Tropical cyclones are a leading cause of electric power outages, and the time required for power system recovery after storm damage is a critical measure of system resilience. However, systematically collected data on power supply disruptions are available for only a limited number of countries, leaving global patterns largely unexplored. In this study, we conducted the first global analysis of electric power system recovery times after 396 storms across 66 countries from 2012 to 2021, using satellite-based daily nighttime lights (NTLs) derived blackouts following storms. The median duration of blackouts detected worldwide was 4 d, with 5th–95th percentiles of 1–12 d. We found that high density urban areas had significant ( P < 0.05) longer blackout events than low density urban areas and rural areas, which was driven by the upper tail of the events (i.e. 95 percentiles of, respectively, 16, 12, and 11 d). We also found that blackout durations have significantly ( P < 0.05) increased over the study period across all levels of urbanization, at a similar rate of 0.9 ± 0.1 d per decade. The temporal variations (i.e. annual means) of blackout duration of high and low density urban clusters negatively correlated with storm travel speed, while those of low density urban clusters and rural areas positively correlated with pre-storm NTL ( P ⩽ 0.05 in all cases). These findings highlight the pressing need to strengthen the resilience of electric power systems to storms, particularly as global reliance on electricity grows and storm activity patterns shift in response to climate change.

Cyclones cause major damage to mangrove ecosystems globally. While this damage is projected to increase as storms intensify with climate change, the consequences of changes in cyclone attributes other than wind speed remain largely unexplored. Here, we show that shifts in cyclone travel speed may also dramatically alter the risks and mechanisms of damage. By developing an interpretable machine learning model trained with all cyclones recorded worldwide from 2001 to 2021, we find that fast-moving cyclones tend to be especially destructive on steeply sloping coasts, exacerbating physical damage, whereas slow-moving cyclones induce predominantly hydrological damage. Between 1981-2000 and 2001-2020, exposure of global mangrove ecosystems to cyclones increased by 13%, accompanied by substantial changes in cyclone travel speeds, with exposure to slow- and fast-moving cyclones doubling in, respectively, the Caribbean and East Asia. Our results highlight opportunities to integrate regional shifts in cyclone attributes under a changing climate into mangrove management strategies.

To analyse the risks from Tropical Cyclones (TC) to electricity supply, we have combined a large ensemble of TC simulations with a spatial model of power networks and people served, for the entire TC belt globally. The model of electricity power failure, measured in terms of population disrupted, was calibrated against nighttime lights satellite imagery of historic TC events. Use of spatially coherent TC simulations enabled the calculation of electricity supply losses at national, regional and global scales for a range of return periods.We estimate that between 65 and 80 million people lose electric power with a return period of 1 in 100 years, depending on the TC model. Most regions show a worsening of TC-induced outages under climate change (RCP8.5 2050), except for the North Indian Ocean, where there is disagreement between TC models. Climate model uncertainty (across four GCMs) influences the estimated global population at risk by a factor of 0.91-1.05 in 2050.

Tropical cyclones pose a major risk to mangroves, yet the evolution of risk in response to altered cyclone activity under climate change remains largely unexplored. Analyzing 1886 tropical cyclones (1980–2020), we found that mangrove ecosystems were most prone to major cyclones (Category 3–5), and that intense cyclones (Category 4–5) contributed 97% of the global risk of damage. Risk hotspots were found in mangroves bordering the Gulf of Mexico/Caribbean Sea, the South Indian Ocean, and the Northwest Pacific. With warming of 2°C, the risk changes were projected to be modest (+3%) at the global scale but substantial and divergent at the regional level. Risk in North America (including Central America) and Oceania was predicted to increase and decrease by more than 10%, respectively. Our results identify regions where cyclone‐activity‐induced ecosystem changes may be expected and where mangrove management needs to prioritize cyclone resilience.

