A notable feature in the first 20-year satellite altimetry records is an anomalously fast sea level rise (SLR) in the western Pacific impacting island nations in this region. This observed trend is due to a combination of internal variability and external forcing. The dominant mode of dynamic sea level (DSL) variability in the tropical Pacific presents as an east-west see-saw pattern. To assess model skill in simulating this variability mode, we compare 38 Coupled Model Intercomparison Project Phase 5 (CMIP5) models with 23-year satellite data, 55-year reanalysis products, and 60-year sea level reconstruction. We find that models underestimate variance in the Pacific sea level see-saw, especially at decadal, and longer, time scales. The interannual underestimation is likely due to a relatively low variability in the tropical zonal wind stress. Decadal sea level variability may be influenced by additional factors, such as wind stress at higher latitudes, subtropical gyre position and strength, and eddy heat transport. The interannual variability of the Nino 3.4 index is better represented in CMIP5 models despite low tropical Pacific wind stress variability. However, as with sea level, variability in the Nino 3.4 index is underestimated on decadal time scales. Our results show that DSL should be considered, in addition to sea surface temperature (SST), when evaluating model performance in capturing Pacific variability, as it is directly related to heat content in the ocean column.

The Florida Keys is one of the most susceptible island chains in the United States to sea level rise induced inundation because most elevations are lower than 2 m above current sea level. By analyzing a digital elevation model (DEM) derived from airborne light detection and ranging (LiDAR) measurements using a geographic information system (GIS), this paper estimates the potential impacts of a series of sea level rise scenarios from 0.15 to 5 m on the Florida Keys. The results showed that a 0.5 m sea level rise by the end of this century would inundate a large area, about 66% of the total area of the Florida Keys. However, this extent of sea level rise would not inundate a large percentage of the current population (<9%) and property (<14%). In contrast, a 1.5 m rise in sea level would inundate 90% of the land and 70% of population and property in the Florida Keys. Comparison of inundation dynamics using hypsometric curves demonstrated that, among the major Keys population centers. Big Pine Key is most susceptible to sea level rise, followed by Key Largo and Key West. Thus, inundation dynamics need to be considered in policy-making.

This thesis assesses the promise and potential failures of five tort cases filed in California city and county governments in 2017. The plaintiffs in these cases are suing the fossil fuel industry, claiming that the actions of the industry contributed substantially to global climate change, which is now causing sea level rise in their coastal communities. If these cases are successful, the budget-constrained city and county governments will be provided with funds necessary for climate change adaptation and mitigation measures that will allow residents to continue living in a hotter climate, with higher sea levels. As the effects of global climate change materialize, it is essential that local governments find ways to adapt.

Scientific evidence points to a changing global climate. The most vital and visible impacts of this phenomenon for sea-level communities are sea-level rise, coastal erosion, and more frequent severe coastal storms. However, limited research has been conducted to date to project the damage from rising maximum water levels and corresponding storm surges, and their impacts on the sustainability of coastal communities. This research focuses on the urban coastal community of Charlottetown, Prince Edward Island (P.E.I.), Canada as part of the C-Change International Community University research Alliance (ICURA), “Managing Adaptation to Environmental Change in Coastal Communities: Canada and the Caribbean.” The stochastic process that underlies, maximum observed water levels in Charlottetown, is modeled using historical data. Maximum observed water levels and storm surges are represented by fitted conditional and marginal univariate probability density functions. The statistical package “Easy-Fit” is used as a tool for analyzing goodness of fit to the historical data for maximum observed water levels in Charlottetown. A System Dynamics (SD) model, using STELLA, is developed to simulate the projected impacts of maximum observed water levels on the City of Charlottetown. The SD model captures the dynamics of the four pillars of community sustainability, namely Environmental, Economic, Social-Cultural and Human sectors identified for the City of Charlottetown. The model defines and evaluates the robustness of alternative adaptation strategies for various model scenarios to projected storms over a long-term planning period. The results quantify the vulnerability of Charlottetown. The analysis of the results from implementing 3 main adaptation strategies for protection, accommodation, and retreat scenarios as well as the ones from the most common current response of “doing nothing”, provide information on the dynamic and pillar-related impacts of storms on Charlottetown. Analysis of these strategy options clearly indicates that doing nothing in the face of more frequent severe storms is an inefficient strategy. Model results show that the protect strategy is unlikely to deliver complete protection, and the retreat option is costly and not well received. The accommodation strategy including a combination of protection options and controlled retreat will provide the most robust option for the coastal City of Charlottetown. The SD model and analysis provides a framework for the evaluation of adaptation strategies for alternative coastal communities.

