Climate change

El Niño Southern Oscillation (ENSO) occurrences have a well-established impact on regional hydroclimatic variability and alterations in crucial climatic factors such as temperature and precipitation. The impact of ENSO on temperature extremes can cause fluctuations in energy consumption, leading to the need for energy utilities to implement more effective management measures. This study aims to evaluate the potential impacts of El Niño Southern Oscillation (ENSO) events on local temperature patterns & extremes and residential energy usage in South Florida. The region of focus consists of three Counties: Miami-Dade, Broward, and Palm Beach. The impact of ENSO occurrences on temperature is assessed by analyzing long-term monthly average, minimum, and maximum temperature data from numerous weather stations in these counties, spanning from 1961 to 2018. The study analyzes variations of monthly electricity usage data acquired from a local power utility company (e.g., Florida Power & Light) and temperature data from 2001 to 2018. Temporal frames that align with the three phases of ENSO (namely warm, cool, and neutral) are employed to assess variations in temperature and energy consumption. Nonparametric hypothesis tests are employed to validate statistically significant variations in temperature and residential energy consumption across the stages of ENSO. This study aims to analyze the potential regional and temporal impacts of ENSO episodes on temperature and residential energy consumption in South Florida. Initial findings indicate that the non-uniform distribution of temperature, affected by El Niño and La Niña occurrences, impacts the amount of energy consumed by households in South Florida.

South Florida is at the frontlines of climate change impacts. Facing increases in heat waves, flooding, and intensity of storms, climate change has direct detriments on the residents of this region. This research examines the evidence of Climate Change Anxiety (CCA) within Broward, Miami-Dade, Monroe, and Palm Beach counties. Using the CCA instrument developed by Susan Clayton and Bryan Karazsia in 2020, this study replicates analyses of variables conducted in prior research on the national level. This research found South Floridians are experiencing moderate levels of anxiety caused by climate change. Additionally, significant relationships exist between CCA and newly examined variables such as family situations, politics, and sociological perceptions. Sociological perceptions such as identities described in Dan Kahan’s Cultural Cognition Theory help us understand how having different views of society and life may alter how an individual is affected by CCA.

Gentrification describes rapid infrastructure development and investment in areas with lower income classes. It may cause potential erasure of the original neighborhood's unique culture and the displacement of residents. Due to rising sea levels and the increase in the frequency and intensity of storms, the inundation of Florida will increase as time passes. This creates an ironic relationship where historical coastal areas inhabited by an affluent population will move inland to historically lower-income populations. This thesis developed a Climate Gentrification Index (CGI) to identify areas at risk of gentrification caused by inundation of storm scenarios in Tampa City, Florida. Socioeconomic data and inundation data produced from a hydrological model were combined to define CGI and areas with high risk were mapped and discussed.

Reefs off the coast of Florida face threats from stressors associated with climate change which leads to phase shifts. Under rapid climate change, a clear understanding of how reefs and their benthic organisms respond is still lacking and needs to be investigated. Using in situ imagery, a sponge cell model, and long-term benthic biota surveys, the effects of climate change on reef dynamics were explored in this dissertation project. Results from the in situ imagery found that differences in spectral signatures are found between functional groups (i.e., corals, sponges, and algae) and different species from substrate. Results based on a sponge cell model and transcriptomics data have found a resilience of these sponges to the predicted thermal extremes. Results from benthic biota surveys suggested that depth and light attenuation have the largest influence on the predicted distribution of corals, sponges, and algae at Pulley Ridge. Climate change has been impacting reef benthic biota starting at the organismal scale up to the reef scale. This research demonstrates the importance of monitoring reefs at a finer scale and determining the thresholds and limits of benthic biota to projected thermal extremes to better inform resource managers to preserve these irreplaceable ecosystems.

As cities respond to accelerating climate impacts, scholars have identified climate gentrification as a phenomenon exerting displacement pressures on low-income communities, including ethnic enclaves. While climate gentrification pathways literature primarily addresses economic causes and effects, an opportunity exists to better understand policy contributions and social impacts surrounding resilience and displacement.
For this dissertation project, I expanded the concept of climate gentrification pathways to examine connections between displacement, resilience strategies, and urban planning. Using an interpretive approach, I explored how an ethnic enclave experienced and responded to displacement pressures, especially regarding social impacts related to (climate) gentrification. In addition, this project compared resilience and planning policies and strategies discourse with community discourse related to climate gentrification.

The term "collapse" has become a widely used term that oversimplifies the intricate histories of human-environment interactions. It has contributed to the belief that civilizations in the Americas and the tropics could not endure over time. However, the Manteño civilization of the Ecuadorian coast challenges this notion. Flourishing for a thousand years (ca. 650–1700 CE), the Manteños inhabited the neotropics at the gates of one of the world's most influential climatic forces, the El Niño-Southern Oscillation (ENSO). To thrive, the Manteños needed to navigate the extremes of ENSO during the Medieval Climate Anomaly (MCA, ca. 950–1250 CE) and the Little Ice Age (LIA, ca. 1400–1700 CE) while capitalizing on ENSO's milder phases. This research uses change detection analysis of Normalized Difference Vegetation Index (NDVI) on Landsat satellite imagery under various ENSO conditions from 1986 to 2020 in southern Manabí, where the 16th-century Manteño territory of Salangome was situated. The findings indicate that the cloud forests found in the highest elevations of the Chongón-Colonche Mountains provide the most resilient environment in the region to adapt to a changing climate. Further investigations of the cloud forest of the Bola de Oro Mountain using Uncrewed Aerial Vehicles (UAV) equipped with LiDAR, ground-truthing, and excavation uncovered a landscape shaped by the Manteños.

