Abstract: Urban water systems across the United States are struggling to adapt to an evolving set of threats. Understanding specific pressures and the regional responses to those pressures requires input from practitioners with knowledge of sociotechnological aspects of urban water systems. The Urban Water Innovation Network (UWIN), a consortium of academic institutions and partners supported by the National Science Foundation Sustainability Research Network program, provides a unique opportunity to engage stakeholder and research communities across the U.S. Interactions between UWIN researchers and water stakeholders from five regions (Southeast Florida, Sun Corridor, Mid-Atlantic, Pacific Northwest, and Front Range) form the basis for case studies on transitions toward sustainability. Analysis of qualitative data on pressures, states, and responses collected during interactions provides insight into the challenging context of urban water management. Top pressures identified include climate change, aging infrastructure, water quality impairments, and funding limitations. Additionally, stakeholders described resistance to change and short-term perspectives among elected officials, limited understanding/ awareness of water systems among decision makers, and lack of leadership on water issues as contributing to pressures. More than technological solutions, practitioners call for improved coordination in water management, strengthened communication with elected officials, and behavioral change among citizens. Regarding stakeholder-scientist interactions, participants sought practical outcomes, such as the organization of seemingly abundant scientific products into usable products. The utility of the pressure-state-response model as a framework for data collection and analysis in the context of understanding transitions toward urban water sustainability is discussed and recommendations for future studies are presented.

Abstract: Plantation records from the southeastern United States have long been an important source for historical, social, and cultural narratives. However, they also represent an underutilized source for meteorological, environmental, and agricultural data from the antebellum period. This study has two goals. Firstly, we advocate for a more systematic application of these records for quantitative analysis. Secondly, we present some early results from such a study using the records of Shirley Plantation in Virginia. We show how these records can be mined for data on weather and agricultural activity and how their broader usefulness is extended with the inclusion of appropriate meta-data. Observations of weather conditions and crop responses to seasonal changes lend themselves to quantitative analysis that can improve our understanding of the local weather and climate of that period. We present a case study comparing last spring freeze date in this region from the late 1820s to 2010s and suggest that last spring freeze now occurs approximately 23 days earlier compared to approximately 200 years ago. We also include summaries of the response of specific crops and cultivars since this knowledge may help the farmers' of today adapt to changing weather conditions. While individual plantation records may have idiosyncratic limitations, plantation records, along with other types of detailed historical records, can still provide rich detail for specific locations or events. Plantation records are not limited to the southeastern US and include diverse geographic locations in less developed areas which were often the same areas were enslaved labor was exploited under the plantation system.

Abstract: Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows changes (e.g.,acceleration) to be detected in one or more components. Study of the sea-level budget provides constraints on missing or poorly known contributions, such as the unsurveyed deep ocean or the still uncertain land water component. In the context of the World Climate Research Programme Grand Challenge entitled "Regional Sea Level and Coastal Impacts", an international effort involving the sea-level community worldwide has been recently initiated with the objective of assessing the various datasets used to estimate components of the sea-level budget during the altimetry era (1993 to present). These datasets are based on the combination of a broad range of space-based and in situ observations, model estimates, and algorithms. Evaluating their quality, quantifying uncertainties and identifying sources of discrepancies between component estimates is extremely useful for various applications in climate research. This effort involves several tens of scientists from about 50 research teams/institutions worldwide (www.wcrp-climate.org/grand-challenges/gc-sea-level, last access: 22 August 2018). The results presented in this paper are a synthesis of the first assessment performed during 2017-2018. We present estimates of the altimetry-based global mean sea level (average rate of 3.1 +/- 0.3mm yr(-1) and acceleration of 0.1 mm yr(-2) over 1993-present), as well as of the different components of the sea-level budget (http://doi.org/10.17882/54854, last access: 22 August 2018). We further examine closure of the sea-level budget, comparing the observed global mean sea level with the sum of components. Ocean thermal expansion, glaciers, Greenland and Antarctica contribute 42%, 21%, 15% and 8% to the global mean sea level over the 1993-present period. We also study the sea-level budget over 2005-present, using GRACE-based ocean mass estimates instead of the sum of individual mass components. Our results demonstrate that the global mean sea level can be closed to within 0.3 mm yr(-1) (1 sigma). Substantial uncertainty remains for the land water storage component, as shown when examining individual mass contributions to sea level.

