards a quantitative analyse with wind testing measurements and roughness calculations. No mechanical rules are suggested, but complementary viewpoints and practices introduced to a normal planning process as well as improvement of consultative knowledge. The “method” is that there is no strict mechanical method, but a deeper understanding of bioclimatic matters. Climate-conscious planning with the developed CASE method, make it possible to design a better micro-climate for new or old built-up areas. Winds can be used in to ventilate exhaust fumes and other pollutants, which improves the quality of air and the healthiness of the urban environment. The analyses and scale-model tests make it possible to shield cold windy areas and to diminish the cooling effect of wind on facades. According to studies in Scandinavian countries this will bring energy savings of 5–15 per cent. The method can be used to: – Evaluation of the cooling effect of wind. Areas and facades exposed to wind. – Evaluation of the wind comfort at the pedestrian level. Windy areas, relative wind speeds. – Enhancing wind-forced ventilation. Positive and negative pressures at the inlets and outlets. – Analysis of the diffusion of pollutants. Ventilation of streets and areas. – Avoiding the damages caused by wind. Planning and designing wind protective solutions. – Characterisation of the wind loading of small and medium-size street architecture items. Designing wind resistant and protective items and plantings. – Analysing the drifting of snow. Placing of snow fences<br>Tiivistelmä Tutkimuksen päätavoitteena oli kehittää käytännöllisiä suunnitteluvälineitä, joilla voidaan parantaa ympäristöä, mikroilmastoa sekä rakennusten ja kaavojen energiataloutta eri ilmastovyöhykkeissä, sekä varautua ilmaston muutokseen. Tutkimuksen osat ovat: – Selvitys tämän hetkisestä ilmastoon ja suunnitteluun liittyvästä osaamisesta. – Selvitys ilmaston muutoksen vaikutuksesta rakennetulle ympäristölle. – Yksinkertaisten mikroilmasto-, luonto- ja rakennetunympäristön analyysien kehittäminen. – Määritellä hyväksyttävän mikroilmaston kriteerit. – Kehittää pienoismallien tuulitestauslaite. – Kehittää metodit testitulosten analysoimiseksi ja johtopäätösten vetämiseksi. – Laatia kaavoitus- ja rakennussuunnitteluohjeet eri ilmastovyöhykkeille. Tärkeä osa tutkimusta oli CASE tuulitestauslaitteen, erilaisten tuulen simulointitekniikoiden ja testausten havainnointimenetelmien kehittäminen. Kehitettiin bioklimaattisen kaavoituksen ja arkkitehtisuunnittelun suunnitteluohjeet eri ilmastovyöhykkeisiin. Kehitetyt analyysimenetelmät antavat laadullisen yleiskuvan, jota voidaan syventää määrällisen analyysin suuntaan käyttämällä tuulitestausmittauksia ja karheuslaskelmia. Mitään mekaanisia metodeita ei ehdoteta, vaan halutaan lisätä tieto-taitoa sekä uusia näkökulmia ja työtapoja nykyisiin kaavoitus- ja konsultointikäytäntöihin. ”Metodi” on siinä, ettei ole mitään kaavamaista metodia, vaan bioklimaattisten tekijöiden syvempi ymmärtäminen. Kehitetyn CASE metodin mukaisella ilmastotietoisella suunnittelulla voidaan aikaansaada parempi mikroilmasto sekä uusilla että vanhoilla rakennetuilla alueilla. Tuulen avulla voidaan tuulettaa pakokaasut ja muut ilmansaasteet, ja näin parantaa rakennetun ympäristön ilmanlaatua ja terveellisyyttä. Analyysien ja pienoismallien tuulitestauksen avulla voidaan suojautua kylmiltä tuulilta ja vähentää tuulen julkisivuja jäähdyttävää vaikutusta. Skandinaavisten tutkimusten mukaan näin voidaan saavuttaa 5–25 prosentin energiansäästö. Metodia voidaan käyttää mm. seuraaviin tarkoituksiin: – Arvioida tuulen jäähdyttävää vaikutusta. Selvittää tuulelle alttiit alueet ja julkisivut. – Arvioida tuulen vaikutusta jalankulun mukavuuteen. Tuuliset alueet ja suhteelliset tuulennopeudet. – Tehostaa painovoimaista ilmanvaihtoa. Positiiviset ja negatiiviset paineet ilmastoinnin sisäänmeno- ja ulostuloaukoissa. – Analysoida saasteiden leviämistä. Katujen ja alueiden tuulettaminen. – Torjua tuulen aiheuttamia tuhoja. Kaavoittaa ja suunnitella tuulelta suojaavia ratkaisuita. – Luonnehtia pieniin ja keskikokoisiin ulkona oleviin rakenteisiin kohdistuvia tuulikuormia. Suunnitella tuulenkestäviä ja suojaavia rakennelmia ja istutuksia. – Analysoida lumen kinostumista. Lumiaitojen sijoittelu

Thesis (M. S.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2005.<br>Dr. Judith A. Curry, Committee Chair ; Dr. Robert Dickinson, Committee Member ; Dr. Peter Webster, Committee Member. Includes bibliographical references.

Scientists started to study the relationship between changing weather patterns and the emission of carbon dioxide (CO2) and other harmful gasses. They soon discovered compelling evidence that CO2 concentration and other gases have been increasing and it was causing temperatures to increase in certain areas on the earth, which disturb historic weather patterns. Climate change has become a very popular field of study in the modern science. Europe first introduced measures to reduce carbon emissions but it was the Kyoto in 1997 where global leaders were asked to participate in a joint protocol to reduce greenhouse gases. South Africa responded to climate change challenges in 2008 with the Long term Mitigation Scenarios (LTMS). The Integrated Resource Plan for electricity to 2030 was developed from the LTMS scenarios and after some major amendments it was accepted and promulgated by Government and has recently been included in the National Development Plan to 2030 (NDP). There are concerns about the achievability of some of the objectives listed in the NDP and this study explored the IRP2010 as the proposed strategy to meet energy demand and reduce emissions. The purpose for this study was to answer this question: Is there an optimum climate change mitigation strategy for South Africa and how can the effect thereof be simulated on economic growth? Through primary and secondary research during the study it was possible to define some 32 categories of energy producing assets that are commercially active or nearly market-ready. The characteristics of the various assets and the relevant fuel are defined in mathematical equations. It was found that the three portfolios that matched the 450TWh electricity requirement would perform substantially better than the NDP portfolio in terms of cost and similar on emissions with marginally fewer employment opportunities created. The proposed electricity strategy in this study was 390TWh and 33.5 Million tonnes of oil consumption by 2030. This strategy was substantially more affordable than the 450TWh strategy. Trends in the Supply and Use tables since 1993 were studied and then forecasted to 2030 to determine consumption levels on electricity and liquid fuel into the future. It was found that electricity demand is seriously overestimated and South Africa would end up with large excess capacity in electricity infrastructures if the NDP energy strategy (IRP2010) is implemented. It is concluded that the NDP energy strategy to 2030 is based on an incorrect electricity demand forecast. It would lead to excessive investment in an electricity infrastructure. Government has confirmed that part of the new infrastructure would be nuclear. It is also found that NDP has not clearly supported nuclear as part of the strategy. Nuclear is partly the reason why the capital requirement of the NDP portfolio is so much higher than the other portfolios. It is the conclusion of this study that South Africa do not need to invest in a nuclear build programme as the electricity demand would be adequately covered by adding the new Medupi and Kusile power stations, Ingula pump storage scheme, some wind and solar renewables, electricity from cogeneration, biogas, biomass, small hydro and imported hydro from neighbour countries. To invest in electricity capacity to generate 450TWh annually by 2030 would result in excessive energy cost, GDP growth could be up to 1% lower due to underperforming capital investments in the electricity infrastructure and higher energy cost would lead to a decline in global competitiveness.

