Combined Effects Of Climate Change Research Articles

Editorial: Exploring the combined effect of climate change and pollution on freshwater ecosystems

Editorial: Exploring the combined effect of climate change and pollution on freshwater ecosystems

Combined effects of climate change and agricultural intensification on soil erosion in uphill shifting cultivation in Northeast India

AbstractShifting cultivation will face increasing pressure from erosion‐related land degradation caused by rising cultivation intensities and climate change. However, empirical knowledge about future trends of soil erosion and thus land degradation in shifting cultivation systems is limited. We use the Environmental Policy Integrated Climate (EPIC) model to first explore the combined effects of climate change and agricultural intensification on soil erosion of uphill shifting cultivation systems, using six surveyed soil profiles. We assess interactions between climate change, the length of the fallow period, and slope inclinations for a near (2021–2050) and far (2071–2100) future period, considering three climate scenarios, five climate models, fallow periods between one and 20 years, and slopes between five and 70% steepness. Our results show a significant nonlinear relationship between global warming and erosion. Until the end of the century, erosion is estimated to increase by a factor of 1.2, 2.2, and 3.1 under the SSP126, SSP370, and SSP585 scenarios, respectively, compared with the historical baseline (1985–2014). Combined effects from climate change, fallow length, and slope inclination indicate that steep slopes require longer fallow periods, with an increase of slope from 5% to 10% multiplying the required fallow length by a mean factor of 2.5, and that fallow periods will need to be extended under higher global warming if erosion rates are to remain at current levels. These findings are novel as they link climate change effects on shifting cultivation systems to different slopes and fallow regimes, making an important contribution to understanding future erosion dynamics of traditional smallholder production systems in mountainous terrain, with relevant implications for policies on agricultural intensification.

Future climate change and urban growth together affect surface runoff in a large-scale urban agglomeration

Climate change and urban growth have been shown to alter hydrological processes, particularly surface runoff. While there is widespread evidence of the combined effects of climate change and urban expansion on surface runoff at the watershed scale, little is known about their combined effects at different scales in large-scale urban agglomerations. Using integrated spatial models, we simulated the combined effects of climate change and urban growth on surface runoff in the Beijing-Tianjin-Hebei urban agglomeration, China, in 2030. We found that the surface runoff increased under both climate change and urban growth scenarios but the relative contributions of these two factors to surface runoff change varied from the regional to the sub-city scale. At regional and city scales, climate change was the main control on surface runoff change, while urban growth had the most effect on surface runoff change in the main urban areas of some cities, i.e., the sub-city scale. The results indicate that one single factor does not give reliable information for managing surface runoff in megacities, as the effects of other factors are ignored. These findings highlight that integrated solutions must be tailored to the appropriate spatial scale to effectively regulate surface runoff change across large-scale urban agglomerations.

Effects of ocean warming and pollution on Sargassum forests

The combined effects of climate change and ocean pollution have resulted in a noteworthy decline of canopy-forming species, impacting marine biodiversity and ecosystem functioning significantly. In this context, Sargassum cymosum, which is widely distributed along the southwestern Atlantic Ocean, serves as an excellent model among canopy-forming species to investigate these impacts on populations in different regions and environmental conditions. Here, we evaluate the ecophysiological responses of two populations of S. cymosum, from Florianopolis (warm-temperate province; WTP) and Fernando de Noronha (tropical province, TP), through of interaction of temperatures and nutrient concentrations, representing marine heatwaves and acute pollution levels. Our findings revealed a decrease in biomass in both populations, highlighting the significance of nutrient enrichment as an anthropogenic filter that might potentially inhibit the expansion of the populations from tropical regions and temperature for WTP ones. These stressors directly impacted the physiological performance of S. cymosum populations, including relative growth rates, photosynthesis, chlorophylls, carotenoids and phenolic compound levels. Although there was an increase in both parameters for the TP population, a significant loss of biomass was observed, with growth rates reaching −1.5% per day.Our results highlight the need for urgent actions to manage the eutrophication process due to its negative association with global warming, which can enhance the impacts and preclude the settlement and survival of Sargassum in warm-temperate areas considering the observed and predicted tropicalization process.

