Jared Bowden

The frequency and intensity of both floods and droughts are expected to increase in response to climate change; however, significant uncertainties remain regarding regional changes, especially for extreme rainfall. In particular, North Carolina���s geographic position makes it vulnerable to several natural hazards that pose significant flooding risks, including hurricanes, severe thunderstorms, and large winter storms. The most obvious problems within NC in recent years are the pluvial and fluvial flooding from notable hurricanes which paralyzed the NC infrastructure for weeks and caused extensive damage to homes and personal property. The heavy rainfall associated with Hurricanes Floyd (1999), Matthew (2016), Florence (2018), Dorian (2019), and Tropical Storm Fred (2021) generated record-breaking fluvial flooding along key economic corridors and in local communities. Though hurricanes receive a lot of attention in resilient design, as they should, transportation engineers, resilience professionals, community planners, and other local officials face additional challenges, including possible changes to rainfall intensity from localized thunderstorms and other ���no-name��� events. Increasing evidence suggests that precipitation intensity and frequency is changing across the Carolinas (SCO); however, what is poorly understood is how the distribution of rainfall (particularly sub-daily) is changing and what the distribution of this rainfall is now and in the future. Understanding sub-daily rainfall distributions is particularly important for developing design storms to assess the resilience of existing infrastructure to current and future events and for flood hazard mapping, used to establish future land use plans and building standards (e.g., freeboard). In addition, in a changing climate, flooding is expected to increase in some locations and decrease in others. As such, it is particularly important to understand where future rainfall patterns may drive future flooding to plan for a rapidly changing future. The objectives of this study are to 1) update statewide intensity-duration-frequency (IDF) curves to account for climate change projections to quantify future risk for the entire state of North Carolina 2) prepare statewide projections of future precipitation extremes using the newest downscaled climate model data (e.g., CMIP6) 3) evaluate the efficacy of existing IDF curve tools and potential applications in North Carolina 4) identify hotspots of future flood risk based on precipitation estimates, particularly in areas outside of mapped FEMA floodplains 5) create an end-user driven system in consultation with key stakeholders for analyzing, displaying, disseminating, and storing the data.

At regional to local scales different downscaling methods are applied to Global Climate Model (GCM) data to create climate change projections that better resolve the climate at both spatial and temporal scales of interest for understanding plausible impacts on the natural and built environment. However, there are growing number of downscaled projections available using numerous methods and the use of these downscaled projections needs to be carefully considered within downstream impact models. One issue is the representation of extreme events in a warmer climate, which is a challenging problem when considering the regional to local scale of the impacts and various types of weather/climate events that are regionally important. Differences are anticipated between the representation of climate extremes between different downscaled projections, but simultaneously there is a need to use the best available information with an acknowledgement of the data limitations for the adaptation of concern. Thus, climate modeling issues lend themselves well to adaptive management strategies as our understanding about climate science improves as well as model advancements (both climate and downstream impact models). Here we propose to provide an incremental step in our knowledge about regional climate change for climate impact analyses and adaptation efforts using advancements in regional climate modeling and dynamical downscaling of the GCMs to relevant scales for many adaptation decisions (both spatial and temporal). These dynamically downscaled simulations of the future climate when combined with other downscaled climate change projections (including statistical, idealized climate modeling experiments, and novel hybrid dynamical-statistical techniques) will provide important sources of information about regional to local climate change that can be used within downstream impact models.

The main objective of the proposed work will be to answer the following research questions: 1-How community-based research can inform best practices for community aqueducts that are impacted by climate change? 2-What are the best science-based indicators communities (rainfall, presence of certain contaminants, etc.) can be trained to implement to identify climate change impacts in their aqueducts? 3-What are the cumulative and short-term health impacts from water pollution on households connected to small water systems in PR? and 4-our main hypothesis is: The negative impact of drinking water service from droughts in community-owned aqueducts contributes to increased bacterial contaminant presence in the home water distribution system and has cumulative health impacts. The expected results are based upon pilot work conducted in participating communities where drought has affected drinking water sources and quality. Through community engagement methods, data collection on rainfall, climate, water quality, and presence of bacteria will be conducted. A survey instrument with questions on human health, mental health, water surface and system infrastructure will be conducted with participants. Results will be presented and discussed with water operators, community leaders, members and other stakeholders to determine the best community-led, but science-based solutions appropriate for each community to mitigate health impacts of drought. It is expected that factors such as number of people served, financial status, level of rainfall, climate modeling projections, source of water, treatment of water and source of power (electricity vs. gravity) among others will impact the solutions developed. Expected outputs and outcomes are educational materials for homeowners, resources developed for water operator, science guided, community generated solutions to assess risk and reduce contamination, increased regional coordination of water operators to obtain more affordable pricing on supplies and infrastructure repairs. Improved compliance with EPA regulations on safe drinking water is an expected outcome.