The history of the UNFCCC climate negotiations over the past 20 years has shown how difficult it is to reach an international climate agreement that is both legally binding and environmentally effective enough to ensure that humankind can avoid the worst consequences projected from climate change. Some experts even see the world drifting towards a 4°C mean temperature rise. It is therefore necessary to start exploring what future, non-cooperative climate change regimes might be expected to look like. One immediate consequence is that adaptation to climate change has become increasingly relevant; on a humanitarian, political, economic and the scientific level. The economic incentive structure of adaptation is different and, actually, more favourable than that of mitigation, with respect to both their inter- and intratemporal externalities. The ability to adapt makes a higher level of climate change tolerable. Furthermore, my research shows that adaptation empowers the poor to develop and to enforce a more equitable use of the atmospheric carbon sink; it may potentially also lead to an overall reduction of carbon emissions. Ultimately, it turns out that even in a non-cooperative, asymmetric world, there are prospects for clean technology transfer and adaptation funding. Drawing on the AK growth model with climate change developed by Buckle (2009a,b), the aim of this work is (i) to create a tractable, transparent economic growth model that includes climate damages and emissions abatement, (ii) to develop an adequate analytical representation of adaptation, and (iii) to analyze with the help of game-theoretic methods how the option to undertake adaptation affects the strategic nature of climate negotiations and, in particular, the outcome under a non-cooperative climate change regime.

Alpine plants are assumed to be in particular danger as the climate changes rapidly worldwide. Specialist alpine species in Norrbotten County, northern Sweden have been surveyed over the last 20 years, providing insight to population dynamics and how the plants might respond to the changing climate. The main current threat to the species is habitat destruction as the climate changes. Variation in the number of plants among populations and years, and correlations with environmental variables were examined. Some species had increased while others had decreased over the years. No uniform relationship for all species and populations were discovered, but some of the species exhibited relationships between population size changes and temperature and precipitation. However, if the future climate in Norrbotten County changes according to the predictions, the habitats of the specialist alpine plants may be severely altered, leaving the species with no alternative places to establish and grow.

Climate change is an increasingly urgent problem. How it is communicated and represented are of interest to those seeking to understand action or inaction on the issue. There is increasing interest on how it is being communicated visually. This research speaks to the growing body of literature on the visual communication of climate change in order to contribute to the wider critical literature addressing the role of images in the communication of climate change. It does so by considering a neglected site of climate change imagery: the Intergovernmental Panel on Climate Change's (IPCC) report covers. The IPCC's report covers from the first ones in 1990, to the latest ones of 2014, are investigated in this quantitative and qualitative case study where the subject matter, both literal and symbolic of this (hitherto unexamined) body of images, is interrogated. This dissertation sought to identify and investigate what, exactly, the IPCC is using to visually represent and communicate climate change outside the realm of its scientific graphs and diagrams. It sought to compare these findings with the larger lexicon of climate change imagery and look at how the IPCC negotiates the communicational and representational problems inherent in the visual communication of climate change. The question ultimately asked was whether the IPCC's cover images are effective representations of climate change. What was found was that the IPCC images departed significantly from standard climate imagery. The conclusions drawn from the initial content and thematic analysis was that the IPCC images are frequently too banal, bland and decontextualized to be effective representations or communicators of climate change but do offer some potentially effective avenues overlooked in other representations.

Transportation Asset Management (TAM) systems are in use at many transportation agencies both in the United States and around the world. These asset management systems serve as strategic resource allocation frameworks and their degree of implementation and maturity varies. Climatic change, with its potentially adverse impacts on both the built and natural environments, has become of increasing concern around the globe. Given the uncertainties associated with changing climatic conditions, transportation agency stakeholders utilize risk-based decision-making approaches to identify climate change impacts that pose the greatest risk to transportation infrastructure assets. In conjunction with criticality assessments, emerging conceptual frameworks seek to identify higher-risk infrastructure assets, which are both critical to system operations and vulnerable to potential climate change impacts, through standalone study efforts. This research develops a risk-oriented decision-making framework to identify vulnerable, higher-risk transportation infrastructure assets within the context of existing transportation asset management systems. The framework assesses the relative maturity of an agency’s transportation asset management system and provides guidance as to how an agency’s existing tools and processes can be used to incorporate climate change considerations. This risk-based decision-making framework is applied to three case studies: one at the Metropolitan Atlanta Rapid Transit Authority, another at the Metropolitan Planning Commission in Savannah – Chatham County, and a statewide case study at the Georgia Department of Transportation. The results of this research demonstrate that readily-available climate projection data can be analyzed and displayed geospatially so that the potential impacts of climatic change on transportation infrastructure can be determined for specific geographic regions. In addition, existing roadway and bridge infrastructure datasets can also be displayed geospatially. The framework uses geospatially-referenced roadway and bridge asset data and multi-criteria decision analysis procedures to develop and visually display criticality scores. Overlaying climate projection data and criticality data helps identify higher-risk transportation infrastructure assets. This research demonstrates that climate change considerations can be effectively incorporated in existing decision-making processes at various levels of maturity of formal TAM systems, making this more broadly accessible to agencies and communities with potential climate hazards.

The goal of this project completed for the Greater Northfield Sustainability Collaborative (GNSC) was to understand how Northfield, Minnesota citizens are experiencing climate change. Thirty individuals were interviewed to find out what they know about climate change, what actions they are taking, what they think the solutions are to the problems, and what barriers they have to more fully engaging with climate change issues. The interview results are intended to promote and advance the community's discussion on climate change via social learning and community engagement activities such as town hall forums and community surveys. These activities encourage citizens in the community to have direct input into the development of the community's climate action plan (CAP). Analysis of the interviews showed that the interviewees are witnessing climate change, that most are taking at least some action such as recycling or lowering thermostats, that they can name barriers to their own inaction, that they say communication about climate change remains confusing and is not widespread in Northfield, and that they are able to provide numerous suggestions for what the local and broader leadership should be doing. The analysis also showed wide individual variation within the group. Interviewees who were less knowledgeable about climate were less likely to be taking action and do not participate in social groups where climate change is discussed. Conclusions are that the whole group would like more and better communication and education from our leaders, that they also expect our leaders to be part of creating solutions to climate change, and that the solutions the interviewees suggested provide a very thorough initial list of mitigation and adaptation strategies for the city's future CAP.

