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Under global warming, a notable intensification of precipitation extremes has posed significant threats to both natural ecosystems and human societies. However, there is still a lack of systematic studies on the variability of hourly precipitation extremes and a comparison with daily precipitation extremes. This study introduces a set of indices for hourly and daily precipitation extremes to systematically examine the changes across eastern China during the summers from 1980 to 2020. The results show that southern China is the sensitive regions with a notable large value of climatology in frequency and intensity for both of hourly and daily precipitation extremes. For the trends, the frequency of hourly precipitation extremes shows a rising trend in southern China, and intensity increased in northern China. Conversely, for daily precipitation extremes, the enhanced intensity and frequency are observed only in southeastern China. Additionally, the eastern coastal area experiences prolonged hourly rainfall with increasing persistence, while the region with an increased duration of daily precipitation is situated further south. Comparing the periods 1980–1999 and 2000–2020, precipitation extremes shift toward more intense and more frequent, with more pronounced variations at the hourly scale. Notably, northeastern China tend to be more intense and shorter‐lived hourly precipitation extremes after 1999, while south China experiences more frequent and longer‐lasting extremes. These changes are partly attributed to the increased unstable conditions, enhanced convective available potential energy and weakened convective inhibition. [ABSTRACT FROM AUTHOR]

In the context of global warming, the frequency, intensity, and duration of heatwave events have markedly increased, bearing profound implications for both natural ecosystems and human societies. To effectively cope with this challenge, it is imperative to accurately identify and comprehensively assess the risks posed by heatwaves. This study undertakes a systematic approach and robust methodology to assess heatwave risks by leveraging a diverse array of data sources—encompassing remote sensing, statistical analyses. The methodology integrates the risk triangle theory alongside established risk assessment frameworks laid out by the Intergovernmental Panel on Climate Change (IPCC). Employing a three‐dimensional evaluation framework encompassing hazard, exposure, and vulnerability, we unravel spatial–temporal patterns, high‐risk zones, and dominant dimensions of heatwave risks contributing to potential disasters. Results indicated that during 1999–2008, roughly 27% of the study areas were affected by high and above risk levels of heatwaves, and the areas with high and very high hazard, exposure, and vulnerability accounted for approximately 19.5%, 10%, and 32.5%, respectively. During 2009–2018, the proportion of areas with high and very high risk, hazard, and exposure increased to about 31%, 26%, and 14%, respectively, while the percentage of areas with high and very high vulnerability decreased to about 24.43%. Notably, Xinjiang and the western part of Northwestern China are characterized by hazard‐dominant conditions, while Southern China's risk profile has shifted from 1999–2008 to 2009–2018 from high hazard and vulnerability conditions to a more complex interaction involving hazard, exposure, and vulnerability. Moreover, Northern China and the northern segment of Southwestern China exhibit simultaneous high‐risk rankings across hazard, exposure, and vulnerability dimensions, forming a comprehensive high‐risk zone. These findings characterize heatwave risk patterns and offer critical insights for risk management decisions, guiding effective disaster prevention and relief measures to ensure socio‐economic stability and public health. [ABSTRACT FROM AUTHOR]

Plants infected by parasitic species might be further stressed by climate warming as both factors can influence the host plant's nutrient acquisition and growth. The root economics space, defined by root functional traits, reflects a plant's nutrient acquisition strategy. However, the combined effects of warming and parasitism on root functional traits and their positions within the root economics space have not been extensively studies. We grew soybean plants in pot cultures outdoor in the absence or presence of parasitism by Cuscuta gronovii and with or without simulated climate warming using infrared heater lamps. We measured various root functional traits of soybean, including root morphological traits, symbiosis with arbuscular mycorrhizal fungi (AMF) and rhizobia and enzyme activity. Correlations among these traits were analysed, and principal component analysis was used to determine the position of the plants in the root economics space. Parasitism significantly reduced AMF colonization rate, nodule biomass, root tissue density (RTD) and phosphatase activity in the rhizosheath, while increasing root nitrogen concentration (RN). Nodule biomass was positively correlated with AMF colonization, indicating an ‘outsourcing’ strategy for nutrient foraging. Parasitized soybeans occupied a trait space with higher RN and lower RTD, indicative of a ‘fast’ nutrient acquisition strategy. Warming did not significantly affect root functional traits or the plants' positions in the root economics space, regardless of parasitism presence. This study is the first to demonstrate that rhizobial colonization, similar to AMF colonization, is part of the ‘outsourcing’ strategy and that parasitism shifts host plants from a ‘slow’ to a ‘fast’ nutrient uptake strategy. These findings provide new insights into plant below‐ground strategies under warming and parasitism. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Societal Impact Statement Summary The iconic Yoshino cherry tree in Japan is experiencing shifts in its blossom timing due to climate warming. To develop a genetically informed predictive model for bud dormancy release, we examined seasonal gene expression in Yoshino cherry trees at three different locations. Our experiments, coupled with the analysis of DORMANCY‐ASSOCIATED MADS‐box (DAM) genes, highlighted DAM4 as the most reliable indicator for the rate of bud dormancy release. Our study demonstrated that seasonal gene expression profiles serve as a valuable indicator for forecasting the timing of dormancy release, benefiting Japanese traditions and providing insights into the biological impacts of climate change. The Yoshino cherry tree Cerasus × yedoensis ‘Somei‐yoshino’ stands out as an iconic springtime symbol in Japan. For the Yoshino cherry trees to bloom in the spring, dormant buds must undergo a period of exposure to low temperatures, allowing them to break dormancy. Key genes related to dormancy release, known as DORMANCY‐ASSOCIATED MADS‐box (DAM), have been extensively studied. However, it remains unclear how these genes function in natural environments to regulate the timing of bud dormancy release. To develop a genetically informed predictive model for bud dormancy release, we explored seasonal changes in genome‐wide gene expression profiles in the Yoshino cherry trees at three distinct sites in Japan. Five distinct genome‐wide transcription profiles, subjectively named as modes—early summer, summer, autumn, winter, and spring—were identified, with the winter and spring modes observed when the daily mean temperature was below approximately 10°C. Our experiments of bud dormancy release, along with the assessment of expression profiles of DAM genes, have revealed that among the six DAM genes, DAM4 expression profile is the most indicative of the rate of bud dormancy break. Our estimates suggest that, on average, the tree needs to be exposed to temperatures below 10.1°C for 61.1 days to suppress DAM4 expression to the threshold required for bud dormancy release. Our projections for the timing of bud dormancy release indicated a delay of approximately 2.3 days per decade from 1990 to 2020. Our study demonstrated that gene expression serves as a valuable indicator for forecasting the timing of dormancy release. [ABSTRACT FROM AUTHOR]

Increasing ant abundance associated with climate warming has been observed in temperate ecosystems. However, how enhanced ant activity affects plant development and phenology remains unclear. In this study, individuals of a perennial forb (Potentilla tanacetifolia) during flowering with and without an ant (Proformica) nest were marked to explore the impacts of ant nests on plant growth and phenology in a temperate steppe on the Mongolian Plateau. Ant nests delayed the start and end flowering dates simultaneously and, consequently, had no effect on flowering duration. However, presence of an ant nest postponed the fruiting date of individuals. Nests further increased numbers of aborted flowers and thus decreased fruit set. These observations suggest that the delayed flowering phenology disrupted synchrony between plant reproduction and pollinators and thus reduced pollination efficiency under ant nests. Given the increasing abundance of ants with rising temperatures under climate warming, plant delayed reproductive phenology and reduced reproductive output will potentially have negative consequences for plant fitness and plant–arthropod interactions, with consequent impacts on resistance and resilience of perennial species in temperate steppes under climate change. [ABSTRACT FROM AUTHOR]