Abstract: This paper presents a new application of an advanced hierarchical sensitivity analysis of a new climate model of barrier island geomorphological evolution. The implemented sensitivity analysis in this study integrates a hierarchical uncertainty framework with a variance-based global sensitivity analysis to decompose the different model input uncertainties. The analysis can provide quantitative and accurate measurements for the relative importance of uncertain model input factors while considering their dependence relationships. The climate model used in this research was the barrier island profile (BIP) model, which is a new computer code developed to simulate barrier island morphological evolution over periods ranging from years to decades under the impacts of accelerated future sea-level rise and long-term changes in the storm climate. In the application of the model, the BIP model was used to evaluate the responses of a series of barrier island cross-sections derived for Santa Rosa Island, Florida, to random storm events and five potential accelerated rates of sea-level rise projected over the next century. The uncertain model input factors thus include the scenario uncertainty caused by alternative future sea-level rise scenarios and the parametric uncertainties of random storm parameters and dune characteristics. The study results reveal that the occurrence of storms is the most important factor for the evolution of sand dunes on the barrier island and the impact of sea-level rise is essential to the morphological change of the island backshore environment. The analysis can provide helpful insights for coastal management and planning. This hierarchical sensitivity analysis is mathematically general and rigorous and can be applied to a wide range of climate models.

Abstract: Many coastal communities around the world are increasingly faced with pressure from sea level rise (SLR). Adapting to the impacts of SLR is now considered inevitable. Many coastal communities in the USA have started to invest in vulnerability assessments that seek to identify the degree of future risk induced by SLR and key vulnerable sectors as well as to provide a sound factual basis for designing and implementing adaptations. However, no study has systematically analyzed the content of these emerging assessments and their quality. This study aims to address this gap by evaluating 64 SLR vulnerability assessments in the USA using an established multi-criteria evaluation framework and by identifying governance factors that affect assessment quality. This study is the first baseline study to understand how the vulnerability of SLR has been assessed by US governments and, more importantly, shed light on pathways for their future improvement. Our analysis finds that the content and quality of the existing assessments vary widely. One-sided assessments that only consider physical exposure are common, and most assessments do not include plans for adaptations. The wealth of the area, amount of funding, mainstreaming efforts, and public awareness are all positively correlated with the assessment quality. We also find that assessments primarily authored by planning staff are lower in quality than those conducted through collaboration. Our findings offer comparative, empirical knowledge for urban planners and coastal managers to improve future vulnerability assessments and adaptation planning for SLR.

Abstract: In Florida, resource use patterns by Armases cinereum (Armases), a highly abundant crab in coastal habitats, may serve as important indicators of habitat condition. Here we investigated feeding patterns of Armases in coastal palm scrub forest to intertidal mangrove forest transition zones (transitions) as well as the relationship between habitat disturbance and Armases' trophic position across three pairs of geographically separated populations in Tampa FL, USA. Each pair of sites represented an unmodified "natural" location as well as a "disturbed" location lacking upland terrestrial palm scrub forested habitat. Laboratory experiments established a baseline understanding of feeding preference of Armases offered strictly mangrove material as well as sources abundant at the transition. In-situ feeding behavior was examined using MixSIAR mixing models with delta13C and delta15N stable isotope tracers. Armases showed a strong preference for consuming partially-decomposed mangrove material from Avicennia germinans and an equally strong preference for Iva frutescens. Armases also displayed predatory behavior under laboratory conditions, confirming omnivory in the presence of mangrove material. Stable isotopes revealed a pattern of elevated trophic position of Armases in disturbed habitats over paired natural locations. Diet reconstruction provided coarse resolution of in-situ feeding and results show high spatial variation: in natural habitats, Armases appears to rely heavily upon upland plant material compared to disturbed habitats where it may consume more animal prey. Combined, these findings support that Armases trophic position and diet may indicate habitat quality in mangrove transitions in the southeastern United States.