The focus of this study is on understanding the multiple and interacting factors that hinder or enable municipal planned climate change adaptation, here called barriers and enablers respectively, and their implications for community based adaptation. To do this I developed a conceptual framework of barriers to and enablers of planned climate change adaptation, which informed a systematic literature review of barriers to planned community based adaptation in developing countries. In this framework barriers were grouped into resource, social and physical barriers. I then conducted empirical case study analysis using qualitative research methods in four South African municipalities to understand what barriers and enablers manifested in these contexts. In light of the reflexive nature of my methodology, my framework was adjusted based on my empirical findings, where contextual barriers were found to better represent the empirical results and subsumed physical barriers. I found my framework useful for analysis, but in the empirical cases, barriers and enablers overlaid and interacted so significantly that in reality it was often difficult to separate them. A key finding was that enablers tended to be more about the way things are done, as opposed to direct opposites of barriers. Comparison of barriers and enablers across the case studies revealed a number of key themes. Municipalities struggle to implement climate change adaptation and community based adaptation within contexts of significant social, economic and ecological challenges. These contextual barriers, when combined with certain cognitive barriers, lead to reactive responses. Existing municipal systems and structures make it difficult to enable climate change adaptation, which is inherently cross‐sectoral and messy, and especially community based adaptation that is bottom‐up and participatory. Lack of locally applicable knowledge, funding and human resources were found to be significant resource barriers, and were often underlain by social barriers relating to perceptions, norms, discourses and governance challenges. Enablers of engaged officials, operating within enabling organisational environments and drawing on partnerships and networks, were able to overcome or circumvent these barriers. When these enablers coincided with windows of opportunity that increased the prioritisation of climate change within the municipality, projects with ancillary benefits were often implemented. Analysis of the barriers and enablers identified in the literature and case studies, informed discussion on whether municipalities are able to implement community based adaptation as defined in the literature, as well as the development of recommendations for how municipal planned climate change adaptation and community based adaptation can be further understood and enabled in the future. These recommendations for practice and research include: (a) To acknowledge and understand the conceptual framings of municipal climate change work, as these framings inform the climate change agenda that is pursued, and hence what municipal climate change adaptation work is done and how it was done. (b) The need for further research into the social barriers that influence the vital enablers of engaged officials, enabling organisational environments, and partnerships and networks. (c) To learn from pilot community‐level interventions that have been implemented by municipalities, as well as from other disciplines and municipalities. (d) To develop top‐down/bottom‐up approaches to enable municipal planned climate change adaptation and community based adaptation, that benefits from high level support and guidance, as well as local level flexibility and learning‐by‐doing. (e) To develop viable mechanisms for municipalities to better engage with the communities they serve.

xvii, 205 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.<br>Fire is a fundamental, transformative, yet poorly understood process in the Earth system; it can radically reorganize ecosystems, alter regional carbon and energy balances, and change global climate. Short-term fire histories can be reconstructed from satellite (seasonal- to interannual-scales), historical (decadal scales), or dendrochronological records (for recent centuries), but only sedimentary charcoal records enable an analysis of the complex interactions between climate, vegetation and people that drive fire activity over longer temporal scales. This dissertation describes the compilation, synthesis and analysis of a global paleofire dataset and its application to understanding past, current, and future changes in fire activity. Specifically, I co-led efforts to compile charcoal records around the world into a single database, and to conduct three meta-analyses to understand the controls on fire at multiple spatial and temporal scales. The first meta-analysis reconstructed global biomass burning since the Last Glacial Maximum (LGM) 21,000 years ago. Results from this study demonstrated that global fire activity is low when conditions are cool and high when conditions are warm. This fundamental relationship between climate and fire is due in large part to associated changes in vegetation productivity. The second meta-analysis examined fire activity in North America during past abrupt climate changes and looked for evidence of continental-scale wildfires associated with a hypothesized comet impact ∼13,000 years ago. This analysis found a correlation between increased fire activity and abrupt climate change, but provided no evidence for continental-scale wildfires. A final meta-analysis disentangled the climate and human influences on global biomass burning during the past 2000 years; it found a close relationship between climate change and biomass burning until ∼1750 A.D., when human activities became a primary driver of global fire activity. Together, these three meta-analyses demonstrate that climate change is the primary control of global fire activity over long time scales. In general, global fire activity increases when the Earth's climate warms and decreases when climate cools. The paleofire data and analyses suggest that the rapid climate changes projected for coming decades will lead to widespread increases in fire frequency and biomass burning. This dissertation includes previously published and unpublished co-authored material.<br>Committee in charge: Patrick Bartlein, Chairperson, Geography; Daniel Gavin, Member, Geography; W. Andrew Marcus, Member, Geography; Cathy Whitlock, Member, Geography; Ronald Mitchell, Outside Member, Political Science

xix, 187 p. : ill. (some col.)<br>In Chapter II I analyze eco-labeling in the tourism industry, specifically the impact of the Blue Flag label for marinas and beaches on prices of marina slip rentals, weekly sailboat charter prices and hotel accommodation prices. The principal findings include that Blue Flag certified marinas appear to enjoy an average premium between 6.6% and 22% for their daily slip rental prices, between 40% and 49% for their monthly slip rental prices, and 23% for their yearly slip rental prices. Within the sailboat charter sector, vessels whose home marina is awarded the Blue Flag on average carry a price premium between 14% and 20% on a weekly sailboat rental. When it comes to hotel accommodation, hotels managing a Blue Flag certified beach enjoy a price premium between 45% and 270%. In Chapter III I employ a dataset on the global frequency of climate-change-related natural disasters to explain the probability of the start and occurrence, in a given year, of civil war and civil war durations during the last half of the 20th century. Extreme cold events are found to have a measurable positive effect on the probability of civil war starting in the affected countries, previous years' extreme heat events have a positive effect on the probability of a civil war occurring in a given year, and droughts have a positive effect on civil war duration. These findings can be used by policymakers as they contemplate climate change mitigation policies. In Chapter IV I investigate the determinants of ratification delay of a major oil pollution international environmental agreement, MARPOL. Importantly, I analyze the impact of oil spills, as well as various country characteristics, on the time a country takes to ratify MARPOL. The major contribution lies in the examination of impacts of environmental pollution events on international political decision making. I find that the amount of oil spilled decreases the time to ratify MARPOL. This is the first study that seeks to address this issue in a quantitative fashion. The results should inform policymakers by giving them insight into relevant determinants of legislative delay in ratifying treaties.<br>Committee in charge: Dr. Trudy Ann Cameron, Chairperson; Dr. Wesley W. Wilson, Member; Dr. Benjamin Hansen, Member; Dr. Ronald Mitchell, Outside Member

80% of Volatile Organic Compounds (VOCs) that are emitted every year to the atmosphere come from biogenic sources (BVOCs), where many different families are included, such as isoprenoids. The production and emission of those compounds is influenced by environmental variables such as light and temperature. Those environmental variables will be affected by global change which has been predicted for the next decades. The main objective of this thesis was to study the effect of global change, and specifically climate change, global warming and eutrophication, on isoprenoid, mono and sesquiterpene contents and emission rates. Moreover, we tested those effects in different families and genotypes, due to the intra and interespecific variability. In order to answer those questions we carried out different experiments, from seminatural conditions to more controlled conditions (lab), because the more control of the environmental sampling parameters the better conditions to study isolated factors. Identification and quantification of both contents and emission was carried out using gas chromatography with mass spectrometry. The main conclusions of the present thesis are: warming and drought increase both terpene content and emission independently of the specie (storing and non-storing species). However, different species responded differently to eutrophication: these responses depended on the species and on the sampling time. Finally, intra and interspecific differences where shown: different genotypes and different species behaved differently in both storing and non-storing species.<br>Un 80% dels Compostos Orgànics Volaltils (COVs) que s’emeten anualment a l’atmosfera provenen de fonts biogèniques (COVBs), entre els que destaquen diferents famílies com per exemple els isoprenoids. La producció i emissió d’aquests compostos està influenciada per variables ambientals com la llum i la temperatura. Aquestes variables ambientals es veuran afectades pel canvi global que s’ha predit per les properes dècades. L’objectiu de la present tesi va estar estudiar l’efecte del canvi global i específicament canvi climàtic, escalfament i eutrofització, sobre el continguts i les emissions de les famílies isoprenoids, mono i sesquiterpens. A més, varem testar aquests efectes en diferents famílies i genotips, donades les variacions intra i interespecífiques. Per aconseguir resoldre aquestes preguntes varem realitzar diferents experiments, des de condicions seminaturals fins a condicions més controlades (de laboratori), on un major control de les condicions ambientals de mostreig permet estudiar efectes de forma aïllada. La identificació i quantificació dels compostons, tant continguts com emesos, es va fer mitjançant cromatografia de gasos i espectrometria de masses. Les principals conclusions d’aquesta tesis són: l’escalfament i la sequera van incrementar tant el contingut com les emissions de terpens en espècies acumuladores i en espècies no acumuladores. No obstant, les respostes de les diferents espècies a l’eutrofització van ser diverses, depenent de l’espècie i de les condicions ambientals del moment de mostreig. Finalment, es van constatar les diferències intra i interespecífiques: espècies diferents i genotips diferents es van comportar de diferent manera, tant en espècies acumuladores com en espècies no acumuladores.

