No description available.

Yes / Climate change and urbanization can increase pressures on groundwater resources, but little is known about how groundwater quality will change. Here, we rely on a global synthesis (n = 9,404) to reveal the drivers of dissolved organic carbon (DOC), which is an important component of water chemistry and substrate for microorganisms which control many biogeochemical reactions. Groundwater ions, local climate and land use explained ~ 31% of observed variability in groundwater DOC, whilst aquifer age explained an additional 16%. We identify a 19% increase in DOC associated with urban land cover. We predict major groundwater DOC increases following changes in precipitation and temperature in key areas relying on groundwater. Climate change and conversion of natural or agricultural areas to urban areas will decrease groundwater quality and increase water treatment costs, compounding existing threats to groundwater resources.

Architecture has the power to reveal the complexities of man in nature through the degree of control in the process of form making. This process offers the opportunity to create different physical and psychological experiences dependent on its articulation. This is a study that explores the introduction of chance into the making process. Through a series of model studies, I explored how basic platonic solids, more specifically cube define spatial boundaries and how asymmetrical space could challenge its regularity and symmetry. Through chemical reactions randomized organic cavities were achieved that exposed contrast between regular exterior form and irregular interior form. This visual accent is embedded in irregular forms and is unrepeatable. The act of making exposes the intricate patterns created that replicate nature and the manifestation of material decay. With this in mind, as part of my thesis, I would like to apply the above discoveries into an observation tower. The orthogonal prisms, once deconstructed, draw attention to newly generated cavities and decay, revealing different conditions throughout from where visitors can enjoy views of Mallacoota's landscape. / Master of Architecture / Nature offers diverse design elements that architects can tap into to enhance human habitation. Building materials play a vital role in shaping visual and structural design in the built environment. Through the act of making, the process revealed the question of aesthetics in architecture through intricate forms and how architectural principles of spatial qualities interplay in creating inhabitable environments. As a part of the climate change investigation, I explored different production methodologies for visualizing the climatic crisis. This research investigates the nature of irregularity resulting from the subtraction of a platonic form. The deterioration process questions whether existing climatic changes are caused by nature or result from man-made actions. Intricate openings captured within defined geometrical boundaries trace the absence of the dissolved material, revealing that components introduced and their chemical reactions can build forms for people to inhabit. By leveraging the site and model studies, the proposed program addresses the local context, climate predictions, and scale and explores architecture performance in varying global warming conditions in the form of the observation tower.

The impacts of climate change on agriculture have been observable for years, particularly with declining yields and reduced productivity. Much research has been performed to examine the relationships between yield and climatic variables, especially temperature and precipitation. By comparison, little research has been conducted to assess the impact that climate change has on the nutrition, particularly the antioxidant content and capacity, of crops. This research project aims to fulfill this knowledge gap. Solanum lycopersicum cv. Micro-Tom plants were cultivated in five growth chambers with different temperatures, hours of light, and watering regimes to simulate different environments. The three temperature regimes were 25°, 32°, and 40°C during the day. The two chosen light durations were 12 and 16 hours (h), and the selected watering frequencies were 3 and 5 days (d). Lycopene and phenolics were quantified via spectrophotometry. Color was assessed via the CIELAB color space, specifically the a* value. The ferric reducing ability of plasma (FRAP) assay assessed the ability of the compounds in each tomato sample to serve as antioxidants. Upon analysis, the highest lycopene concentration (72.68 mg per kg fresh weight) was found in tomatoes exposed to 32°C, three days between irrigation cycles, and 16 hours of light. The highest level of phenolics (0.41660 mg gallic acid equivalent per g fresh weight) was observed in tomatoes exposed to 32°C with three days between watering cycles. The largest a* value (11.21), which corresponds to an intense red hue, was seen in tomatoes exposed to 32°C with 16 hours of light. The greatest level of antioxidant capacity [162.12 micromolar Fe(II)] as measured by the FRAP assay occurred in tomatoes exposed to 32°C with three days between irrigation cycles. Overall, antioxidant content and capacity increased the most at 32°C with three days between watering periods. Photoperiod was unimportant. By varying environmental conditions, “designer crops” with specific antioxidant content can seemingly be produced without genetic manipulation. This work enhances the body of knowledge concerning effects of abiotic stress on food crop antioxidants, which is important given the gravity of climate change.