This study identifies and critically assesses the social and physical consequences of, and possible responses to, sea-level rise and loss of land in the area that is now covered by the southern North Sea and English Channel/La Manche during the Mesolithic period. It suggests that Mesolithic studies still, despite debate on the matter, frame hunter fisher gatherers in economic terms. In this way, nature is seen as a separate entity to culture, the changing environment, therefore, becomes an external force against which people struggle. However, as an alternative, this thesis advocates an understanding of Mesolithic hunter fisher gatherers as an integral part of their changing world, suggesting that they would have had a fundamental awareness of these changes through a sensorial engagement, and acted accordingly. That said, it also suggests that, while not all people living in the area were equally affected by sea-level rise, the associated loss of land could have profoundly impacted people’s sense of place and being. It also highlights that, although sea-level rise and climate change occurred globally and on a millennial-scale, it unfolded and was experienced at a local and generational level. It therefore makes a case that to understand the human experience of early Holocene sea-level rise, it must be studied at the local-scale. This provides us with a better understanding of the effects of sea-level rise – a sense of the experience of it, rather than simply recording it as an abstract concept. Further, the local scale can identify problems that are not necessarily obvious from the larger scale. In this way, this thesis captures some of the nuances of environmental change that are frequently missing from the archaeological literature, and highlights the intense relationship between humans and their environment, providing a fresh approach to Mesolithic environment relations and a richer and more complex story of the effects of early Holocene sea-level rise.

This thesis focuses on exploring the concept of managed realignment as a potential climate change adaptation strategy in Sweden. The empirics is based on the qualitative case study research within three Swedish municipalities of Trelleborg, Halmstad and Karlstad. The concept of territorial governance was used as the analysis framework for the empirical data. The aim of this thesis is to contribute to further research on managed realignment in Sweden, point out on current constraints and potentials of managed realignment within Swedish context and the current needs for making it a potential climate adaptation strategy in Sweden.

Transportation agencies in coastal urban areas face a significant challenge to enhance the long-term resilience of their networks to flooding and storm surge events exacerbated by sea level rise. The problem of sea-level rise adaptation is characterized by deep uncertainty that makes it complex to assess the value of adaptation investments. To enable informed adaptation decisions, the present study created a dynamic stochastic modeling framework based on the theoretical underpinnings of complex adaptive systems that integrates: (i) stochastic simulation of sea-level rise stressors based on the data obtained from downscaled climate studies pertaining to future projections of sea-level and precipitation; (ii) dynamic modeling of roadway conditions by considering regular decay of roadways, as well as structural damages caused by storm surge events; and (iii) a decision-theoretic modeling of agency infrastructure management and adaptation processes based on cognitive psychology, bounded rationality, and regret theories. In this framework, resilience is examined based on trend changes in the network performance measures (e.g., life cycle costs and performance). The created framework and model were tested in a case study related to the road network of the city of Miami-Beach, which global assessments rank first iv among the world's urban areas most exposed to sea-level rise risks. The results indicated that: (i) SLR Adaptation investment and life cycle costs of roadway infrastructure are negatively correlated. In addition, it was shown that the sensitivity of network’s life cycle cost to actual sea-level rise scenario decreases when adaptation investment increases. These finding emphasize the importance of proactive improvement of the network resilience to alleviate the long-term costs of sea-level rise. (ii) When funding is sufficient for all required adaptation actions, mid-term adaptation planning yields lower life cycle cost. When funding is insufficient, aggregated investment in long-term adaptation planning intervals yields lower network LCC. These findings imply that different adaptation planning approaches should be taken for different levels of adaptation investment. (iii) The agency’s perception of SLR and risk attitude do not have significant effect on life cycle cost of roadway networks. Hence, implementation of adaptation action based on any perception of sea-level rise and risk attitude can significantly reduce the life cycle costs of roadway networks under the impacts of SLR. (iv) The devised performance target has negative correlation with life cycle cost of a roadway network affected by SLR impacts. Therefore, compromising the network performance condition will never result in lower life cycle costs.