Levee construction aboveground and hydrocarbon removal from belowground in coastal wetlands can create hydrologic changes that increase plant stress through flooding. But the significance of the subsidence they cause individually or in combination is contested. This study untangled them to demonstrate elevational limits of salt marshes by studying dredged and natural waterways in two salt marshes in Louisiana, USA. The areas had a homogenous plant cover before drilling for oil and gas extraction peaked in the 1960s, and now are a mixed network of natural waterways and dredged canals used to drill wells with an average drill date of 1965.8 ± 2.7 (µ ± 1 SEM; n = 18) and well depth of 4661.0 m ± 56.6 (µ ± 1 SEM; n = 18). Aerial imagery was used to document how canals widened to become 2 to 4 times larger than their original construction width at the high production site and 50% larger at the low production site, whereas increases at the nearby natural channels were much less. Light detection and ranging (LIDAR) measurements at the high production site from 2002 showed that the marsh surface near wells subsided by 34 cm compared to undredged sites. Elevation in marshes at producing and dry wells were equal at the low production site, but high production well locations were even lower than at dry wells. An elevation vs. percent open water curve developed from these data overlapped with an independent analysis of a brackish marsh. A relative subsidence rate between 7.4 to 10.4 mm y−1 transformed these salt marshes to an open water habitat within a few decades. The local creation of accommodation space through hydrocarbon removal and leveed wetlands is a parsimonious explanation for the spatial and temporal land loss rates on this deltaic coast over the last 80 years of oil and gas exploration. Substantial losses from the accelerating rates of sea level rise are indicated to occur before 2050.

Hurricanes pose an increasing threat to coastal environments as the intensity and severity of hurricanes are predicted to increase under the changing climate. Coastal wetlands are effective nature-based defenses of coastal cities against storms. However, the ecosystems themselves are also susceptible to the impacts of hurricanes, which are highly complex and not fully understood. Here we utilize multi-decadal satellite data archives (Landsat 1984-2014 and MODIS 2005-2015) and long-term coast-wide field-based environmental data (1978-2018) to investigate the impacts of hurricanes Katrina (2005), Gustav (2008), and Isaac (2012) on the coastal marshes in Louisiana, USA, where the hurricanes made landfall. While the hurricanes had immediate impacts on the marshes' biomass and area at an ecosystem scale, general recovery was observed in the next one and two years. We also found that the most severe damage always occurred in the intermediate and brackish marshes of the Breton Sound basin, where the nitrogen concentration in the water was significantly higher compared to areas with less damage (P < 0.01). Because excess nutrient can reduce the marshes' root growth and degrade their root mat, we posit that the long-term nutrient enrichment in the area, which resulted from the diverted Mississippi River water, has increased the marshes' susceptibility to hurricanes. The results highlight the resilience of coastal marsh ecosystems against hurricanes, but also underline the profound synergistic effects of climatic and anthropogenic factors on the sustainability of coastal ecosystems, which have important implications for coastal management under the current climate trend.

AbstractCoastal marshes are important carbon sinks facing serious threats from climatic stressors. Current research reveals that the growth of individual marsh plants is susceptible to a changing climate, but the responses of different marsh systems at a landscape scale are less clear. Here, we document the multi‐decadal changes in the phenology and the area of the extensive coastal marshes in Louisiana, USA, a representative of coastal ecosystems around the world that currently experiencing sea‐level rise, temperature warming, and atmospheric CO2 increase. The phenological records are constructed using the longest continuous satellite‐based record of the Earth's ecosystems, the Landsat data, and an advanced modeling technique, the nonlinear mixed model. We find that the length of the growing seasons of the intermediate and brackish marshes increased concomitantly with the atmospheric CO2 concentration over the last 30 years, and predict that such changes will continue and accelerate in the future. These phenological changes suggest a potential increase in CO2 uptake and thus a negative feedback mechanism to climate change. The areas of the freshwater and intermediate marshes were stable over the period studied, but the areas of the brackish and saline marshes decreased substantially, suggesting ecosystem instability and carbon storage loss under the anticipated sea‐level rise. The marshes' phenological shifts portend their potentially critical role in climate mitigation, and the different responses among systems shed light on the underlying mechanisms of such changes.