Dust and high cloud interactions are critical for climate change, primarily due to the dominant roles of high cloud in the greenhouse effect and the continental precipitation. Nonetheless, disentangling the specific impacts of dust from the overlying meteorology influence on high clouds presents great challenges. In this study, we construct a meteorological pattern that successfully reveal the intricate connection between high cloud distribution and atmospheric conditions. Through this strong bounded relationship, we find that dust exhibits notable controls over the facilitation or inhibition of ice particle growth contingent upon the prevailing meteorological fields. More dust can increase precipitation rate and shorten high cloud lifetime particularly under favorable meteorology. These findings underscore the crucial role of dust concentration in mitigating global warming for future climate change. Plain Language Summary: Dust particles in the atmosphere play a crucial role in the formation and dissipation of high clouds, which can significantly impact global climate and weather patterns. By analyzing satellite observations and climate model data, we discovered that dust can either enhance or suppress the growth of ice crystals, depending on the atmospheric conditions. In moist environments with favorable weather, increased dust leads to larger ice crystals and more precipitation, accelerating the life cycle of high clouds. Conversely, in dry conditions with unfavorable weather, excessive dust competes for limited moisture, resulting in smaller ice crystals, although it can still increase rainfall during the dissipation stage of high clouds. As climate change progresses and dust storms become more frequent, the increased presence of dust in the atmosphere may lead to more extreme weather events and potentially mitigate some of the warming effects caused by high clouds. Understanding these complex interactions between dust, high clouds, and weather conditions is essential for improving climate models and predicting future changes in Earth's water cycle and energy balance. Key Points: Extracted first principal component, highly correlated with high cloud fraction, isolating meteorological effects on cloudsDust facilitates ice crystal formation and precipitation, catalyzing cloud lifecycle and ultimately modifying radiative effectsIncreased dust accelerates high cloud lifecycle, causing more extreme weather and mitigating climate warming [ABSTRACT FROM AUTHOR]

Horizontal and vertical moisture advection in the lower troposphere of the Arctic under progressing global warming is examined using a large‐scale ensemble model data set. Advection is decomposed into terms related to the basic state of the atmosphere and transient eddies and compared against a non‐warming experiment. During summer, horizontal moisture advection increases mainly by transient eddies advecting moisture from the lower latitudes. During winter, enhanced evaporation due to reduced sea ice becomes a source of moisture diminishing the role of transient eddies moistening the atmosphere. This effect intensifies under extreme global warming, turning the change in total horizontal advection in the lower troposphere negative. Diminished horizontal advection during winter is counteracted by vertical advection accompanied with enhanced evaporation and upper‐level horizontal advection maintaining the increase in column moisture. These results improve our understanding of how the water cycle in the Arctic responds via atmospheric processes under global warming. Plain Language Summary: This study uses a data set with a large number of members to investigate how the atmosphere is moistened in the Arctic (north of 70˚N) under various stages of global warming. The movement of moisture is summarized in terms of horizontal and vertical components of advection, a measure of how the atmosphere is moistened in a given specific humidity gradient and wind, which is decomposed into parts related to the average state of the atmosphere and parts related to high‐frequency phenomena, such as cyclones. It is found that (a) during summer, moisturization of the Arctic is mainly driven by horizontal movement of moisture from a remote source in the lower latitude, (b) during winter, this moisturization due to horizontal movement of moisture is suppressed and is driven more by vertical movement of moisture due to reduction of sea ice and increased evaporation. As global warming progresses, the role or horizontal movement of moisture is taken over by the local process of evaporation and vertical movement of moisture. This research helps us understand how the water cycle in the Arctic changes with severe global warming and improves our knowledge of the atmospheric processes that govern the climate system through various feedbacks. Key Points: Moisture advection in the Arctic under progressing global warming is examined using a large‐scale ensemble model simulation data setMoistening effect of horizontal advection in the lower troposphere is enhanced for summer and diminished for winter under extreme warmingEnhanced horizontal advection in the upper layer and surface evaporation are consistent with increased column moisture during winter [ABSTRACT FROM AUTHOR]

As global warming intensifies, the coupling relationship between negative Indian Ocean Dipole (nIOD) and La Niña has substantially changed. However, the characteristics and mechanisms of these changes are not yet fully understood. Here, we find that the impact of La Niña on nIOD has considerably weakened since 1999, with the frequency of nIOD occurrences during La Niña years plummeting to a mere one‐third of the pre‐1999 levels. This is primarily attributed to the early onset of Indian summer monsoon and the decrease in La Niña intensity, while the effect of variations in Bjerknes feedback is relatively minor. Model simulations suggest that the influence of La Niña on nIOD will continue to weaken under future global warming through similar mechanisms as in the observations, increasing the complexity of air‐sea coupling in the Indian Ocean. Plain Language Summary: The negative Indian Ocean Dipole (nIOD) has significant impacts on both local and global climate change. La Niña is a major trigger for nIOD. However, as the globe warms up, the connection between nIOD and La Niña has changed a lot. This study analyze observation and reanalysis data from the 1950s onwards to see how nIOD and La Niña are linked. We find that La Niña has had less impact on nIOD since 1999. This is because the summer monsoon starts earlier, causing changes in wind patterns over the Indian Ocean. La Niña normally brings westerly wind anomalies in the Indian Ocean, but these winds are weakened because of the early monsoon. This makes it harder for nIOD to form. The feedback loop known as the Bjerknes feedback doesn't play a big role in maintaining nIOD. Furthermore, the reduction in La Niña intensity also contribute to weakening the relationship between La Niña and nIOD. Models predict that La Niña's impact on nIOD will continue to weaken under future global warming, increasing the complexity of air‐sea coupling in the Indian Ocean and leading to more challenges in forecasting. Key Points: The relationship between La Niña and negative Indian Ocean Dipole has weakened significantly in this centuryThe spring‐summer easterly anomaly induced by the premature summer monsoon weakens the La Niña‐induced westerly anomalyThe impact of La Niña on negative Indian Ocean Dipole will continue to weaken under future global warming [ABSTRACT FROM AUTHOR]

The physical processes governing a tropical cyclone's lifecycle are largely understood, but key processes occur at scales below those resolved by global climate models. Increased resolution may help simulate realistic tropical cyclone intensification. We examined fully coupled, global storm‐resolving models run at resolutions in the range 28–2.8 km in the atmosphere and 28–5 km in the ocean. Simulated tropical cyclone activity, peak intensity, intensification rate, and horizontal wind structure are all more realistic at a resolution of ∼5 km compared with coarser resolutions. Rapid intensification, which is absent at typical climate model resolutions, is also captured, and exhibits sensitivity to how, and if, deep convection is parameterized. Additionally, the observed decrease in inner‐core horizontal size with increasing intensification rate is captured at storm‐resolving resolution. These findings highlight the importance of global storm‐resolving models for quantifying risk and understanding the role of intense tropical cyclones in the climate system. Plain Language Summary: Simulating strong tropical storms (i.e., major hurricanes, super typhoons) with climate models is challenging because important processes that act to intensify a storm occur over spatial scales that are too small for global models to capture. Typical models lack sufficient resolution in the atmosphere and ocean, often constrained by computational resources. Recently, in a few models, resolution has increased to a point where each grid cell represents an area of just a few square kilometres, a significant leap of one or two orders of magnitude. We analyzed tropical storms simulated by these state‐of‐the‐art, so‐called storm‐resolving models and found that peak tropical storm intensity and the rate at which storms intensify are both more realistic. These models also simulate the rapid intensification of tropical storms and capture the small eye diameters often seen in the most intense storms. Our work provides evidence that storm‐resolving resolution may help us better understand the role of tropical storms in the climate system and predict their behavior in a warming climate. Key Points: Simulated tropical cyclone characteristics analyzed in two fully coupled global climate models at atmospheric resolutions of 28 to 2.8 kmTropical cyclone intensification rate is close to observations at resolutions of 5 km or finer, and rapid intensification is capturedStorm‐resolving models also capture the observed relationship between high intensification rate and small inner‐core size [ABSTRACT FROM AUTHOR]