Human impacts such as habitat loss, species invasions and climate change are thought to be leading to biodiversity losses. However. little is known about the relative magnitudes of these effects. The purpose of this study is to determine to what extent climate change may have been responsible for observed changes in avian species' abundances. I investigated this question using data from the North American Breeding Bird Survey, one of the largest and most comprehensive biodiversity databases available. I found that 40% of the bird populations studied show significant linear changes in abundance from 1970 to 1999. Over the same period, temperature shows significant linear chances at 13% of the survey routes studied, whereas precipitation does not show significant trends. I analyzed the spatial relationships between abundance and climate and found that they are not strong (median R 2 = 0.119) but are generally consistent through time. Temporal trends in abundance were only very weakly related to trends in either temperature or temperature sub-optimality from 1970 to 1999. I found that temperature change is spatially autocorrelated over very long distances, whereas abundance change is autocorrelated over much shorter distances. Observed abundance changes in bird abundance are more likely to reflect local processes such as habitat modification.

Australia has experienced pronounced climate change since 1950, especially in forested areas where a reducing trend in annual precipitation has occurred. However, the interaction between forests and water at multiple scales, in different geographical locations, under different management regimes and in different forest types with diverse species is not fully understood. Therefore, some interactions between forests and hydrological variables, and in particular whether the changes are mediated by management or climate, remain controversial. This thesis investigates the responses of Australia’s terrestrial ecosystems to both historical and projected climate change using remote sensing data and ecohydrological models. The thesis is structured in seven chapters, and contains five research chapters. Vegetation dynamics and sensitivity to precipitation change on the Australian continent for the past long drought period (2002-2010) are explored in Chapter 2 using multi-resource vegetation indices (VIs; normalized difference vegetation index (NDVI) and leaf area index (LAI)) and gridded climate data. During drought, precipitation and VIs declined across 90% and 80% of the whole continent, respectively, compared to the baseline period of 2000-2001. The most dramatic declines in VIs occurred in open shrublands near the centre of Australia and in southwestern Australia coinciding with significant reductions in precipitation and soil moisture. Overall, a strong relationship between water (precipitation and soil moisture) and VIs was detected in places where the decline in precipitation was severe. For five major vegetation types, cropland showed the highest sensitivity to water change, followed by grassland and woody savanna. Open shrublands showed moderate sensitivity to water change, while evergreen broadleaf forests only showed a slight sensitivity to soil moisture change. Although there was no consistent significant relationship between precipitation and VIs of evergreen broadleaf forests, forests in southeastern Australia, where precipitation had declined since 1997, appear to have become more sensitive to precipitation change than in southwestern Australia. The attribution of impacts from climate change and vegetation on streamflow change at the catchment scale for southwestern Australia are described in Chapter 3. This region is characterized by intensive warming and drying since 1970. Along with these significant climate changes, dramatic declines in streamflow have occurred across the region. Here, 79 catchments were analyzed using the Mann-Kendall trend test, Pettitt’s change point test, and the theoretical framework of the Budyko curve to study changes in the rainfall-runoff relationship, and effects of climate and vegetation change on streamflow. A declining trend and relatively consistent change point (2000) of streamflow were found in most catchments, with over 40 catchments showing significant declines (p < 0.05, -20% to -80%) between the two periods of 1982-2000 and 2001-2011. Most of the catchments have been shifting towards a more water-limited climate condition since 2000. Although streamflow is strongly related to precipitation for the period of 1982 to 2011, change of vegetation (land cover/use change and growth of vegetation) dominated the decrease in streamflow in about two-thirds of catchments. The contributions of precipitation, temperature and vegetation to streamflow change for each catchment varied with different catchment characters and climate conditions. In Chapter 4, the magnitude and trend of water use efficiency (WUE) of forest ecosystems in Australia, and their response to drought from 1982 to 2014, were analyzed using a modified version of the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model in the BIOS2 modelling environment. Instead of solely relying on the ratio of gross primary productivity (GPP) to evapotranspiration (ET) as WUE (GPP/ET), the ratio of net primary productivity (NPP) to Transpiration (ETr) (NPP/ETr) was also adopted to more comprehensively understand the response of vegetation to drought. For the study period, national average annual forest WUE was 1.39 ± 0.80 g C kg−1 H2O for GPP/ET and 1.48 ± 0.28 g C kg−1 H2O for NPP/ETr. The WUE increased in the entire study area during this period (with a rate of 0.003 g C kg−1 H2O yr-1 for GPP/ET; p < 0.005 and a rate of 0.0035 g C kg−1 H2O yr-1 for NPP/ETr; p < 0.01), whereas different trends were detected in different biomes. A significantly increasing trend of annual WUE was only found in woodland areas due to higher magnitudes of increases in GPP and NPP than ET and ETr. The exception was in eucalyptus open forest area where ET and ETr decreased more than reductions in GPP and NPP. The response of WUE to drought was further analyzed using 1-48 month scales standardised precipitation-evapotranspiration index (SPEI). More severe (SPEI < -1) and frequent droughts (over ca. 8 years) occurred in the north than in the southwest and southeast of Australia since 1982. The response of WUE to drought varied significantly regionally and across forest types. The response of WUE to drought varied significantly regionally and across forest types, due to the different responses of carbon sequestration and water consumption to drought. The cumulative lagged effect of drought on monthly WUE derived from NPP/ETr was consistent and relatively short and stable between biomes (< 4 months), but notably varied for WUE based on GPP/ET, with a long time lag (mean of 16 months). As Chapters 2-4 confirmed that climate change has been playing an important role in the water yield and vegetation dynamics in Australia, the response of water yield and carbon sequestration to projected future climate change scenarios were integrated using the Water Supply Stress Index and Carbon model (WaSSI-C) ecohydrology model in Chapter 5. This model was calibrated with the latest water and carbon observations from the OzFlux network. The performance of the WaSSI-C model was assessed with measures of Q from 222 Hydrologic Reference Stations (HRSs) in Australia. Across the 222 HRSs, the WaSSI-C model generally captured the spatial variability of mean annual and monthly Q as evaluated by the Correlation Coefficient (R2 = 0.1-1.0), Nash-Sutcliffe Efficiency (NSE = -0.4-0.97), and normalized Root Mean Squared Error by Q (RMSE/Q = 0.01-2.2). Then 19 Global Climate Models (GCMs) from the Coupled Model Intercomparison Project phase 5 (CMIP5), across all Representative Concentration Pathways (RCPs) (RCP2.6, RCP4.5, RCP6.0 and RCP8.5), were used to investigate the potential impacts of climate change on water and carbon fluxes. Compared with the baseline period of 1995-2015 across the 222 HRSs, the temperature was projected to rise by an average of 0.56 to 2.49 ˚C by 2080, while annual precipitation was projected to vary significantly. All RCPs demonstrated a similar spatial pattern of change of projected Q and GPP by 2080, however, the magnitude varied widely among the 19 GCMs. Overall, future climate change may result in a significant reduction in Q but may be accompanied by an increase in ecosystem productivity. Mean annual Q was projected to decrease by 5 - 211 mm yr-1 (34% - 99%) by 2080, with over 90% of the watersheds declining. On the contrary, GPP was projected to increase by 17 - 255 g C m-2 yr-1 (2% - 17%) by 2080 in comparison with 1995-2015 in southeastern Australia. A significant limitation of WaSSI-C model is that it only runs serially. High resolution simulations at the continental scale are therefore not only computationally expensive but also present a run-time memory burden. In Chapter 6, using distributed (Message Passing Interface, MPI) and shared (Open Multi-Processing, OpenMP) memory parallelism techniques, the model was parallelized (and renamed as dWaSSI-C), and this approach was very effective in reducing the computing run-time and memory use. By using the parallelized model, several experiments were carried out to simulate water and carbon fluxes over the Australian continent to test the sensitivity of the model to input data-sets of different resolutions, as well as the sensitivity of the model to its WUE parameter for different vegetation types. These simulations were completed within minutes using dWaSSI-C, and this would not have been possible with the serial version. Results show that the model is able to simulate the seasonal cycle of GPP reasonably well when compared to observations at 4 eddy flux sites in Australia. The sensitivity analysis showed that simulated GPP was more sensitive to WUE during the Australian summer as compared to winter, and woody savannas and grasslands showed higher sensitivity than evergreen broadleaf forests and shrublands. With the parallelized dWaSSI-C model, it will now be much easier and faster to conduct continental scale analyses of the impacts of climate change and land cover change on water and carbon. Overall, vegetation and water of Australian ecosystems have become very sensitive to climate change after a considerable decline in streamflow. Australian ecosystems, especially in temperate Australia, are projected to experience warmer and drier climate conditions with increasing drought risk. However, the prediction from different models varied significantly due to the uncertainty of each climate model. The impacts of different forest management scenarios should be studied to find the best land use pattern under the changing climate. Forest management methods, such as thinning and reforestation, may be conducted to mitigate the impacts of drought on water yield and carbon sequestration in the future.