Microhabitat conditions drive uncertainty of risk and shape neophobic responses in Trinidadian guppies, Poecilia reticulata.

In response to uncertain risks, prey may rely on neophobic phenotypes to reduce the costs associated with the lack of information regarding local conditions. Neophobia has been shown to be driven by information reliability, ambient risk and predator diversity, all of which shape uncertainty of risk. We similarly expect environmental conditions to shape uncertainty by interfering with information availability. In order to test how environmental variables might shape neophobic responses in Trinidadian guppies (Poecilia reticulata), we conducted an in situ field experiment of two high-predation risk guppy populations designed to determine how the 'average' and 'variance' of several environmental factors might influence the neophobic response to novel predator models and/or novel foraging patches. Our results suggest neophobia is shaped by water velocity, microhabitat complexity, pool width and depth, as well as substrate diversity and heterogeneity. Moreover, we found differential effects of the 'average' and 'variance' environmental variables on food- and predator-related neophobia. Our study highlights that assessment of neophobic drivers should consider predation risk, various microhabitat conditions and neophobia being tested. Neophobic phenotypes are expected to increase the probability of prey survival and reproductive success (i.e. fitness), and are therefore likely linked to population health and species survival. Understanding the drivers and consequences of uncertainty of risk is an increasingly pressing issue, as ecological uncertainty increases with the combined effects of climate change, anthropogenic disturbances and invasive species.

Linking environmental monitoring data and the predicted effects of climate change for urban coastal management: A case study of Dublin Bay

Environmental managers of coastal regions must consider the combined effects of climate change and multiple other stressors simultaneously. While routine monitoring programmes exist, this information is usually summarised as a metric or index for ecological status classification and does not integrate the biological and environmental data in a format that is useful for managers. We present a framework using conditional inference tree analyses and Bayesian Network methodology that synthesises monitoring data, identifies links between environmental and biological variables, and predicts the effects of climate change for Dublin Bay, Ireland. The ecological quality status of phytoplankton biomass was usually high but degraded when silica became limiting. Sediment organic content was positively related to benthic invertebrate richness and the abundance of wading birds, although invertebrate communities were most indicative of pristine conditions when sediment organic content was low. Importantly, climate change simulations showed that the ecological status of Dublin Bay will decline in future, which highlights the importance of removing other stressors from the ecosystem.

Contribution of Communication to the Economic Evaluation of the Direct Use Value of Lake Dem in Burkina Faso

In Burkina Faso, wetlands play an important role in the country’s economy. Dem Lake, one of the Ramsar sites of international importance inscribed in 2009, and is today facing severe degradation under the combined effect of climate change, poverty, population growth, and pressure from anthropogenic activities. Also, the goods and services of the Dem Lake ecosystems have not yet been studied to provide us with information on their costs. This lack of price leads local populations and political and private decision-makers to behave as if the value of the natural heritage is nil. The objective of this study is to assess the economic value of some supply services of Lake Dem. Thus, it is a question of identifying the main services provided by the lake and then estimating their economic value. The tool used is that of the market price technique. This technique measures the quantities of goods consumed or sold and determines the prices at which they are offered on the market. The research made it possible to identify consumer goods by sector of activity such as market gardening, agricultural production, fish production, grazing and the water resource provided by the ecosystem. Similarly, we were able to determine on the basis of the communication, the quantity of the various non-timber forest products that enter into household consumption. The results revealed that the total value of the supply services is estimated at more than two billion two hundred million francs (2,200,000,000) CFA. This estimate does not provide knowledge of the total economic value of Lake Dem, because it is only the direct use value of a few goods and services that have been assessed. Similarly, the indirect use, option and bequest values have not been assessed.

