Matching Items (9)
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- All Subjects: Climate Change
- Creators: White, Dave
Description
The numerical climate models have provided scientists, policy makers and the general public, crucial information for climate projections since mid-20th century. An international effort to compare and validate the simulations of all major climate models is organized by the Coupled Model Intercomparison Project (CMIP), which has gone through several phases since 1995 with CMIP5 being the state of the art. In parallel, an organized effort to consolidate all observational data in the past century culminates in the creation of several "reanalysis" datasets that are considered the closest representation of the true observation. This study compared the climate variability and trend in the climate model simulations and observations on the timescales ranging from interannual to centennial. The analysis focused on the dynamic climate quantity of zonal-mean zonal wind and global atmospheric angular momentum (AAM), and incorporated multiple datasets from reanalysis and the most recent CMIP3 and CMIP5 archives. For the observation, the validation of AAM by the length-of-day (LOD) and the intercomparison of AAM revealed a good agreement among reanalyses on the interannual and the decadal-to-interdecadal timescales, respectively. But the most significant discrepancies among them are in the long-term mean and long-term trend. For the simulations, the CMIP5 models produced a significantly smaller bias and a narrower ensemble spread of the climatology and trend in the 20th century for AAM compared to CMIP3, while CMIP3 and CMIP5 simulations consistently produced a positive trend for the 20th and 21st century. Both CMIP3 and CMIP5 models produced a wide range of the magnitudes of decadal and interdecadal variability of wind component of AAM (MR) compared to observation. The ensemble means of CMIP3 and CMIP5 are not statistically distinguishable for either the 20th- or 21st-century runs. The in-house atmospheric general circulation model (AGCM) simulations forced by the sea surface temperature (SST) taken from the CMIP5 simulations as lower boundary conditions were carried out. The zonal wind and MR in the CMIP5 simulations are well simulated in the AGCM simulations. This confirmed SST as an important mediator in regulating the global atmospheric changes due to GHG effect.
ContributorsPaek, Houk (Author) / Huang, Huei-Ping (Thesis advisor) / Adrian, Ronald (Committee member) / Wang, Zhihua (Committee member) / Anderson, James (Committee member) / Herrmann, Marcus (Committee member) / Arizona State University (Publisher)
Created2013
Description
As climate change becomes a greater challenge in today's society, it is critical to understand young people's perceptions of the phenomenon because they will become the next generation of decision-makers. This study examines knowledge, beliefs, and behaviors among high school students. The subjects of this study include students from high school science classes in Phoenix, Arizona, and Plainfield, Illinois. Using surveys and small group interviews to engage students in two climatically different locations, three questions were answered:
1) What do American students know and believe about climate change? How is knowledge related to beliefs?
2) What types of behaviors are students exhibiting that may affect climate change? How do beliefs relate to behavioral choices?
3) Do climate change knowledge, beliefs, and behaviors vary between geographic locations in the United States?
The results of this study begin to highlight the differences between knowledge, beliefs, and behaviors around the United States. First, results showed that students have heard of climate change but often confused aspects of the problem, and they tended to focus on causes and impacts, as opposed to solutions. Related to beliefs, students tended to believe that climate change is caused by both humans and natural trends, and would affect plant and animal species more than themselves and their families. Second, students were most likely to participate in individual behaviors such as turning off lights and electronics, and least likely to take public transportation and eat a vegetarian meal. Individual behaviors seem to be most relevant to this age group, in contrast to policy solutions. Third, students in Illinois felt they would be more likely to experience colder temperatures and more precipitation than those in Arizona, where students were more concerned about rising temperatures.
Understanding behaviors, motivations behind beliefs and choices, and barriers to actions can support pro-environmental behavior change. Educational strategies can be employed to more effectively account for the influences on a young person's belief formation and behavior choices. Providing engagement opportunities with location-specific solutions that are more feasible for youth to participate in on their own could also support efforts for behavior change.