No

Climate change is not only a natural phenomenon, but also a global social issue. Many studies try to explore the mechanisms behind climate change and the consequences of climate change, and provide information for developing the measures to mitigate or adapt to it. For example, the IPCC reviews and assesses climate-change-related scientific information produced worldwide, thus aiming to support decision-making from a scientific perspective. However, though various international and regional climate change policies are developed to combat climate change, yet the implementation of climate change policies need to be further improved, especially requiring active public engagement in taking actions on climate change. The policies regarding saving energy and reducing emissions are closely related to people’s daily life, which requires the public actively change their consumption habits and lifestyle. China, as the biggest GHG emitter, is stressed to reduce its emissions during previous climate negotiations. This thesis emphasizes the severity of climate change in China through reviewing relevant studies and visualizing China’s future climate change, which meanwhile points out the necessity of addressing climate change in China. In addition, China’s climate change policies and the achievements thereof is critically reviewed, which reveals the existing problems and difficulties of policy implementation, and thereby emphasizes the importance of public engagement in implementing climate change policy. Moreover, 26 informants have been interviewed through China’s biggest social media – Tencent QQ, through which informants’ perceptions of climate change, expressed attitudes to and reported actions of addressing climate change is analysed. Furthermore, barriers to informants’ engagement with climate change is exposed. Accordingly, this thesis discusses several suggestions for enhancing public engagement with climate change.

Ecosystem-based adaptation as a concept of adapting to the adverse effects of climate change has become a popular approach that enjoys a good reputation. However, the evidence base for it is rather thin. This thesis sets out to explore the challenges and limitations linked to projects that engage in the concept, in order to estimate the potential threat that may lie in the ignorance of them. Timescales of projects related to the concept shall be the second major focus of this thesis as it has not been sufficiently examined yet by the literature. Empirical material has been gathered and analyzed in the form of interviews with people who have been and are currently working in projects related to ecosystem-based adaptation. The results allow recommendations for the implementation of future projects, as lessons learned were identified.

The recent quantification of the reservoir of carbon held in permafrost soils has rekindled the concern that the terrestrial biosphere will transition from a carbon sink to a carbon source during the 21st century. This dissertation is a compilation of four modelling studies that investigate the permafrost carbon feedback, its consequences for the projected future behaviour of the carbon cycle, and the origins of the proportionally between cumulative CO$_2$ emissions and near surface temperature change. The dissertation is centred around five questions: 1) what is the strength and timing of the permafrost carbon feedback to climate change? 2) If anthropogenic CO2 emissions cease, will atmospheric CO2 concentration continue to increase? 3) Can climate warming be reversed using artificial atmospheric carbon-dioxide removal? 4) What are the underlying physical mechanisms that explain the existence in Earth system models of the proportionality between cumulative CO2 emissions and mean global near surface temperature change? And 5) can strong terrestrial carbon cycle feedbacks, such as the permafrost carbon feedback, disrupt this proportionality? By investigating the these questions using the University of Victoria Earth System Climate Model (UVic ESCM) and analytical mathematics the following conclusions are drawn: 1) The permafrost carbon feedback to climate change is simulated to have a strength of 0.25 C (0.1 to 0.75)C by the year 2100 CE independent of emission pathway followed in the 21st century. This range is contingent on the size of the permafrost carbon pool and the simulated model climate sensitivity. 2) If CO2 emissions were to suddenly cease, the UVic ESCM suggests that whether or not CO2 would continue to build up in the atmosphere is contingent on climate sensitivity and the concentration of non-CO2 greenhouse gasses in the atmosphere. For a given model climate sensitivity there is a threshold value of radiative forcing from non-CO2 greenhouse gasses above which CO2 will continue to build up in the atmosphere for centuries after cessation of anthropogenic CO2 emissions. For a UVic ESCM the threshold value for the Representative Concentration Pathway (RCP) derived emission scenarios is approximately 0.6 Wm^-2 of non-CO2 greenhouse gas radiative forcing. The consequences of being above this threshold value are mild, with the model projecting a further 11-22 ppmv rise in atmosphere CO2 concentration after emissions cease. 3) If technologies were developed and deployed to remove carbon from the atmosphere simulations with the UVic ESCM suggest that a Holocene-like climate could be restored by the end of the present millennium (except under a high climate sensitivity and high emission scenario). However, more carbon must be removed from the atmosphere than was originally emitted to it. 4) The proportionality between cumulative CO2 emissions and global mean temperature change seen in most Earth system model simulations appears to arises from two factors: I) the stability of the airborne fraction of emitted carbon provided by the ocean uptake of carbon begin nearly a function of CO2 emission rate; and II) the diminishing heat uptake by the oceans compensating for the reduced radiative forcing per unit mass CO2 at high atmospheric CO2 concentrations. 5) Strong terrestrial carbon cycle feedbacks can disrupt the proportionality between cumulative CO2 emissions and global mean temperature change. However, within the range of emission rates project for the RCPs the permafrost carbon feedback is not strong enough to disrupt the relationship. Overall, the addition of the permafrost carbon pool to the UVic ESCM alters model behaviour in ways that if representative of the natural world will make stabilizing climate or reversing climate change more difficult than has previously been foreseen. / Graduate / 0768 / 0373 / andrewhughmacdougall@gmail.com