A framework to assess future water-resource under climate change in northern Morocco using hydro-climatic modelling and water-withdrawal scenarios

Study regionThe Bas-Loukkos catchment, a Mediterranean catchment in northern Morocco exposed to growing water withdrawal caused mainly by agricultural development. Study focusFor adaptation to climate change, water managers have to consider the high and various uncertainties. To assess impacts of climate change on projected water resources, this study aimed to develop a smart analysis framework to provide scientific information by exploring the complexity of many projections combined with hydrological models. Uncertainties were quantified using 13 pair-wise combinations of 5 regional climate models forced by 4 global climate models under two emissions scenarios (RCP4.5 and RCP8.5), data with and without bias correction (using empirical quantile mapping), and two sets of GR2M hydrological model parameters corresponding to different precipitation conditions. The Budyko hypothesis was used to analyse combined effects of climate change on water resources according to water-withdrawal scenarios. Climate and hydrological projections have been analyzed over three periods: short-term [2020–2040], medium-term [2041–2060] and long-term [2081–2100]. New hydrological insights for the regionResults from all simulations indicate that, in the long term (2081–2100), precipitation and discharge will decrease by ca. 21–38% and ca. 50–71%, respectively, compared to the reference period (1981–2005). Consequently, this decline in water resources will require water management strategies to adapt to the future climatic conditions and water demand.

Integrative systematics and evolutionary history of Berylmys bowersi (Mammalia, Rodentia, Muridae).

The Bower's Berylmys (Berylmys bowersi) is one of the largest rodent species with a wide distribution range in southern China and the Indochinese Peninsula. The taxonomy and evolutionary history of the B. bowersi is still controversial and confusing. In this study, we used two mitochondrial (Cyt b and COI) and three nuclear (GHR, IRBP, and RAG1) genes to estimate the phylogeny, divergence times, and biogeographic history of B. bowersi. We also explored morphological variations among the specimens collected across China. Our phylogenetic analyses indicated that the traditional B. bowersi contains at least two species: B. bowersi and B. latouchei. Berylmys latouchei was considered a junior synonym of B. bowersi distributed in eastern China, which is confirmed to be distinguishable at specific level because of its larger size, relatively larger and whiter hind feet, and several cranial traits. The estimated split of B. bowersi and B. latouchei was at the early Pleistocene (ca. 2.00 Mya), which might be the outcome of the combined effects of climate change in the early Pleistocene and isolation by the Minjiang River. Our results highlight the Wuyi Mountains in northern Fujian, China, as a glacial refugia during the Pleistocene and call for more intensive surveys and systematic revisions of small mammals in eastern China.

Spatiotemporal Variability of Alpine Meadow Aboveground Biomass and Sustainable Grazing in Light of Climate Warming

Understanding spatiotemporal variability of aboveground biomass (AGB) in alpine grassland ecosystems is required to better formulate sustainable grazing strategies, especially in climate-sensitive areas such as the Qinghai-Tibet Plateau. Drawing from recent modeling results, we analyzed spatial variability in grassland AGB over seasonal and annual timescales. Theoretical livestock carrying capacity (LCC) was predicted in relation to projected warming and simulated pika disturbance. We found that elevation and slope were key determinants of the distribution of AGB and its change. Although grasses and shrubs occupied an equivalent area, the latter generated approximately double the amount of total biomass, but the former generated slightly more available biomass. Although pika habitat extended over 45.3% of the study area, the impacts of pika only reduced the total available AGB (AGBV) by < 0.07%. The actual LCC (2.16 SU · ha−1 [sheep unit per hectare]) of the study area was lower than the theoretical LCC (2.77−2.96 SU · ha−1). Under climate warming scenarios of 1.0°C, 1.5°C, and 2.0°C, the actual LCC can be increased by 0.82-1.25, 0.99-1.53, and 0.77−1.23 SU · ha−1, respectively. Although systematic climate warming increased AGB, impacts were especially marked at lower elevations and on north-facing slopes because of higher soil water availability. Results highlight that rather than implementing LCC in a static manner in light of climate warming, deeper understanding of biomass availability and the combined effects of climate change and topographic heterogeneity is required to support better management of grasslands.