Summary: Rising global temperatures pose a threat to plant immunity, making them more susceptible to diseases. The impact of temperature on plant immunity against biotrophic and hemi‐biotrophic pathogens is well documented, while its effect on necrotrophs remains poorly understood. We venture into the uncharted territory of necrotrophic fungal pathogens in the face of rising temperatures. We discuss the role of the plant hormones salicylic acid (SA) and jasmonic acid (JA) in providing resistance to necrotrophs and delve into the temperature sensitivity of the SA pathway. Additionally, we explore the repercussions of increased temperatures on plant susceptibility to necrotrophs. We put forward a research agenda with an experimental framework aimed at providing a comprehensive understanding of how plants and pathogens adapt to increasing temperatures. [ABSTRACT FROM AUTHOR]

The effects of climate change are now more pervasive than ever. Marine ecosystems have been particularly impacted by climate change, with marine heatwaves (MHWs) being a strong driver of mass mortality events. Even in the most optimistic greenhouse gas emission scenarios, MHWs will continue to increase in frequency, intensity and duration. For this reason, understanding the resilience of marine species to the increase of MHWs is crucial to predicting their viability under future climatic conditions. In this study, we explored the consequences of MHWs on the resilience (the ability of a population to resist and recover after a disturbance) of a Mediterranean key octocoral species, Paramuricea clavata, to further disturbances to their population structure. To quantify P. clavata's capacity to resist and recover from future disturbances, we used demographic information collected from 1999 to 2022, from two different sites in the NW Mediterranean Sea to calculate the transient dynamics of their populations. Our results showed that the differences in the dynamics of populations exposed and those not exposed to MHWs were driven mostly by differences in mean survivorship and growth. We also showed that after MHWs P. clavata populations had lower resistance and slower rates of recovery than those not exposed to MHWs. Populations exposed to MHWs had lower resistance elasticity to most demographic processes compared to unexposed populations. In contrast, the only demographic process showing some differences when comparing the speed of recovery elasticity values between populations exposed and unexposed to MHWs was stasis. Finally, under scenarios of increasing frequency of MHWs, the extinction of P. clavata populations will accelerate and their capacity to resist and recover after further disturbances will be hampered. Overall, these findings confirm that future climatic conditions will make octocoral populations even more vulnerable to further disturbances. These results highlight the importance of limiting local impacts on marine ecosystems to dampen the consequences of climate change. [ABSTRACT FROM AUTHOR]

Clarifying the effects of biodiversity on ecosystem stability in the context of global environmental change is crucial for maintaining ecosystem functions and services. Asynchronous changes between trophic levels over time (i.e. trophic community asynchrony) are expected to increase trophic mismatch and alter trophic interactions, which may consequently alter ecosystem stability. However, previous studies have often highlighted the stabilising mechanism of population asynchrony within a single trophic level, while rarely examining the mechanism of trophic community asynchrony between consumers and their food resources. In this study, we analysed the effects of population asynchrony within and between trophic levels on community stability under the disturbances of climate warming, fishery decline and de‐eutrophication, based on an 18‐year monthly monitoring dataset of 137 phytoplankton and 91 zooplankton in a subtropical lake. Our results showed that species diversity promoted community stability mainly by increasing population asynchrony both for phytoplankton and zooplankton. Trophic community asynchrony had a significant negative effect on zooplankton community stability rather than that of phytoplankton, which supports the match‐mismatch hypothesis that trophic mismatch has negative effects on consumers. Furthermore, the results of the structural equation models showed that warming and top‐down effects may simultaneously alter community stability through population dynamics processes within and between trophic levels, whereas nutrients act on community stability mainly through the processes within trophic levels. Moreover, we found that rising water temperature decreased trophic community asynchrony, which may challenge the prevailing idea that climate warming increases the trophic mismatch between primary producers and consumers. Overall, our study provides the first evidence that population and trophic community asynchrony have contrasting effects on consumer community stability, which offers a valuable insight for addressing global environmental change. [ABSTRACT FROM AUTHOR]

Photocatalytic (PC) CO2 reduction reaction (CO2RR) into value‐added oxygenated products is one of the most promising ways of solving climate warming change and energy crisis simultaneously. To reach higher selectivity and productivity of fuel products, it still remains great challenge in controlling both simultaneous sequential multi‐electron/proton shuttling through different transporting pathway, which determines the intermediates and final products. Consequently, a multifunctional nickel‐perylene‐carbon nitride nanosheet (NS‐P‐g‐C3N4‐Ni) are constructed rationally to strengthen the electron and proton transfer via different pathway at the same time through molecule‐level carbon backbone with excellent conductivity/charge capacity and proton transport via pendant functional group of ‐NH2 from water oxidation sites of Ni metal cluster on perylene skeleton. CO2 adsorption is enhanced and reduction energy is reduced by the complexation of N‐atom site of NS‐P‐g‐C3N4‐Ni and adjustment of co‐planarity, optimizing conduction band and band gap with energy controllable techniques. In situ FT‐IR/Raman/EPR spectra identified and verified the transformation of active intermediates (*CO2•−, *COOH and H*COO−) adsorbed on the NS‐P‐g‐C3N4‐Ni by complexation and highly selective production of formic acid (60%) is achieved. This work sheds light on the construction of effective well‐structured sites in photocatalytic CO2 reduction to produce value‐added products with higher selectivity and productivity. [ABSTRACT FROM AUTHOR]

We describe the bias adjustment and downscaling to a resolution of 1 × 1 km of daily temperature, precipitation and solar radiation of a multimodel ensemble of Coupled Model Intercomparison Project Phase 6 (CMIP6) GCMs with the local observational data set BhutanClim for Bhutan and an analysis of the results for 1996–2100. The GCMs were selected based on their ability to reproduce local temporal and spatial precipitation patterns, resulting in a total of 14 models for each shared socioeconomic pathway (SSP). The results are shown for five global warming levels (GWLs) 1.5, 2, 3, 4 and 5°C, providing insight into the projected impacts of climate change at different warming levels. The daily temperature and precipitation data are publicly available, which is of great benefit for climate impact studies, such as ecological, hydrological or infrastructure‐related studies. In this paper, we discuss showcase climate indicators. Peak‐over‐threshold climate indicators such as hot days above 30°C are relevant for human health. In the capital city of Thimphu, these are currently rare, at 4 days per year, but might increase to more than 80 for GWL5.0. Precipitation increases in the summer months, but slightly decreases in the drier winter months. Accordingly, the 3‐month SPEI drought index is projected to increase in summer, but strongly decreases in the winter months, mostly pronounced in February. The increasing severity of late‐winter and spring droughts might have a negative impact on vegetation, wildfires and water supply. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION High temperature stress (HTS) has become a serious threat to rice grain quality and few studies have examined the effects of HTS across multiple stages on rice grain quality. In the present study, we conducted 2 years of HTS treatments under three temperature regimes (32/22 °C, 40/30 °C and 44/34 °C) and HTS durations of 2 days and 4 days at three critical stages: booting, flowering, and a combination of booting and flowering. We employed the heat degree days (HDD) metric, which accounts for both the level and duration of HTS, to quantify the relationships between grain quality traits and HTS.The results revealed the diverse effects of HTS on rice grain quality at different stages, durations and temperature levels. HTS significantly (P < 0.05) reduced grain quality, with the highest sensitivities (reduction per 1 °C day−1 increase in HDD) observed at the flowering stage, followed by the combined and booting stages treatments under mild HTS treatment (40/30 °C). However, under extreme HTS treatments (44/34 °C) for 4 days, rice grains subjected to combined HTS treatment experienced complete mortality.Pre‐exposed to HTS at the booting stage within a certain intensity can alleviate the adverse effects of post‐flowering HTS on grain quality. This provides valuable insights for assessing the potential impact of multiple HTS events on the grain quality under future climate warming. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Global change is affecting the distribution and population dynamics of plant species across the planet, leading to trends such as shifts in distribution toward the poles and to higher elevations. Yet, we poorly understand why individual species respond differently to warming and other environmental changes, or how the trait composition of communities responds. Here we ask two questions regarding plant species and community changes over 42 years of global change in a temperate montane forest in Québec, Canada: (1) How did the trait composition, alpha diversity, and beta diversity of understory vascular plant communities change between 1970 and 2010, a period over which the region experienced 1.5°C of warming and changes in nitrogen deposition? (2) Can traits predict shifts in species elevation and abundance over this time period? For 46 understory vascular species, we locally measured six aboveground traits, and for 36 of those (not including shrubs), we also measured five belowground traits. Collectively, they capture leading dimensions of phenotypic variation that are associated with climatic and resource niches. At the community level, the trait composition of high‐elevation plots shifted, primarily for two root traits: specific root length decreased and rooting depth increased. The mean trait values of high‐elevation plots shifted over time toward values initially associated with low‐elevation plots. These changes led to trait homogenization across elevations. The community‐level shifts in traits mirrored the taxonomic shifts reported elsewhere for this site. At the species level, two of the three traits predicting changes in species elevation and abundance were belowground traits (low mycorrhizal fraction and shallow rooting). These findings highlight the importance of root traits, which, along with leaf mass fraction, were associated with shifts in distribution and abundance over four decades. Community‐level trait changes were largely similar across the elevational and temporal gradients. In contrast, traits typically associated with lower elevations at the community level did not predict differences among species in their shift in abundance or distribution, indicating a decoupling between species‐ and community‐level responses. Overall, changes were consistent with some influence of both climate warming and increased nitrogen availability. [ABSTRACT FROM AUTHOR]

