Probabilistic-based hurricane risk assessment and mitigation considering the potential impacts of climate change

Studies are suggesting that hurricane hazard patterns (e.g. intensity and frequency) may change as a consequence of the changing global climate. As hurricane patterns change, it can be expected that hurricane damage risks and costs may change as a result. This indicates the necessity to develop hurricane risk assessment models that are capable of accounting for changing hurricane hazard patterns, and develop hurricane mitigation and climatic adaptation strategies. This thesis proposes a comprehensive hurricane risk assessment and mitigation strategies that account for a changing global climate and that has the ability of being adapted to various types of infrastructure including residential buildings and power distribution poles. The framework includes hurricane wind field models, hurricane surge height models and hurricane vulnerability models to estimate damage risks due to hurricane wind speed, hurricane frequency, and hurricane-induced storm surge and accounts for the timedependant properties of these parameters as a result of climate change. The research then implements median insured house values, discount rates, housing inventory, etc. to estimate hurricane damage costs to residential construction. The framework was also adapted to timber distribution poles to assess the impacts climate change may have on timber distribution pole failure. This research finds that climate change may have a significant impact on the hurricane damage risks and damage costs of residential construction and timber distribution poles. In an effort to reduce damage costs, this research develops mitigation/adaptation strategies for residential construction and timber distribution poles. The costeffectiveness of these adaptation/mitigation strategies are evaluated through the use of a Life-Cycle Cost (LCC) analysis. In addition, a scenario-based analysis of mitigation strategies for timber distribution poles is included. For both residential construction and timber distribution poles, adaptation/mitigation measures were found to reduce damage costs. Finally, the research develops the Coastal Community Social Vulnerability Index (CCSVI) to include the social vulnerability of a region to hurricane hazards within this hurricane risk assessment. This index quantifies the social vulnerability of a region, by combining various social characteristics of a region with time-dependant parameters of hurricanes (i.e. hurricane wind and hurricane-induced storm surge). Climate change was found to have an impact on the CCSVI (i.e. climate change may have an impact on the social vulnerability of hurricane-prone regions).

Nitrogen Oxides in the North Atlantic Troposphere: Impacts of Boreal Wildfire and Anthropogenic Emissions