xi, 129 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.<br>Climate change is disrupting the underpinnings of effective water management by profoundly impacting hydrological patterns. Political entities mandated with freshwater management must respond to society's water needs as availability fluctuates and, in doing so, will encounter difficult ethical dilemmas because existing water laws are ill-equipped to resolve such problems. This thesis takes Chile's water laws as representative of the challenges in addressing ethical disparities arising from freshwater management in a changing climate and proposes that "water ethics" can effectively be used to manage freshwater resources. I examine the 1981 Water Code with a critical eye towards ethical shortcomings and also examine distributive impacts upon indigent farmers and indigenous communities. I conclude that Chile's existing water laws are inequitable because they deny legitimacy to diverse socio-cultural norms regarding water use. Principles of modern water laws must incorporate diverse cultural water laws using a legally pluralistic and ethical approach to management.<br>Committee in Charge: Dr. Anita M. Weiss, Chair; Professor Derrick Hindery; Professor Stuart Chinn

Scotland’s vernacular earth-built heritage has received inadequate recognition over a number of decades, being the reserve of a small group of academic, architectural and conservation practitioners, with negative perceptions of the structures and their inhabitants having been developed over the long-term. This has ultimately contributed to the loss of a wide number of earth building traditions previously widespread across Scotland. Heritage custodians have invested in the restoration and maintenance of a select few sites, but wider recognition of the significance of extant structures, including the intangible aspects of inherited traditions, remains limited. This thesis therefore seeks in the first instance to promote improved understandings of Scotland’s earth-built heritage through historical appraisals that underline its wider heritage value within global, regional and local contexts, whilst demonstrating the limitations of survey evidence hitherto relied upon. Heritage policies and management procedures are increasingly driven in response to the climate changes projected for the remainder of the twenty-first century, partly informed by the impacts of changes that have already been observed. As a result of this, new fields of research such as heritage climatology have developed with a view to offering bases from which to develop longer term mitigation and management strategies that recognise potential changes to the causes and processes of deterioration in the historic environment. Alongside the development of academic interest in climate and heritage has been an ever-increasing accessibility to advanced analysis methods through technical apparatus (often portable) that can be used to create improved evidence repositories based on processes-led approaches to investigation. Scotland’s earth-built heritage is susceptible to a range of climate-related phenomena that are likely to manifest in different ways over coming decades. Conservation strategies have continued to rely, however, upon the empirical observations and the experience of very few individuals since the latter-twentieth century. Consequently, the ad hoc approaches to the management of Scotland’s earth-built heritage and lack of strategic planning that have been typical to this point require amendment. This interdisciplinary thesis therefore seeks to contribute to addressing the issues outlined above through the exploration and application of portable scientific sampling apparatus that allow for in situ, rapid and non-intrusive insights to be gained at various scales of interest. These, together with other minimally intrusive approaches to assessing performance in earth building materials, allow for the development of processes-led strategies to extending the evidence base beyond that presently relied upon. Amongst the key outcomes of this are the generation of a locally-focused dataset of climate projections that are used to develop understandings of future climate conditions in the Carse of Gowrie, Perthshire, and in turn garner insights as to how these will impact in relation to the earth-built heritage for which this region is noted. Temperature and humidity monitoring evidence gathered from within the walls of extant structures over the course of fourteen months from March 2012 to April 2013 are set against contemporary external weather conditions and alongside measurements of moisture ingress. These serve to highlight both aspects of inherent resilience and points of particular risk to the future integrity of earth-built structures. An extended benefit of this work is the demonstration that the novel procedures used are easily replicated and could be employed in a variety of local contexts to develop suites of intra-site data across Scotland, with the potential for offering evidence-based inferences relevant to management procedures and policy discussion. The utility of the understandings and methods of investigation long established in the field of soil science but conspicuously overlooked in earth buildings research is also addressed, with insights into micro-scale processes offered using micromorphological and micromorphometric methods and the results being directly related to macro-scale observations.

Anthropogenic climate change poses a serious threat to biodiversity. Accurate predictions of the ecological consequences of future abiotic change will require a broad perspective that takes into account multiple climate variables, species-specific responses, and intra- and interspecific dynamics. I addressed these issues in the context of a marine rocky intertidal community to determine how abiotic and biotic factors can mediate the effects of climate change. I began with two studies on the organismal-level effects of multiple abiotic variables. In the first study, I found that acute exposure to low salinity reduced the survival of littorine snails facing thermal stress, but that ocean acidification (OA) had no such effect. In a second study, I showed that sustained exposure to increased temperature and OA had positive and additive effects on the growth and feeding of the purple ochre sea star. These findings demonstrate that studies of multiple climate variables will be important not only to identify additive and non-additive effects, but also to determine which climate variables will be detrimental for a given species. Next, I measured how species-specific responses to climate change can alter species interactions. By quantifying the effects of body size on the feeding behaviours of sea stars preying on mussels, I demonstrated that climate-driven changes in body size can have profound impacts on the strength of this interaction. Finally, I investigated how population-level responses to multiple abiotic variables can be affected by the presence of an interacting species. I built a predator-prey model that simulates the ecologically important interaction between the purple ochre sea star and its preferred prey, mussels. Using empirical estimates of sea star and mussel responses to increased temperature and OA, I simulated their interaction under various climate scenarios. I found that predation exacerbated the effects of climate change on mussel populations, and that climate change increased the strength of the sea star-mussel interaction. My work demonstrates that the effects of climate change will likely be mediated by a combination of biotic and abiotic factors, and that these factors should be considered when making predictions about the ecological consequences of climate change.