1) What do American students know and believe about climate change? How is knowledge related to beliefs?
2) What types of behaviors are students exhibiting that may affect climate change? How do beliefs relate to behavioral choices?
3) Do climate change knowledge, beliefs, and behaviors vary between geographic locations in the United States?
The results of this study begin to highlight the differences between knowledge, beliefs, and behaviors around the United States. First, results showed that students have heard of climate change but often confused aspects of the problem, and they tended to focus on causes and impacts, as opposed to solutions. Related to beliefs, students tended to believe that climate change is caused by both humans and natural trends, and would affect plant and animal species more than themselves and their families. Second, students were most likely to participate in individual behaviors such as turning off lights and electronics, and least likely to take public transportation and eat a vegetarian meal. Individual behaviors seem to be most relevant to this age group, in contrast to policy solutions. Third, students in Illinois felt they would be more likely to experience colder temperatures and more precipitation than those in Arizona, where students were more concerned about rising temperatures.
Understanding behaviors, motivations behind beliefs and choices, and barriers to actions can support pro-environmental behavior change. Educational strategies can be employed to more effectively account for the influences on a young person's belief formation and behavior choices. Providing engagement opportunities with location-specific solutions that are more feasible for youth to participate in on their own could also support efforts for behavior change.
ContributorsKruke, Laurel (Author) / Larson, Kelli (Thesis advisor) / Klinsky, Sonja (Committee member) / White, Dave (Committee member) / Arizona State University (Publisher)
Created2015
Description
The Global Change Assessment Model (GCAM) is an integrated assessment tool for exploring consequences and responses to global change. However, the current iteration of GCAM relies on NetCDF file outputs which need to be exported for visualization and analysis purposes. Such a requirement limits the uptake of this modeling platform for analysts that may wish to explore future scenarios. This work has focused on a web-based geovisual analytics interface for GCAM. Challenges of this work include enabling both domain expert and model experts to be able to functionally explore the model. Furthermore, scenario analysis has been widely applied in climate science to understand the impact of climate change on the future human environment. The inter-comparison of scenario analysis remains a big challenge in both the climate science and visualization communities. In a close collaboration with the Global Change Assessment Model team, I developed the first visual analytics interface for GCAM with a series of interactive functions to help users understand the simulated impact of climate change on sectors of the global economy, and at the same time allow them to explore inter comparison of scenario analysis with GCAM models. This tool implements a hierarchical clustering approach to allow inter-comparison and similarity analysis among multiple scenarios over space, time, and multiple attributes through a set of coordinated multiple views. After working with this tool, the scientists from the GCAM team agree that the geovisual analytics tool can facilitate scenario exploration and enable scientific insight gaining process into scenario comparison. To demonstrate my work, I present two case studies, one of them explores the potential impact that the China south-north water transportation project in the Yangtze River basin will have on projected water demands. The other case study using GCAM models demonstrates how the impact of spatial variations and scales on similarity analysis of climate scenarios varies at world, continental, and country scales.
ContributorsChang, Zheng (Author) / Maciejewski, Ross (Thesis advisor) / Sarjoughian, Hessam S. (Committee member) / White, Dave (Committee member) / Luo, Wei (Committee member) / Arizona State University (Publisher)
Created2015
Description
Drawing from the fields of coastal geography, political ecology, and institutions, this dissertation uses Cape Cod, MA, as a case study, to investigate how chronic and acute climate-related coastal hazards, socio-economic characteristics, and governance and decision-making interact to produce more resilient or at-risk coastal communities. GIS was used to model the impacts of sea level rise (SLR) and hurricane storm surge scenarios on natural and built infrastructure. Social, gentrification, and tourism indices were used to identify communities differentially vulnerable to coastal hazards. Semi-structured interviews with planners and decision-makers were analyzed to examine hazard mitigation planning.
