Response of Eastern Arabian Sea to Extreme climatic Events with Special Reference to Selected Pelagic Fishes

The thesis attempts to study the changes in oceanographic parameters associated with extreme climatic events,the influence of oceanographic as well as meteorological parameters on fishes.The characteristics of major pelagic fishes of southwest coast of India(Oil sardine and Indian mackerel) have been described here.A description on study area and period of study is also described .The impact of extreme climatic events on the oceanographic variability of Eastern Arabian Sea.The extreme climatic event,the Indian Ocean Dipole associated with EI Nino Southern Oscillation is taken into consideration.The variability in oil sardine and mackerel landings of southwest coast of India during the study period.The trend analysis of the landings has been done and also a prediction model is applied for the landings.The influence of environmental parameters on oil sardine as well as mackerel fishery has been explained .With regression analysis ,the significant relation between environmental parameters and fish landings are also been recognized.The prediction of landings is done with these environmental parameters.

Extreme climatic events: impacts of drought and high temperature on physiological processes in agronomically important plants

Climate models predict more frequent and more severe extreme events (e.g., heat waves, extended drought periods, flooding) in many regions for the next decades. The impact of adverse environmental conditions on crop plants is ecologically and economically relevant. This review is focused on drought and heat effects on physiological status and productivity of agronomically important plants. Stomatal opening represents an important regulatory mechanism during drought and heat stress since it influences simultaneously water loss via transpiration and CO2 diffusion into the leaf apoplast which further is utilized in photosynthesis. Along with the reversible short-term control of stomatal opening, stomata and leaf epidermis may produce waxy deposits and irreversibly down-regulate the stomatal conductance and non-stomatal transpiration. As a consequence photosynthesis will be negatively affected. Rubisco activase—a key enzyme in keeping the Calvin cycle functional—is heat-sensitive and may become a limiting factor at elevated temperature. The accumulated reactive oxygen species (ROS) during stress represent an additional challenge under unfavorable conditions. Drought and heat cause accumulation of free amino acids which are partially converted into compatible solutes such as proline. This is accompanied by lower rates of both nitrate reduction and de novo amino acid biosynthesis. Protective proteins (e.g., dehydrins, chaperones, antioxidant enzymes or the key enzyme for proline biosynthesis) play an important role in leaves and may be present at higher levels under water deprivation or high temperatures. On the whole plant level, effects on long-distance translocation of solutes via xylem and phloem and on leaf senescence (e.g., anticipated, accelerated or delayed senescence) are important. The factors mentioned above are relevant for the overall performance of crops under drought and heat and must be considered for genotype selection and breeding programs.

Missing Rings in Pinus halepensis – The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events

Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees to adverse environmental conditions. The demonstrated relationship of MR formation to ECE across this dendrochronological network in the Mediterranean basin shows the potential of MR analysis to reconstruct the history of past climatic extremes and to predict future forest dynamics in a changing climate.

Extreme pointer years in tree-ring records of central Spain as evidence of climatic events and the eruption of the Huaynaputina Volcano (Peru, 1600 AD)

The study of pointer years of numerous tree-ring chronologies of the central Iberian Peninsula (Sierra de Guadarrama) could provide complementary information about climate variability over the last 405 yr. In total, 64 pointer years have been identified: 30 negative (representing minimum growths) and 34 positive (representing maximum growths), the most significant of these being 1601, 1963 and 1996 for the negative ones, and 1734 and 1737 for the positive ones. Given that summer precipitation was found to be the most limiting factor for the growth of Pinus in the Sierra de Guadarrama in the second half of the 20th century, it is also an explanatory factor in almost 50% of the extreme growths. Furthermore, these pointer years and intervals are not evenly distributed throughout time. Both in the first half of the 17th and in the second half of 20th, they were more frequent and more extreme and these periods are the most notable for the frequency of negative pointer years in Central Spain. The interval 1600–1602 is of special significance, being one of the most unfavourable for tree growth in the centre of Spain, with 1601 representing the minimum index in the regional chronology. We infer that this special minimum annual increase was the effect of the eruption of Huaynaputina, which occurred in Peru at the beginning of 1600 AD. This is the first time that the effects of this eruption in the tree-ring records of Southern Europe have been demonstrated.

Attribution of extreme weather events in Africa: A preliminary exploration of the science and policy implications

At the most recent session of the Conference of the Parties (COP19) in Warsaw (November 2013) the Warsaw international mechanism for loss and damage associated with climate change impacts was established under the United Nations Framework Convention on Climate Change (UNFCCC). The mechanism aims at promoting the implementation of approaches to address loss and damage associated with the adverse effects of climate change. Specifically, it aims to enhance understanding of risk management approaches to address loss and damage. Understanding risks associated with impacts due to highly predictable (slow onset) events like sea-level rise is relatively straightforward whereas assessing the effects of climate change on extreme weather events and their impacts is much more difficult. However, extreme weather events are a significant cause of loss of life and livelihoods, particularly in vulnerable countries and communities in Africa. The emerging science of probabilistic event attribution is relevant as it provides scientific evidence on the contribution of anthropogenic climate change to changes in risk of extreme events. It thus provides the opportunity to explore scientifically-backed assessments of the human influence on such events. However, different ways of framing attribution questions can lead to very different assessments of change in risk. Here we explain the methods of, and implications of different approaches to attributing extreme weather events with a focus on Africa. Crucially, it demonstrates that defining the most appropriate attribution question to ask is not a science decision but needs to be made in dialogue with those stakeholders who will use the answers.

