Climate extremes: observations, modeling, and impacts

Prolonged drought periods over the last four decades increase flood intensity in southern Africa

In semi-arid sub-Saharan Africa, climate change and the intensification of human activities have altered the hydrological balance and modified the recurrence of extreme hydroclimatic events, such as droughts and floods. The geomorphological heterogeneity of river catchments across the region, the variable human pressure, and the lack of continuous hydroclimatic data preclude the definition of proper mitigation strategies, with a direct effect on the sustainability of rural communities. Here, for the first time in Africa, we characterize hydrological extreme events using a multidisciplinary approach that includes sedimentary data from dams. We focus on the Limpopo River basin to evaluate which factors control flood magnitude since the 1970. Extreme flood events were identified across the basin in 1988-89, 1995-96, 1999-2000, 2003-04, 2010-11, 2013-14 and 2016-17. The statistical analysis of sedimentary flood records revealed a dramatic increase in their magnitude over the studied period. A positive correlation between maximum river flow and antecedent prolonged drought conditions was found in South Africa and Mozambique. Most importantly, since 1980, we observed the likely decoupling of extreme floods from the magnitude of La Niña events, suggesting that the natural interannual variability driven by El Niño-Southern Oscillation (ENSO) has been disrupted by climate changes and human activities.

Temperature-driven homogenization of an ant community over 60 years in a montane ecosystem

Identifying the mechanisms underlying the changes in the distribution of species is critical to accurately predict how species have responded and will respond to climate change. Here, we take advantage of a late-1950s study on ant assemblages in a canyon near Boulder, Colorado, USA, to understand how and why species distributions have changed over a 60-year period. Community composition changed over 60 years with increasing compositional similarity among ant assemblages. Community composition differed significantly between the periods, with aspect and tree cover influencing composition. Species that foraged in broader temperature ranges became more widespread over the 60-year period. Our work highlights that shifts in community composition and biotic homogenization can occur even in undisturbed areas without strong habitat degradation. We also show the power of pairing historical and contemporary data and encourage more mechanistic studies to predict species changes under climate change.

Sensitivity of amphibian embryos to timing and magnitude of present and future thermal extremes

Ongoing climate change is increasing the frequency and intensity of extreme temperature events. Unlike the gradual increase on average environmental temperatures, these short-term and unpredictable temperature extremes impact population dynamics of ectotherms through their effect on individual survival. While previous research has predominantly focused on the survival rate of terrestrial embryos under acute heat stress, less attention has been dedicated to the nonlethal effects of ecologically realistic timing and magnitude of temperature extremes on aquatic embryos. In this study, we investigated the influence of the timing and magnitude of current and projected temperature extremes on embryonic life history traits and hatchling behavior in the alpine newt, Ichthyosaura alpestris. Using a factorial experiment under controlled laboratory conditions, we exposed 3- or 10-day-old embryos to different regimes of extreme temperatures for 3 days. Our results show that exposure to different extreme temperature regimes led to a shortened embryonic development time and an increase in hatchling length, while not significantly affecting embryonic survival. The duration of development was sensitive to the timing of temperature extremes, as early exposure accelerated embryo development. Exposure to temperature extremes during embryonic development heightened the exploratory activity of hatched larvae. We conclude that the timing and magnitude of ecologically realistic temperature extremes during embryogenesis have nonlethal effects on life history and behavioral traits. This suggests that species' vulnerability to climate change might be determined by other ecophysiological traits beyond embryonic thermal tolerance in temperate pond-breeding amphibians.

Intra- and interspecific diversity in a tropical plant clade alter herbivory and ecosystem resilience

Declines in biodiversity generated by anthropogenic stressors at both species and population levels can alter emergent processes instrumental to ecosystem function and resilience. As such, understanding the role of biodiversity in ecosystem function and its response to climate perturbation is increasingly important, especially in tropical systems where responses to changes in biodiversity are less predictable and more challenging to assess experimentally. Using large-scale transplant experiments conducted at five neotropical sites, we documented the impacts of changes in intraspecific and interspecific plant richness in the genus Piper on insect herbivory, insect richness, and ecosystem resilience to perturbations in water availability. We found that reductions of both intraspecific and interspecific Piper diversity had measurable and site-specific effects on herbivory, herbivorous insect richness, and plant mortality. The responses of these ecosystem-relevant processes to reduced intraspecific Piper richness were often similar in magnitude to the effects of reduced interspecific richness. Increased water availability reduced herbivory by 4.2% overall, and the response of herbivorous insect richness and herbivory to water availability were altered by both intra- and interspecific richness in a site-dependent manner. Our results underscore the role of intraspecific and interspecific richness as foundations of ecosystem function and the importance of community and location-specific contingencies in controlling function in complex tropical systems.

Geographical distribution and ecological niche dynamics of Crassostrea sikamea (Amemiya, 1928) in China's coastal regions under climate change

Global climate change drives species redistribution, threatening biodiversity and ecosystem heterogeneity. The Kumamoto oyster, Crassostrea sikamea (Amemiya, 1928), one of the most promising aquaculture species because of its delayed reproductive timing, was once prevalent in southern China. In this study, an ensemble species distribution model was employed to analyze the distribution range shift and ecological niche dynamics of C. sikamea along China's coastline under the current and future climate scenarios (RCP 2.6-8.5 covering 2050 s and 2100 s). The model results indicated that the current habitat distribution for C. sikamea consists of a continuous stretch extending from the coastlines of Hainan Province to the northern shores of Jiangsu Province. By the 2050 s, the distribution range will stabilize at its southern end along the coast of Hainan Province, while expanding northward to cover the coastal areas of Shandong Province, showing a more dramatic trend of contraction in the south and invasion in the north by the 2100 s. In RCP8.5, the southern end retracts to the coasts of Guangdong, whereas the northern end covers all of China's coastal areas north of 34°N. C. sikamea can maintain relatively stable ecological niche characteristics, while it may occupy different ecological niche spaces under future climate conditions. Significant niche expansion will occur in lower temperature. We concluded C. sikamea habitats are susceptible to climate change. The rapid northward expansion of C. sikamea may open new possibilities for oyster farming in China, but it will also have important consequences for the ecological balance and biodiversity of receiving areas. It's imperative that we closely examine and strategize to address these repercussions for a win-win situation.

Combined effects of fire and drought are not sufficient to slow shrub encroachment in tallgrass prairie

Woody encroachment-the spread of woody vegetation in open ecosystems-is a common threat to grasslands worldwide. Reversing encroachment can be exceedingly difficult once shrubs become established, particularly clonal species that resprout following disturbance. Single stressors are unlikely to reverse woody encroachment, but using multiple stressors in tandem could be successful in slowing or reversing encroachment. We explored whether increasing fire frequency in conjunction with multi-year drought could reduce growth and survival of encroaching shrubs in a tallgrass prairie in northeastern Kansas, USA. Passive rainout shelters (~ 50% rainfall reduction) were constructed over mature clonal shrubs (Cornus drummondii) and co-existing C4 grasses in two fire treatments (1-year and 4-year burn frequency). Leaf- and whole-plant level physiological responses to drought and fire frequency were monitored in shrubs and grasses from 2019 to 2022. Shrub biomass and stem density following fire were unaffected by five years of consecutive drought treatment, regardless of fire frequency. The drought treatment had more negative effects on grass leaf water potential and photosynthetic rates compared to shrubs. Shrub photosynthetic rates were remarkably stable across each growing season. Overall, we found that five consecutive years of moderate drought in combination with fire was not sufficient to reduce biomass production or stem density in an encroaching clonal shrub (C. drummondii). These results suggest that moderate but chronic press-drought events do not sufficiently stress encroaching clonal shrubs to negatively impact their resilience following fire events, even when fire frequency is high.

Will a changing climate affect hatching success in cavity-nesting birds: A case study with Eastern Bluebirds (Sialia sialis)?