There is a consensus of scientific thought that humana ctivities are altering the gaseous composition of the atmosphere and leading to global climate change. This thesis addresses the question of how this global climate change will manifest itself at the regional level. In particular, a dynamic simulation model integrating both climate change and climatically sensitives ocio-economic activities will be developed. This model will explore the regional variations in both climate change and socio-economic activity. Three Local Authorities in Scotland were chosen for this study, Argyll on the west coast, Stirling inland and Fife on the east coast. This provides a west-east transect across central Scotland. Meteorological data, covering the period 1970-1998, was collected from twelve sites spread across these regions. These data were analysed in order to provide a climatic profile of each of the regions, and to identify any evidence of climate change in the form of trends in the data. Data relating to socio-economic factors was taken from a variety of sources. Mere possible this covered the same period in time as the climate data. Both sets of data were examined to determine evidence of climate sensitivity in the socioeconomic data using suitable statistical techniques. A simple, yet thermodynamically sound, dynamic climate model was developed and calibrated for each region using the data from the previous analysis. This model allowed increasing levels of atmospheric carbon dioxide (C02) to directly affect the mean surface temperature of the three regions. Precipitation changes from the UKCIP02 regional climate model were included This allowed seasonal temperature and precipitation totals to be simulated, on a regional basis, under different climate change scenarios. Simulations, calibrated on datafrom 1970-1998, were run forward to 2100. The climate results were similar to the outputfrom the UKCIP02 model. Six sectors of a socio-economic model were constructed population, employment, land use, water resources, housing and emissions. Where statistically significant relationships, between climatic and the local socio-economic variables were found, these were included in the model. Simulations for the period 1970-2100, were run under four different climate change scenarios, and that of constant climate, in order to assessth eir impact on the six sectors at the regional scale. The results indicate considerable regional variations in the impacts both of climate change and the associated climatically sensitive activities. Argyll in the west, for example, could benefit from increased tourism and the potential for agricultural expansion. If in-migration is allowed to offset labour shortages, then the west sees a reversal of the population decline of previous decades. Climate change has little impact on the economy of the inland and eastern regions. However, a problem does emerge with water resources in the east. Summer droughts are seen to increase in frequency, suggesting that both the costs and benefits of climate change will be unevenly distributed. The implications of these results for the management of change are then discussed along with future research needs.

Accurate forecasts of future regional temperature and rainfall patterns in many regions largely depend on characterizing anthropogenic trends in tropical Pacific climate. However, strong interannual to decadal-scale tropical Pacific climate variability, combined with sparse spatial and temporal coverage of instrumental climate datasets in this region, have obscured potential anthropogenic climate signals in the tropical Pacific. In this dissertation, I present sea-surface temperature (SST) and salinity proxy records that span over the 20th century using living corals from several islands in the central tropical Pacific. I reconstruct the SST proxy records via coral Sr/Ca, that are combined with coral oxygen isotopic (d18O) records to quantify changes in seawater d18O (hereafter d18Osw) as a proxy for salinity. Chapter 2 investigates the spatial and temporal character of SST and d18Osw-based salinity trends in the central tropical Pacific from 1972-1998, as revealed by corals from Palmyra (6ºN, 162ºW), Fanning (4ºN, 159ºW) and Christmas (2ºN, 157ºW) Islands. The late 20th century SST proxy records exhibit warming trends that are larger towards the equator, in line with a weakening of equatorial Pacific upwelling over this period. Freshening trends revealed by the salinity proxy records are larger at those sites most affected by the Inter-Tropical Convergence Zone (ITCZ), suggesting a strengthening and/or an equatorward shift of the ITCZ. Taken together, the late 20th century SST and salinity proxy records document warming and freshening trends that are consistent with a trend towards a weakened tropical Pacific zonal SST gradient under continued anthropogenic forcing. Chapter 3 characterizes the signatures of natural and anthropogenic variability in central tropical Pacific SST and d18Osw-based salinity over the course of 20th century using century-long coral proxy records from Palmyra. On interannual timescales, the SST proxy record from Palmyra tracks El Niño-Southern Oscillation (ENSO) variability. The salinity proxy record tracks eastern Pacific-centered ENSO events but is poorly correlated to central Pacific-centered ENSO events - the result of profound differences in precipitation and ocean advection that occur during the two types of ENSO. On decadal timescales, the coral SST proxy record is significantly correlated to the North Pacific Gyre Oscillation (NPGO), suggesting that strong dynamical links exist between the central tropical Pacific and the North Pacific. The salinity proxy record is significantly correlated to the Pacific Decadal Oscillation (PDO), but poorly correlated to the NPGO, suggesting that, as was the case with ENSO, these two modes of Pacific decadal climate variability have unique impacts on equatorial precipitation and ocean advection. However, the most striking feature of the salinity proxy record is a prominent late 20th century freshening trend that is likely related to anthropogenic climate change. Taken together, the coral data provide key constraints on tropical Pacific climate trends, and when used in combination with model simulations of 21st century climate, can be used to improve projections of regional climate in areas affected by tropical Pacific climate variability.