Coral reefs around the globe have undergone widespread degradation due to a myriad of natural and anthropogenic stressors. Climate warming, in particular, has emerged as an especially pressing threat, reshaping not only the biodiversity of coral-reef ecosystems worldwide, but also undermining the vital ecosystem services they provide. Yet amidst this decline, there is growing evidence that many coral species are expanding their ranges poleward into historically cooler subtropical and temperate marine environments thereby establishing critical refugia in response to climate warming. However, understanding the long-term viability and potential of these emerging refugia under ongoing climate change remains an area of active research, constrained by the temporal limitations of modern ecological studies. In addressing these challenges, this dissertation explores insights from a newly discovered late Holocene record of coral community development off southeast Florida, shedding light on historical coral range expansions, and providing critical context for assessing the future response of reef-building coral communities to continued climate warming. Using a combination of high-precision uranium-thorium dating and detailed paleoecological analysis of well-preserved subfossil coral skeletons, we provide new evidence that diverse coral communities dominated by Acropora spp. expanded to the nearshore hardbottom habitats off northern Broward County during a period of warming in the subtropical western Atlantic between 3500 and 1800 years before present. However, despite this historical precedent of range expansion in response to regional warming, modern comparisons reveal a significant shift towards low diversity coral assemblages dominated by stress-tolerant coral taxa, suggesting that ongoing range expansions may be constrained by new challenges that were absent during the late Holocene. These findings underscore the need for comprehensive conservation strategies informed by historical baselines to navigate the complex dynamics of coral reefs in the face of climate change.

Climate change has intensified thermal anomalies in coral reef ecosystems, contributing to coral bleaching and decline. As corals die, reef fragmentation increases, and species interactions in the benthos change. However, it is unclear which competitive interactions may prevail and structure future reef ecosystems. The aim of this thesis was to evaluate the effect of thermal anomalies on coral reef benthic competitive interactions. Photoquadrats in southeast Florida reef sites were assessed over 15-years to generate interaction metrics and determine effects on hard coral survivorship. A state-transition model was created to predict the resultant community across 100 years with thermal scenarios concordant with the IPCC RCP 4.5 and 8.5. Interaction doubled across three thermal anomaly events and ended up mainly composed of pairwise examples between Dictyota, Halimeda, Niphates erecta, and Erythropodium caribaeorum. Century projections confirm that soft coral and sponge interactions will increase through thermal anomalies. The survival of hard corals was more successful when colonies were in permanent or intermittent interactions than when colonies were solitary (indirect interactions). Living hard corals were mostly found interacting with the macroalgae, Dictyota, and sponge Aplysina cauliformis, while corals that died were mainly in interactions with the soft coral E. caribaeorum, and sponges N. erecta, C. delitrix, D. anchorata, and Ircinia campana. Future reefs will be composed of more interactions between soft corals and sponges as thermal anomalies intensify, which will result in a patchier and flatter community.

Mixed conifer forests in the Sierra Nevada, California, face threats from frequent highseverity fire associated with climate change and fuel accumulation leading to vegetation shifts at local and landscape scales. Under rapid climate change, a clear understanding of how vegetation responds to single and/or repeated wildfires is still lacking and needs to be investigated. Using field and satellite data, the effects of wildfire on vegetation dynamics were explored at the plot and landscape levels in this dissertation project. Results from the field data suggest that management activities may be required in high-severity burned areas to restore dominance of mixed conifer forests and regain historical species composition in areas where live trees persist. Results from satellite data suggested that large shrub patches, created after mixed severity fire, fragment the homogenous mixed conifer dominated forest of the Sierra Nevada to create a more heterogeneous landscape, however the extent of diversity and fragmentation were dependent on fire severity and scales. Natural wildfires may restore landscape heterogeneity to conditions equivalent to the pre-Columbian era, but effects under the projected climate change scenario for 21st century remain uncertain. Mixed conifer dominated forests are predicted to be the dominant component of the Sierra Nevada landscape under historical fire probabilities and excluding higher probability of high-severity fire over the next 100 years.

One of the largest restoration programs in the world, the Comprehensive Everglades Restoration Plan (CERP) aims to restore freshwater flows to the Everglades and Florida Bay estuary. Coupled with climate change, future changes from restoration highlight the need to implement an ecosystem-based fisheries management (EBFM) approach in Florida Bay. The Ecopath framework was used to develop and apply a mass-balanced food web model to the spatiotemporal dynamics of hydrological restoration and climate change through time. Results suggest Florida Bay is stabilized through large detrital energy pathways and low nutrient inputs, but subject to species distribution shifts due primarily to sea-level rise and salinity variation. A suite of winners and losers predicted provide an opportunity to ensure management strategies are designed appropriately to best achieve desired results for the future of the Florida Bay ecosystem.