The objective of this study is to identify areas across North America that have (or have not) experienced detectable changes in ecologically-relevant climate variables. The goal is to improve the quality and efficiency of investigations into climate change effects on biodiversity by providing a means to narrow such analyses to areas that truly experienced detectable and biologically-relevant environmental changes. To do this we will use existing publicly-available observational and global climate model (GCM) datasets to estimate the range of internal climate variability (ICV), and then test whether observed trends exceeded the estimated level of background variability or ���������������noise������������������. ICV is a result of coupled interactions in the climate system between the ocean, atmosphere, land surface, and cryosphere. Examples of ICV include the El Nino Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). ICV can be considered the ���������������noise������������������ in the ���������������signal-to-noise ratio������������������ (SNR) when characterizing the strength of the global climate change signal. Thus, the larger (smaller) the ICV for a particular location or climate variable, the harder (easier) it will be to ascertain whether an observed trend is distinguishable from background ICV. We will leverage recent advancements in trend detection and ICV estimation in order to: 1) better understand climate trend uncertainty due to ICV, and 2) estimate the Time of Emergence (ToE) of any relevant climate trends in the recent past and near-term future. Because there are a wide range of species������������������ responses and sensitivities to many different climate variables and climate thresholds, we will apply our method to a large suite of climate variables and indices in collaboration with USGS ecologists. This study provides an opportunity to improve species status and trends assessments by reducing uncertainty about whether observed biological trends are potentially outside of the range of natural ecological variability.

The frequency and intensity of both floods and droughts are expected to increase in response to climate change; however, significant uncertainties remain regarding regional changes, especially for extreme rainfall. In particular, North Carolina������������������s geographic position makes it vulnerable to several natural hazards that pose significant flooding risks, including hurricanes, severe thunderstorms, and large winter storms. The most obvious problems within NC in recent years are the pluvial and fluvial flooding from notable hurricanes which paralyzed the eastern NC highway system for days to weeks. The heavy rainfall associated with Hurricanes Floyd (1999), Matthew (2016), Florence (2018), and Dorian (2019) generated record-breaking fluvial flooding along key economic corridors including I-95, I-40, US-70, NC-12, and US-64, and created a chain of transportation infrastructure problems that affected emergency response operations and the transportation of goods. In particular, I-95 facilitates 40 percent of the Nation������������������s GDP while US-70 and I-40 are key routes for supporting the military, agriculture and the economy in eastern NC. Though hurricanes receive a lot of attention in resilient design, as they should, transportation engineers face additional challenges, including possible changes to rainfall intensity from localized thunderstorms and even drought. NC officials, recognizing the risks posed by a changing climate, developed Executive Order 80 (EO80) to help protect the people, natural environment, and economy of North Carolina. NC DOT is likewise working to implement solutions to become more resilient to weather extremes in a changing climate. This objective of this study is to improve confidence in climate change projections by quantifying future precipitation extremes within NC for resilient design (e.g., precipitation intensity, duration, frequency curves). This project will incorporate guidance developed for the National Cooperative Highway Transportation Research Board, NCHRP 15-61, with additional methods and numerical model experiments to improve confidence in future precipitation extremes, and to inform design concepts for potential future events.

This project will develop an improved understanding of the coupled dynamics among the natural processes that underpin drought and poor air quality, the human systems that manage water resources and electricity supply, and localized human exposure to fine particulate matter and ozone pollution, all under the influence of two anthropogenic drivers: technology adoption and climate change.

Styrene is neurotoxic at occupational levels, but has received little study at environmental levels experienced by the general population, despite widespread exposure. Our study team has found that annual average ambient styrene levels are adversely associated with neurologic function and symptoms, including decrements in visual, sensory, and vestibular function. Exposure to styrene in the general population occurs primarily through inhalation of industrial and vehicle emissions, tobacco smoke, and off-gassing of building materials. It is produced from petroleum-derived benzene and ethylbenzene, which explains why over half of US styrene production occurs near oil and gas operations in the Gulf states. Benzene, ethylbenzene, toluene, and xylenes (i.e., BTEX) are also neurotoxic at occupational levels. The proposed study is significant because there are virtually no data describing the safety of most of these neurotoxicants at general population levels, despite widespread exposure. The objective of this study is to investigate the acute and chronic neurotoxicity of styrene and BTEX at levels relevant to the general population. Our central hypothesis is that, even at general population levels, higher ambient styrene/BTEX levels are associated with reduced peripheral nerve and neuro-behav���������ioral function and increased neurologic symptoms. We will test this in a prospective, well-characterized cohort of 23,370 Gulf state residents enrolled in the Gulf Long-Term Follow-up Study in 2011-2013������������������a socioeconomically disadvantaged, medically underserved, and racially diverse population with significant unexplained health disparities. This population has average blood styrene levels 2-3 times higher than those observed in the general population, but much lower than the ~25-fold higher levels typically observed in occupationally exposed populations. We have extensive information on all cohort members, from enrollment and follow-up interviews, on demographic, lifestyle, occupational, and health factors; geocoded residential histories; measured blood levels of styrene and BTEX from 965 cohort members during the last year of enrollment; and results of extensive peripheral neurologic function and neurobehavioral tests administered to 3,403 members 2-4 years after enrollment. We propose to: (1) Generate high resolution temporally- and spatially-referenced ambient (air) styrene and BTEX concentra������������������tions in the Gulf region over a 6 year follow-up period, (2) Evaluate estimated ambient styrene and BTEX concentrations against measured blood styrene and BTEX levels, and (3) Determine associations of styrene and BTEX exposures, both individually and as a mixture, with neurologic symptoms and neurobehavioral and peripheral neurologic function, accounting for other neurotoxic air pollutants. This study is innovative because we will be the first to investigate the neurotoxicity of styrene at general population levels and we will do so using state-of-the-art air quality exposure data fusion methods that have not previously been applied to styrene or BTEX. The Public Health Impact of this research is high because exposure to styrene and BTEX is widespread and these chemicals are known to be neurotoxic at occupational levels.