A significant body of evidence indicates that climate change is influencing many aspects of avian ecology. Yet, how climate change is affecting, and is expected to influence some aspects of the breeding ecology of cavity-nesting birds remains uncertain. To explore the potential linkage between timing of first clutch, and the influence of ambient temperature on hatching success, we used Eastern Bluebird (Sialia sialis) nest records over a nine-year period from Alabama, USA. We investigated changes to annual clutch initiation dates, as well as variability in hatching success associated with ambient air temperatures during the incubation period. Using a simple linear model, we observed earlier annual egg laying dates over the nine years of this study with a difference of 24 days between earliest egg-laying date of the season. Daily temperature minima increased 2 °C across the nine-year time frame of this study. These data also indicate that Eastern Bluebird hatching success was the highest when mean ambient air temperature during incubation was between 19 °C and 24 °C (78%, as opposed to 69% and 68% above and below this temperature range, respectively). Our findings of increasing maxima, earlier maxima each year, and the lower minima of temperatures within our study area could expand the breadth of temperatures experienced by nesting Eastern Bluebirds possibly exposing them to temperatures outside of what promotes nesting success. These findings with a cavity-nesting bird highlight an optimal range of ambient temperatures associated with highest hatching success, conditions likely to be affected by climate change.

Exploring the potential of endophyte-plant interactions for improving crop sustainable yields in a changing climate

Climate change poses a major threat to global food security, significantly reducing crop yields as cause of abiotic stresses, and for boosting the spread of new and old pathogens and pests. Sustainable crop management as a route to mitigation poses the challenge of recruiting an array of solutions and tools for the new aims. Among these, the deployment of positive interactions between the micro-biotic components of agroecosystems and plants can play a highly significant role, as part of the agro-ecological revolution. Endophytic microorganisms have emerged as a promising solution to tackle this challenge. Among these, Arbuscular Mycorrhizal Fungi (AMF) and endophytic bacteria and fungi have demonstrated their potential to alleviate abiotic stresses such as drought and heat stress, as well as the impacts of biotic stresses. They can enhance crop yields in a sustainable way also by other mechanisms, such as improving the nutrient uptake, or by direct effects on plant physiology. In this review we summarize and update on the main types of endophytes, we highlight several studies that demonstrate their efficacy in improving sustainable yields and explore possible avenues for implementing crop-microbiota interactions. The mechanisms underlying these interactions are highly complex and require a comprehensive understanding. For this reason, omic technologies such as genomics, transcriptomics, proteomics, and metabolomics have been employed to unravel, by a higher level of information, the complex network of interactions between plants and microorganisms. Therefore, we also discuss the various omic approaches and techniques that have been used so far to study plant-endophyte interactions.

Processes governing species richness in communities exposed to temporal environmental stochasticity: A review and synthesis of modelling approaches

Research into the processes governing species richness has often assumed that the environment is fixed, whereas realistic environments are often characterised by random fluctuations over time. This temporal environmental stochasticity (TES) changes the demographic rates of species populations, with cascading effects on community dynamics and species richness. Theoretical and applied studies have used process-based mathematical models to determine how TES affects species richness, but under a variety of frameworks. Here, we critically review such studies to synthesise their findings and draw general conclusions. We first provide a broad mathematical framework encompassing the different ways in which TES has been modelled. We then review studies that have analysed models with TES under the assumption of negligible interspecific interactions, such that a community is conceptualised as the sum of independent species populations. These analyses have highlighted how TES can reduce species richness by increasing the frequency at which a species becomes rare and therefore prone to extinction. Next, we review studies that have relaxed the assumption of negligible interspecific interactions. To simplify the corresponding models and make them analytically tractable, such studies have used mean-field theory to derive fixed parameters representing the typical strength of interspecific interactions under TES. The resulting analyses have highlighted community-level effects that determine how TES affects species richness, for species that compete for a common limiting resource. With short temporal correlations of environmental conditions, a non-linear averaging effect of interspecific competition strength over time gives an increase in species richness. In contrast, with long temporal correlations of environmental conditions, strong selection favouring the fittest species between changes in environmental conditions results in a decrease in species richness. We compare such results with those from invasion analysis, which examines invasion growth rates (IGRs) instead of species richness directly. Qualitative differences sometimes arise because the IGR is the expected growth rate of a species when it is rare, which does not capture the variation around this mean or the probability of the species becoming rare. Our review elucidates key processes that have been found to mediate the negative and positive effects of TES on species richness, and by doing so highlights key areas for future research.

Insight on thermal stress response of demosponge Chondrosia reniformis (Nardo, 1847)

Global warming has led to an increase in extreme weather and climate phenomena, including floods and heatwaves. Marine heatwaves have frightening consequences for coastal benthic communities around the world. Each species exhibits a natural range of thermal tolerance and responds to temperature variations through behavioral, physiological, biochemical, and molecular adjustments. Physiological stress leading to disease and mass mortality appears when tolerance thresholds are exceeded. Sessile species are therefore particularly affected by these phenomena. Among these sessile species, marine sponges are important members of coral reef ecosystems. To better understand the sponge thermal stress response, we tested the response of demosponge Chondrosia reniformis (Nardo, 1847) to three different temperatures (8 °C, 24 °C and 30 °C) during two exposure periods of time (4 and 14 h). Histological studies of whole parts of the sponge, biochemical analyses (Defense enzymes) and gene expression levels of some target genes were undertaken in this study. The exposure to cold temperature (8 °C) resulted in inhibition of antioxidant enzymes and less modification in the gene expression level of the heat shock proteins (HSPs). These latter were strongly upregulated after exposure to a temperature of 24 °C for 4 h. However, exposure to 30 °C at both periods of time resulted in indication of HSP, antioxidant enzymes, the gene involved in the apoptosis process (Bcl-2: B-cell lymphoma 2), the gene involved in inflammation (TNF: Tumor Necrosis Factor), as well as the aquaporin gene, involved in H2O2 permeation. Moreover, the normal organization of the whole organism was disrupted by the extension and fusion of choanocyte chambers and alteration of the pinacoderm. Interestingly, exposure to sublethal temperatures may show that this sponge has an adaptation threshold temperature. These insights into the adaptation mechanisms of sponges contribute to better management and conservation of sponges and to the prediction of ecosystem trajectories with future climate change.

Bet-hedging in parasitoids: when optimization is not the best strategy to cope with climatic extremes

Bet-hedging occurs when unreliable environments select for genotypes exhibiting a lower variance in fitness at the cost of a lower mean fitness for each batch of progeny. This means that at the level of the genotype, the production of mostly non-optimal phenotypes may be favored when at least some phenotypes are successful. As extreme unreliable climatic events are increasing because of climate change, it is pertinent to investigate the potential of bet-hedging strategies that allow insects to cope with climate change. Evidence for bet-hedging is scarce in most insects, including parasitoids, but the unique lifestyle and biology of parasitoids leads to the expectation that bet-hedging may occur frequently. Here, we evaluate a range of parasitoid traits for which a bet-hedging strategy could be envisioned even if bet-hedging has not been identified as such yet. Under-identification of bet-hedging in nature could have resulted from a major focus of studies on parasitoid life history evolution and foraging behavior on optimality models, predicting how mean fitness can be maximized. Most environmental factors, however, vary unpredictably. Life history and behavioral adaptations are thus expected to be affected by environmental stochasticity. In this paper, we review different aspects of parasitoid behavior, physiology, and life histories and ask the question whether parasitoid traits could have evolved under selection by environmental stochasticity.

Combined effects of climate warming and pharmaceuticals on a tri-trophic freshwater food web

Multiple anthropogenic stressors influence the functioning of lakes and ponds, but their combined effects are often little understood. We conducted two mesocosm experiments to evaluate the effects of warming (+4 °C above ambient temperature) and environmentally relevant concentrations of a mixture of commonly used pharmaceuticals (cardiovascular, psychoactive, antihistamines, antibiotics) on tri-trophic food webs representative of communities in ponds and other small standing waters. Communities were constituted of phyto- and zooplankton and macroinvertebrates (molluscs and insects) including benthic detritivores, grazers, omnivorous scrapers, omnivorous piercers, water column predators, benthic predators, and phytophilous predators. We quantified the main and interactive effects of warming and pharmaceuticals on each trophic level in the pelagic community and attributed them to the direct effects of both stressors and the indirect effects arising through biotic interactions. Warming and pharmaceuticals had stronger effects in the summer experiment, altering zooplankton community composition and causing delayed or accelerated emergence of top insect predators (odonates). In the summer experiment, both stressors and top predators reduced the biomass of filter-feeding zooplankton (cladocerans), while warming and pharmaceuticals had opposite effects on phytoplankton. In the winter experiment, the effects were much weaker and were limited to a positive effect of warming on phytoplankton biomass. Overall, we show that pharmaceuticals can exacerbate the effects of climate warming in freshwater ecosystems, especially during the warm season. Our results demonstrate the utility of community-level studies across seasons for risk assessment of multiple emerging stressors in freshwater ecosystems.