Presented is a modified test for generating crack permeability data for cementitious materials. Single-parallel cracks were generated in mortar specimens. The width of the cracks was analysed through stereomicroscope and computer tomography, and the water permeability of the cracks was determined. Reduction factors and crack flow models were generated, and the reliability of those predictions was assessed. Cracks analysed through stereomicroscope produced reliable crack permeability predictions ( r 2 = 0.97–0.98), highlighting the importance of testing multiple (≥ 7) replicates. The modified test produced accurate cracks (i.e., cracks that were within 20 µm of their desired crack width) and was easy to use allowing rapid permeability data (i.e., 10 h for 21 specimens) to be generated. The modified test will be of great use for those wanting to generate rapid, accurate, and reliable crack permeability data for cementitious materials.

Coastal wetland restoration can be complex and expensive, so knowing long‐term consequences makes it important to inform decisions about if, when, and where to conduct restoration. We determined temporal changes in land gain and loss in receiving basins and adjacent reference areas for two diversions of the Mississippi River in south Louisiana (Davis Pond and Caernarvon initiated in 1991 and 2002, respectively). Water from both diversions went into receiving basins with vegetated areas as did the adjoining reference areas. The results from two different types of satellite imagery analyses demonstrate a net land loss after diversions began. The results were confirmed for the Caernarvon diversion using a before–after/control–impact analysis of independently collected data over a larger area of the estuary. These results are consistent with an analysis of land gain and loss after a natural levee break on the Mississippi River in 1973. The positive influences of adding new sediments were apparently counter‐balanced by other factors, and consistent with the conclusion from other studies indicating that increased nutrient supply and flooding are, by themselves, negative influences on marsh health. Modeling the ecosystem effects of diversions can be calibrated and tested using landscape‐scale analyses like this to understand the chronic and delayed effects, including the unintended consequences. Basing the legitimacy of river diversion on ecosystem modeling will be premature without successfully reproducing empirical results like these in ecosystem models.

The importance and vulnerability of coastal marshes necessitate effective ways to closely monitor them. Optical remote sensing is a powerful tool for this task, yet its application to diverse coastal marsh ecosystems consisting of different marsh types is limited. This study samples spectral and biophysical data from freshwater, intermediate, brackish, and saline marshes in Louisiana, and develops statistical and machine learning models to assess the marshes' biomass with combined ground, airborne, and spaceborne remote sensing data. It is found that linear models derived from NDVI and EVI are most favorable for assessing Leaf Area Index (LAI) using multispectral data (R-2 = 0.7 and 0.67, respectively), and the random forest models are most useful in retrieving LAI and Aboveground Green Biomass (AGB) using hyperspectral data (R-2 = 0.91 and 0.84, respectively). It is also found that marsh type and plant species significantly impact the linear model development (P < .05 in both cases). Sensors with coarser spatial resolution yield lower LAI values because the fine water networks are not detected and mixed into the vegetation pixels. The Landsat OLI-derived map shows the LAI of coastal mashes in Louisiana mostly ranges from 0 to 5.0, and is highest for freshwater marshes and for marshes in the Atchafalaya Bay delta. The CASI-derived maps show that LAI of saline marshes at Bay Batiste typically ranges from 0.9 to 1.5, and the AGB is mostly less than 900 g/m(2). This study provides solutions for assessing the biomass of Louisiana's coastal marshes using various optical remote sensing techniques, and highlights the impacts of the marshes' species composition on the model development and the sensors' spatial resolution on biomass mapping, thereby providing useful tools for monitoring the biomass of coastal marshes in Louisiana and diverse coastal marsh ecosystems elsewhere.

Drought poses serious threats to the valuable coastal marsh ecosystems, especially considering that the frequency, intensity, and acuteness of drought may increase with prospective climate change. We study the drought-associated phenological changes of Louisiana coastal marshes through combining remote sensing-derived phenological record (i.e., Landsat-derived Normalized Difference Vegetation Index, or NDVI) and field-based environmental data during the past 30 yr. We find that drought condition in southeast Louisiana is characterized by decreased discharge of the Mississippi River and reduced precipitation, which correlate with the continental weather patterns over the conterminous United States influenced by La Nina. The peak NDVI day of saline marshes delays for two months (P < 0.01), from mid-July to mid-September, and their growth duration consequently shortens for two months (P < 0.01) in drought years. Such phenological changes might result from the inhibition of the growth of Spartina alterniflora, a dominant species in saline marshes whose biomass peaks earlier than the coexisting species, perhaps due to reduced freshwater input and increased water deficit. Drought might also cause Spartina dieback via similar mechanisms. Our results underline the correlation between drought in southeast Louisiana and La Nina and highlight the sensitivity of saline marshes to drought, thereby providing valuable information for coastal marsh management and conservation facing climate change.