Disentangling the relative effects of climate change and anthropogenic activities on paddy expansion in the northern Sanjiang Plain of China

Since the changes in paddy areas would significantly affect food security and agricultural sustainability, it has received worldwide attention guided by the United Nations 2030 Sustainable Development Goals. However, the process of paddy field change was complex, which was affected by both climate change and anthropogenic activities. Most existing studies focused on the spatial–temporal evolution of paddy field in different regions, while the quantitative separation of climatic and anthropogenic contributions to paddy field expansion was rare but imperative. This study adopted the patch-generating land use simulation (PLUS) model to simulate the paddy field expansion under different scenarios. Based on satellite-based land use data, meteorological data, socioeconomic data, physical geographical data, and transport data, it proposed four indicators, including ACI (anthropogenic contribution index), CCI (climatic contribution index), RII (relative importance index), and CEI (combined effects index) to quantitatively disentangle the climatic and anthropogenic contribution at different scales, and further determined the relative importance and combined effects of climate change and anthropogenic activities. These indicators were applied to the case of northern Sanjiang Plain of China and found that the total area of paddy fields in this area expanded greatly from 2638.88 km2 in 1995 to 19363.80 km2 in 2020. 1) At the regional scale (the northern Sanjiang Plain of China), the effect of climate change was slightly larger than that of anthropogenic activities on the paddy field expansion, with an inhibitory interactive effect of climate change and anthropogenic activities. 2) At the city scale (Hegang, Jiamusi and Shuangyashan), the effect of climate change was slightly stronger than anthropogenic activities in Hegang and Jiamusi, whereas Shuangyashan was the opposite. 3) At the county scale (15 counties), paddy field expansion of the central NSP was dominated by anthropogenic activities, while the northern part was disturbed more by climate change. 4) At the grid scale (30-m resolution), 51.17% of the grids had anthropogenic activities contributing more than climate change to paddy field expansion, and 88.60% of the grids presented an inhibitory interactive effect of climate change and anthropogenic activities. Thus, the indicators established for in this study can not only provide a better understanding of the relative effects of climate change and anthropogenic activities on paddy field expansion, but also give some policy implications for sustainable agricultural practice in both China and other developing countries.

Combined effects of climate change on urban resilience in the Tibetan Plateau

Urban resilience refers to the ability of a city or region to adapt to changes and risks. However, the comprehensive impacts and mechanisms of adaptation and responses to climate change have not been sufficiently examined. Using the measured level of resilience of the Tibetan Plateau (TP) region from 1991 to 2020, the comprehensive static and dynamic effects of temperature and precipitation on urban resilience and the mechanisms thereof are discussed. The results are as follows: (1) The level of general urban resilience on the TP is rising in a fluctuating manner, and the regional differences are gradually increasing. (2) Temperature and precipitation factors play a significant role in increasing the level of resilience on the TP, and the degree of promotion shows regional heterogeneity. (3) Ecological resilience on the TP is most affected by temperature. Economic resilience is most affected by precipitation.

Simulating the effect of climate change on soil microbial community in an Abies georgei var. smithii forest.