The results of these assessments demonstrate there is considerable variation in coastal hazard impacts across Cape Cod towns. First, biophysical vulnerability is highly variable with the Outer Cape (e.g., Provincetown) at risk for being temporarily and/or permanently isolated from the rest of the county. In most towns, a Category 1 accounts for the majority of inundation with impacts that will be intensified by SLR. Second, gentrification in coastal communities can create new social vulnerabilities by changing economic bases and disrupting communities’ social networks making it harder to cope. Moreover, higher economic dependence on tourism can amplify towns’ vulnerability with reduced capacities to recover. Lastly, low political will is an important barrier to effective coastal hazard mitigation planning and implementation particularly given the power and independence of town government on Cape Cod. Despite this independence, collaboration will be essential for addressing the trans-boundary effects of coastal hazards and provide an opportunity for communities to leverage their limited resources for long-term hazard mitigation planning.
This research contributes to the political ecology of hazards and vulnerability research by drawing from the field of institutions, by examining how decision-making processes shape vulnerabilities and capacities to plan and implement mitigation strategies. While results from this research are specific to Cape Cod, it demonstrates a broader applicability of the “Hazards, Vulnerabilities, and Governance” framework for assessing other hazards (e.g., floods, fires, etc.). Since there is no “one-size-fits-all” approach to mitigating coastal hazards, examining vulnerabilities and decision-making at local scales is necessary to make resiliency and mitigation efforts specific to communities’ needs.
The results of these assessments demonstrate there is considerable variation in coastal hazard impacts across Cape Cod towns. First, biophysical vulnerability is highly variable with the Outer Cape (e.g., Provincetown) at risk for being temporarily and/or permanently isolated from the rest of the county. In most towns, a Category 1 accounts for the majority of inundation with impacts that will be intensified by SLR. Second, gentrification in coastal communities can create new social vulnerabilities by changing economic bases and disrupting communities’ social networks making it harder to cope. Moreover, higher economic dependence on tourism can amplify towns’ vulnerability with reduced capacities to recover. Lastly, low political will is an important barrier to effective coastal hazard mitigation planning and implementation particularly given the power and independence of town government on Cape Cod. Despite this independence, collaboration will be essential for addressing the trans-boundary effects of coastal hazards and provide an opportunity for communities to leverage their limited resources for long-term hazard mitigation planning.
This research contributes to the political ecology of hazards and vulnerability research by drawing from the field of institutions, by examining how decision-making processes shape vulnerabilities and capacities to plan and implement mitigation strategies. While results from this research are specific to Cape Cod, it demonstrates a broader applicability of the “Hazards, Vulnerabilities, and Governance” framework for assessing other hazards (e.g., floods, fires, etc.). Since there is no “one-size-fits-all” approach to mitigating coastal hazards, examining vulnerabilities and decision-making at local scales is necessary to make resiliency and mitigation efforts specific to communities’ needs.
ContributorsGentile, Lauren Elyse (Author) / Bolin, Bob (Thesis advisor) / Wentz, Elizabeth (Committee member) / White, Dave (Committee member) / York, Abigail (Committee member) / Arizona State University (Publisher)
Created2016
Description
Rapid urban expansion and the associated landscape modifications have led to significant changes of surface processes in built environments. These changes further interact with the overlying atmospheric boundary layer and strongly modulate urban microclimate. To capture the impacts of urban land surface processes on urban boundary layer dynamics, a coupled urban land-atmospheric modeling framework has been developed. The urban land surface is parameterized by an advanced single-layer urban canopy model (SLUCM) with realistic representations of urban green infrastructures such as lawn, tree, and green roof, etc. The urban atmospheric boundary layer is simulated by a single column model (SCM) with both convective and stable schemes. This coupled SLUCM-SCM framework can simulate the time evolution and vertical profile of different meteorological variables such as virtual potential temperature, specific humidity and carbon dioxide concentration. The coupled framework has been calibrated and validated in the metropolitan Phoenix area, Arizona. To quantify the model sensitivity, an advanced stochastic approach based on Markov-Chain Monte Carlo procedure has been applied. It is found that the development of urban boundary layer is highly sensitive to surface characteristics of built terrains, including urban land use, geometry, roughness of momentum, and vegetation fraction. In particular, different types of urban vegetation (mesic/xeric) affect the boundary layer dynamics through different mechanisms. Furthermore, this framework can be implanted into large-scale models such as Weather Research and Forecasting model to assess the impact of urbanization on regional climate.