Elevation‐dependent warming (EDW) has been a topic of intense debate due to limited observed data in global highland areas. This study aims to fill this gap by utilizing CRU and ERA5 datasets from 1981 to 2021 to explore the trends of climate change and its elevation dependency. The anomalies of temperature indicators (Tmean, Tmax, and Tmin) in both ERA5 and CRU showed significant warming trends over global highlands. Moreover, the response of temperature indicators to elevation across global highlands is not spatially uniform. The linear regression model based on the elevation showed significant warming signals for the temperature indicators at various elevations over the global highlands. On a regional scale, Tmean and Tmax predominantly showed linear EDW over EU highlands, while Tmean in Asian highlands exhibited EDW signals at 4–5 km. Tmin showed EDW at 2.5–5.5 km with ERA5 and 3–5 km with CRU. In the Andes, EDW was prominent at 2.5–4 km. Overall, EDW signals are evident in all studied regions but vary across them. While assessing the driving factors, the results of this study indicate that total column water vapour (TCWV), snow depth (SD), snow albedo, and normalized difference vegetation index (NDVI) correlated positively with the temperature indicators. These findings emphasize the significance of elevation‐specific interactions between environmental factors and temperature in forecasting temperature changes in mountainous areas. Additionally, temperature exhibited coherence with teleconnection indices from the Atlantic and Pacific Oceans. Asian and European (EU) highlands exhibited interzonal coherence with the Pacific and Atlantic Oceans, while North American (NA) highlands showed coherence, followed by South American (SA) highlands. These findings provide a comprehensive understanding of EDW and its implications for highland regions globally, including the potential for more severe depletion of snow/ice resources in a warmer future. [ABSTRACT FROM AUTHOR]

The impacts of environmental change on Lake Biwa have been explored for decades, with water monitoring and palaeolimnological studies revealing how environmental forcing, including climate warming, eutrophication, water level manipulation and human manipulation of fish populations, has influenced the food web of Lake Biwa. However, these studies have rarely accounted for microbial food‐web components. This knowledge gap is mostly due to the lack of time series spanning more than a couple of decades, coupled with the high taxonomical expertise required to identify organisms belonging to very diverse groups. The use of a sedimentary DNA approach allows for the reconstruction of past changes in the diversity, composition and structure of the microbial eukaryotic community of aquatic systems. The application of 18S metabarcoding has been proven successful to describe the response of unicellular eukaryotes (protists) and aquatic fungi in lake ecosystems, encompassing a large taxonomic and functional diversity such as phototrophs, heterotrophs and mixotrophs. We applied 18S metabarcoding to 31 sediment core samples from Lake Biwa, spanning the past 100 years and explored the response of microbial eukaryotic communities to changes in multiple environmental stressors, including nutrient levels, lake water level, climate, as well as fish and zooplankton biomass for the period 1973–2010. We found that the manipulation of the water level and changes in fish community composition were the primary factors impacting (indirectly) the structure of the lake microbial eukaryotic community with minor, but significant, effects of climate warming and phosphorus levels. Co‐occurrence network analysis highlighted the potential food web impacts on the microbial eukaryotic community, suggesting that organisms from this compartment were impacted by both bottom‐up and top‐down processes. [ABSTRACT FROM AUTHOR]

In the Earth's general circulation, polar jets act as baroclinic pumps of angular momentum and heat. Reanalysis datasets indicate that shear changes near jets induce upward displacements of the jet cores, suggesting a weakening thermodynamic pumping over the last 50 years. From secondary flow theory, a well‐established principle in fluid dynamics, an increased frequency of heatwaves and persistent winter storms is expected. The ageostrophic wind shear between 700 and 50 hPa indicates the strength of this secondary circulation. The weakening tendency during the reanalysis period also exists in multimodel simulations under the RCP8.5 emissions scenario for the 21st century. The reduction between the periods 2005–2025 and 2081–2100 reaches 18%, 5.3% and 19%, respectively, for the North America, Mid‐Europe and East Asia sectors of the Northern Hemisphere polar jet. Within this background, cold‐surge events are the result of synergic co‐working of several factors. The occurrence trend for transitional season winter extreme events also is examined. The winter extremes seemingly have larger temperature drops. However, in a warming climate, they emerge more rapidly from extreme cold states. The storm tracks, especially over North America, have equatorward extensions, indicating that winter storms can reach lower latitudes. Due to the temperature‐dependence of air viscosity, secondary flows decrease more slowly than the main zonal flow. This imposes an important adjustment to the traditional polar amplification effects on midlatitude winter extremes. During a warmer winter (the primary manifestation of a warmer climate), spatially uniform positive trends in cold extreme events are not expected. There are, however, regions experiencing more winter extremes. These regions show consistent patterns in both the reanalysis period and the remainder of the 21st century. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Time Period Major Taxa Studied Methods Results Main Conclusions As global climate changes, there is a clear mismatch between the temporal and spatial characteristics of body temperature and environmental temperature, confounding the assessment of thermal stress for organisms in many ecological studies. Here, we hindcast the hourly body temperatures of intertidal molluscs to explore the differences between them and environmental temperatures (air and water temperatures) in multiple metrics of thermal stress.Intertidal shores in East Asia (0°–45°N, 100°E–140°E).40 years, 1980 to 2019.Mollusca.We collected habitat zonation data and measured the morphological characteristics of 25 intertidal molluscs living in East Asia. For three different types of intertidal molluscs (i.e., bivalves, limpets and snails), we built corresponding heat budget models (HBMs) to hindcast the hourly body temperatures from 1980 to 2019. We analysed the thermal stress of intertidal species faced in three metrics, annual extreme high temperatures (T99), seasonal daily maximum temperatures (DMT) and heatwaves, and compared them with environmental temperatures.We found that T99 of body temperatures and their interannual warming rates are significantly higher than those of environmental temperatures. Moreover, there were non‐negligible mismatches between the seasonal thermal pattern and heatwaves of body temperatures and environmental temperatures, suggesting that the deleterious impacts of global warming on intertidal species are underestimated and cannot be directly revealed by environmental temperatures.Thermal stress patterns of body temperature were significantly different from those of environmental temperature, and the thermal stress faced by intertidal species had been persistently underestimated. These results emphasise that body temperature should be used as the appropriate metric for evaluating and predicting the impacts of global warming and weather extremes in the intertidal biological system. [ABSTRACT FROM AUTHOR]