The recent quantification of the reservoir of carbon held in permafrost soils has rekindled the concern that the terrestrial biosphere will transition from a carbon sink to a carbon source during the 21st century. This dissertation is a compilation of four modelling studies that investigate the permafrost carbon feedback, its consequences for the projected future behaviour of the carbon cycle, and the origins of the proportionally between cumulative CO$_2$ emissions and near surface temperature change. The dissertation is centred around five questions: 1) what is the strength and timing of the permafrost carbon feedback to climate change? 2) If anthropogenic CO2 emissions cease, will atmospheric CO2 concentration continue to increase? 3) Can climate warming be reversed using artificial atmospheric carbon-dioxide removal? 4) What are the underlying physical mechanisms that explain the existence in Earth system models of the proportionality between cumulative CO2 emissions and mean global near surface temperature change? And 5) can strong terrestrial carbon cycle feedbacks, such as the permafrost carbon feedback, disrupt this proportionality? By investigating the these questions using the University of Victoria Earth System Climate Model (UVic ESCM) and analytical mathematics the following conclusions are drawn: 1) The permafrost carbon feedback to climate change is simulated to have a strength of 0.25 C (0.1 to 0.75)C by the year 2100 CE independent of emission pathway followed in the 21st century. This range is contingent on the size of the permafrost carbon pool and the simulated model climate sensitivity. 2) If CO2 emissions were to suddenly cease, the UVic ESCM suggests that whether or not CO2 would continue to build up in the atmosphere is contingent on climate sensitivity and the concentration of non-CO2 greenhouse gasses in the atmosphere. For a given model climate sensitivity there is a threshold value of radiative forcing from non-CO2 greenhouse gasses above which CO2 will continue to build up in the atmosphere for centuries after cessation of anthropogenic CO2 emissions. For a UVic ESCM the threshold value for the Representative Concentration Pathway (RCP) derived emission scenarios is approximately 0.6 Wm^-2 of non-CO2 greenhouse gas radiative forcing. The consequences of being above this threshold value are mild, with the model projecting a further 11-22 ppmv rise in atmosphere CO2 concentration after emissions cease. 3) If technologies were developed and deployed to remove carbon from the atmosphere simulations with the UVic ESCM suggest that a Holocene-like climate could be restored by the end of the present millennium (except under a high climate sensitivity and high emission scenario). However, more carbon must be removed from the atmosphere than was originally emitted to it. 4) The proportionality between cumulative CO2 emissions and global mean temperature change seen in most Earth system model simulations appears to arises from two factors: I) the stability of the airborne fraction of emitted carbon provided by the ocean uptake of carbon begin nearly a function of CO2 emission rate; and II) the diminishing heat uptake by the oceans compensating for the reduced radiative forcing per unit mass CO2 at high atmospheric CO2 concentrations. 5) Strong terrestrial carbon cycle feedbacks can disrupt the proportionality between cumulative CO2 emissions and global mean temperature change. However, within the range of emission rates project for the RCPs the permafrost carbon feedback is not strong enough to disrupt the relationship. Overall, the addition of the permafrost carbon pool to the UVic ESCM alters model behaviour in ways that if representative of the natural world will make stabilizing climate or reversing climate change more difficult than has previously been foreseen. / Graduate / 2015-05-01 / 0768 / 0373 / andrewhughmacdougall@gmail.com

abstract: In the American Southwest, an area which already experiences a significant number of cooling degree days, anthropogenic climate change is expected to result in higher average temperatures and the increasing frequency, duration, and severity of heat waves. Climatological forecasts predict heat waves will increase by 150-840% in Los Angeles County, California and 340-1800% in Maricopa County, Arizona. Heat exposure is known to increase both morbidity and mortality and rising temperatures represent a threat to public health. As a result there has been a significant amount of research into understanding existing socio-economic vulnerabilities to extreme heat which has identified population subgroups at greater risk of adverse health outcomes. Additionally, research has shown that man-made infrastructure can mitigate or exacerbate these health risks. However, while recent socio-economic heat vulnerability research has developed geospatially explicit results, research which links it directly with infrastructure characteristics is limited. Understanding how socio-economic vulnerabilities interact with infrastructure systems is a critical component to developing climate adaptation policies and programs which efficiently and effectively mitigate health risks associated with rising temperatures. The availability of cooled space, whether public or private, has been shown to greatly reduce health risks associated with extreme heat. However, a lack of fine-scale knowledge of which households have access to this infrastructure results in an incomplete understanding of the health risks associated with heat. This knowledge gap could result in the misallocation of resources intended to mitigate negative health impacts associated with heat exposure. Additionally, when discussing accessibility to public cooled space there are underlying questions of mobility and mode choice. In addition to captive riders, a growing emphasis on walking, biking and public transit will likely expose additional choice riders to extreme temperatures and compound existing vulnerabilities to heat. / Dissertation/Thesis / Doctoral Dissertation Civil Engineering 2016