Nitrogen oxides play a crucial role in the budget of tropospheric ozone (O sub(3)) and the formation of the hydroxyl radical. Anthropogenic activities and boreal wildfires are large sources of emissions in the atmosphere. However, the influence of the transport of these emissions on nitrogen oxides and O sub(3) levels at hemispheric scales is not well understood, in particular due to a lack of nitrogen oxides measurements in remote regions. In order to address these deficiencies, measurements of NO, NO sub(2) and NO sub(y) (total reactive nitrogen oxides) were made in the lower free troposphere (FT) over the central North Atlantic region (Pico Mountain station, 38 degree N 28 degree W, 2.3 km asl) from July 2002 to August 2005. These measurements reveal a well-defined seasonal cycle of nitrogen oxides (NO sub(x) = NO+NO sub(2) and NO sub(y)) in the background central North Atlantic lower FT, with higher mixing ratios during the summertime. Observed NO sub(x) and NO sub(y) levels are consistent with long-range transport of emissions, but with significant removal en-route to the measurement site. Reactive nitrogen largely exists in the form of PAN and HNO sub(3) ( similar to 80-90% of NO sub(y)) all year round. A shift in the composition of NO sub(y) from dominance of PAN to dominance of HNO sub(3) occurs from winter-spring to summer-fall, as a result of changes in temperature and photochemistry over the region. Analysis of the long-range transport of boreal wildfire emissions on nitrogen oxides provides evidence of the very large-scale impacts of boreal wildfires on the tropospheric NO sub(x) and O sub(3) budgets. Boreal wildfire emissions are responsible for significant shifts in the nitrogen oxides distributions toward higher levels during the summer, with medians of NO sub(y) (117-175 pptv) and NO sub(x) (9-30 pptv) greater in the presence of boreal wildfire emissions. Extreme levels of NO sub(x) (up to 150 pptv) and NO sub(y) (up to 1100 pptv) observed in boreal wildfire plumes suggest that decomposition of PAN to NO sub(x) is a significant source of NO sub(x), and imply that O sub(3) formation occurs during transport. Ozone levels are also significantly enhanced in boreal wildfire plumes. However, a complex behavior of O sub(3) is observed in the plumes, which varies from significant to lower O sub(3) production to O sub(3) destruction. Long-range transport of anthropogenic emissions from North America also has a significant influence on the regional NO sub(x) and O sub(3) budgets. Transport of pollution from North America causes significant enhancements on nitrogen oxides year-round. Enhancements of CO, NO sub(y) and NO sub(x) indicate that, consistent with previous studies, more than 95% of the NO sub(x) emitted over the U.S. is removed before and during export out of the U.S. boundary layer. However, about 30% of the NO sub(x) emissions exported out of the U.S. boundary layer remain in the airmasses. Since the lifetime of NO sub(x) is shorter than the transport timescale, PAN decomposition and potentially photolysis of HNO sub(3) provide a supply of NO sub(x) over the central North Atlantic lower FT. Observed Delta O sub(3)/ Delta NO sub(y) and large NO sub(y) levels remaining in the North American plumes suggest potential O sub(3) formation well downwind from North America. Finally, a comparison of the nitrogen oxides measurements with results from the global chemical transport (GCT) model GEOS-Chem identifies differences between the observations and the model. GEOS-Chem reproduces the seasonal variation of nitrogen oxides over the central North Atlantic lower FT, but does not capture the magnitude of the cycles. Improvements in our understanding of nitrogen oxides chemistry in the remote FT and emission sources are necessary for the current GCT models to adequately estimate the impacts of emissions on tropospheric NO sub(x) and the resulting impacts on the O sub(3) budget.

IMPACTS OF CLIMATE CHANGE ON SOIL MICROORGANISMS IN NORTHERN HARDWOOD FORESTS

As global climate continues to change, it becomes more important to understand possible feedbacks from soils to the climate system. This dissertation focuses on soil microbial community responses to climate change factors in northern hardwood forests. Two soil warming experiments at Harvard Forest in Massachusetts, and a climate change manipulation experiment with both elevated temperature and increased moisture inputs in Michigan were sampled. The hyphal in-growth bag method was to understand how soil fungal biomass and respiration respond to climate change factors. Our results from phospholipid fatty acid (PLFA) analyses suggest that the hyphal in-growth bag method allows relatively pure samples of fungal hyphae to be partitioned from bacteria in the soil. The contribution of fungal hyphal respiration to soil respiration was examined in climate change manipulation experiments in Massachusetts and Michigan. The Harvard Forest soil warming experiments in Massachusetts are long-term studies with 8 and 18 years of +5 °C warming treatment. Hyphal respiration and biomass production tended to decrease with soil warming at Harvard Forest. This suggests that fungal hyphae adjust to higher temperatures by decreasing the amount of carbon respired and the amount of carbon stored in biomass. The Ford Forestry Center experiment in Michigan has a 2 x 2 fully factorial design with warming (+4-5 °C) and moisture addition (+30% average ambient growing season precipitation). This experiment was used to examine hyphal growth and respiration of arbuscular mycorrhizal fungi (AMF), soil enzymatic capacity, microbial biomass and microbial community structure in the soil over two years of experimental treatment. Results from the hyphal in-growth bag study indicate that AMF hyphal growth and respiration respond negatively to drought. Soil enzyme activities tend to be higher in heated versus unheated soils. There were significant temporal variations in enzyme activity and microbial biomass estimates. When microbial biomass was estimated using chloroform fumigation extractions there were no differences between experimental treatments and the control. When PLFA analyses were used to estimate microbial biomass we found that biomass responds negatively to higher temperatures and positively to moisture addition. This pattern was present for both bacteria and fungi. More information on the quality and composition of the organic matter and nutrients in soils from climate change manipulation experiments will allow us to gain a more thorough understanding of the mechanisms driving the patterns reported here. The information presented here will improve current soil carbon and nitrogen cycling models.