Qinghai-Tibet Plateau is considered a region vulnerable to the effects of climate change. Studying the effects of climate change on the structure and function of soil microbial communities will provide insight into the carbon cycle under climate change. However, to date, changes in the successional dynamics and stability of microbial communities under the combined effects of climate change (warming or cooling) remain unknown, which limits our ability to predict the consequences of future climate change. In this study, in situ soil columns of an Abies georgei var. smithii forest at 4,300 and 3,500 m elevation in the Sygera Mountains were incubated in pairs for 1 year using the PVC tube method to simulate climate warming and cooling, corresponding to a temperature change of ±4.7°C. Illumina HiSeq sequencing was applied to study alterations in soil bacterial and fungal communities of different soil layers. Results showed that warming did not significantly affect the fungal and bacterial diversity of the 0-10 cm soil layer, but the fungal and bacterial diversity of the 20-30 cm soil layer increased significantly after warming. Warming changed the structure of fungal and bacterial communities in all soil layers (0-10 cm, 10-20 cm, and 20-30 cm), and the effect increased with the increase of soil layers. Cooling had almost no significant effect on fungal and bacterial diversity in all soil layers. Cooling changed the structure of fungal communities in all soil layers, but it showed no significant effect on the structure of bacterial communities in all soil layers because fungi are more adapted than bacteria to environments with high soil water content (SWC) and low temperatures. Redundancy analysis (RDA) and hierarchical analysis showed that changes in soil bacterial community structure were primarily related to soil physical and chemical properties, whereas changes in soil fungal community structure primarily affected SWC and soil temperature (Soil Temp). The specialization ratio of fungi and bacteria increased with soil depth, and fungi were significantly higher than bacteria, indicating that climate change has a greater impact on microorganisms in deeper soil layers, and fungi are more sensitive to climate change. Furthermore, a warmer climate could create more ecological niches for microbial species to coexist and increase the strength of microbial interactions, whereas a cooler climate could have the opposite effect. However, we found differences in the intensity of microbial interactions in response to climate change in different soil layers. This study provides new insights to understand and predict future effects of climate change on soil microbes in alpine forest ecosystems.

Groundwater Practices and Vulnerability at a Pocket of the Northwest Region of Bangladesh: A Study Based on Social and Hydrogeological Factors

The combined effects of climate change and anthropogenic factors are causing the depletion of the groundwater level in the Northwest region of Bangladesh, leading to the rise of socio-economic stress among the rural marginalised communities. This research aims to assess the current water practices by identifying the changes in water supply sources and associated socio-economic stress to rural marginalised communities. Both social and hydrogeological factors have been taken into consideration for vulnerability assessment. The social factors are (a) percentage of indigenous households, (b) percentage of poor households, (c) percentage using unhygienic water sources and (d) percentage of households having water scarcity. On the other hand, the hydrogeological factors are (a) depth of topsoil, (b) elevation, (c) stream density, (d) slope of the elevation, (e) land use and (f) soil. The geospatial-based weighted linear combination technique combines all the social and hydrogeological factors. The resultant areas are characterised by five categories: very low to very high vulnerability. According to social and hydrogeological factors, Sapahar, Tilna, Dibar, Sihara and Nirmail unions are in the most vulnerable zone.

Cascading, interactive, and indirect effects of climate change on aquatic communities, habitats, and ecosystems

AbstractClimate‐change is rapidly and intensively altering aquatic communities and habitats. While previous work has focused on direct effects of potential drivers, indirect and interactive effects on organisms and ecosystems have received less attention. Here, we give an overview of contributions to a special issue in Limnology and Oceanography that addresses this knowledge gap. Contributions covered diverse habitats, from polar to tropical regions, alpine streams to coral reefs. Several studies relied on time‐series to identify indirect effects, thus emphasizing our need to maintain high‐quality time‐series data. Time‐series are particularly crucial now that the pace of climate‐change on aquatic‐ecosystems is accelerating. Another common theme is the role of species‐specific characteristics in physiology, behavior or genetics in aquatic ecosystem function. The addition of inter‐ and intra‐specific variability to investigations of climate‐change may be challenging particularly since ecosystem studies typically involve a large parameter space of environmental and biological variables across spatial and temporal scales. However, the results demonstrate that inclusion of species‐specific dynamics, although challenging, can deliver mechanistic insights into aquatic ecosystem patterns and processes. Some contributions leverage habitat changes from disturbances or climate shifts to document capacity for resilience or recovery of pelagic and benthic communities. Jointly, the results in this special issue document fruitful approaches and provide urgent information needed for deciphering aquatic ecosystem responses to climate forcings. This information is foundational if we wish to tackle the combined effects of climate change and other human impacts with maximum efficacy and minimize unintended consequences for biodiversity and ecosystem functioning.