Mapping and explaining the distribution of vegetation helps land managers to make systematic conservation planning decisions. This is typically achieved using models that correlate the distribution of species with environmental factors, and can predict the vegetation at unsurveyed locations. These Species Distribution Models (SDMs) have numerous unresolved issues, but serve as a useful first-pass approximation for planning purposes.This thesis investigates some of the uncertainties of SDMs, including the impact of data accuracy, the incorporation of spatial processes, the evaluation of alternative models, and the benefits and challenges of producing models at the landscape scale. The research was conducted on the Illawarra Escarpment, 80 km south of Sydney, Australia (34.4 oS, 150.9 oE). The escarpment contains a north-south trend in eucalypts (Eucalyptus spp.) that cannot be explained in terms of elevation or geology. It also exhibits a patchy distribution of rainforest communities, some unique to the Illawarra. It is not known which environmental factors determine the distribution of either the eucalypts or rainforest species, or how they may respond to a changing climate.Species distributions are sensitive to the accuracy of data used, and yet many models only use elevation as a surrogate for temperature, or use simple elevation sensitive interpolations from weather stations. I collected hourly temperature data from 40 sites on the Illawarra Escarpment, and investigated whether elevation was an adequate surrogate for temperatures in this landscape. I then investigated whether temperature surfaces could be improved by considering other topographic and geographic factors, including exposure to wind, distance to coast, radiation, and the average conditions in the surrounding neighbourhood. Elevation was well correlated with moderate seasonal temperatures (e.g. summer minima and winter maxima), but was poorly correlated with the extreme temperatures (summer maxima, winter minima) that are physiologically limiting for many species. Using neighbourhood influences, exposure to wind and distance to coast improved the accuracy of temperature surfaces, and increased the explanatory performance of vegetation models. I concluded that elevation was not always an adequate surrogate for temperature. Temperatures are also affected by other topographic and geographic factors, and these should be considered when developing models for systematic conservation planning activities.Species distribution models are typically based solely on niche factors. Where spatial processes are included, it is typically by employing autologistic regression, or other techniques that use survey data as a predictor. This precludes the models being used to make predictions in times or places where survey data is unavailable, and reduces ecological explanation because it is an interpolation technique. I used neighbourhood (contextual) indices based on environmental factors as an alternative method to overcome these problems. I demonstrate that contextual indices improve SDMs over purely niche-based models, and are capable of predicting unknown populations in unsurveyed areas. I conclude that contextual indices have numerous advantages over autologistic regression, and can capture a continuum between niche and dispersal limited species.Models that predict how species will respond to climate change either use coarse-scale climate surfaces, or idealised predictions of uniform warming. These methods may dramatically over-estimate extinction risk because they neglect fine-scale variations in warming, and refugia where species can persist despite unfavourable regional conditions. I created fine-scale estimates of warming by combining 35 years of Bureau of Meteorology observations with one year of intensive fine-scale temperature monitoring. I found that warming was greatest at inland locations, at lower elevations, away from streams, and at sites exposed to hot, dry northwesterly winds. As species are biased in the geographic and topographic positions they occupied, some species have experienced more warming than others and are at greater threat from climate change. I concluded that it was important to continue developing methods to downscale coarse-grained climate surfaces, and suggest that the accuracy of this process could be improved by using a range of topographic factors.There are many methods for selecting predictors in SDMs, and the competing models often make highly variable predictions. I addressed this uncertainty by comparing the performance of models with and without a given environmental factor. I found that there was relatively strong support for the geology and winter minimum temperature predictors, as well as predictors based on contextual indices, as there was a significant drop in model performance when these predictors were excluded. In contrast, there was less support for summer maximum temperature, as other temperature predictors could combine to produce similar model performance. Model performance varied more between models for different species than between different predictor combinations for the same species. I concluded that it was inappropriate to assess models based on subjective benchmarks, such as an AUC of more than 0.7. A comparison between competing models for the same species gives a better indication of the validity of the model building procedure.The results of this research provide important insights into the benefits and challenges of creating SDMs at the landscape scale (extent of 10–200 km). It is a major challenge to obtain spatially and thematically accurate environmental predictors and biotic data at this scale, and studies should include the collection of data to ensure models are adequate. Landscapes will not have as much environmental variation as coarse-scale models, and this will limit the ability to transfer the models to new study areas. However, there are a number of benefits that justify these studies. Producing accurate temperature surfaces at the landscape scale will result in less pseudoreplication and less predictor colinearity. This will improve the robustness of models. Landscape scale studies also allow modellers to capture fine-scale refugia, and this will improve the accuracy of climate change predictions. Finally, many ecological processes operate at a scale that is too fine to be detected with coarse-scale models. Landscape scale models may be the only alternative to detect these processes. There is no optimal scale for SDMs, however, and a future challenge is to better integrate coarse and fine-scale models to make more ecologically robust predictions.

There is growing concern in the United States and abroad that changes in climate may have serious adverse impacts on communities and their civil infrastructure systems. In response, governments and agencies have begun to investigate adaptation: actions taken to reduce the vulnerability or increase the resiliency of natural and human systems in light of expected climate change. In the transportation sector, adaptation planning has predominantly pursued risk-based strategies that seek to identify climate impacts, and assess infrastructure vulnerabilities across multiple asset types, in network-level planning. However, given the complexity of the myriad asset types of which engineered civil infrastructure systems are composed, these frameworks may not adequately address the unique concerns of these various individual asset types. This research develops a risk-based framework to assess and prioritize at a network-level the risks of highway culvert assets to the projected impacts of climate change, specifically focusing on increases in extreme precipitation, and the associated potential for flooding. The framework is applied in a series of case studies using culvert management data provided by four state DOTs, and national climate change projection and infrastructure datasets. The framework developed proposes a new characterization of infrastructure climate change risk, based upon the catastrophe model, to address the need for qualitative approaches to risk given the uncertain nature of climate change, and the sometimes sparse inventory and attribute data for various assets. This characterization proposes three “dimensions” of infrastructure climate risk (climate change impact exposure, asset climate impact vulnerability, and asset criticality) to assign culvert asset priorities. The research develops a method to project the geospatial extent and changes in magnitude of extreme precipitation events; it also develops two measures of culvert vulnerability to increased flow conditions based upon data collected in general culvert management activities. This research demonstrates that existing data sources can be reasonably combined in an analytical assessment framework to identify climate change impact risks to highway culvert assets, providing an additional resource to the existing climate change adaptation planning and risk management toolkit in the transportation infrastructure sector, and also laying a foundation for further refinement of these methods. The results of this research demonstrate that existing climate change projection data, when used alongside culvert inventory and attribute data, provides a reasonable means by which to analyze the projected exposure of culvert assets to climate change impacts. This research also demonstrates that existing culvert management data provides a reasonable foundation upon which to assess the relative vulnerability of culverts to increased flow conditions, although additional research is necessary to develop these methods. The structure of the proposed framework provides a viable means by which quantitative climate change projections, asset vulnerability, and asset criticality data can be combined in a mixed-methods approach to qualitatively characterize climate change impact risks to highway culvert assets despite uncertainty in climate change projections and other inputs.

The recent elevated North Atlantic hurricane activity has generated considerable interests in the interaction between tropical cyclones (TCs) and climate change. The possible connection between TCs and the changing climate has been indicated by observational studies based on historical TC records; they indicate emerging trends in TC frequency and intensity in some TC basins, but the detection of trends has been hotly debated due to TC track data issues. Dynamical climate modeling has also been applied to the problem, but brings its own set of limitations owing to limited model resolution and uncertainties. The final goal of this study is to project the future changes of North Atlantic TC behavior with global warming for the next 50 years using the Nested Regional Climate Model (NRCM). Throughout the course of reaching this goal, various uncertainties and limitations in simulating TCs by the NRCM are identified and explored. First we examine the TC tracking algorithm to detect and track simulated TCs from model output. The criteria and thresholds used in the tracking algorithm control the simulated TC climatology, making it difficult to objectively assess the model's ability in simulating TC climatology. Existing tracking algorithms used by previous studies are surveyed and it is found that the criteria and thresholds are very diverse. Sensitivity of varying criteria and thresholds in TC tracking algorithm to simulated TC climatology is very high, especially with the intensity and duration thresholds. It is found that the commonly used criteria may not be strict enough to filter out intense extratropical systems and hybrid systems. We propose that a better distinction between TCs and other low-pressure systems can be achieved by adding the Cyclone Phase technique. Two sets of NRCM simulations are presented in this dissertation: One in the hindcasting mode, and the other with forcing from the Community Climate System Model (CCSM) to project into the future with global warming. Both of these simulations are assessed using the tracking algorithm with cyclone phase technique. The NRCM is run in a hindcasting mode for the global tropics in order to assess its ability to simulate the current observed TC climatology. It is found that the NRCM is capable of capturing the general spatial and temporal distributions of TCs, but tends to overproduce TCs particularly in the Northwest Pacific. The overpredction of TCs is associated with the overall convective tendency in the model added with an outstanding theory of wave energy accumulation leading to TC genesis. On the other hand, TC frequency in the tropical North Atlantic is under predicted due to the lack of moist African Easterly Waves. The importance of high-resolution is shown with the additional simulation with two-way nesting. The NRCM is then forced by the CCSM to project the future changes in North Atlantic TCs. An El Nino-like SST bias in the CCSM induced a high vertical wind shear in tropical North Atlantic, preventing TCs from forming in this region. A simple bias correction method is applied to remove this bias. The model projected an increase both in TC frequency and intensity owing to enhanced TC genesis in the main development region, where the model projects an increased favorability of large-scale environment for TC genesis. However, the model is not capable of explicitly simulating intense (Category 3-5) storms due to the limited model resolution. To extrapolate the prediction to intense storms, we propose a hybrid approach that combines the model results and a statistical modeling using extreme value theory. Specifically, the current observed TC intensity is statistically modeled with the General Pareto distribution, and the simulated intensity changes from the NRCM are applied to the statistical model to project the changes in intense storms. The results suggest that the occurrence of Category 5 storms may be increased by approximately 50% by 2055.