Building up resilience of construction sector SMEs and their supply chains to extreme weather events

Wider scientific community now accept that the threat of climate change as real and thus acknowledge the importance of implementing adaptation measures in a global context. In the UK , the physical effects of climate change are likely to be directly felt in the form of extreme weather events, which are predicted to escalate in number and severity in future under the changing climatic conditions. Construction industry; which consists of supply chains running across various other industries, economies and regions, will also be affected due to these events. Thus, it is important that the construction organisations are well prepared to withstand the effects of extreme weather events not only directly affecting their organisations but also affecting their supply chains which in turn might affect the organisation concerned. Given the fact that more than 99% of construction sector businesses are SMEs, the area can benefit significantly from policy making to improve SME resilience and coping capacity. This paper presents the literature review and synthesis of a doctoral research study undertaken to address the issue of extreme weather resilience of construction sector SMEs and their supply chains. The main contribution of the paper to both academia and practitioners is a synthesis model that conceptualises the factors that enhances resilience of SMEs and their supply chains against extreme weather events. This synthesis model forms the basis of a decision making framework that will enable SMEs to both reduce their vulnerability and enhance their coping capacity against extreme weather. The value of this paper is further extended by the overall research design that is set forth as the way forward.

Long-term Trends in Magnitude and Frequency of Extreme Rainfall Events in Florida

This study computed trends in extreme precipitation events of Florida for 1950-2010. Hourly aggregated rainfall data from 24 stations of the National Climatic Data Centre were analyzed to derive time-series of extreme rainfalls for 12 durations, ranging from 1 hour to 7 day. Non-parametric Mann-Kendall test and Theil-Sen Approach were applied to detect the significance of trends in annual maximum rainfalls, number of above threshold events and average magnitude of above threshold events for four common analysis periods. Trend Free Pre-Whitening (TFPW) approach was applied to remove the serial correlations and bootstrap resampling approach was used to detect the field significance of trends. The results for annual maximum rainfall revealed dominant increasing trends at the statistical significance level of 0.10, especially for hourly events in longer period and daily events in recent period. The number of above threshold events exhibited strong decreasing trends for hourly durations in all time periods.

Living through extreme weather events and natural disasters: How resilient are our high-rise high-density typologies?

The inner city Brisbane suburbs of the West End peninsula are poised for redevelopment. Located within walking distance to CBD workplaces, home to Queensland’s highest value cultural precinct, and high quality riverside parklands, there is currently a once-in-a-lifetime opportunity to redevelop parts of the suburb to create a truly urban neighbourhood. According to a local community association, local residents agree and embrace the concept of high-density living, but are opposed to the high-rise urban form (12 storeys) advocated by the City’s planning authority (BCC, 2011) and would prefer to see medium-rise (5-8 storeys) medium-density built form. Brisbane experienced a major flood event which inundated the peninsula suburbs of West End in summer January 2011. The vulnerability of taller buildings to the vagaries of climate and more extreme weather events and their reliance on main electricity was exposed when power outages immediately before, during and after the flood disaster seriously limited occupants’ access and egress when elevators were disabled. Not all buildings were flooded but dwellings quickly became unliveable due to disabled air-conditioning. Some tall buildings remained uninhabitable for several weeks after the event. This paper describes an innovative design research method applied to the complex problem of resilient, sustainable neighbourhood form in subtropical cities, in which a thorough comparative analysis of a range of multiple-dwelling types has revealed the impact that government policy regarding design of the physical environment has on a community’s resilience. The outcomes advocate the role of climate-responsive design in averting the rising human capital and financial costs of natural disasters and climate change.

Managing health risks of extreme weather events : need for a systematic approach

The Climate Commission recently outlined the trend of major extreme weather events in different regions of Australia, including heatwaves, floods, droughts, bushfires, cyclones and storms. These events already impose an enormous health and financial burden onto society and are projected to occur more frequently and intensely. Unless we act now, further financial losses and increasing health burdens seem inevitable. We seek to highlight the major areas for interdisciplinary investigation, identify barriers and formulate response strategies.

Turning up the Heat on Admissions: A Study of the Impacts of Extreme Heat Events on Tasmanian Hospital Admissions 2003-2010

Introduction: Extreme heat events (both heat waves and extremely hot days) are increasing in frequency and duration globally and cause more deaths in Australia than any other extreme weather event. Numerous studies have demonstrated a link between extreme heat events and an increased risk of morbidity and death. In this study, the researchers sought to identify if extreme heat events in the Tasmanian population were associated with any changes in emergency department admissions to the Royal Hobart Hospital (RHH) for the period 2003-2010. Methods: Non-identifiable RHH emergency department data and climate data from the Australian Bureau of Meteorology were obtained for the period 2003-2010. Statistical analyses were conducted using the computer statistical computer software ‘R’ with a distributed lag non-linear model (DLNM) package used to fit a quassi-Poisson generalised linear regression model. Results: This study showed that RR of admission to RHH during 2003-2010 was significant over temperatures of 24 C with a lag effect lasting 12 days and main effect noted one day after the extreme heat event. Discussion: This study demonstrated that extreme heat events have a significant impact on public hospital admissions. Two limitations were identified: admissions data rather than presentations data were used and further analysis could be done to compare types of admissions and presentations between heat and non-heat events. Conclusion: With the impacts of climate change already being felt in Australia, public health organisations in Tasmania and the rest of Australia need to implement adaptation strategies to enhance resilience to protect the public from the adverse health effects of heat events and climate change.