ContributorsSong, Jiyun (Author) / Wang, Zhihua (Thesis advisor) / Vivoni, Enrique R (Committee member) / Mascaro, Giuseppe (Committee member) / Myint, Soe W (Committee member) / Sailor, David (Committee member) / Arizona State University (Publisher)
Created2016
Description
The hydrologic cycle in drylands is complex with large spatiotemporal variationsacross scales and is particularly vulnerable to changes in climate and land cover. To
address the challenges posed by hydrologic changes, a synergistic approach that
combines numerical models, ground and remotely sensed observations, and data analysis
is crucial. This dissertation uses innovative detection and modeling techniques to assess
key hydrologic variables in drylands, including irrigated water use, streamflow, and
snowpack conditions, answering following research questions that also have broad
societal implications: (1) What are the individual and combined effects of future climate
and land use change on irrigation water use (IWU) in the Phoenix Metropolitan Area
(PMA)?; (2) How can temporal changes in streamflow and the impacts of flash flooding
be detected in dryland rivers?; and (3) What are the impacts of rainfall-snow partitioning
on future snowpack and streamflow in the Colorado River Basin (CRB)?
Firstly, I conducted a scenario modeling using the Variable Infiltration Capacity
(VIC) model under future climate and land use change scenarios. Results showed that
future IWU will change from -0.5% to +6.8% in the far future (2071-2100) relative to the
historical period (1981-2010). Secondly, I employed CubeSat imagery to map streamflow
presence in the Hassayampa River of Arizona, finding that the imaging capacity of
CubeSats enabled the detection of ephemeral flow events using the surface reflectance of
the near-infrared (NIR) band. Results showed that 12% of reaches were classified as
intermittent, with the remaining as ephemeral. Finally, I implemented a physically-based
rainfall-snow partitioning scheme in the VIC model that estimates snowfall fraction from
the wet-bulb temperature using a sigmoid function. The new scheme predicts more
significant declines in snowfall (-8 to -11%) and streamflow (-14 to -27%) by the end of
the 21st century over the CRB, relative to historical conditions.
Overall, this dissertation demonstrates how innovative technologies can enhance
the understanding of dryland hydrologic changes and inform decision-making of water
resources management. The findings offer important insights for policymakers, water
managers, and researchers who seek to ensure water resources sustainability under the
effects of climate and land use change.