Use of CMIP6 scenarios as a reference to understand the responses of macrophyte germination and seedling growth to future warming and allelopathy co-stressors

The application of appropriate references such as CMIP6 climate scenarios for benchmarking studies of climate change on ecosystems can promote consistency among different climate change research. However, the use of CMIP6 climate scenarios is not common among experiments on the effects of climate change on freshwater ecosystems. Also, little is known about the impact of ecological factor such as allelopathy of alien species on macrophyte germination and seedling growth under different climate scenarios. In our study, by simulating three annual mean temperature changes at global warming levels of 1.5 °C (low warming scenario), 2 °C (medium warming scenario) and 4 °C (high warming scenario) corresponding to CMIP6 multi-model mean change at the corresponding global warming level, we conducted a mesocosm experiment to investigate their possible effects of different climate scenarios and allelopathy co-stressors on macrophyte germination and seedling growth. Our study showed that three warming scenarios all can facilitate macrophyte propagule germination and seedling growth, but the effect paths vary with CMIP6 warming scenarios and there are more influence pathways under high warming scenarios than under low and medium warming scenarios. Higher aqueous extract concentrations of Eichhornia crassipes can significantly stimulate macrophyte propagule germination and seedling growth. And the medium and high warming scenarios may exacerbate the impacts of allelopathic substances on macrophyte germination and seedling growth, and their effects depend on the combination of the two stressors. These results indicated that medium- and high-temperature scenarios may have greater ecological effects on macrophytes than low-temperature scenarios. Thus, our results highlighted that future climate studies need proper benchmarks such as CMIP6 warming scenarios, because it can provide relatively more accurate and realistic simulations, valid comparative results, comprehensive understanding and supportive coordination among researchers.

Identification of influential weather parameters and seasonal drought prediction in Bangladesh using machine learning algorithm

Droughts pose a severe environmental risk in countries that rely heavily on agriculture, resulting in heightened levels of concern regarding food security and livelihood enhancement. Bangladesh is highly susceptible to environmental hazards, with droughts further exacerbating the precarious situation for its 170 million inhabitants. Therefore, we are endeavouring to highlight the identification of the relative importance of climatic attributes and the estimation of the seasonal intensity and frequency of droughts in Bangladesh. With a period of forty years (1981-2020) of weather data, sophisticated machine learning (ML) methods were employed to classify 35 agroclimatic regions into dry or wet conditions using nine weather parameters, as determined by the Standardized Precipitation Evapotranspiration Index (SPEI). Out of 24 ML algorithms, the four best ML methods, ranger, bagEarth, support vector machine, and random forest (RF) have been identified for the prediction of multi-scale drought indices. The RF classifier and the Boruta algorithms shows that water balance, precipitation, maximum and minimum temperature have a higher influence on drought intensity and occurrence across Bangladesh. The trend of spatio-temporal analysis indicates, drought intensity has decreased over time, but return time has increased. There was significant variation in changing the spatial nature of drought intensity. Spatially, the drought intensity shifted from the northern to central and southern zones of Bangladesh, which had an adverse impact on crop production and the livelihood of rural and urban households. So, this precise study has important implications for the understanding of drought prediction and how to best mitigate its impacts. Additionally, the study emphasizes the need for better collaboration between relevant stakeholders, such as policymakers, researchers, communities, and local actors, to develop effective adaptation strategies and increase monitoring of weather conditions for the meticulous management of droughts in Bangladesh.

Identification of candidate regulators of the response to early heat stress in climate-adapted wheat landraces via transcriptomic and co-expression network analyses

Introduction

Climate change is likely to lead to not only increased global temperatures but also a more variable climate where unseasonal periods of heat stress are more prevalent. This has been evidenced by the observation of spring-time temperatures approaching 40°C in some of the main spring-wheat producing countries, such as the USA, in recent years. With an optimum growth temperature of around 20°C, wheat is particularly prone to damage by heat stress. A warming climate with increasingly common fluctuations in temperature therefore threatens wheat crops and subsequently the lives and livelihoods of billions of people who depend on the crop for food. To futureproof wheat against a variable climate, a better understanding of the response to early heat stress is required.

Methods

Here, we utilised DESeq2 to identify 7,827 genes which were differentially expressed in wheat landraces after early heat stress exposure. Candidate hub genes, which may regulate the transcriptional response to early heat stress, were identified via weighted gene co-expression network analysis (WGCNA), and validated by qRT-PCR.

Results

Two of the most promising candidate hub genes (TraesCS3B02G409300 and TraesCS1B02G384900) may downregulate the expression of genes involved in the drought, salinity, and cold responses-genes which are unlikely to be required under heat stress-as well as photosynthesis genes and stress hormone signalling repressors, respectively. We also suggest a role for a poorly characterised sHSP hub gene (TraesCS4D02G212300), as an activator of the heat stress response, potentially inducing the expression of a vast suite of heat shock proteins and transcription factors known to play key roles in the heat stress response.

Discussion

The present work represents an exploratory examination of the heat-induced transcriptional change in wheat landrace seedlings and identifies several candidate hub genes which may act as regulators of this response and, thus, may be targets for breeders in the production of thermotolerant wheat varieties.

Assessing the global vulnerability of dryland birds to heatwaves

As global average surface temperature increases, extreme climatic events such as heatwaves are becoming more frequent and intense, which can drive biodiversity responses such as rapid population declines and/or shifts in species distributions and even local extirpations. However, the impacts of extreme climatic events are largely ignored in conservation plans. Birds are known to be susceptible to heatwaves, especially in dryland ecosystems. Understanding which birds are most vulnerable to heatwaves, and where these birds occur, can offer a scientific basis for adaptive management and conservation. We assessed the relative vulnerability of 1196 dryland bird species to heatwaves using a trait-based approach. Among them, 888 bird species are estimated to be vulnerable to heatwaves (170 highly vulnerable, eight extremely vulnerable), of which ~91% are currently considered non-threatened by the IUCN, which suggests that many species will likely become newly threatened with intensifying climate change. We identified the top three hotspot areas of heatwave-vulnerable species in Australia (208 species), Southern Africa (125 species) and Eastern Africa (99 species). Populations of vulnerable species recorded in the Living Planet Database were found to be declining significantly faster than those of non-vulnerable species (p = .048) after heatwaves occurred. In contrast, no significant difference in population trends between vulnerable and non-vulnerable species was detected when no heatwave occurred (p = .34). This suggests that our vulnerability framework correctly identified vulnerable species and that heatwaves are already impacting the population trends of these species. Our findings will help prioritize heatwave-vulnerable birds in dryland ecosystems in risk mitigation and adaptation management as the frequency of heatwaves accelerates in the coming decades.

Complex adaptive systems-based framework for modeling the health impacts of climate change

Introduction

Climate change is a global phenomenon with far-reaching consequences, and its impact on human health is a growing concern. The intricate interplay of various factors makes it challenging to accurately predict and understand the implications of climate change on human well-being. Conventional methodologies have limitations in comprehensively addressing the complexity and nonlinearity inherent in the relationships between climate change and health outcomes.

Objectives

The primary objective of this paper is to develop a robust theoretical framework that can effectively analyze and interpret the intricate web of variables influencing the human health impacts of climate change. By doing so, we aim to overcome the limitations of conventional approaches and provide a more nuanced understanding of the complex relationships involved. Furthermore, we seek to explore practical applications of this theoretical framework to enhance our ability to predict, mitigate, and adapt to the diverse health challenges posed by a changing climate.

Methods

Addressing the challenges outlined in the objectives, this study introduces the Complex Adaptive Systems (CAS) framework, acknowledging its significance in capturing the nuanced dynamics of health effects linked to climate change. The research utilizes a blend of field observations, expert interviews, key informant interviews, and an extensive literature review to shape the development of the CAS framework.

Results and discussion

The proposed CAS framework categorizes findings into six key sub-systems: ecological services, extreme weather, infectious diseases, food security, disaster risk management, and clinical public health. The study employs agent-based modeling, using causal loop diagrams (CLDs) tailored for each CAS sub-system. A set of identified variables is incorporated into predictive modeling to enhance the understanding of health outcomes within the CAS framework. Through a combination of theoretical development and practical application, this paper aspires to contribute valuable insights to the interdisciplinary field of climate change and health. Integrating agent-based modeling and CLDs enhances the predictive capabilities required for effective health outcome analysis in the context of climate change.