The objective of this study is to identify areas across North America that have (or have not) experienced detectable changes in ecologically-relevant climate variables. The goal is to improve the quality and efficiency of investigations into climate change effects on biodiversity by providing a means to narrow such analyses to areas that truly experienced detectable and biologically-relevant environmental changes. To do this we will use existing publicly-available observational and global climate model (GCM) datasets to estimate the range of internal climate variability (ICV), and then test whether observed trends exceeded the estimated level of background variability or ���������������noise������������������. ICV is a result of coupled interactions in the climate system between the ocean, atmosphere, land surface, and cryosphere. Examples of ICV include the El Nino Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). ICV can be considered the ���������������noise������������������ in the ���������������signal-to-noise ratio������������������ (SNR) when characterizing the strength of the global climate change signal. Thus, the larger (smaller) the ICV for a particular location or climate variable, the harder (easier) it will be to ascertain whether an observed trend is distinguishable from background ICV. We will leverage recent advancements in trend detection and ICV estimation in order to: 1) better understand climate trend uncertainty due to ICV, and 2) estimate the Time of Emergence (ToE) of any relevant climate trends in the recent past and near-term future. Because there are a wide range of species������������������ responses and sensitivities to many different climate variables and climate thresholds, we will apply our method to a large suite of climate variables and indices in collaboration with USGS ecologists. This study provides an opportunity to improve species status and trends assessments by reducing uncertainty about whether observed biological trends are potentially outside of the range of natural ecological variability.

The proposed study is a four-year project to conduct research on the impacts on land use, air quality and regional climate change of biofuel use in Southern and East regions of Africa. Data collection will occur in southern Malawi, centered on several communities participating in a Structured Conditional Transfer program for household cookstove replacements being initiated by a non-governmental organization. Data collected will include those on land use/land cover change, air pollutant emissions, ambient air pollution concentrations, fuel demand and household behavior and decisions. Dr. Pamela Jagger from UNC-CH is the Principal Investigator of the study. Dr. Grieshop will serve as co-PI on the project and will lead the air pollutant emission and air quality measurement components of the study. Air pollutant measurements will include focused emission measurements on indoor air pollution sources (e.g. cookstoves) and other small biofuel-based sources (e.g. brick and charcoal kilns). A network of small, low-cost air quality monitors will be deployed to examine community and regional air quality and also to examine emission sources (e.g. agricultural burning) via near-field concentration measurements.

Wastewater infrastructure is designed to provide safe and efficient conveyance and treatment of sewage to protect human health and the environment. Increasingly though, climate change threatens the effectiveness of this infrastructure, particularly in coastal communities. High tide flooding and extreme precipitation events, as well as sea level rise result in immediate and long-term losses of system functionality. Of special concern to rural areas and small towns is the functionality of decentralized, or on-site wastewater treatment technologies. These systems are at risk with impaired ability to process contaminants, which may lead to human illness, ecosystem damage, and ultimately the un-livability of communities that depend on them. The proposed study will evaluate a suite of onsite wastewater technologies under various climate conditions to help coastal communities cost effectively and legally implement climate adaptation plans for wastewater infrastructure. The research will be conducted in the coastal Carolinas in partnership with communities already experiencing infrastructure threats due to climate change. The study will demonstrate the relative effectiveness of alternative wastewater technologies on the removal of three pollutants: fecal bacteria, phosphorus, and nitrogen. The effort builds on existing understanding of decentralized wastewater infrastructure functionality by wastewater facility operators, private septic experts, and coastal community decision makers. Interview data from these experts will be synthesized into a dataset that will aid in economic analysis of potential adaptation measures. New sampling data will be collected to evaluate existing onsite wastewater systems that are representative of environmental conditions throughout the coastal Carolinas. Economic analysis will be used to estimate the marginal economic return on wastewater infrastructure climate adaptation technologies. Legal analysis will identify alternative wastewater technology regulatory barriers and solutions to these barriers. Finally the research will result in transferable protocols that coastal decision makers and adaptation professionals can use to plan and prepare for climate change with regards to decentralized wastewater infrastructure.