Scenario planning is a technique used to inform decision-making under uncertainty, and is increasingly applied in the field of climate change adaptation and policy. This paper describes applications that combine previously distinct scenario methods in new and innovative ways. It draws on numerous recent independent case studies to illustrate emerging practices, such as far stronger connections between researcher-driven and participatory approaches and cycling between exploratory and normative perspectives. The paper concludes with a call for greater support for, and collaboration among, practitioners with the argument that mixed methods are most effective for decision-making in the context of climate change challenges.

<p> Tropical precipitation is linked through the moist static energy (MSE) budget to the global distribution of sea surface temperatures (SSTs), and large deviations from the present-day SST distribution have been inferred for past climates and projected for global warming. We use idealized SST perturbation experiments in multiple atmospheric general circulation models (AGCMs) to examine the hydrologic and energetic responses in the zonal mean and in the African Sahel to SST perturbations. We also use observational data to assess the prospects for emergent constraints on future rainfall in the Sahel. </p><p> The tropical zonal mean anomalous MSE fluxes in the NOAA Geophysical Fluid Dynamics Laboratory (GFDL) AM2.1 AGCM due to SST anomalies caused by either historical greenhouse gas or aerosol forcing primarily occur through the time-mean, zonal mean (Hadley) circulation. Away from the Intertropical Convergence Zone (ITCZ), this largely stems from altered efficiency of the Hadley circulation energy transport, i.e. the gross moist stability (GMS). A thermodynamic scaling-based estimate that relates GMS change to the local climatological moisture and temperature change relative to the ITCZ captures most of the qualitative GMS responses. It also yields a heuristic explanation for the well known correlation between low-latitude MSE fluxes and the ITCZ latitude. </p><p> Severe Sahelian drying with uniform SST warming in AM2.1 is eliminated when the default convective parameterization is replaced with an alternate. The drying is commensurate with MSE convergence due to suppressed ascent balanced by MSE divergence due to increased dry advection from the Sahara. These qualitative energetic responses to uniform warming are shared by five other GFDL models and ten CMIP5 models, although they do not translate into quantitative predictors of the Sahel rainfall response. Climatological values and interannual variability in observations and reanalyses suggest that drying in AM2.1 is exacerbated by an overly top-heavy ascent profile and positive feedbacks through cloud radiative properties. Simulations with patterned SST anomalies suggest a major role for mean SST variations in discrepancies among models and potentially in observed decadal variations of Sahelian precipitation.</p>

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2016. / The diaries of Jan van Riebeeck contains one of the oldest documentary records of weather phenomena for the southwestern Cape. They contain descriptions of daily wind direction and strength and daily rainfall events. The primary aim of this research is to reconstruct a comprehensive weather chronology for the southwestern Cape region from these diaries, spanning the period 1652-1665, and place this in context with the 20th-21st C climate for the region. The study further aims to examine the relationships between the 17th C society and natural environment. All climate and environmental information is extracted from the diaries and tabulated. Qualitative information on wind and rain was classified and transformed into quantitative data. Contemporary data retrieved from the Royal Observatory and the South African Weather Services are used to make comparisons between the historical study period and contemporary conditions. However, due to the qualitative nature of the historical data, statistical analysis demonstrated that such comparisons are limited. Within the historical period, analysis of the number of rain days demonstrated a distinct wet period in the first half followed by progressive drying. Wind data from the diaries reflected distinct seasonality linked to shifts in the position of the ITCZ. Additionally, unusual events including snow, hail, the Black south-easterly and ‘dirty rain’ are explored. Qualitative data revealed a heavy reliance on climate to support crops and livestock, and a range of environmental stresses to human health, infrastructure and food security. / LG2017