Conclusion

This paper serves as a valuable resource for policymakers, researchers, and public health professionals by employing a CAS framework to understand and assess the complex network of health impacts associated with climate change. It offers insights into effective strategies for safeguarding human health amidst current and future climate challenges.

Climate-Change Impacts on Cephalopods: A Meta-Analysis

Aside from being one of the most fascinating groups of marine organisms, cephalopods play a major role in marine food webs, both as predators and as prey, while representing key living economic assets, namely for artisanal and subsistence fisheries worldwide. Recent research suggests that cephalopods are benefitting from ongoing environmental changes and the overfishing of certain fish stocks (i.e., of their predators and/or competitors), putting forward the hypothesis that this group may be one of the few "winners" of climate change. While many meta-analyses have demonstrated negative and overwhelming consequences of ocean warming (OW), acidification (OA), and their combination for a variety of marine taxa, such a comprehensive analysis is lacking for cephalopod molluscs. In this context, the existing literature was surveyed for peer-reviewed articles featuring the sustained (≥24 h) and controlled exposure of cephalopod species (Cephalopoda class) to these factors, applying a comparative framework of mixed-model meta-analyses (784 control-treatment comparisons, from 47 suitable articles). Impacts on a wide set of biological categories at the individual level (e.g., survival, metabolism, behavior, cell stress, growth) were evaluated and contrasted across different ecological attributes (i.e., taxonomic lineages, climates, and ontogenetic stages). Contrary to what is commonly assumed, OW arises as a clear threat to cephalopods, while OA exhibited more restricted impacts. In fact, OW impacts were ubiquitous across different stages of ontogeny, taxonomical lineages (i.e., octopuses, squids, and cuttlefish). These results challenge the assumption that cephalopods benefit from novel ocean conditions, revealing an overarching negative impact of OW in this group. Importantly, we also identify lingering literature gaps, showing that most studies to date focus on OW and early life stages of mainly temperate species. Our results raise the need to consolidate experimental efforts in a wider variety of taxa, climate regions, life stages, and other key environmental stressors, such as deoxygenation and hypoxia, to better understand how cephalopods will cope with future climate change.

Predicting the Potential Distribution of Haloxylon ammodendron under Climate Change Scenarios Using Machine Learning of a Maximum Entropy Model

Haloxylon ammodendron (H. ammodendron) is a second-class protected plant of national significance in China that is known for its growth in desert and semidesert regions, where it serves as a desert ecosystem guardian by playing a substantial role in maintaining ecosystem structure and function. The changing global climate has substantially altered the growth conditions for H. ammodendron. This study focuses on identifying the key variables influencing the distribution of H. ammodendron and determining their potential impact on future distribution. We employed the Maxent model to evaluate the current climate suitability for H. ammodendron distribution and to project its future changes across various shared socioeconomic pathway (SSP) scenarios. Our findings indicate that precipitation during the warmest quarter and precipitation during the wettest month are the most influential variables affecting the potentially suitable habitats of H. ammodendron. The highly suitable habitat area for H. ammodendron currently covers approximately 489,800 km2. The Maxent model forecasts an expansion of highly suitable H. ammodendron habitat under all future SSP scenarios, with the extent of unsuitable areas increasing with greater global warming. The increased highly suitable habitats range from 40% (SSP585) to 80% (SSP126) by the 2070s (2060-2080). Furthermore, our results indicate a continued expansion of desertification areas due to global warming, highlighting the significant role of H. ammodendron in maintaining desert ecosystem stability. This study offers valuable insights into biodiversity preservation and ecological protection in the context of future climate change scenarios.

Bioacoustic IoT Sensors as Next-Generation Tools for Monitoring: Counting Flying Insects through Buzz

The global loss of biodiversity is an urgent concern requiring the implementation of effective monitoring. Flying insects, such as pollinators, are vital for ecosystems, and establishing their population dynamics has become essential in conservation biology. Traditional monitoring methods are labour-intensive and show time constraints. In this work, we explore the use of bioacoustic sensors for monitoring flying insects. Data collected at four Italian farms using traditional monitoring methods, such as hand netting and pan traps, and bioacoustic sensors were compared. The results showed a positive correlation between the average number of buzzes per hour and insect abundance measured by traditional methods, primarily by pan traps. Intraday and long-term analysis performed on buzzes revealed temperature-related patterns of insect activity. Passive acoustic monitoring proved to be effective in estimating flying insect abundance, while further development of the algorithm is required to correctly identify insect taxa. Overall, innovative technologies, such as bioacoustic sensors, do not replace the expertise and data quality provided by professionals, but they offer unprecedented opportunities to ease insect monitoring to support conservation biodiversity efforts.

Climate change and ecosystem shifts in the southwestern United States

Climate change shifts ecosystems, altering their compositions and instigating transitions, making climate change the predominant driver of ecosystem instability. Land management agencies experience these climatic effects on ecosystems they administer yet lack applied information to inform mitigation. We address this gap, explaining ecosystem shifts by building relationships between the historical locations of 22 ecosystems (c. 2000) and abiotic data (1970-2000; bioclimate, terrain) within the southwestern United States using 'ensemble' machine learning models. These relationships identify the conditions required for establishing and maintaining southwestern ecosystems (i.e., ecosystem suitability). We projected these historical relationships to mid (2041-2060) and end-of-century (2081-2100) periods using CMIP6 generation BCC-CSM2-MR and GFDL-ESM4 climate models with SSP3-7.0 and SSP5-8.5 emission scenarios. This procedure reveals how ecosystems shift, as suitability typically increases in area (~ 50% (~ 40% SD)), elevation (12-15%) and northing (4-6%) by mid-century. We illustrate where and when ecosystems shift, by mapping suitability predictions temporally and within 52,565 properties (e.g., Federal, State, Tribal). All properties had ≥ 50% changes in suitability for ≥ 1 ecosystem within them, irrespective of size (≥ 16.7 km2). We integrated 9 climate models to quantify predictive uncertainty and exemplify its relevance. Agencies must manage ecosystem shifts transcending jurisdictions. Effective mitigation requires collective action heretofore rarely instituted. Our procedure supplies the climatic context to inform their decisions.

Ecological time lags in biodiversity response to habitat changes

The decline of biodiversity can occur with a substantial delay following habitat loss, degradation, and other environmental changes, such as global warming. Considerable time lags may be involved in these responses. However, such time lags typically pose a significant but often unrecognized challenge for biodiversity conservation across a wide range of taxa and ecosystems. Here, we synthesize the current knowledge, categories, manifestations under different scenarios and impacts of ecological time lags. Our work reveals that studies on ecosystem structure lags are far more than ecosystem process and function lags. Due to the presence of these time-lag effects, the 'window phase' typically exists, which is widely recognized as 'relaxation time', providing a particular opportunity for biodiversity conservation. The manifestations of time lags vary under different scenarios. In addition, the different mechanisms that can result in ecological time lags are hierarchically nested, in which mechanisms at the population and metapopulation level have routinely been suggested as explanations for ecological time lags. It generally takes longer time to reach equilibrium at the metapopulation level than it takes for effects to be fully expressed at the level of individuals. Finally, we propose corresponding implications for biodiversity conservation and management. Our research will provide priorities for science and management on how to address the impact of ecological time lags to mitigate future attrition of biodiversity.

High Summer Temperatures and Heat Stroke Mortality in Spain

BACKGROUND

Heat stroke is a significant cause of mortality in response to high summer temperatures. There is limited evidence on the pattern and magnitude of the association between temperature and heat stroke mortality. We examined this association in Spain, using data from a 27-year follow-up period.

METHODS

We used a space-time-stratified case-crossover design. We analyzed data using conditional quasi-Poisson regression with distributed lag nonlinear models.

RESULTS

Spain recorded a total of 285 heat stroke deaths between 1990 and 2016. Heat stroke deaths occurred in 6% of the days in the summer months. The mean temperature was, on average, 5 °C higher on days when a heat stroke was recorded than on days without heat stroke deaths. The overall relative risk was 1.74 (95% confidence interval = 1.54, 1.96) for a 1 °C rise in mean temperature above the threshold of 16 °C, at which a heat stroke death was first recorded. We observed lagged effects as long as 10 days.