Ecosystem impacts of feral rabbits on World Heritage sub-Antarctic Macquarie Island: A palaeoecological perspective

The introduction and establishment of non-indigenous species through human activities often poses a major threat to natural biodiversity. In many parts of the world management efforts are therefore focused on their eradication. The environment of World Heritage sub-Antarctic Macquarie Island has been severely damaged by non-indigenous species including rabbits, rats and mice, introduced from the late AD 1800s. An extensive eradication programme is now underway which aims to remove all rabbits and rodents. To provide a long-term context for assessing the Island's pre-invasion state, invasion impacts, and to provide a baseline for monitoring its recovery, we undertook a palaeoecological study using proxies in a lake sediment core. Sedimentological and diatom analyses revealed an unproductive catchment and lake environment persisted for ca. 7100 years prior to the introduction of the invasive species. After ca. AD 1898, unprecedented and statistically significant environmental changes occurred. Lake sediment accumulation rates increased >100 times due to enhanced catchment inputs and within-lake production. Total carbon and total nitrogen contents of the sediments increased by a factor of four. The diatom flora became dominated by two previously rare species. The results strongly suggest a causal link between the anthropogenic introduction of rabbits and the changes identified in the lake sediments. This study provides an example of how palaeoecology may be used to determine baseline conditions prior to the introduction of non-indigenous species, quantify the timing and extent of changes, and help monitor the recovery of the ecosystem and natural biodiversity following successful non-indigenous species eradication programmes.

Linking Ah receptor mediated effects of sediments and impacts on fish to key pollutants in the Yangtze Three Gorges Reservoir, China – A comprehensive perspective

The Three Gorges Reservoir (TGR), created in consequence of the Yangtze River's impoundment by the Three Gorges Dam, faces numerous anthropogenic impacts that challenge its unique ecosystem. Organic pollutants, particularly aryl hydrocarbon receptor (AhR) agonists, have been widely detected in the Yangtze River, but only little research was yet done on AhR-mediated activities. Hence, in order to assess effects of organic pollution, with particular focus on AhR-mediated activities, several sites in the TGR area were examined applying the "triad approach". It combines chemical analysis, in vitro, in vivo and in situ investigations to a holistic assessment. Sediments and the benthic fish species Pelteobagrus vachellii were sampled in 2011/2012, respectively, to identify relevant endpoints. Sediment was tested in vitro with the ethoxyresorufin-O-deethylase (EROD) induction assay, and in vivo with the Fish Embryo Toxicity Test and Sediment Contact Assay with Danio rerio. Activities of phase I (EROD) and phase II (glutathione-S-transferase) biotransformation enzymes, pollutant metabolites and histopathological alterations were studied in situ in P. vachellii. EROD induction was tested in vitro and in situ to evaluate possible relationships. Two sites, near Chongqing and Kaixian city, were identified as regional hot-spots and further investigated in 2013. The sediments induced in the in vitro/in vivo bioassays AhR-mediated activities and embryotoxic/teratogenic effects - particularly on the cardiovascular system. These endpoints could be significantly correlated to each other and respective chemical data. However, particle-bound pollutants showed only low bioavailability. The in situ investigations suggested a rather poor condition of P. vachellii, with histopathological alterations in liver and excretory kidney. Fish from Chongqing city exhibited significant hepatic EROD induction and obvious parasitic infestations. The polycyclic aromatic hydrocarbon (PAH) metabolite 1-hydroxypyrene was detected in bile of fish from all sites. All endpoints in combination with the chemical data suggest a pivotal role of PAHs in the observed ecotoxicological impacts.