The effect of recent climate change in Central Asia poses a significant and potentially serious challenge to the region’s agricultural sector. An investigation of the aerosol-climate- crop yield correlation in this region is essential for a better understanding of the effect of aerosols and climate on Central Asian agriculture. Our goal is to investigate the linkages between aerosol, climate and major crop production (cotton, maize, wheat, and rice) in specified agricultural regions in the five Central Asian countries. Our approach is to perform the Pearson’s Correlation Coefficient analysis in order to observe the statistical correlation between crop yield, temperature, precipitation, and aerosol optical depth (AOD), for each indicated agricultural region in the selected countries. Besides, using NASA GIOVANNI website tools, we retrieve distribution maps and time series of temperature, precipitation and AOD to facilitate the analyses. The research shows that in some aspects, the relation between AOD, climate, and crop yield is different in Central Asia than in previous global or large scale research hypotheses. The statistical correlations vary not only across countries but also across agricultural regions. For example, in Kazakhstan, opposite correlations exist between precipitation and AOD in two different agricultural regions even though both regions are rain-fed. In the more arid countries (with lower rain rates) such as Turkmenistan and Uzbekistan, no correlation exists between crop production and temperature, precipitation, and AOD, while the less arid (with higher rain rate) countries (Kazakhstan, Kyrgyzstan, and Tajikistan) indicate a positive correlation.

The primary aim of the research work is to focus on the effects of climate change for maintaining physical infrastructures (i.e. such as buildings, dams, bridges, road pavements and other road infrastructures). As infrastructure requires major investment, it is important to build necessary management system to cope with future changes. This means that recognition of likely climate change impacts and appropriate adaptation measures are critical. However, most infrastructures has been designed, built and maintained on the premise that the future climate will be similar to that experienced in the past. Since the occurrence of the most recent climate disasters in Queensland, Australia, it has become mandatory to put especial policies for design and maintenance purposes of infrastructures . Recognition of the risks associated with climate change is a valuable initial step towards improved planning of new infrastructure investments and mitigating. Road infrastructure especially pavement requires special type of maintenance policy as the material of pavement like bitumen is very much sensitive to these types of effects such as moisture or temperature.<br>Thesis (Masters)<br>Master of Philosophy (MPhil)<br>Griffith School of Engineering<br>Science, Environment, Engineering and Technology<br>Full Text

The primary question that the thesis investigates is: what impacts could climate change have on cattle water demand and supply in Khurutshe, Botswana. This thesis is pursued in light of the fact that there is a lack of knowledge on climate change and cattle water demand and supply. Thus, this thesis aims at filling the gap in knowledge on climate change and cattle water resources in Botswana and other semi-arid environments. A cattle water demand and supply model is developed to investigate the primary question of the thesis. The model is driven by rainfall and temperature over time as these variables largely determine cattle water supply and demand, respectively. Climate scenarios for 2050 are constructed using SimCLIM (developed by the International Global Change Institute of the University of Waikato) based on HadCM3 and CSIRO Mk2 General Circulation Models (GCMs). Three Special Report on Emission Scenarios (SRES) are used: A1B, A1FT and A1T. These emission scenarios were selected based on their coverage for possible future Greenhouse Gas emissions (GHG). Climate scenarios show that by 2050 the temperature for the Khurutshe area could increase by as much as 3 oC depending on the GCM and SRES emission scenario and that there could be a decline in rainfall of up to 14% per month. CSIRO Mk2 displayed the maximum decline in rainfall while HadCM3 depicted the maximum increase in temperature. The model is implemented in the Khurutshe of the Kgatleng District, Botswana. The results reported are for Masama Ranch and also for the whole of the Khurutshe area. The results show that climate change could lead to an annual increase of more than 20% in cattle water demand by 2050 due to an increase in temperature. In addition, climate change could lead to a decline in the contribution of surface pan water to cattle water supply. Overall, there could be an increase in abstraction of groundwater for cattle by 2050 due to an increase in demand and a decline in forage water content and surface pan water. Observations in semi-arid environments of Africa indicate that farmers encounter problems of declining borehole yields and local depletion in groundwater in summer and drought years when demand peaks. In addition, it has been observed that during drought more cattle are lost as a result of lack of water, particularly for those whose cattle are reliant on surface water. Thus, the results from this study indicate that climate change could enhance this problem. In the thesis I have shown the importance of integrating climate change impacts on water demand and supply when assessing water resources, which has been ignored in the past. Some of the policy options that are discussed are tradable pumping permits for controlling abstraction and allocation issues in the Khurutshe aquifer and, controlling stocking numbers. This is in recognition of the fact that climate change could result in more reliance on groundwater for both cattle farming and urban water supply hence compromising sustainability and allocation issues especially for the Khurutshe aquifer which is earmarked to supply the city of Gaborone and surrounding villages in drought periods.

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.<br>Doctorat en Sciences économiques et de gestion<br>info:eu-repo/semantics/nonPublished

Particulate matter suspended in air (i.e. aerosol particles) exerts a substantial influence on the climate of our planet and is responsible for causing severe public health problems in many regions across the globe. Human activities have altered the natural and anthropogenic emissions of aerosol particles through direct emissions or indirectly by modifying natural sources. The climate effects of the latter have been largely overlooked. Humans have dramatically altered the land surface of the planet causing changes in natural aerosol emissions from vegetated areas. Regulation on anthropogenic and natural aerosol emissions have the potential to affect the climate on regional to global scales. Furthermore, the regional climate effects of aerosol particles could potentially be very different than the ones caused by other climate forcers (e.g. well mixed greenhouse gases). The main objective of this work was to investigate the climatic effects of land use and air pollution via aerosol changes. Using numerical model simulations it was found that land use changes in the past millennium have likely caused a positive radiative forcing via aerosol climate interactions. The forcing is an order of magnitude smaller and has an opposite sign than the radiative forcing caused by direct aerosol emissions changes from other human activities. The results also indicate that future reductions of fossil fuel aerosols via air quality regulations may lead to an additional warming of the planet by mid-21st century and could also cause an important Arctic amplification of the warming. In addition, the mean position of the intertropical convergence zone and the Asian monsoon appear to be sensitive to aerosol emission reductions from air quality regulations. For these reasons, climate mitigation policies should take into consideration aerosol air pollution, which has not received sufficient attention in the past.

Thesis (M.A.)--University of North Carolina at Chapel Hill, 2009.<br>Title from electronic title page (viewed Mar. 10, 2010). "... in partial fulfillment of the requirements for the degree of a Master of Arts in the Department of Political Science." Discipline: Political Science; Department/School: Political Science.