The Deepwater Horizon oil spill, the second largest marine oil spill in history, contaminated over a thousand kilometers of coastline in the Louisiana salt marshes and seriously threatened this valuable ecosystem. Measuring the impacts of the oil spill over the large and complex coast calls for the application of remote sensing techniques. This study develops a method for post-Deepwater Horizon oil spill monitoring of the damaged marsh vegetation using Landsat imagery. This study utilizes 10 years of Landsat data, from 2005 to 2014, to examine the longevity of the oil spill’s impacts on the marsh vegetation. AVIRIS data collected between 2010 and 2012 are used to validate the Landsat results. Landsat imagery documents the significant effect of oiling on the Normalized Difference Vegetation Index (NDVI) of the marsh vegetation in 2010 and 2011 (p < 0.01 in both cases). These results are corroborated by the AVIRIS data, which recorded the most severe impact in May 2011 followed by progressive recovery in October 2011 and October 2012. The Landsat imagery, combined with relevant environmental information and appropriate statistical tools, provides a robust and low-cost method for long-term post-oil spill monitoring of the marshes, revealing that the major aboveground impacts (at 30 m scale) of the Deepwater Horizon oil spill on Louisiana salt marshes lasted for two years. The method presented is applicable for other hazardous events whenever pre-event referencing and long-term post-event monitoring are desired, thereby offering an effective and economical tool for disaster management.

Coastal ecosystems are under multiple stresses ranging from global climate change to regional hazardous weather and human interventions. Coastal marshes in Louisiana are inherently vulnerable to these threats because they are microtidal and inhabit a narrow portion of the intertidal zone. Phenological dynamics of the marshes offer valuable information on the stressors' impacts, yet they have rarely been reported or compared. Here, we study the landscape-level phenologies of the marshes under different climatic conditions, using Landsat-derived Normalized Difference Vegetation Index (NDVI) records (30 x 30 m(2) spatial resolution) and a nonlinear mixed model that enables a quantitative analysis of nonlinear and piecewise functions involving repeated measures. In 2007 (a normal year), the Gaussian function was the best phenological model for Louisiana coastal marshes (pseudo R-2 0.56-0.85), showing that: (1) NDVI of all marshes peaked within one month from late July to mid-August; (2) freshwater marshes had the highest peak NDVI, followed by intermediate, brackish, and saline marshes; and (3) saline marshes had the longest growth duration, followed by brackish, and then intermediate and freshwater marshes. Phenological shifts were found in years featuring extreme weather events: (1) a two-month delay in the peak NDVI day of saline marshes in 1999 (a drought year) compared to 2007; and (2) a shortening in growth duration of all marshes by approximately half in 2005 (a hurricane year). This work presents a methodgology to analyze and predict Louisiana coastal marshes' phenological dynamics in response to current and future stresses. (C) 2015 Elsevier B.V. All rights reserved.

Salt marshes, inhabiting a narrow portion of the intertidal zone, are vulnerable to various environmental alterations related to climate change. We model Louisiana salt marshes phenology from 1984-2011 using moderate resolution multispectral remote sensing data (i.e. Landsat imagery). Peak Normalized Difference Vegetation Index (NDVI), as an indicator of peak biomass, did not show any significant temporal trend. The annual temperature, sea-level, and atmospheric CO2 concentration increased over time, while the annual precipitation shows no temporal trend. Four principal components are calculated from the original environmental variables (what are these?), but r, none of them was significantly correlated with the peak NDVIs. Therefore, it may be concluded that although the marshes' habitat is climatic-sensitive, their peak NDVIs are resilient to climate change. The long-term record of the salt marsh peak NDVI may serve as a baseline for examining effects of other disastrous events.