Quantifying the independent contributions of climate and land use change to ecosystem services

Ecosystem services (ESs) are critical to human welfare and play an important role in supporting sustainable social and economic development. Climate change (CLC) and land use change (LUCC) are two of the most important factors influencing ESs. However, few studies have tried to distinguish the independent contributions of CLC and LUCC to ESs. Using meteorological, soil, land use, and remote sensing data for Liaoning Province (China) from 2000 to 2020, the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and Carnegie-Ames Stanford Approach (CASA) model were used to construct scenario simulation frameworks based on three hypothetical scenarios: 1) CLC effect only; 2) LUCC effect only; 3) a combined effect of CLC and LULC. The three scenario simulation frameworks were then used to determine the independent contributions of CLC and LUCC to net primary productivity (NPP), water yield (WY), soil retention (SR), and their temporal dynamics. Results showed that under the combined effect of CLC and LULC, NPP, WY and SR in Liaoning Province exhibited a trend of gradual increase from 2000 to 2020, increasing by 124.62 gC/m2, 30.64 mm/a and 0.63 t/km2, respectively. Under the CLC only scenario, WY and SR changed by 6.24% and 2%, respectively, exhibiting a more significant effect than under the LUCC only scenario. In contrast, NPP changed by 25.71% under the LUCC only scenario, which was more significant than under the CLC only scenario. Overall, CLC was found to be the dominant factor affecting changes in WY and SR in Liaoning Province, with independent contribution rates of 81.79%-84.02% and 73.57%-85.44%, respectively, whereas LUCC was the dominant factor affecting changes in NPP with an independent contribution rate of 86.12%-92.50%. Decreased precipitation levels and an increase in temperature were the two primary factors driving fluctuations in the independent contributions of CLC to WY and SR, while large-scale forest land area damage and rapid urbanization were the two primary factors driving fluctuations in the independent contribution of LUCC to NPP. The results of this study identify the specific effects of different climatic conditions on ESs and highlight the conflict between urbanization and ecosystem service provision, providing a theoretical foundation for improving and increasing ESs and regional sustainable development in Liaoning Province.

A System Dynamics Model of Urban Rainstorm and Flood Resilience to Achieve the Sustainable Development Goals

The combined effects of climate change and accelerated urbanization have increased the risk of urban rainstorm and flood disasters, which seriously affects the achievement of the Sustainable Development Goals (SDGs) in cities. Improving urban flood resilience is one of main ways to deal with flooding. This study established an urban rainstorm and flood resilience model to sort out the behavioral mechanisms of multiple subjects (government, flood control department, residents and media) and the internal action mechanisms from different dimensions (economic, social, natural, infrastructure and information) of urban rainstorm and flood resilience using system dynamics approach, and to investigate the urban rainstorm and flood resilience in Xi'an city. The results show that the damage losses rate reduced by 44.44%, 10.8%, 9.48% and 3.37% by improving flood resilience, resident engagement, government attention degree and information construction level, respectively. The degree of improvement of urban rainstorm and flood resilience varied for six development scenarios when predict flood resilience. The development pattern can be divided into the beginning phase, preparation phase and development phase, and three improvement strategies are proposed based on the development pattern of flood resilience. This study helps to provide refined strategies for urban rainstorm and flood resilience assessment construction.