Abstract: The potential impact of global temperature change on global crop yield has recently been assessed with different methods. Here we show that grid-based and point-based simulations and statistical regressions (from historic records), without deliberate adaptation or CO2 fertilization effects, produce similar estimates of temperature impact on wheat yields at global and national scales. With a 1 °C global temperature increase, global wheat yield is projected to decline between 4.1% and 6.4%. Projected relative temperature impacts from different methods were similar for major wheat-producing countries China, India, USA and France, but less so for Russia. Point-based and grid-based simulations, and to some extent the statistical regressions, were consistent in projecting that warmer regions are likely to suffer more yield loss with increasing temperature than cooler regions. By forming a multi-method ensemble, it was possible to quantify �method uncertainty� in addition to model uncertainty. This significantly improves confidence in estimates of climate impacts on global food security.

Abstract: Environmental stress gradients can affect species distributions and interspecific interactions. Because environmental stress depends on both intensity and duration, understanding the consequences of stress requires experiments that simultaneously manipulate both dimensions. In Apalachicola Bay, Florida (U.S.A.) the southern oyster drill (Stramonita haemastoma) is a major predator of the eastern oyster (Crassostrea virginica). Drill predation appears to be salinity-dependent: in a recent field study, predation rates were positively correlated with salinity. Salinity in the bay is typically high (> 20) during the dry summer months, conditions that favor both oysters and the drill. However, periodic freshets can dramatically reduce salinity, which inhibits (or kills) drills, but not oysters. In this study, we used field measurements of salinity and drill densities to inform mesocosm experiments. We investigated the specific combinations of intensity and duration of low-salinity stress that inhibit drill predation. In these experiments, more intense salinity reductions reduced feeding both during and after the low-salinity stress event. During the event, longer durations (15 d) were necessary for mild salinity reductions (-5) to reduce the feeding rate by the same amount as a short (5 d) exposure of more intense (-10 or -15) salinity reduction. Both conditions may create a predation refuge for oysters, consistent with field observations. Given that the recent collapse of the Apalachicola Bay oyster population was preceded by several years without low-salinity events to inhibit predation, our results provide a mechanism by which a predator may have contributed to the loss of a historically productive and sustainable fishery.

Abstract: Arthropod vectors are responsible for the transmission of many infectious diseases. Currently, more than three billion people living in endemic areas are exposed to vector-borne pathogens. Substantial differences in the biology of arthropod vectors make it extremely challenging to predict the incidence of vector-borne diseases in the future. However, global warming and urbanization both profoundly affect the ecology and distribution of arthropod vectors. Such processes often result in a biotic homogenization of species in a non-random process of biodiversity loss. The data presently available indicate a trend towards progressive increases in the presence and abundance of vectors capable of thriving in urban environments amongst humans, thus, increasing the contact between vectors and human hosts. As a consequence, we expect the incidence of vector-borne diseases to increase. In our opinion, resources should be made available and directed to strategies within the Integrated Vector Management framework, focusing on proven vector control tools. Besides, a substantial reduction of IVM costs would be achieved by observing environmental guidelines and providing basic sanitary infrastructure at early stages of its development. This could help to increase IVM effectiveness in attenuating social determinants of health and social inequities due to exposure to vectors.

Abstract: Coral reefs are among the most species-rich, productive and economically valuable ecosystems on Earth but increasingly frequent pantropical coral bleaching events are threatening their persistence on a global scale. The 2015-2016 El Nino led to the hottest sea surface temperatures on record and widespread bleaching of shallow-water corals. However, the causes of spatial variation in bleaching are poorly understood, and near-surface estimates of heat stress, such as those inferred from satellites, cannot be generalized across the broad depth ranges occupied by corals. Here, using in situ temperatures recorded across reefs from the near surface to 30-50 m depths in the western, central and eastern Pacific, we show that during the peak of the 2015-2016 anomaly, temperature fluctuations associated with internal waves reduced cumulative heat exposure by up to 88%. The durations of severe thermal anomalies above 8 degrees C-days, at which point widespread coral bleaching and mortality are likely, were also decreased by >36% at some sites and were prevented entirely at others. The impact of internal waves across depths on coral reefs has the potential to create and support thermal refuges in which heat stress and coral bleaching risk may be modulated, but future effects depend on the response of internal wave climates to continued warming and strengthening ocean stratification.