CONCLUSIONS

Although heat stroke represents a small fraction of total heat-attributable mortality during the summer, it is strongly associated with high temperatures, providing an immediately visible warning of heat-related risk.

Seasonal advance of intense tropical cyclones in a warming climate

Intense tropical cyclones (TCs), which often peak in autumn1,2, have destructive impacts on life and property3-5, making it crucial to determine whether any changes in intense TCs are likely to occur. Here, we identify a significant seasonal advance of intense TCs since the 1980s in most tropical oceans, with earlier-shifting rates of 3.7 and 3.2 days per decade for the Northern and Southern Hemispheres, respectively. This seasonal advance of intense TCs is closely related to the seasonal advance of rapid intensification events, favoured by the observed earlier onset of favourable oceanic conditions. Using simulations from multiple global climate models, large ensembles and individual forcing experiments, the earlier onset of favourable oceanic conditions is detectable and primarily driven by greenhouse gas forcing. The seasonal advance of intense TCs will increase the likelihood of intersecting with other extreme rainfall events, which usually peak in summer6,7, thereby leading to disproportionate impacts.

Experimental heatwaves facilitate invasion and alter species interactions and composition in a tropical host-parasitoid community

As mean temperatures increase and heatwaves become more frequent, species are expanding their distributions to colonise new habitats. The resulting novel species interactions will simultaneously shape the temperature-driven reorganization of resident communities. The interactive effects of climate change and climate change-facilitated invasion have rarely been studied in multi-trophic communities, and are likely to differ depending on the nature of the climatic driver (i.e., climate extremes or constant warming). We re-created under laboratory conditions a host-parasitoid community typical of high-elevation rainforest sites in Queensland, Australia, comprising four Drosophila species and two associated parasitoid species. We subjected these communities to an equivalent increase in average temperature in the form of periodic heatwaves or constant warming, in combination with an invasion treatment involving a novel host species from lower-elevation habitats. The two parasitoid species were sensitive to both warming and heatwaves, while the demographic responses of Drosophila species were highly idiosyncratic, reflecting the combined effects of thermal tolerance, parasitism, competition, and facilitation. After multiple generations, our heatwave treatment promoted the establishment of low-elevation species in upland communities. Invasion of the low-elevation species correlated negatively with the abundance of one of the parasitoid species, leading to cascading effects on its hosts and their competitors. Our study, therefore, reveals differing, sometimes contrasting, impacts of extreme temperatures and constant warming on community composition. It also highlights how the scale and direction of climate impacts could be further modified by invading species within a bi-trophic community network.

The Neurotoxic Effect of Environmental Temperature Variation in Adult Zebrafish (Danio rerio)

Neurotoxicity consists of the altered functionality of the nervous system caused by exposure to chemical agents or altered chemical-physical parameters. The neurotoxic effect can be evaluated from the molecular to the behavioural level. The zebrafish Danio rerio is a model organism used in many research fields, including ecotoxicology and neurotoxicology. Recent studies by our research group have demonstrated that the exposure of adult zebrafish to low (18 °C) or high (34 °C) temperatures alters their brain proteome and fish behaviour compared to control (26 °C). These results showed that thermal variation alters the functionality of the nervous system, suggesting a temperature-induced neurotoxic effect. To demonstrate that temperature variation can be counted among the factors that generate neurotoxicity, eight different protein datasets, previously published by our research group, were subjected to new analyses using an integrated proteomic approach by means of the Ingenuity Pathway Analysis (IPA) software (Release December 2022). The datasets consist of brain proteome analyses of wild type adult zebrafish kept at three different temperatures (18 °C, 26 °C, and 34 °C) for 4 days (acute) or 21 days (chronic treatment), and of BDNF+/- and BDNF-/- zebrafish kept at 26 °C or 34 °C for 21 days. The results (a) demonstrate that thermal alterations generate an effect that can be defined as neurotoxic (p value ≤ 0.05, activation Z score ≤ -2 or ≥2), (b) identify 16 proteins that can be used as hallmarks of the neurotoxic processes common to all the treatments applied and (c) provide three protein panels (p value ≤ 0.05) related to 18 °C, 34 °C, and BDNF depletion that can be linked to anxiety-like or boldness behaviour upon these treatments.

Overexpression of a Plant-Specific Gγ Protein, AGG3, in the Model Monocot Setaria viridis Confers Tolerance to Heat Stress

The vascular plant-specific, cysteine-rich type III Gγ proteins, which are integral components of the heterotrimeric G-protein complex, play crucial roles in regulating a multitude of plant processes, including those related to crop yield and responses to abiotic stresses. The presence of multiple copies of type III Gγ proteins in most plants and a propensity of the presence of specific truncated alleles in many cultivated crops present an ambiguous picture of their roles in modulating specific responses. AGG3 is a canonical type III Gγ protein of Arabidopsis, and its overexpression in additional model crops offers the opportunity to directly evaluate the effects of protein expression levels on plant phenotypes. We have shown that AGG3 overexpression in the monocot model Setaria viridis leads to an increase in seed yield. In this study, we have investigated the response of the S. viridis plants overexpressing AGG3 to heat stress (HS), one of the most important abiotic stresses affecting crops worldwide. We show that a short span of HS at a crucial developmental time point has a significant effect on plant yield in the later stages. We also show that plants with higher levels of AGG3 are more tolerant to HS. This is attributed to an altered regulation of stress-responsive genes and improved modulation of the photosynthetic efficiency during the stress. Overall, our results confirm that AGG3 plays a crucial role in regulating plant responses to unfavorable environmental conditions and may contribute positively to avoiding crop yield losses.

Saharan, Aral-Caspian and Middle East dust travels to Finland (1980-2022)

Studies on atmospheric dust and long-range transport of mineral dust have been a focus of atmospheric science in recent years. With its wide range of direct and indirect effects, mineral dust is one of the most uncertain elements in the mechanisms of climate change, and a deeper understanding of its role is essential for understanding future processes. The aim of our research was to provide the first systematic data on the so far episodically documented northward transport mineral dust from arid-semiarid areas. So, in this paper, we present dust storm events from lower latitudes reaching the Finnish atmosphere, based on the MERRA-2 model Dust Column Mass Density data and after a multistep verification procedure using independent data source. In total, 86 long-range dust storm events were identified between 1980 and 2022, when air masses loaded with dust reached Finland. Based on backward-trajectories different sources were identified: 59 were Saharan, 22 were Aral-Caspian, and five were associated with Middle Eastern source areas. Considerable variation in inter-annual frequencies was observed among the source areas, which may be due to changes in circulation conditions and the effects of human activity (agriculture and land use changes in Aral Sea region). There is a clear maximum of dust events in spring (60%), followed by summer and autumn (where 10 of the 11 autumn episodes were from the Sahara). However, the number and proportion of scarce winter events have more than doubled since 2010 compared to the preceding 30 years, but no autumn events were registered during this period. This clear temporal variation coincides with changes in dust transport observed in other regions of Europe, driven by greater atmospheric meridionality associated with climate change and driven by reduced temperature difference between low and high latitudes due to enhanced temperature increases at Arctic regions.

Can we meaningfully estimate the impacts of climate on zooplankton biodiversity? A review on uses and limitations of marine time series

Climate events compromise ecosystems functioning and services. Marine zooplankton play a key role linking primary producers and higher consumers, in the carbon export to deeper regions, and respond quickly to environmental change. We conducted a systematic review to assess the effects of climate on marine zooplankton diversity. We describe the major findings, uses and limitations raised in the literature from worldwide time series ≥5 years. Thirty-five studies were included and only 6 presented extractable data (i.e., those that could be extracted from images) for the most studied group (i.e., copepods). Responses to climate were conflicting, and studies were mostly restricted to the global north, applied richness, alpha- and beta-diversity equally, and had a large number of unresolved taxonomic identification. Standardized open long-term data would meaningfully help unveiling assemblage reorganization and allow meta-analyses to improve our understanding of the effects of climate change and variability on zooplankton biodiversity.