Global degradation trends of grassland and their driving factors since 2000

ABSTRACT Grassland is the second largest terrestrial ecosystem and a fundamental land resource for human survival and development. Although grassland degradation is a recognized and crucial ecological problem, there is no consensus on the area, scope, and degree of its global degradation trends, making the implementation of Sustainable Development Goals (SDG) 15.3 for achieving a land degradation-neutral world uncertain. This study quantitatively explored global grassland degradation trends from 2000 to 2020 by coupling vegetation growth and its response to climate change. Furthermore, the driving factors behind these trends were analyzed, especially in hotspots. Results show that the improvement in global grassland has been remarkable since 2000, with a 1.92 times larger area than degrading grassland, amounting to 372.47 × 104 and 193.57 × 104 km2, respectively. Africa and Asia lead in global grassland degradation and improvement, respectively. Globally, the combined effects of climate change and human activities are the main driving factors for grassland degradation and improvement, accounting for 84.72 and 87.76%, respectively. Notably, human activities played a crucial role in reversing the trend of grassland degradation in some hotspots. Finally, this study provides an essential scientific reference and support for realizing SDG 15.3 on global and regional scales.

Combined effects of climate change and BDE-209 dietary exposure on the behavioural response of the white seabream, Diplodus sargus

Decabromodiphenyl-ether (BDE-209) is a persistent organic pollutant ubiquitously found in marine environments worldwide. Even though this emerging chemical contaminant is described as highly toxic, bioaccumulative and biomagnifiable, limited studies have addressed the ecotoxicological implications associated with its exposure in non-target marine organisms, particularly from a behavioural standpoint. Alongside, seawater acidification and warming have been intensifying their impacts on marine ecosystems over the years, compromising species welfare and survival. BDE-209 exposure as well as seawater acidification and warming are known to affect fish behaviour, but information regarding their interactive effects is not available. In this study, long-term effects of BDE-209 contamination, seawater acidification and warming were studied on different behavioural traits of Diplodus sargus juveniles. Our results showed that D. sargus exhibited a marked sensitivity in all the behaviour responses after dietary exposure to BDE-209. Fish exposed to BDE-209 alone revealed lower awareness of a risky situation, increased activity, less time spent within the shoal, and reversed lateralization when compared to fish from the Control treatment. However, when acidification and/or warming were added to the equation, behavioural patterns were overall altered. Fish exposed to acidification alone exhibited increased anxiety, being less active, spending more time within the shoal, while presenting a reversed lateralization. Finally, fish exposed to warming alone were more anxious and spent more time within the shoal compared to those of the Control treatment. These novel findings not only confirm the neurotoxicological attributes of brominated flame retardants (like BDE-209), but also highlight the relevance of accounting for the effects of abiotic variables (e.g. pH and seawater temperature) when investigating the impacts of environmental contaminants on marine life.

Spatial variability of lightning intensity over the Mediterranean sea correlates with seawater properties

The divergence of total alkalinity (TA) from conservation with salinity (S) and relatively acidic conditions (pH) in surface seawater was suggested to explain the high prevalence of lightning superbolts in the Mediterranean sea, North sea and upwelling regions of the oceans. In this study we tested the combined effects of changes in S, TA and pH of Mediterranean sea surface water on the intensity of laboratory generated electrical sparks, which are considered to be analogous to cloud to sea-surface intensity of lightning discharges. The experimental results were used to develop a multivariate linear equation (MLE) of Lightning Flash Intensity (LFI) as a function of S, TA/S and pH. This relation was validated with wintertime (DJF) LFI measurements along a Mediterranean sea zonal profile during the period 2009–2020 compared to corresponding climate model outputs of S, TA and pH. Based on the resulting MLE, the combined effects of climate change, ocean acidification and the damming of the Nile, may have increased LFI in the Levantine Sea by 16 ± 14% until now relative to the pre-Aswan Dam period. Furthermore, assuming that salinization and acidification of the Levantine Sea will continue at current trends, the LFI is predicted to increase by 25 ± 13% by the year 2050.