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This work has contributed to the understanding of dominant runoff generation at the large catchment scale and to the understanding of the relationships between landscape properties and hydrological behaviour. The developed models were used to estimate the climate change impact on the hydrology in the study catchment. A multivariate geochemical tracer survey was carried out in North Esk catchment in north east Scotland. A generic typology was developed using multivariate statistical methods to characterise the hydrochemical tracer response. Upland headwater runoff was dominant downstream in winter and provided significant flows during base flow periods in summer. These insights were complemented by a conjunctive analysis of long-term river flow data and a one year stable isotope survey. Integrative metrics of transit times, hydrometric responses, and catchment characteristics were explored for relationships at the large catchment scale. The evaluation that the associated soils and bedrocks, themselves controlling the flow path distribution, have a strong influence on the integrated hydrological catchment response. The empirically-based understanding of dominant runoff generation processes in the North Esk uplands and lowlands were used in a stepwise rainfall-runoff model development. Tracers were directly incorporated to reduce structural and parameter uncertainty. The integration of tracers helped reduce parameter uncertainty. These tracer-aided models increased confidence for using them to explore the effects of environmental change. Climate change impacts in the catchment where explored by forcing the models with projected climate change forcing from the UK Climate Projections 2009. The results revealed landscape-specific changes in the hydrological response with increased summer drought risk in the lowlands and diminishing snow influence and increased winter floods in the uplands. The spatial integration mediated the extremes observed in the subcatchments.

<p> Yellow-cedar is a long-lived conifer of the North Pacific Coastal Temperate Rainforest region that is thought to be undergoing a continued natural range expansion in southeast Alaska. Yellow-cedar is locally rare in northeastern portions of the Alexander Archipelago, and the fairly homogenous climate and forest conditions across the region suggest that yellow-cedar&rsquo;s rarity could be due to its local migrational history rather than constraints on its growth. Yellow-cedar trees in northern range edge locations appear to be healthy, with few dead trees; additionally, yellow-cedar tend to be younger than co-dominant mountain and western hemlock trees, indicating recent establishment in existing forests.</p><p> To explore yellow-cedar&rsquo;s migration in the region, and determine if the range is expanding into unoccupied habitat, I located 11 leading edge yellow-cedar populations near Juneau, Alaska. I used the geographic context of these populations to determine the topographic, climatic, and disturbance factors associated with range edge population establishment. I used those same landscape variables to model suitable habitat for the species at the range edge. Based on habitat modeling, yellow-cedar is currently only occupying 0.8 percent of its potential landscape niche in the Juneau study area. Tree ages indicate that populations are relatively young for the species, indicating recent migration, and that most populations established during the Little Ice Age climate period (1100 &ndash; 1850).</p><p> To determine if yellow-cedar is continuing to colonize unoccupied habitat in the region, I located 29 plots at the edges of yellow-cedar stands to measure regeneration and expansion into existing forest communities. Despite abundant suitable habitat, yellow-cedar stand expansion appears stagnant in recent decades. On average, seedlings only dispersed 4.65 m beyond stand boundaries and few seedlings reached mature heights both inside and outside of existing yellow-cedar stands. Mature, 100 &ndash; 200-year-old trees were often observed abruptly at stand boundaries, indicating that most stand boundaries have not moved in the past ~150 years. When observed, seedlings were most common in high light understory plant communities and moderately wet portions of the soil drainage gradient, consistent with the species&rsquo; autecology in the region.</p><p> Despite an overall lack of regeneration via seed, yellow-cedar is reproducing via asexual layering in high densities across stands. Layering may be one strategy this species employs to slowly infill habitat and/or persist on the landscape until conditions are more favorable for sexual reproduction. This study leads to a picture of yellow-cedar migration as punctuated, and relatively slow, in southeast Alaska. Yellow-cedar&rsquo;s migration history and currently limited spread at the northeastern range edge should be considered when planning for the conservation and management of this high value tree under future climate scenarios.</p>

<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>

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.

Climate Change Effects and Water Vulnerability in the Molalla Pudding River Basin, Oregon, USA

The dragonfly communities in Sweden may be affected in many ways. Loss of habitats, habitat alteration or even environmental toxins might have a negative impact on the communities. A new threat to the communities and to the species in general is climate change. In this study I examined whether the dragonfly composition had changed in an area in central Sweden between 1997 and 2010. I did a nestedness matrix to see if the dragonfly composition (only using partivoltine species) was more or less nested in 2010 than it was in 1997, i.e. if there was more unexpected species recorded in the area. I also looked at the surrounding of the lakes and whether the species were considered to be generalist species or specialist species. I found that the dragonfly composition had changed during these 13 years and that the composition was more nested in 1997 than in 2010, i.e. there was more unexpected species in the 2010 survey. I also recorded seven new species for the area and that six species had disappeared. Six species had gone from being generalists to being specialists. The surroundings had not changed significantly and I thus see climate change as a possible explanation to these changes.

ABSTRACT In the recent times, due to the increasing rate of global warming, the Southern African region, especially, Lesotho has been experiencing continuous climatic change characterized by drastic reduction in rainfall, increase in the rate of dryness and heat, with depletion of the amount of water, flora and fauna resources. The situation has been so for years without many questions and answers with regard to how it affects food production and security in the country. Against this background, this paper investigates the chain of interactions between climatic change, expressed in the rate of rainfall and drought condition, the indigenous adaptation mechanisms and food production in Lesotho. The paper addresses the estimate of drought condition in Lesotho, Southern Africa, the nature of food production activities in the area and the extent to which continuous climatic change has affected the state of food production.

This text/video thesis investigates how Canadian fathers feel about the threat of losing pond hockey, a revered game they love, to climate change. It responds to the David Suzuki Foundation’s (DSF) assertion that under a global ‘business as usual’ rate of producing greenhouse gases, the skating season of the world’s largest ‘rink’--the Rideau Canal--would shrink from a nine week historical average to just one week by century’s end (DSF, 2009a). Seven outdoor-hockey-loving fathers were interviewed, which revealed their willingness to share feelings of concern, sadness, fear, uncertainty, and need for action to mitigate against and adapt to the ill-effects of climate change on this game, and more serious social situations. Despite concerns it was revealed they took few substantial actions against climate change, which they recognized might affect themselves, their children, communities, and future generations. Conversation, at times nostalgic, helped make these issues more salient.