East Asian summer rainfall stimulated by subseasonal Indian monsoonal heating

The responses of the East Asian summer monsoon (EASM) to the Indian summer monsoon (ISM) have been the subject of extensive investigation. Nevertheless, it remains uncertain whether the ISM can serve as a predictor for the EASM. Here, on the basis of both observations and a large-ensemble climate model experiment, we show that the subseasonal variability of abnormal diabatic heating over India enhances precipitation over central East China, the Korean Peninsula, and southern Japan in June. ISM heating triggers Rossby wave propagation along the subtropical jet, promoting southerly winds over East Asia. The southerly winds helps steer anomalous mid-tropospheric warm advection and lower-tropospheric moisture advection toward East Asia, providing conditions preferential for rainband formation. Cluster analysis shows that, depending on jet structures, ISM heating can serve as a trigger as well as a reinforcer of the rainband.

Interactions of urbanisation, climate variability, and infectious disease dynamics: insights from the Coimbatore district of Tamil Nadu

Climate change and shifts in land use/land cover (LULC) are critical factors affecting the environmental, societal, and health landscapes, notably influencing the spread of infectious diseases. This study delves into the intricate relationships between climate change, LULC alterations, and the prevalence of vector-borne and waterborne diseases in Coimbatore district, Tamil Nadu, India, between 1985 and 2015. The research utilised Landsat-4, Landsat-5, and Landsat-8 data to generate LULC maps, applying the maximum likelihood algorithm to highlight significant transitions over the years. This study revealed that built-up areas have increased by 67%, primarily at the expense of agricultural land, which was reduced by 51%. Temperature and rainfall data were obtained from APHRODITE Water Resources, and with a statistical analysis of the time series data revealed an annual average temperature increase of 1.8 °C and a minor but statistically significant rainfall increase during the study period. Disease data was obtained from multiple national health programmes, revealing an increasing trend in dengue and diarrhoeal diseases over the study period. In particular, dengue cases surged, correlating strongly with the increase in built-up areas and temperature. This research is instrumental for policy decisions in public health, urban planning, and climate change mitigation. Amidst limited research on the interconnections among infectious diseases, climate change, and LULC changes in India, our study serves as a significant precursor for future management strategies in Coimbatore and analogous regions.

A pervasive phosphorylation cascade modulation of plant transcription factors in response to abiotic stress

MAIN CONCLUSION

Transcriptional regulation of stress-responsive genes is a crucial step in establishing the mechanisms behind plant abiotic stress tolerance. A sensitive method of regulating transcription factors activity, stability, protein interaction, and subcellular localization is through phosphorylation. This review highlights a widespread regulation mechanism that involves phosphorylation of plant TFs in response to abiotic stress. Abiotic stress is one of the main components limiting crop yield and sustainability on a global scale. It greatly reduces the land area that is planted and lowers crop production globally. In all living organisms, transcription factors (TFs) play a crucial role in regulating gene expression. They participate in cell signaling, cell cycle, development, and plant stress response. Plant resilience to diverse abiotic stressors is largely influenced by TFs. Transcription factors modulate gene expression by binding to their target gene's cis-elements, which are impacted by genomic characteristics, DNA structure, and TF interconnections. In this review, we focus on the six major TFs implicated in abiotic stress tolerance, namely, DREB, bZIP, WRKY, ABF, MYB, and NAC, and the cruciality of phosphorylation of these transcription factors in abiotic stress signaling, as protein phosphorylation has emerged as one of the key post-translational modifications, playing a critical role in cell signaling, DNA amplification, gene expression and differentiation, and modification of other biological configurations. These TFs have been discovered after extensive study as stress-responsive transcription factors which may be major targets for crop development and important contributors to stress tolerance and crop production.

Effect of brief exposures of anesthesia on thermotolerance and metabolic rate of the spotted-wing fly, Drosophila suzukii: Differences between sexes?

The spotted-wing fly, Drosophila suzukii, is a world-wide pest insect for which there is increasing interest in its physiological traits including metabolism and thermotolerance. Most studies focus only on survival to different time exposures to extreme temperatures, mainly in female flies. In addition, it has not been tested yet how anesthesia affects these measurements. We analyzed the effects of anesthesia by brief exposures to cold, anoxia by CO2 or N2 on three standard thermotolerance assays, as well as the aerobic metabolic rate in both sexes. For heat tolerance we measured CTmax by thermolimit respirometry, and CTmin and chill-coma recovery time for cold tolerance. Aerobic metabolism was calculated by CO2 production of individual flies in real time by open flow respirometry. Results showed that females have a significantly higher V̇CO2 for inactive (at 25 °C) and maximum metabolic rate than males. This difference is mainly explained by body mass and disappears after mass correction. Males had a more sensitive MR to temperature than females showed by a significantly higher Q10 (2.19 vs. 1.98, for males and females, respectively). We observed a significantly lower CTmin (X2 = 4.27, P = 0.03) in females (3.68 ± 0.38 °C) than males (4.56 ± 0.39 °C), although we did not find significant effects of anesthesia. In contrast, anesthesia significantly modifies CTmax for both sexes (F3,62 = 7.86, P < 0.001) with a decrease of the CTmax in cold-anesthetized flies. Finally, we found a significantly higher CTmax in females (37.87 ± 0.07 °C) than males (37.36 ± 0.09 °C). We conclude that cold anesthesia seems to have detrimental effects on heat tolerance, and females have broader thermotolerance range than males, which could help them to establish in invaded temperate regions with more variable environmental temperatures.

Meta-analysis reveals impacts of disturbance on reptile and amphibian body condition

Ecosystem disturbance is increasing in extent, severity and frequency across the globe. To date, research has largely focussed on the impacts of disturbance on animal population size, extinction risk and species richness. However, individual responses, such as changes in body condition, can act as more sensitive metrics and may provide early warning signs of reduced fitness and population declines. We conducted the first global systematic review and meta-analysis investigating the impacts of ecosystem disturbance on reptile and amphibian body condition. We collated 384 effect sizes representing 137 species from 133 studies. We tested how disturbance type, species traits, biome and taxon moderate the impacts of disturbance on body condition. We found an overall negative effect of disturbance on herpetofauna body condition (Hedges' g = -0.37, 95% CI: -0.57, -0.18). Disturbance type was an influential predictor of body condition response and all disturbance types had a negative mean effect. Drought, invasive species and agriculture had the largest effects. The impact of disturbance varied in strength and direction across biomes, with the largest negative effects found within Mediterranean and temperate biomes. In contrast, taxon, body size, habitat specialisation and conservation status were not influential predictors of disturbance effects. Our findings reveal the widespread effects of disturbance on herpetofauna body condition and highlight the potential role of individual-level response metrics in enhancing wildlife monitoring. The use of individual response metrics alongside population and community metrics would deepen our understanding of disturbance impacts by revealing both early impacts and chronic effects within affected populations. This could enable early and more informed conservation management.

Predicting rare events using neural networks and short-trajectory data

Estimating the likelihood, timing, and nature of events is a major goal of modeling stochastic dynamical systems. When the event is rare in comparison with the timescales of simulation and/or measurement needed to resolve the elemental dynamics, accurate prediction from direct observations becomes challenging. In such cases a more effective approach is to cast statistics of interest as solutions to Feynman-Kac equations (partial differential equations). Here, we develop an approach to solve Feynman-Kac equations by training neural networks on short-trajectory data. Our approach is based on a Markov approximation but otherwise avoids assumptions about the underlying model and dynamics. This makes it applicable to treating complex computational models and observational data. We illustrate the advantages of our method using a low-dimensional model that facilitates visualization, and this analysis motivates an adaptive sampling strategy that allows on-the-fly identification of and addition of data to regions important for predicting the statistics of interest. Finally, we demonstrate that we can compute accurate statistics for a 75-dimensional model of sudden stratospheric warming. This system provides a stringent test bed for our method.

Co-expression network analysis of diverse wheat landraces reveals markers of early thermotolerance and a candidate master regulator of thermotolerance genes

Triticum aestivum L. (bread wheat) is a crop relied upon by billions of people around the world, as a major source of both income and calories. Rising global temperatures, however, pose a genuine threat to the livelihood of these people, as wheat growth and yields are extremely vulnerable to damage by heat stress. Here we present the YoGI wheat landrace panel, comprising 342 accessions that show remarkable phenotypic and genetic diversity thanks to their adaptation to different climates. We quantified the abundance of 110 790 transcripts from the panel and used these data to conduct weighted co-expression network analysis and to identify hub genes in modules associated with abiotic stress tolerance. We found that the expression of three hub genes, all heat-shock proteins (HSPs), were significantly correlated with early thermotolerance in a validation panel of landraces. These hub genes belong to the same module, with one (TraesCS4D01G207500.1) being a candidate master-regulator potentially controlling the expression of the other two hub genes, as well as a suite of other HSPs and heat-stress transcription factors (HSFs). In this work, therefore, we identify three validated hub genes, the expression of which can serve as markers of thermotolerance during early development, and suggest that TraesCS4D01G207500.1 is a potential master regulator of HSP and HSF expression - presenting the YoGI landrace panel as an invaluable tool for breeders wishing to determine and introduce novel alleles into modern varieties, for the production of climate-resilient crops.