Assessing perceptions of environmental risk and environmental justice and their impacts on neighborhood attachment in a predominately Hispanic community

This study examines and relates concepts from environmental risk perception and environmental justice and focuses on the perception of environmental problems, their consequent health risks and their impact on neighborhood attachment in a predominately Hispanic community along the U.S.-Mexico border. The findings indicate that the perception of environmental problems in the immediate area varies by problem and demographic subgroup. Ethnicity and income have the highest number of statistically significant associations across ten environmental problems. This result lies in the fact that Hispanics in El Paso County and those with low annual incomes live in neighborhoods that are faced with more severe environmental problems. Thus the findings lend support to the environmental justice claim that the poor and minorities bear the brunt of environmental degradation. ^ The findings also provide evidence that public perception of health risks from an environmental problem is influenced by the perceived severity of an environmental problem in the immediate area. Those who believe the problem is serious on a local level are the ones who are most likely to believe that they could become ill or injured from that problem and that the illness/injury will be serious. ^ The findings of this study also indicate that the young, Hispanics, those who perceive considerable environmental problems in their neighborhood, those who believe that their neighborhood has more environmental problems than others, and those who are angry about those problems are most likely to want to move from their neighborhood. ^ Efforts need to be made to enact policies and programs designed to reduce the environmental hazards in disadvantaged Hispanic communities along the U.S.-Mexico border. Future environmental education campaigns need to complement community-based projects with the media. Programs that involve and empower the community, particularly the youth, in improving the neighborhood could provide a sense of control and pride within their community in solving these problems. These neighborhood improvement efforts could also lead to the development and strengthening of social ties within the community, as well as enhanced community cohesiveness in tackling these problems. ^

A comprehensive review of the environmental impacts and human health risks associated with the occurrence of waste pharmaceuticals in water sources of the United States, and policy implications

The occurrence of waste pharmaceuticals has been identified and well documented in water sources throughout North America and Europe. Many studies have been conducted which identify the occurrence of various pharmaceutical compounds in these waters. This project is an extensive review of the documented evidence of this occurrence published in the scientific literature. This review was performed to determine if this occurrence has a significant impact on the environment and public health. This project and review found that pharmaceuticals such as sex hormone drugs, antibiotic drugs and antineoplastic/cytostatic agents as well as their metabolites have been found to occur in water sources throughout the United States at levels high enough to have noticeable impacts on human health and the environment. It was determined that the primary sources of this occurrence of pharmaceuticals were waste water effluent and solid wastes from sewage treatment plants, pharmaceutical manufacturing plants, healthcare and biomedical research facilities, as well as runoff from veterinary medicine applications (including aquaculture). ^ In addition, current public policies of US governmental agencies such as the Environmental Protection Agency (EPA), Food and Drug Administration (FDA), and Drug Enforcement Agency (DEA) have been evaluated to see if they are doing a sufficient job at controlling this issue. Specific recommendations for developing these EPA, FDA, and DEA policies have been made to mitigate, prevent, or eliminate this issue.^ Other possible interventions such as implementing engineering controls were also evaluated in order to mitigate, prevent and eliminate this issue. These engineering controls include implementing improved current treatment technologies such as the advancement and improvement of waste water treatment processes utilized by conventional sewage treatment and pharmaceutical manufacturing plants. In addition, administrative controls such as the use of “green chemistry” in drug synthesis and design were also explored and evaluated as possible alternatives to mitigate, prevent, or eliminate this issue. Specific recommendations for incorporating these engineering and administrative controls into the applicable EPA, FDA, and DEA policies have also been made.^

Ocean acidification impacts on sperm mitochondrial membrane potential bring sperm swimming behaviour near its tipping point