ContributorsWang, Zhaocheng (Author) / Vivoni, Enrique R (Thesis advisor) / White, Dave D (Committee member) / Mascaro, Giuseppe (Committee member) / Huang, Huei-Ping (Committee member) / Wang, Zhihua (Committee member) / Arizona State University (Publisher)
Created2023
Description
In the United States, some 94 million people (29% of the US population) live in areas immediately adjacent to a coast. The global phenomenon of climate-induced environmental change is largely framed as a one-way cause-and-effect relationship, where individuals, communities, and populations inhabiting at-risk locations are either forced to relocate or do so of their own accord. Yet residents of such at-risk areas are increasingly actively choosing to remain, even as risk intensifies. Using a mixed-methods approach, this dissertation examines environmental perceptions, the internalization of risk, the influence of information sources, and how individuals residing in coastal locations process their migration decisions. Established migration and hazard frameworks and theory are poorly positioned to understand the environments’ role in migration decisions. From these perspectives, environmental factors are near exclusively framed as negative affective biophysical push factors. Migration frameworks also fail to adequately incorporate reasons for non-migration. This dissertation directly addresses both these gaps in understanding. This research utilizes data from across the Gulf Coast, with a focus on fieldwork from Terrebonne Parish, Louisiana, and a dataset of 123 surveys and 63 interviews across a diverse group of coastal residents. Residents perceive of their environment in much more robust terms than just the biophysical. A majority of terms incorporated social and cultural aspects of environment, and environmental meaning was expressed across a continuum of proximal (most important/close) to more distal (less important/distant) scales. Little support is found for the traditional idea that economic or natural-environmental factors are more influential in decisions to migrate away from ones’ home. In predicting migration intention, socially and environmentally derived variables improved migration model performance. This dissertation demonstrates that internalization of risk by coastal residents is not a straightforward relationship, but rather one mediated by; social-environmental factors, personal experience, sense of place, and trust, which in turn influences intention to migrate, move locally, or remain in place. Residents perceive of their environment far more broadly than current risk-management planning allows. Results provide coastal residents, as well as community leaders and emergency managers who perceive environment differently, new tools for productive engagement and future policy development within coastal landscapes.
ContributorsTill, Charlotte Emma (Author) / BurnSilver, Shauna (Thesis advisor) / Tsuda, Takeyuki (Committee member) / White, Dave (Committee member) / Arizona State University (Publisher)
Created2022
Description
Our thesis project, blanknationalpark.com, asked one question : how is climate change impacting National Parks in America? We decided to travel to three different areas: Joshua Tree, Glacier and Everglades National Park. It didn’t take long to discover that there was never a definitive answer. The effects of climate change looked different in every park we visited. Joshua Tree was struggling with changes in temperature, climate regime and an increase in fires. The U.S Geological Survey predicted that all of the glaciers in Glacier National Park could be gone by 2030. Everglades National Park was facing the constant threat of sea-level rise, invasive species and stronger hurricanes. However, in every park, one thing was certain - they all would not have their iconic features in the future due to climate change. For our thesis, we created blanknationalpark.com to emphasize the fact that Joshua Tree National Park won’t have Joshua Trees in the coming centuries, glaciers would cease to exist in Glacier National Park and the entire Everglades ecosystem itself will be underwater in the next century and a half. Thus, our project name, “Blank National Park”, pays tribute to the uncertainty of what these famous landscapes could look like in the future. Our main goal was to provide the public with a visual experience that is not only informative but engaging so that we could provide an educational experience about a critical situation without appearing too dismal. We chose to include our last page, ‘Solutions’, to establish hope for the future, and encourage people to take action to help preserve National Parks and the world we live in.
ContributorsCutler, Alison Jane (Co-author) / Nagaishi, Ayano (Co-author) / White, Dave (Thesis director) / Muench, Sarah (Committee member) / Walter Cronkite School of Journalism & Mass Comm (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Intensive global animal agricultural practices have proved to be a cause for concern, resulting, in part, from consumer preferences and an increasing global demand for protein, especially meat. Countries like Argentina, contribute to Greenhouse Gas emissions substantially through their livestock sector. Improved resource management can help to promote sustainable agriculture by reducing the amount of water and energy used to produce livestock, and improve livestock practices in order to reduce GHG emissions. The integration of resource management between food, energy, and water systems can help to decrease livestock-based emissions, through efficiency improvements targeted towards animal agricultural practices. This paper can act as a reference for other researchers studying the FEW nexus, to increase their understanding of how to improve coordination across water, energy, and agricultural sectors by using Argentina’s livestock sector as an example. Furthermore, policy and decision makers in Argentina can use information about FEW systems to make informed decisions about the allocation and prioritization of integrated management between food, energy, and water sectors, to help them implement integrated mitigation strategies within their livestock sector to help reduce GHG emissions.
ContributorsGregorio, Gisselle Marie (Author) / White, Dave (Thesis director) / Eakin, Hallie (Committee member) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12