The role of climate change and urban development on compound dry-hot extremes across US cities

Compound dry-hot extreme (CDHE) events pose greater risks to the environment, society, and human health than their univariate counterparts. Here, we project decadal-length changes in the frequency and duration of CDHE events for major U.S. cities during the 21st century. Using the Weather Research and Forecasting (WRF) model coupled to an urban canopy parameterization, we find a considerable increase in the frequency and duration of future CDHE events across all U.S. major cities under the compound effect of high-intensity GHG- and urban development-induced warming. Our results indicate that while GHG-induced warming is the primary driver of the increased frequency and duration of CDHE events, urban development amplifies this effect and should not be neglected. Furthermore, We show that the highest frequency amplification of major CDHE events is expected for U.S. cities across the Great Plains South, Southwest, and the southern part of the Northwest National Climate Assessment regions.

Global transportation infrastructure exposure to the change of precipitation in a warmer world

Transportation infrastructures are generally designed to have multi-decadal service lives. Transport infrastructure design, however, is largely based on historical conditions. Yet, in the face of global warming, we are likely going to experience more intense and frequent extreme events, which may put infrastructure at severe risk. In this study, we comprehensively analyze the exposure of road and railway infrastructure assets to changes in precipitation return periods globally. Under ~2 degrees of warming in mid-century (RCP 8.5 scenario), 43.6% of the global transportation assets are expected to experience at least a 25% decrease in design return period of extreme rainfall (a 33% increase in exceedance probability), which may increase to 69.9% under ~4 degrees of warming by late-21st century. To accommodate for such increases, we propose to incorporate a safety factor for climate change adaptation during the transportation infrastructure design process to ensure transportation assets will maintain their designed risk level in the future. Our results show that a safety factor of 1.2 would work sufficient for most regions of the world for quick design process calculations following the RCP4.5 path.

The increase in intensity and frequency of surface air temperature extremes throughout the western South Atlantic coast

The climate is changing. At this stage, it is important to specify an 'extreme' climate and identify patterns that indicate its potential harm worldwide, including the coastal zones. Herein, we considered extremes based on the "Peaks Over Threshold" method from the "Extreme Value Theory". We looked after geographical patterns of surface air temperature (SAT) extremes (e.g., Tmax, Tmin, daily temperature range (DTR), and inter-daily temperature range) over the last 40 years throughout the Brazilian coast. Overall, we found a trend increase in intensity and frequency, but the duration was barely affected. The latitudinal pattern of extremes and the temperatures considered extremes followed the settled perception that areas in higher latitudes will be more affected by the extent of warming. Additionally, the seasonal pattern of DTR demonstrated to be a good approach to make inferences about air mass changes, but joint analyses on extremes with other atmospheric variables are desirable. Given the potential effects of extreme climates on society and natural systems over the world, our study highlights the urge for action to mitigate the effects of the increase in SAT in coastal zones.

Temperature variability and metabolic adaptation in terrestrial and aquatic ectotherms

Thermodynamics is a major factor determining rates of energy expenditure, rates of biochemical dynamics, and ultimately the biological and ecological processes linked with resilience to global warming in ectothermic organisms. Nonetheless, whether ectothermic organisms exhibit general adaptive metabolic responses to cope with worldwide variation in thermal conditions has remained as an open question. Here we combine a model comparison approach with a global dataset of standard metabolic rates (SMR), including 1,160 measurements across 788 species of aquatic invertebrates, insects, fishes, amphibians and reptiles, to investigate the association between metabolic rates and environmental temperatures in their respective habitats. Our analyses suggest that variation in SMR after removing allometric and thermodynamic effects is best explained by the temperature range encountered across seasons, which always provided a better fit than the average temperature for the hottest and coldest month and mean annual temperatures. This pattern was consistent across taxonomic groups and robust to sensitivity analyses. Nonetheless, aquatic and terrestrial lineages responded differently to seasonality, with SMR declining - 6.8% °C^-1 of thermal range across seasons in aquatic organisms and increasing 2.8% °C^-1 in terrestrial organisms. These responses may reflect alternative strategies to mitigate the impact of increments in warmer temperatures on energy expenditure, either by means of metabolic reduction in thermally homogeneous water bodies or effective behavioral thermoregulation to exploit temperature heterogeneity on land.

A multi-modal machine learning approach to detect extreme rainfall events in Sicily

In 2021 almost 300 mm of rain, nearly half of the average annual rainfall, fell near Catania (Sicily Island, Italy). Such events took place in just a few hours, with dramatic consequences on the environmental, social, economic, and health systems of the region. These phenomena are now very common in various countries all around the world: this is the reason why, detecting local extreme rainfall events is a crucial prerequisite for planning actions, able to reverse possibly intensified dramatic future scenarios. In this paper, the Affinity Propagation algorithm, a clustering algorithm grounded on machine learning, was applied, to the best of our knowledge, for the first time, to detect extreme rainfall areas in Sicily. This was possible by using a high-frequency, large dataset we collected, ranging from 2009 to 2021 which we named RSE (the Rainfall Sicily Extreme dataset). Weather indicators were then been employed to validate the results, thus confirming the presence of recent anomalous rainfall events in eastern Sicily. We believe that easy-to-use and multi-modal data science techniques, such as the one proposed in this study, could give rise to significant improvements in policy-making for successfully contrasting climate change.

Potential Effects of High Temperature and Heat Wave on Nanorana pleskei Based on Transcriptomic Analysis

In the context of climate change, understanding how indigenous amphibians of the Qinghai-Tibet plateau react to stresses and their coping mechanisms could be crucial for predicting their fate and successful conservation. A liver transcriptome for Nanorana pleskei was constructed using high-throughput RNA sequencing, and its gene expression was compared with frogs acclimated under either room temperature or high temperature and also heat wave exposed ones. A total of 126,465 unigenes were produced, with 66,924 (52.92%) of them being annotated. Up to 694 genes were found to be differently regulated as a result of abnormal temperature acclimatization. Notably, genes belonging to the heat shock protein (HSP) family were down-regulated in both treated groups. Long-term exposure to high-temperature stress may impair the metabolic rate of the frog and trigger the body to maintain a hypometabolic state in an effort to survive challenging times. During heat waves, unlike the high-temperature group, mitochondrial function was not impaired, and the energy supply was largely normal to support the highly energy-consuming metabolic processes. Genes were more transcriptionally suppressed when treated with high temperatures than heat waves, and the body stayed in low-energy states for combating these long-term adverse environments to survive. It might be strategic to preserve initiation to executive protein activity under heat wave stress. Under both stress conditions, compromising the protection of HSP and sluggish steroid activity occurred in frogs. Frogs were more affected by high temperatures than by heat waves.

Characteristics of the extreme precipitation and its impacts on ecosystem services in the Wuhan Urban Agglomeration

Summer extreme precipitation is one of the most frequent, intense, and influential extreme weather events that occurs frequently in the Wuhan Urban Agglomeration (WUA). Preventing meteorological disasters and coping with climate change necessitate understanding the characteristics and causes of extreme precipitation and its impact on ecosystems. In this study, the spatiotemporal characteristics of summer extreme precipitation in the WUA are analysed from 1961 to 2020. Then, NCEP reanalysis data and the relevant circulation index are used to explore the causes of extreme precipitation. Finally, how extreme precipitation influences key ecosystem services, such as water yield, water regulation, and soil conservation, is investigated. The results reveal that (1) extreme precipitation in the WUA has shown an obvious upwards trend over the past 60 years. Huanggang, Xianning, Huangshi, Wuhan, and E'zhou city demonstrate the highest values. The extreme precipitation increased significantly after 1980s, especially the R97.5P and PRCPTOT with change rate of 12.1 mm/10a and 18.82 mm/10a respectively. (2) Atmospheric circulation variation is a dominant factor affecting extreme precipitation in the WUA and causes the meridional distribution of the "+ - +" wave train in eastern China. The intensity and location of the Western Pacific subtropical high are closely related to extreme precipitation. Furthermore, the weakening of the East Asian summer monsoon circulation is also conducive to the occurrence of extreme precipitation. (3) The spatial distribution of water yield and runoff retention in abnormal extreme precipitation years are similar to the variation patterns of the total amount of extreme precipitation. Water yield and runoff retention in high-value extreme precipitation years are higher than that in low-value extreme precipitation years, while soil conservation shows no difference. In addition, ecosystem services have a synergistic relationship in high-value areas and a trade-off relationship in low-value areas. This study can contribute to the understanding of extreme precipitation in the WUA and its interaction with ecosystem services.