Broadcast spawning marine invertebrates are susceptible to environmental stressors such as climate change, as their reproduction depends on the successful meeting and fertilization of gametes in the water column. Under near-future scenarios of ocean acidification, the swimming behaviour of marine invertebrate sperm is altered. We tested whether this was due to changes in sperm mitochondrial activity by investigating the effects of ocean acidification on sperm metabolism and swimming behaviour in the sea urchin Centrostephanus rodgersii. We used a fluorescent molecular probe (JC-1) and flow cytometry to visualize mitochondrial activity (measured as change in mitochondrial membrane potential, MMP). Sperm MMP was significantly reduced in delta pH -0.3 (35% reduction) and delta pH -0.5 (48% reduction) treatments, whereas sperm swimming behaviour was less sensitive with only slight changes (up to 11% decrease) observed overall. There was significant inter-individual variability in responses of sperm swimming behaviour and MMP to acidified seawater. We suggest it is likely that sperm exposed to these changes in pH are close to their tipping point in terms of physiological tolerance to acidity. Importantly, substantial inter-individual variation in responses of sperm swimming to ocean acidification may increase the scope for selection of resilient phenotypes, which, if heritable, could provide a basis for adaptation to future ocean acidification.

Impacts of ocean acidification on sediment processes in shallow waters of the arctic ocean

Despite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO2 and usually have a lower buffering capacity than warmer waters, acidification rates in these areas are faster than those in sub-tropical regions. The present study investigates the effects of ocean acidification on sediment composition, processes and sediment-water fluxes in an Arctic coastal system. Undisturbed sediment cores, exempt of large dwelling organisms, were collected, incubated for a period of 14 days, and subject to a gradient of pCO2 covering the range of values projected for the end of the century. On five occasions during the experimental period, the sediment cores were isolated for flux measurements (oxygen, alkalinity, dissolved inorganic carbon, ammonium, nitrate, nitrite, phosphate and silicate). At the end of the experimental period, denitrification rates were measured and sediment samples were taken at several depth intervals for solid-phase analyses. Most of the parameters and processes (i.e. mineralization, denitrification) investigated showed no relationship with the overlying seawater pH, suggesting that ocean acidification will have limited impacts on the microbial activity and associated sediment-water fluxes on Arctic shelves, in the absence of active bio-irrigating organisms. Only following a pH decrease of 1 pH unit, not foreseen in the coming 300 years, significant enhancements of calcium carbonate dissolution and anammox rates were observed. Longer-term experiments on different sediment types are still required to confirm the limited impact of ocean acidification on shallow Arctic sediment processes as observed in this study.

Ramadan school holidays as a natural experiment : impacts of seasonality on school dropout in Bangladesh

In 2000, Ramadan school vacation coincided with the original annual exam period of December in Bangladesh. This forced schools to pre-pone their final exam schedules in November, which was the month before the harvest begins. 'Ramadan 2000' is a natural experiment that reduced the labor demand for children during the exam period. Using household level panel data of 2000 and 2003, and after controlling for various unobservable variations including individual fixed effects, aggregate year effects, and subdistrict-level year effects, this paper finds evidence of statistically significant impact of seasonal labor demand on school dropout in Bangladesh among the children from agricultural households.

Impacts of solar lanterns in geographically challenged locations : experimental evidence from Bangladesh

Despite continuous efforts to improve the coverage, the access to electricity remains insufficient in many developing countries, particularly in geographically challenged locations, due mostly to the high cost of grid extension. To rigorously investigate the effectiveness of solar products as an alternative in remote areas, we conducted a randomized controlled trial in river islands of northern Bangladesh where no grid-based electricity is available. We found that solar lanterns significantly increased home study hours among schooled children, especially in the night and before exams. School attendance rate also initially increases due to the provision of solar lamps, although such effects fade away over time. The increased study time and initial school attendance rate, however, did not improve children's exam results. We also found marginal improvements on health-related indicators, such as eye redness and irritation, but negligible impacts on respiratory indicators. Households that received solar lanterns substituted the traditional lighting sources with modern technology, leading to a significant decrease in annual biomass fuel consumptions, particularly kerosene. Finally, treated households showed a greater self-reported willingness to purchase solar products compared with the control group.