Thesis advisor: Jeremy D. Shakun / The deglacial extent chronology of the southeastern Laurentide Ice Sheet as it retreated through the northeastern United States and southern Quebec has been well constrained by multiple lines of evidence. By comparison, few data exist to constrain the thinning history of the southeastern Laurentide, resulting in lingering uncertainty about volume changes and dynamics of this ice mass during the deglacial period. To address the lack of thinning information, my team collected 120 samples for in-situ `10Be exposure dating from various elevations at numerous mountains in New England and southern Quebec. Monte Carlo regression analyses using the analytical uncertainties of exposure ages from each mountain are used to determine the most-likely timing and rate of ice thinning for that location, a technique known as the ‘dipstick approach’. While this larger project is ongoing, I have processed and measured 10Be concentrations of 42 samples for this thesis and present my preliminary results and interpretation here. Exposure ages from Peekamoose Mt. in southern NY suggest ice thinning early in the deglacial period (~19.5 – 17.5 ka), near the onset of the Heinrich Stadial I cold period. Samples from Franconia Notch, NH, and Mt. Mansfield, VT, suggest ice thinning from approximately 15 – 13 ka in northern New England, roughly coincident with the Bølling-Allerød warm period. Exposure ages from each of the northern New England dipsticks are nearly identical within 1σ internal uncertainty, indicating that ice thinning was rapid. Higher elevation (>1200 m a.s.l.) samples from the northern New England mountains appear to contain inherited 10Be from previous periods of exposure, indicating a lack of glacial erosion on these surfaces. My high-elevation samples with inherited 10Be suggest that these summit landscapes were preserved beneath cold-based, non-erosive ice during the last glacial and deglacial periods. 40 samples that have yet to be processed will provide more information on ice thinning around Killington Mt., VT, Mt. Greylock, MA, Mt. Bigelow, ME, and Mt. Jacques-Cartier, Quebec. Ultimately, this information will be used to create probabilistic reconstructions of the lowering southeastern Laurentide ice surface during its retreat. / Thesis (MS) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22421号 / 工博第4682号 / 新制||工||1731(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 大津 宏康, 教授 三村 衛, 准教授 PIPATPONGSA Thirapong / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

It is important to understand the processes that regulate phosphorus (P) fluxes to coastal environments, because P is an important nutrient in coastal ecosystems. Phosphorus adsorbs to the surface of minerals in sediment and bedrock, and an influx of seawater can cause some of that P to desorb, raising the P concentration of ambient water. Although seawater-induced P desorption is thought to be an important source of P to coastal environments, the chemical reactions that underlie it have not been established. Previous work provides some relevant surface reactions and associated affinity constants between various aqueous P species and the surface of calcite and in dilute calcium carbonate-P solutions. However, these reactions with their respective affinity constants from the literature fail to predict the behavior of P with calcite in seawater. In this study, we conducted a series of batch experiments involving both adsorption and desorption of P in seawater, freshwater, dilute seawater, and mixtures of seawater and freshwater. We used these results in the geochemical model PHREEQC and the parameter estimation model PEST to optimize the affinity constants for the existing surface reactions. We found that after making minor adjustments to the affinity constants, the existing surface complexation models of calcite surface reactions from the published literature are sufficient to explain seawater-induced P desorption. Specifically, our results suggest that CaPO4- and either CaHPO40 or HPO42- may be important species in the P adsorption/desorption reactions in freshwater-seawater mixing.