Different and unified responses of soil bacterial and fungal community composition and predicted functional potential to 3 years’ drought stress in a semiarid alpine grassland

Introduction

Soil microbial communities are key to functional processes in terrestrial ecosystems, and they serve as an important indicator of grasslands status. However, the responses of soil microbial communities and functional potential to drought stress in semiarid alpine grasslands remain unclear.

Methods

Here, a field experiment was conducted under ambient precipitation as a control, −20% and −40% of precipitation to explore the responses of soil microbial diversity, community composition, and predicted functional potential to drought stress in a semiarid alpine grassland located in the northwest of China. Moreover, 16S rRNA gene and ITS sequencing were used to detect bacterial and fungal communities, and the PICRUST and FUNGuild databases were used to predict bacterial and fungal functional groups.

Results

Results showed drought stress substantially changes the community diversity of bacteria and fungi, among which the bacteria community is more sensitive to drought stress than fungi, indicating that the diversity or structure of soil bacteria community could serve as an indicator of alpine grasslands status. However, the fungal community still has difficulty maintaining resistance under excessive drought stress. Our paper also highlighted that soil moisture content, plant diversity (Shannon Wiener, Pieiou, and Simpson), and soil organic matter are the main drivers affecting soil bacterial and fungal community composition and predicted functional potential. Notably, the soil microbial functional potential could be predictable through taxonomic community profiles.

Conclusion

Our research provides insight for exploring the mechanisms of microbial community composition and functional response to climate change (longer drought) in a semiarid alpine grassland.

Global change effects on Mediterranean small mammal population dynamics: Demography of Algerian mice (Mus spretus) along land use and climate gradients

Climate and land use change are key global change drivers shaping future species' distributions and abundances. Negative interactions among effects of drivers can reduce the accuracy of models aimed at predicting such distributions. Here we analyse how climate and land use affected population dynamics and demography of the Algerian mouse (Mus spretus), an open-land thermophilic Mediterranean small mammal. Change to a warmer and drier climate would facilitate the expansion of the species, whereas landscape change (forest encroachment following extensive land abandonment) would produce its retreat. We correlated abundance and demography parameters computed from captures obtained in 16 plots during a 10-years period (2008-2017; SEMICE small mammal monitoring) with climate, vegetation and land use change. Climate became warmer and dryer, and afforestation due to encroachment occurred in 81 % of plots. Expected positive effects of climate warming, derived from bioclimatic niche models, were counterbalanced by negative effects of both increasing hydric deficit and changes in vegetation and landscape structure. Abundance showed a slight but significant decline (-5 %). The species' range was more resilient to change, as shown by occupancy analyses, apparently due to strong local effects of vegetation structure on occupancy. This result highlighted that negative population trends would not necessarily produce range retractions. Simultaneously analysing both abundance trends and occupancy patterns may thus allow for deeper understanding and more accurate predictions of expected population trends in response to interacting global change drivers.

Dual-Mode Integrated Janus Films with Highly Efficient NaH2 PO2 -Enhanced Infrared Radiative Cooling and Solar Heating for Year-Round Thermal Management

The currently available materials cannot meet the requirements of human thermal comfort against the hot and cold seasonal temperature fluctuations. In this study, a dual-mode Janus film with a bonded interface to gain dual-mode functions of both highly efficient radiative cooling and solar heating for year-round thermal management is designed and prepared. The cooling side is achieved by embedding NaH2 PO2 particles with high infrared radiation (IR) emittance into a porous polymethyl methacrylate (PMMA) film during pore formation process, which is reported for the first time to the knowledge. A synergistic enhancement of NaH2 PO2 and 3D porous structure leads to efficient radiant cooling with high solar reflectance (R̅solar ≈ 92.6%) and high IR emittance (ε̅IR ≈ 97.2%), especially the ε̅IR value is much greater than that of the reported best porous polymer films. In outdoor environments under 750 mW cm-2 solar radiation, the dual-mode Janus film shows subambient cooling temperature of ≈8.8 °C and heating temperature reaching ≈39.3 °C, indicating excellent thermal management capacity. A wide temperature range is obtained only by flipping the dual-mode Janus film for thermal management. This work provides an advanced zero-energy-consumption human thermal management technique based on the high-performance dual-mode integrated Janus film material.

Influence of Soil Moisture on Bioaccumulation, Growth, and Recruitment of Folsomia candida Exposed to Phenanthrene-Polluted Soil

Climate change has resulted in an increased occurrence of summer droughts in large parts of the world. Low soil moisture has marked impacts on the physiology of soil invertebrates and lowers degradation rates of organic contaminants in soil. Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic contaminants that readily accumulate in the lipids of soil organisms. Here, we exposed springtails (Collembola, small soil living arthropods) to phenanthrene (a common PAH) in combination with a range of soil water contents to investigate the combined effects of these factors on the bioaccumulation, survival, recruitment, and body growth in a full factorial experiment. The results showed that phenanthrene up to 60 mg/kg dry soil had moderate effects on survival (<20%), whereas dry soil (4% soil water content) caused approximately 60% mortality. The bioaccumulation of phenanthrene increased almost 3-fold when soil water content decreased from 22 to 4%. We observed a joint effect of low soil water content and phenanthrene on recruitment, suggesting a synergistic interaction. The recruitment EC50 values of phenanthrene decreased from approximately 40 mg/kg dry soil at 22% soil water content to approximately 10 mg/kg dry soil at 12% soil water content. Our results show that the effects of phenanthrene are more pronounced in dry soil partly because bioaccumulation is enhanced when soils become dry.

The interrelationship between food security, climate change, and gender-based violence: A scoping review with system dynamics modeling

Gender-based violence (GBV) is a global public health and human rights problem that is exacerbated by social and environmental stressors for a multitude of interpersonal, cultural, and economic reasons. Through sudden disruptions in the microclimate of a region, climate shocks often have a negative impact on food security, which correlates with increases in GBV. Associations between the various combinations of GBV, climate change, and food insecurity have been documented in the growing international literature, but questions remain about these associations that require further clarification. The impact of the COVID-19 pandemic caused by SARS-CoV-2 provides insight through a real time demonstration into these interactions. This review of the global literature examines the interplay between GBV, climate change, and food insecurity-including recent literature regarding the COVID-19 pandemic. This review covers original research studies employing both quantitative and qualitative methodology, those that conducted secondary analyses of existing data sources and perspective pieces derived from observed evidence. An additional analytic layer of system dynamics modeling allowed for the integration of findings from the scoping review and discovery of additional insights into the interplay between disasters, food insecurity, and GBV. Findings from this review suggest that the development and adaptation of evidence-based, focused interventions and policies to reduce the effects of climate shocks and bolster food security may ultimately decrease GBV prevalence and impact.

Impacts of extreme weather events on terrestrial carbon and nitrogen cycling: A global meta-analysis

Some weather events like drought, increased precipitation, and warming exert substantial impact on the terrestrial C and N cycling. However, it remains largely unclear about the effect of extreme weather events (extreme drought, heavy rainfall, extreme heat, and extreme cold) on terrestrial C and N cycling. This study aims to analyze the responses of pools and fluxes of C and N in plants, soil, and microbes to extreme weather events by conducting a global meta-analysis of 656 pairwise observations. Results showed that extreme weather events (extreme drought, heavy rainfall, and extreme heat) decreased plant biomass and C flux, and extreme drought and heavy rainfall decreased the plant N pool and soil N flux. These results suggest that extreme weather events weaken the C and N cycling process in terrestrial ecosystems. However, this study did not determine the impact of extreme cold on ecosystem C and N cycling. Additional field experiments are needed to reveal the effects of extreme cold on global C and N cycling patterns.