The summer rainfall region of South Africa is dominated by convective thunderstorm development from October to March. The result is that lightning is a common event over most of the country during this time. The South African Weather Service (SAWS) installed a stateof- the-art Lightning Detection Network (LDN) in late 2005 in order to accurately monitor lightning across South Africa. Data from this network for 2006 was utilised in order to develop an initial climatology of lightning in South Africa. Analyses were performed of lightning ground flash density, flash median peak current and flash multiplicity on a 0.2° grid across South Africa. The highest ground flash density values were found along the eastern escarpment of the country, extending onto the high interior plateau. There is a general decrease in flash density from east to west, with almost no lightning recorded on the west coast of the country. The regions of highest flash density recorded the highest percentages of negative polarity lightning. The percentage of positive lightning was higher in the winter months, as was the median peak current of lightning of both polarities. The median peak current distribution displayed distinct bands of current values oriented in northwest to southeast bands across the country. The bands of higher median peak current correspond to the regions to the rear of the interior trough axis in areas dominated by stratiform cloud development and were more dominant in the mid summer months. The highest flash multiplicity was recorded in the regions of highest flash density. Along the southern escarpment, on the eastern side of South Africa, flash multiplicity values exceeded 3 flashes per square kilometer. The highest flash multiplicity of negative polarity lightning was recorded in the spring and early summer. Throughout the year, the percentage of single stroke flashes for positive lightning is high. Topography and the position of the surface trough have a very strong influence on the ground flash density and median peak current distributions, but not on the flash multiplicity distribution. The results from the analyses of the three lightning variables were then combined to determine risk indexes of high intensity lightning and of positive polarity lightning. The eastern part of South Africa is at extreme risk from both large amounts of lightning and from positive polarity lightning, whereas the regions in the northwest of the country that are dominated by mining are at extreme risk from mainly positive polarity lightning.

Thesis advisor: Corinne I. Wong / The South American Monsoon System is the dominant convective system over tropical South America during austral summer that is critical to a region heavily dependent on agricultural and hydroelectric production. An understanding of the controls on moisture conditions throughout Brazil is critical to assessing recurrent droughts and global climate change responses. An increasing number of monsoon reconstructions from δ¹⁸O records provide insight into last millennium variation of regional monsoon intensity. However, the relationship between past variations in monsoon intensity and local moisture conditions has yet to be investigated. In this study, we develop speleothem ⁸⁷Sr/⁸⁶Sr values as a paleo-moisture proxy from a cave site located in central Brazil. Increasing speleothem ⁸⁷Sr/⁸⁶Sr values and decreasing δ²³⁴U values over the last millennium indicate progressively wetter conditions. A similar trend in monsoon intensity is not evident in δ¹⁸O records from the region, suggesting that monsoon intensity is decoupled from the local moisture conditions through the late Holocene. The potential decoupling between the monsoon and local moisture conditions suggests that processes independent from those governing monsoon intensity may play a critical role in dictating moisture variability in the region. / Thesis (MS) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

<p> Climate change has the potential to expose sea turtle nests to higher temperatures, which may negatively impact sea turtle hatchling vigor. In this study, loggerhead and green hatchlings were sampled from the Boca Raton, Florida beach and via lab incubation, and hatchling vigor was determined. Elevated nest temperatures decreased loggerhead and green turtle hatchling performance and corticosterone levels, with the most significant effects found in hatchlings exposed to maximum incubation temperatures above 35 &deg;C during late development. Lab-incubated loggerhead post-hatchling corticosterone levels and growth rates were also determined. The differences seen in corticosterone levels with overall nest incubation temperatures, mean temperatures during early, middle or late stages of development, and its negative correlation with hatchling performance improves our understanding of the underlying physiological mechanisms linking elevated incubation temperatures and sub-lethal physiological effects that may significantly impact hatchling survival, a critical step for sea turtle conservation in south Florida and elsewhere.</p><p>

Thesis. 1978. M.Arch.--Massachusetts Institute of Technology. Dept. of Architecture. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: leaves 182-186. / M.Arch.

University of Technology, Sydney. Faculty of Engineering. / 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.

No description available.

A procedure for model-assisted climate impact assessment is developed. The approach combines data from observations and atmospheric general circulation models (GCNs), and provides the basis for a potentially valuable means of using information derived from GCMs for climate impact assessments on local scales. The first component of this procedure is an extension of the 'climate inverse' method of Kim al. (1984). Daily mesoscale temperature and precipitation values are stochastically specifed on the basis of observational data representing the average over an area corresponding to a GCN grid element. Synthetic local data sets generated in this manner resemble the corresponding observations with respect to various spatial and temporal statistical measures. A method for extrapolation to grid-scale 'scenarios' of a changed climate on the basis of control and experimental integrations of a GCM, in conjunction with observational data, is also presented. The statistical characteristics of daily time series from each of these data sources are portrayed in terms of the parameters of a multivariate time-domain stochastic model. Significant differences between the model data sets are applied to the corresponding parameters derived from the observations, and synthetic data Bets representing the inferred changed climate are generated using Monte-Carlo simulations. The use of the procedure is illustrated in a case study. The potential climatic impacts of a doubling of atmospheric carbon dioxide concentrations on three important North American grain cropping regions is investigated using two 'physiological' crop models. Although the specific results must be interpreted with caution, they are moderately optimistic and demonstrate possible means by which agricultural production may adapt to climatic changes. / Graduation date: 1987