The enforcement of a global hydrofluorocarbon (HFC) refrigerant phase down led to the introduction of hydrofluoroolefins (HFOs) as a low Global Warming Potential (GWP) substitute, given their low atmospheric lifetime. However, to this date it is not fully clear the long‐term atmospheric fate of HFOs primary degradation products: trifluoro acetaldehyde (TFE), trifluoro acetyl fluoride (TFF), and trifluoroacetic acid (TFA). It particularly concerns the possibility of forming HFC‐23, a potent global warming agent. Although the atmospheric reaction networks of TFE, TFF, and TFA have a fair level of complexity, the relevant atmospheric chemical pathways are well characterized in the literature, enabling a comprehensive hazard assessment of HFC‐23 formation as a secondary HFO breakdown product in diverse scenarios. A lower bound of the HFOs effective GWP in a baseline scenario is found above regulatory thresholds. While further research is crucial to refine climate risk assessments, the existing evidence suggests a non‐negligible climate hazard associated with HFOs. [ABSTRACT FROM AUTHOR]

Platycodon grandiflorus has long been used for its medicinal, culinary and ornamental properties. With increasing market demand and the depletion of wild resources, understanding the distribution and factors affecting its habitat suitability is crucial for its conservation and sustainable utilization. This study aims to predict the suitable habitat for P. grandiflorus in China considering current and future climate scenarios. The MaxEnt model, with an AUC value of 0.846, demonstrated good predictive ability for the current and future distribution of P. grandiflorus. It also identified the central, eastern, and southern regions as suitable habitats, with the critical environmental factors being precipitation, temperature, and elevation. Future scenarios under both SSP126 and SSP585 projections indicate an increase in suitable habitats, particularly in northeastern and central China, albeit with a shift in the distribution center towards the northeast by 2041–2060 and 2081–2100 under different scenarios. P. grandiflorus' distribution is significantly influenced by environmental factors, with precipitation and temperature being pivotal. Taken together, our study predicts an expansion of suitable habitats under future climate scenarios and the northward shift in the distribution center underlines the impact of global warming on the distribution of P. grandiflorus. The findings are crucial for the conservation, effective utilization, and strategic planning for the cultivation of P. grandiflorus in the face of climate change. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Taxon Methods Results Main Conclusion Species with disjunct geographic distributions provide natural opportunities to investigate incipient or recent allopatric divergence. The combination of both genetic and ecological data may be fruitful to decipher the causes of such patterns: (i) actual vicariance, (ii) successful colonisation from one source to a new range (dispersal, biological introduction) or (iii) parallel convergent evolution.Southern France and Northern Spain.The bee orchid Ophrys aveyronensis (and its two recognised subspecies O. a. subsp. aveyronensis and O. a. subsp. vitorica) displays a disjunct geographic distribution with two subranges separated by 600 km on both sides of the Pyrenees mountain range.As allopatric divergence is often complex to document in the wild, we used a combination of population genomics and ecological niche modelling (ENM) to investigate the causes of this intriguing biogeographic pattern.The population genomic data demonstrate that all the studied populations exhibit similar patterns of genetic diversity and dramatic decrease in effective size compared with the ancestral population. Significant genetic differentiation and reciprocal monophyly exist between populations of the two subranges of O. aveyronensis, despite a very recent divergence time as young as ca. 1500 generations ago. Moreover, paleo‐ENM analyses support that the disjunct geographic distribution of O. aveyronensis is consistent with a range split of a broad ancestral range, contraction and distinct longitudinal and latitudinal shifts in response to climate warming during the Holocene.The congruence of the results obtained from both population genomics and ENM approaches documents how very recent continental allopatric divergence initiated speciation in this system. O. aveyronensis provides a promising opportunity to study the onset of reproductive isolation and parallel evolution following an initial stage of geographic separation in a group with high diversification rate. [ABSTRACT FROM AUTHOR]

Drosophila subobscura is an excellent model species for testing genetic variation in thermal adaptation due to its rich inversion chromosomal polymorphism. In Palearctic populations, the inversions of this species can be classified as "cold", "warm" or "nonthermal" adapted. Based on this classification the Chromosomal Thermal Index (CTI) was developed, which allows measuring the thermal adaptation of populations and monitoring changes over time. Here, we aim to use this index in American colonizing populations of D. subobscura for the first time to obtain new information on the species thermal adaptation. Thus, thermal adapted inversions ("cold" and "warm") were defined for the American continent and CTI was computed in South American (1981 and 1999 samples) and North American (1985 and 2004 samples) populations of D. subobscura. In general, both American populations showed an inverse relationship between CTI values and latitude, with CTI values decreasing when latitude increases. When comparing populations sampled in different years, an increase in CTI values was detected in four out of six temporal comparisons (only one was significant) of South America (1981 and 1999) and in six out of seven populations of North America (1985 and 2004). A global analysis using a one‐way repeated measures anova of CTI values in both American hemispheres showed a trend of increase for "warm" adapted inversions in Chile and North America, but this increase was only significant for the latter. Overall, these results are in agreement with global warming expectations, although natural selection acted differently in the colonized hemispheres. [ABSTRACT FROM AUTHOR]

The deployment of engineered substrates seeded with newly settled corals is a technique being developed to increase the numbers of juvenile corals on reefs with the goal of improving reef resilience in response to climate warming. Using a hierarchical sampling design, we explored the spatial scales at which seeded coral (spat) survival and growth varied in situ and investigated the environmental drivers of seeded spat success in the southern inshore Great Barrier Reef. After 10 months, variation in spat survival and size was greatest at the smallest spatial scale (1–2 m) (27 and 11% of variation, respectively), indicating the scale at which the main drivers of post‐settlement survival and growth are occurring. Crustose coralline algae (CCA) cover on seeding units prior to deployment was a significant driver of short‐ and long‐term spat survival (22% of variation). Survival of Acropora millepora and A. muricata spat did not differ according to benthic community variation. Increasing cover of branching Acropora corals was correlated with decreased survival and the size of Montipora aequituberculata spat, although CCA cover on plugs remained the most influential factor determining survival. Interspecific variation in spat survival and size and higher survival and size in the side‐facing orientation of the seeding units suggest natural variation in response to the seeding method, warranting further experiments to refine species selection and deployment methods prior to upscaling. High within‐site variation in seeded spat survival and size highlights the need for future studies of ecological factors driving post‐settlement mortality at fine spatial scales. [ABSTRACT FROM AUTHOR]

The elemental allelopathy hypothesis states that the metal‐rich litter of hyper‐accumulating species may have a detrimental impact on neighbouring plants giving a competitive advantage to hyper‐accumulators. Here, we aim to specify the conditions of application of this hypothesis in realistic field conditions, and its relative importance compared to other positive effects found in metalliferous systems.We disentangled the litter‐induced elemental allelopathy and canopy effects of two metallophyte species (Arenaria multicaulis and Hutchinsia alpina) with different levels of leaf Zn and Cd accumulation on two ecotypes of Agrostis capillaris with different levels of metal tolerance. The experiment was conducted in two habitats with contrasting pollution levels in a former mining valley in the Pyrenees (France).The metallophyte species that accumulates more metals (Hutchinsia alpina) showed a strong elemental allelopathy effect on the target with lower metal tolerance in the habitat with lower pollution level, while the metallophyte species that accumulates less metals (Arenaria multicaulis) had no litter effect. Both metallophyte species had positive canopy effects likely due to improvement of micro‐climatic conditions. The drought that occurred during the experiment may have influenced these canopy effects, increasing their importance during the course of the study. For Hutchinsia alpina, the positive canopy effects were stronger than the negative litter effects, resulting in overall positive effects on both target ecotypes.Synthesis. Our results brought a better understanding of the occurrence of elemental allelopathy in metallophyte communities and its relative importance as compared to micro‐climatic facilitation in a global warming context. [ABSTRACT FROM AUTHOR]