With the impending fossil fuel crisis, the search for and development of alternative chemical/material substitutes is pivotal in reducing mankind's dependency on fossil resources. One of the potential substitute candidates is polyhydroxyalkanoate (PHA). PHA is a carbon-neutral and valuable polymer that could be produced from many renewable carbon sources by microorganisms, making it a sustainable and environmental-friendly material. At present, PHA is not cost competitive compared to fossil-derived products. Encouraging and intensifying research work on PHA is anticipated to enhance its economic viability in the future. The development of various biomolecular and chemical techniques for PHA analysis has led to the identification of many PHA-producing microbial strains, some of which are deposited in culture collections. Research work on PHA could be rapidly initiated with these ready-to-use techniques and microbial strains. This review aims to facilitate the start-up of PHA research by providing a summary of commercially available PHA-accumulating microbial cultures, PHA biosynthetic pathways, and methods for PHA detection, extraction and analysis.

A gas chromatography-mass spectrometry method for quantification of polyhydroxyalkanoates (PHAs), containing 4-carbon to 16-carbon monomers, even in the absence of standards, was developed. Strong linear correlations existed between PHA carbon number and retention time/response factor (R(2) ≥ 0.987). Based on the correlations, high recovery values, between 100.5% and 114.3%, were obtained for PHA polymers.

A work applied response surface methodology coupled with Box-Behnken design (RSM-BBD) has been developed to enhance styrene recovery from waste polystyrene (WPS) through pyrolysis. The relationship between styrene yield and three selected operating parameters (i.e., temperature, heating rate, and carrier gas flow rate) was investigated. A second order polynomial equation was successfully built to describe the process and predict styrene yield under the study conditions. The factors identified as statistically significant to styrene production were: temperature, with a quadratic effect; heating rate, with a linear effect; carrier gas flow rate, with a quadratic effect; interaction between temperature and carrier gas flow rate; and interaction between heating rate and carrier gas flow rate. The optimum conditions for the current system were determined to be at a temperature range of 470-505 degrees C, a heating rate of 40 degrees C/min, and a carrier gas flow rate range of 115-140 mL/min. Under such conditions, 64.52% WPS was recovered as styrene, which was 12% more than the highest reported yield for reactors of similar size. It is concluded that RSM-BBD is an effective approach for yield optimization of styrene recovery from WPS pyrolysis. (C) 2014 Elsevier Ltd. All rights reserved.

A rapid HPLC-DAD method for analysis of concentrated BTEX and styrene (BTEXS) aqueous mixtures is reported. Good resolutions of close to or greater than 1.5 were obtained for high equimolar BTEXS concentrations of up to 2.0 mM. At 5.5 min per sample analysis, this method is also one of the fastest HPLC methods to date, providing high throughput analysis and lowering the analysis price.

Pyrolysis is one important way to treat polystyrene waste and upcycle it into useful materials. A comparative pyrolysis study of virgin polystyrene (VPS) and two types of commonly used polystyrene products, expanded polystyrene (EPS) and polystyrene container (CPS) was carried out. Various values were found in the thermodynamic study and kinetic study of VPS, EPS, and CPS pyrolysis, suggesting distinct thermal degradation characteristics of these materials. The energy barrier order of the pyrolysis processes was EPS, CPS, VPS, showing activation energy of 230, 219, and 145 kJ mol−1, respectively. The order of amount of heat absorbed was EPS, CPS, VPS, with enthalpy of 224, 213, and 139 kJ mol−1, respectively. The reaction favorability order was EPS, CPS, and VPS with Gibbs free energy of 118, 132, and 210 kJ mol−1, respectively. Thermogravimetric analysis indicated the use of high heating rate would increase the reaction rate and shorten the reaction time. Product evolution profiles showed that VPS and CPS pyrolysis produced mainly aromatics, while EPS pyrolysis produced aromatics at the initial phase of the reaction and aliphatic hydrocarbon at the latter phase. The diverse pyrolysis behaviors of VPS, EPS, and CPS demonstrated that an examination on different polystyrene materials was desired to optimize the pyrolysis conditions and product distribution, and thus benefit the process of valuable materials recovery.