Efficiency and spatial equity impacts of high-speed rail extensions in urban areas

Urban areas benefit from significant improvements in accessibility when a new high speed rail (HSR) project is built. These improvements, which are due mainly to a rise in efficiency, produce locational advantagesand increase the attractiveness of these cities, thereby possibly enhancing their competitivenessand economic growth. However, there may be equity issues at stake, as the main accessibility benefits are primarily concentrated in urban areas with a HSR station, whereas other locations obtain only limited benefits. HSR extensions may contribute to an increase in spatial imbalance and lead to more polarized patterns of spatial development. Procedures for assessing the spatial impacts of HSR must therefore follow a twofold approach which addresses issues of both efficiency and equity. This analysis can be made by jointly assessing both the magnitude and distribution of the accessibility improvements deriving from a HSR project. This paper describes an assessment methodology for HSR projects which follows this twofold approach. The procedure uses spatial impact analysis techniques and is based on the computation of accessibility indicators, supported by a Geographical Information System (GIS). Efficiency impacts are assessed in terms of the improvements in accessibility resulting from the HSR project, with a focus on major urban areas; and spatial equity implications are derived from changes in the distribution of accessibility values among these urban agglomerations.

Implementation of a module for risk of ozone impacts assessment to vegetation in the integrated assessment modelling system for the Iberian peninsula. Evaluation for wheat and holm oak

A module to estimate risks of ozone damage to vegetation has been implemented in the Integrated Assessment Modelling system for the Iberian Peninsula. It was applied to compute three different indexes for wheat and Holm oak; daylight AOT40 (cumulative ozone concentration over 40 ppb), cumulative ozone exposure index according to the Directive 2008/50/EC (AOT40-D) and PODY (Phytotoxic Ozone Dose over a given threshold of Y nmol m−2 s−1). The use of these indexes led to remarkable differences in spatial patterns of relative ozone risks on vegetation. Ozone critical levels were exceeded in most of the modelling domain and soil moisture content was found to have a significant impact on the results. According to the outputs of the model, daylight AOT40 constitutes a more conservative index than the AOT40-D. Additionally, flux-based estimations indicate high risk areas in Portugal for both wheat and Holm oak that are not identified by AOT-based methods.

Impacts of the EU Biofuel Target on Agricultural Markets and Land Use - A Comparative Modelling Assessment

The Renewable Energy Directive (2009/28/EC) requires that 20% of the EU's energy needs should come from renewable sources by 2020, and includes a target for the transport sector of 10% from biofuels. This report analyses and discusses the global impacts of this biofuel target on agricultural production, markets and land use, as simulated by three agricultural sector models, AGLINK-COSIMO, ESIM and CAPRI. The impacts identified include higher EU production of ethanol and biodiesel, and of the crops used to produce them, as well as more imports of both biofuels. Trade flows of biofuel feedstocks also change to reflect greater EU demand, including a significant increase in vegetable oil imports. However, as the extra demand is small in world market terms, the impact on world market prices is limited. With the EU biofuel target, global use of land for crop cultivation is higher by 5.2 million hectares. About one quarter is area within the EU, some of which would otherwise have left agriculture.

Direct and indirect economic impacts of drought in the agri-food sector in the Ebro River basin (Spain).

The economic evaluation of drought impacts is essential in order to define efficient and sustainable management and mitigation strategies. The aim of this study is to evaluate the economic impacts of a drought event on the agricultural sector and measure how they are transmitted from primary production to industrial output and related employment. We fit econometric models to determine the magnitude of the economic loss attributable to water storage. The direct impacts of drought on agricultural productivity are measured through a direct attribution model. Indirect impacts on agricultural employment and the agri-food industry are evaluated through a nested indirect attribution model. The transmission of water scarcity effects from agricultural production to macroeconomic variables is measured through chained elasticities. The models allow for differentiating the impacts deriving from water scarcity from other sources of economic losses. Results show that the importance of drought impacts are less relevant at the macroeconomic level, but are more significant for those activities directly dependent on water abstractions and precipitation. From a management perspective, implications of these findings are important to develop effective mitigation strategies to reduce drought risk exposure.