Summary: The diversity of plant–pollinator interactions is grounded in floral resources, with nectar considered one of the main floral rewards plants produce for pollinators. However, a global evaluation of the number of animal‐pollinated nectar‐producing angiosperms and their distribution world‐wide remains elusive.We compiled a thorough database encompassing 7621 plant species from 322 families to estimate the number and proportion of nectar‐producing angiosperms reliant on animal pollination. Through extensive sampling of plant communities, we also explored the interplay between nectar production, floral resource diversity, latitudinal and elevational gradients, contemporary climate, and environmental characteristics.Roughly 223 308 animal‐pollinated angiosperms are nectar‐producing, accounting for 74.4% of biotic‐pollinated species. Global distribution patterns of nectar‐producing plants reveal a distinct trend along latitudinal and altitudinal gradients, with increased proportions of plants producing nectar in high latitudes and altitudes. Conversely, tropical communities in warm and moist climates exhibit greater floral resource diversity and a lower proportion of nectar‐producing plants.These findings suggest that ecological trends driven by climate have fostered the diversification of floral resources in warmer and less seasonal climates, reducing the proportion of solely nectar‐producing plants. Our study provides a baseline for understanding plant–pollinator relationships, plant diversification, and the distribution of plant traits. [ABSTRACT FROM AUTHOR]

Summary: Climate warming poses a significant threat to global crop production and food security. However, our understanding of the molecular mechanisms governing thermoresponsive development in crops remains limited.Here we report that the auxiliary subunit of N‐terminal acetyltransferase A (NatA) in rice OsNAA15 is a prerequisite for rice thermoresponsive growth. OsNAA15 produces two isoforms OsNAA15.1 and OsNAA15.2, via temperature‐dependent alternative splicing. Among the two, OsNAA15.1 is more likely to form a stable and functional NatA complex with the potential catalytic subunit OsNAA10, leading to a thermoresponsive N‐terminal acetylome. Intriguingly, while OsNAA15.1 promotes plant growth under elevated temperatures, OsNAA15.2 exhibits an inhibitory effect.We identified two glycolate oxidases (GLO1/5) as major substrates from the thermoresponsive acetylome. These enzymes are involved in hydrogen peroxide (H2O2) biosynthesis via glycolate oxidation. N‐terminally acetylated GLO1/5 undergo their degradation through the ubiquitin‐proteasome system. This leads to reduced reactive oxygen species (ROS) production, thereby promoting plant growth, particularly under high ambient temperatures.Conclusively, our findings highlight the pivotal role of N‐terminal acetylation in orchestrating the glycolate‐mediated ROS homeostasis to facilitate thermoresponsive growth in rice. [ABSTRACT FROM AUTHOR]

An exponential rise in the atmospheric vapour pressure deficit (VPD) is among the most consequential impacts of climate change in terrestrial ecosystems. Rising VPD has negative and cascading effects on nearly all aspects of plant function including photosynthesis, water status, growth and survival. These responses are exacerbated by land–atmosphere interactions that couple VPD to soil water and govern the evolution of drought, affecting a range of ecosystem services including carbon uptake, biodiversity, the provisioning of water resources and crop yields. However, despite the global nature of this phenomenon, research on how to incorporate these impacts into resilient management regimes is largely in its infancy, due in part to the entanglement of VPD trends with those of other co‐evolving climate drivers. Here, we review the mechanistic bases of VPD impacts at a range of spatial scales, paying particular attention to the independent and interactive influence of VPD in the context of other environmental changes. We then evaluate the consequences of these impacts within key management contexts, including water resources, croplands, wildfire risk mitigation and management of natural grasslands and forests. We conclude with recommendations describing how management regimes could be altered to mitigate the otherwise highly deleterious consequences of rising VPD. Summary statement: Rising atmospheric vapour pressure deficit (or VPD) is one of the most widespread and significant consequences of climate warming for terrestrial ecosystems. This article reviews the mechanistic bases of these usually deleterious impacts and synthesises that information into a set of management recommendations to mitigate them. [ABSTRACT FROM AUTHOR]

In the face of rising global temperatures, the mechanisms behind an organism's ability to acclimate to heat stress remain enigmatic. The rice leaf folder, Cnaphalocrocis medinalis, traditionally viewed as temperature‐sensitive, paradoxically exhibits robust larval acclimation to heat stress. This study used the heat‐acclimated strain HA39, developed through multigenerational exposure to 39°C during the larval stage, and the unacclimated strain HA27 reared at 27°C to unravel the transgenerational effects of heat acclimation and its regulatory mechanisms. Heat acclimation for larvae incurred a fitness cost in pupae when exposed to high temperature, yet a significant transgenerational effect surfaced, revealing heightened fitness benefit in pupae from HA39, even without additional heat exposure during larval recovery at 27°C. This transgenerational effect exhibited a short‐term memory, diminishing after two recovery generations. Moreover, the effect correlated with increased superoxide dismutase (SOD) enzyme activity and expression levels of oxidoreductase genes, representing physiological and molecular foundations of heat acclimation. Heat‐acclimated larvae displayed elevated DNA methylation levels, while pupae from HA39, in recovery generations, exhibited decreased methylation indicated by the upregulation of a demethylase gene and downregulation of two methyltransferase genes at high temperatures. In summary, heat acclimation induces DNA methylation, orchestrating heat‐stress memory and influencing the expression levels of oxidoreductase genes and SOD activity. Heat‐stress memory enhances the acclimation of the migratory insect pest to global warming. [ABSTRACT FROM AUTHOR]

Ciliates are a well‐defined, species‐rich, versatile group of heterotrophic and mixotrophic protists. Their response to increased temperature during global warming is critical for the structure and functioning of freshwater food webs.I conducted a meta‐analysis of the literature from field studies and experimental evidence to assess the parameters characterising the thermal response of freshwater ciliates. The shape of the thermal performance curve predicts the ciliates' survival at supraoptimal temperatures (i.e., the width of the thermal safety margin).The ciliates' typical thermal safety margin is c. 5°C. More than two‐thirds of the freshwater ciliates dwelling permanently or occasionally in the pelagial cannot survive at temperatures exceeding 30°C. Likewise, cold‐stenothermic species, which represent a significant fraction of euplanktonic ciliates, cannot survive by evolutionary adaptation to rapidly warming environments.The statistical analysis revealed that the ciliates' thermal performance is affected by their planktonic lifestyle (euplanktonic vs. tychoplanktonic), ability to form cysts and nutritional ecology. Bactivorous ciliates have the widest temperature niche, and algivorous ciliates have the narrowest temperature niche.Phenotypic plasticity and genetic variation, favouring the selection of pre‐adapted species in a new environment, are widespread among freshwater ciliates. However, the lack of evidence for the temperature optima and imprecisely defined tolerance limits of most species hampers the present analysis. The extent of acclimation and adaptation requires further research with more ciliate species than the few chosen thus far.Recent eco‐evolutionary experimental work and modelling approaches have demonstrated that the ciliates' thermal responses follow general trends predicted by the metabolic theory of ecology and mechanistic functions inherent in enzyme kinetics. The present analysis identified current knowledge gaps and avenues for future research that may serve as a model study for other biota. Thermal adaptation may conflict with adaptation to other stressors (predators, food availability, pH), making general predictions on the future role of freshwater ciliates in a warmer environment difficult, if not impossible, at present. [ABSTRACT FROM AUTHOR]

The presence of bacteria belonging to the Pseudomonas syringae complex in the natural vegetation of several Icelandic habitat types has been recently reported, raising questions about the risk to Icelandic crops, particularly given the expected increase in agricultural activity due to climate warming. This study takes advantage of Iceland's unique characteristics and the discovery of P. syringae in Peltigera lichens to gain a better understanding of the potential risk posed by this newly discovered ecological niche. The main objective was to evaluate the pathogenic potential and fitness in crops of P. syringae strains isolated from Peltigera lichen sampled in Iceland, focusing on strains that belong to phylogroups 1 and 2, which commonly contain epidemic strains. The results indicate that P. syringae strains isolated from Icelandic Peltigera lichen have a comparable fitness to epidemic strains in 8 out of 10 tested plant species (rice, tomato, thale cress, annual mugwort, spinach, garlic chives, tobacco and kale). Furthermore, pathogenicity assessment on three plant species highlighted that certain strains also caused similar symptoms and disease severity compared to epidemic strains. These findings provide valuable insights into the potential risks posed by P. syringae from Icelandic natural habitats and illustrate how strains from these habitats have a wide pathogenic potential to crops without having encountered these crops in the last several thousand years of their presence in Iceland. [ABSTRACT FROM AUTHOR]

With its focus on the species level of the Anthropos, there is growing concern that the Anthropocene analytic lacks the conceptual nuance needed to grapple with the unevenly distributed harms and responsibilities tied up with issues of biodiversity loss, global warming, and land use change. Conceptual variants like the patchy Anthropocene have been proposed to better capture the justice implications of these socio‐ecological crises, directing attention to their spatially ubiquitous yet context‐specific character. The figure of the plantation has come to play an important role in this scholarship due to the contribution intensive agriculture had made to these interlinking crises. Through empirical study of the regenerative agricultural movement, this paper reflects on how regenerative farmers use different sites (fields, soils, livestock stomachs) to apprehend their agro‐ethical responsibilities to more‐than‐human actors both near to and far from the landscapes they manage. Our aims here are two‐fold. First, we provide a more affirmative account of agricultural management than is currently offered by plantation farming: a model of food production that is not just 'in' the Anthropocene, but 'for' it. Second, we contribute to ongoing discussions unfolding in the social sciences around the tools needed to conceptualise the interlinking spatial and justice aspects of the Anthropocene transition. By bringing the patchy analytic into conversation with more established geographic writing on scale, volume, and horizontal connections, we show the merit of juxtaposing multiple models of spatial relation as a way of gaining ethical and conceptual traction on complex socio‐ecological issues. We argue that the 'polymorphic' spatial imaginaries of regenerative agriculturalists can offer some guidance on the tools needed to attend to the specificity of local Anthropocene outcomes in relation to socio‐ecological forces actuating the world at much greater spatio‐temporal scales. [ABSTRACT FROM AUTHOR]

Climate warming accelerates permafrost thawing, causing warming‐driven disasters like ground collapse and retrogressive thaw slump (RTS). These phenomena, involving intricate multiphysics interactions, phase transitions, nonlinear mechanical responses, and fluid‐like deformations, and pose increasing risks to geo‐infrastructures in cold regions. This study develops a thermo‐hydro‐mechanical (THM) coupled single‐point three‐phase material point method (MPM) to simulate the time‐dependent phase transition and large deformation behavior arising from the thawing or freezing of ice/water in porous media. The mathematical framework is established based on the multiphase mixture theory in which the ice phase is treated as a solid constituent playing the role of skeleton together with soil grains. The additional strength due to ice cementation is characterized via an ice saturation‐dependent Mohr–Coulomb model. The coupled formulations are solved using a fractional‐step‐based semi‐implicit integration algorithm, which can offer both satisfactory numerical stability and computational efficiency when dealing with nearly incompressible fluids and extremely low permeability conditions in frozen porous media. Two hydro‐thermal coupling cases, that is, frozen inclusion thaw and Talik closure/opening, are first benchmarked to show the method can correctly simulate both conduction‐ and convection‐dominated thermal regimes in frozen porous systems. The fully THM responses are further validated by simulating a 1D thaw consolidation and a 2D rock freezing example. Good agreements with experimental results are achieved, and the impact of hydro‐thermal variations on the mechanical responses, including thaw settlement and frost heave, are successfully captured. Finally, the predictive capability of the multiphysics MPM framework in simulating thawing‐triggered large deformation and failure is demonstrated by modeling an RTS and the settlement of a strip footing on thawing ground. [ABSTRACT FROM AUTHOR]

BACKGROUND: Understanding how parasitoids respond to temperature is crucial for improving biological control strategies under the context of global warming. This study examined the suitability of Myzus persicae and its parasitoid Aphidius gifuensis to varying temperature conditions, as well as the stage‐specific response of A. gifuensis to high temperatures. RESULTS: High temperatures had a significant impact on the both M. persicae and A. gifuensis. When exposed to 36°C, M. persicae developed more slowly and produced smaller adults compared to control, regardless of the duration of exposure (2, 4 or 6 h); additionally, the survival rate of M. persicae nymphs sharply decreased under these conditions. Exposure to 36°C for 4 h negatively impacted the development of A. gifuensis. Female parasitoids exposed to 32°C developed into smaller adults, whereas males exposed to all three temperature levels were smaller compared to control group. Female parasitoids exposed to high temperatures, regardless of the specific heat level and duration, exhibited reduced longevity and decreased fecundity. None of the parasitoids exposed to 36°C for 6 h daily developed into adults. Heat treated during early developmental stages (2 and 4 days old) had a greater influence on parasitoid development, whereas heat treatment at 4 and 6 days old had a more significant impact on its fecundity. CONCLUSION: High temperatures not only directly affected the performance of A. gifuensis, but also exerted indirect effects by influencing the quality of the host aphids M. persicae. The deleterious effects of high temperature on larvae can persist into the adult stage, affecting the longevity and reproduction of adults. These findings are important for the utilization of A. gifuensis in the control of M. persicae in warming environments. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Arctic freshwater ecosystems are on the “frontline” of climate change, but due to a lack of direct long‐term monitoring data, indirect approaches, such as algal‐based paleolimnology, must be used to reconstruct past limnological conditions. Our understanding of the responses of small‐ to mid‐sized Arctic lakes to climate warming has increased over the last ~30 years. However, until recently, little was known about even the basic limnological conditions of Canada's “Northern Great Lakes,” such as Lake Hazen, Great Bear Lake, and Great Slave Lake. In this summary, we show that a continuum of algal changes, observable in the sedimentary archives of shallow ponds to very large Arctic lakes, signals the crossing of key aquatic thresholds linked to changing ice covers and thermal regimes, declining wind speeds, and other climate‐related variables. With recent accelerated warming, even the largest and most resilient Arctic waterbodies are now fundamentally different than they were just a few decades ago. These changes will undoubtedly cascade throughout the food web leading to important changes for local Indigenous populations as well as the global community. [ABSTRACT FROM AUTHOR]

Understanding how phytoplankton growth responds to temperature is critical for forecasting marine productivity in a warming ocean. While previous laboratory studies have shown that phytoplankton thermal traits such as optimal temperature (Topt) can be affected by nutrient availability, it is unclear whether this can be extrapolated to natural communities. To address this, we tested the impacts of nutrient availability on the thermal responses of two cosmopolitan diatom genera, Pseudo‐nitzschia and Leptocylindrus, through a series of in situ manipulation experiments on natural phytoplankton communities. Analysis of the thermal performance curves revealed that nutrient limitation during summer not only limited the growth of these two genera but also reduced their Topt and the maximum growth rates (μmax). Topt was close to or lower than in situ temperature under ambient nutrient conditions, suggesting that further warming may have a detrimental effect on their growth. However, increasing nutrient supply could counteract this by enhancing Topt and μmax. To further confirm the interactive effects of nutrients and temperature on diatoms, we analyzed a 20‐yr monitoring dataset on Pseudo‐nitzschia, Leptocylindrus, and the whole diatom assembly in Hong Kong coastal waters. We found that the abundances of marine diatoms were significantly higher at high temperatures under nutrient‐rich environments while relatively low under low nutrient concentrations. Findings on natural diatom cell density align with the growth performance derived from in situ manipulation experiments, suggesting that abundant nutrients bolster marine diatoms in coping with warming. Our results highlight the importance of considering the influence of nutrient availability on thermal response of phytoplankton growth, which sheds light on how marine primary production may change under climate warming. [ABSTRACT FROM AUTHOR]

Liverworts are an ancient plant lineage that occurs worldwide with the highest species richness in cool and humid habitats such as tropical montane and temperate rain forests. It has been proposed that liverworts originated under such temperate climatic conditions and have later expanded into more tropical conditions, but how this is reflected in their phylogenetic diversity along the strong climatic gradients associated with elevation remains unexplored. We studied the phylogenetic diversity of regional liverwort floras along the elevational gradient in the tropical Andes, comparing indices that emphasize deeper and shallower phylogenetic relationships, and relating these to temperature‐ and precipitation‐related variables, as well as to climatic extremes and seasonality. We found that whereas liverwort species richness peaks at around 2000 m a.s.l., richness‐corrected phylogenetic diversity increases with elevation, and the standardized effect of size of phylogenetic diversity is highest at 2500–4000 m a.s.l. This is in accordance with an origin of liverworts under cool conditions, followed by more recent diversification in warmer climates at lower elevations. We further found temperature‐related climatic parameters to be stronger predictors of phylogenetic diversity of liverworts than precipitation‐related variables, and climatic extremes to have a stronger influence than climatic seasonality. We interpret these patterns as reflecting the physiological challenges of adapting to low temperatures as well as rare occurrences of extreme climatic events. All this reveals a strong signal of the evolutionary dynamics of this ancient plant lineage linked with its physiological adaptations to climatic conditions. The age of this group and its poikilohydric nature, i.e. its inability to regulate water loss, lead to patterns that contrast with those of vascular plants, allowing for discerning evolutionary generalities that are independent of physiology and lineage age. [ABSTRACT FROM AUTHOR]

Tropical wetlands account for ∼20% of the global total methane (CH4) emissions, but uncertainties remain in emission estimation due to the inaccurate representation of wetland spatiotemporal variations. Based on the latest satellite observational inundation data, we constructed a model to map the long‐term time series of wetland extents over the Sudd floodplain, which has recently been identified as an important source of wetland CH4 emissions. Our analysis reveals an annual, total wetland extent of 5.73 ± 2.05 × 104 km2 for 2003–2022, with a notable accelerated expansion rate of 1.19 × 104 km2 yr−1 during 2019–2022 driven by anomalous upstream precipitation patterns. We found that current wetland products generally report smaller wetland areas, resulting in a systematic underestimation of wetland CH4 emissions from the Sudd wetland. Our study highlights the pivotal role of comprehensively characterizing the seasonal and interannual dynamics of wetland extent to accurately estimate CH4 emissions from tropical floodplains. Plain Language Summary: Methane (CH4) plays an important role in global warming. About one‐fifth of global CH4 emissions come from tropical wetlands, with the Sudd wetland in tropical Africa presenting as a hotspot for CH4 emissions. In this study, we generate a monthly wetland map series based on the latest satellite observation for the Sudd wetland. Our results show that wetland area dynamics present large seasonal and interannual variabilities. However, current widely used wetland products tend to indicate smaller sizes and variations of wetlands, which might lead to the underestimation of wetland CH4 emissions. We point out that refined maps of tropical wetlands can help reduce the uncertainties of CH4 emission estimations. Key Points: Extended monthly inundation maps across the Sudd wetland for 2003–2022Rapid growth of the Sudd wetland extent for 2019–2022 driven by upstream precipitationUnderestimation of methane emissions from the Sudd wetland due to the inadequate characterization of wetland extent [ABSTRACT FROM AUTHOR]

Midlatitude Europe (ME) emerges as a prominent heatwave hotspot with rapid increases in summer surface air temperature and heatwave days since 1979, surpassing the global land averages by approximately 2.6 and 2.3 times, respectively. The circulation analogs‐based dynamic adjustment reveals that approximately 38% and 35% of these trends result from shifts in zonal dipolar circulation patterns over the North Atlantic (NA) and Europe, crucial for the enhanced warming compared to the global land average. The circulation changes are associated with warming sea surface temperatures in the NA. This warming pattern resembles the Atlantic Multidecadal Variability and is predominantly induced by greenhouse gases. Moreover, the stronger air temperature response in ME to decreased aerosols amplifies warming, contributing to the rapid increase in heatwave frequency. These findings highlight a prominent influence of anthropogenic forcings on the swift surge of European heatwaves compared to global land, with a potential implication for adaptation strategies and risk management. Plain Language Summary: Midlatitude Europe is experiencing a significant increase in heatwaves, with summer temperatures and heatwave occurrences rising much faster than the global land averages since 1979. One of the key contributors to this rapid warming is the changes in zonal dipolar circulation patterns over the NA and Europe, which are linked to the warm sea surface temperatures in the NA. This warming pattern, resembling the Atlantic Multidecadal Variability, is largely caused by greenhouse gases and additionally influenced by reduced aerosols and natural forcing. Furthermore, the stronger response of air temperatures in midlatitude Europe to decreased aerosol emissions intensifies summer warming, contributing to a rapid increase in heatwave days. These findings highlight the significant impact of anthropogenic forcings on the observed surge of heatwaves in Europe compared to global land, with an important implication for developing strategies to adapt to these changing climate conditions and managing the associated risks. Key Points: Midlatitude Europe exhibits more rapid increases in summer heatwave frequency than the global land averages in recent decadesAtmospheric circulation changes contributing about one third of the observed warming trend, further intensify the rapid increases in summer heatwave frequencyLocal air temperature response to reduced aerosol emissions contributes about half of the enhanced warming compared to the global land average [ABSTRACT FROM AUTHOR]

The recently‐observed poleward shift in western North Pacific tropical cyclone (TC) genesis has increased the TC threat to East Asia. We find that the poleward shift of TC genesis since 1979 is linked to mega‐ENSO. A downscaling analysis of TC genesis latitude given the constraint of mega‐ENSO using 30 models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) show a continued increasing poleward shift with additional warming. We use the dynamic genesis potential index as a TC proxy in future CMIP6 simulations. These simulations show enhanced TC formation in the subtropics and decreased TC formation in the tropics. Modeled TCs in CMIP6 high‐resolution models that well represent mega‐ENSO project future poleward shifts in TC genesis. Both observations and simulations show that extra‐tropical North Pacific sea surface temperature warming associated with mega‐ENSO are the primary driver of the TC genesis poleward shift. Our study provides new insights into climate change‐driven TC migration. Plain Language Summary: The observed poleward shift in tropical cyclone (TC) genesis over the western North Pacific has increased the threat from these storms to East Asia. Until now, it remains unclear whether TC genesis will continue to move poleward in the future, due to both a relatively short reliable observational TC record as well as model inconsistencies. This study provides evidence that the poleward migration of TC genesis will likely continue due to anthropogenic warming. We find that there is a strong relationship between TC genesis latitude and a mode of Pacific sea surface temperature (SST) variability termed mega‐ENSO. We find using a suite of 30 climate models comprising the Coupled Modeled Intercomparison Project Phase 6 (CMIP6) that future poleward trends in TC genesis latitude are likely to continue. This poleward shift is observed whether using projected trends in mega‐ENSO or an index that measures the conduciveness of the environment for TC formation. Modeled tropical cyclones in high resolution simulations from CMIP6 also show a continued projected poleward shift in TC genesis. This poleward shift in TC genesis appears largely related to changes in extra‐tropical SST warming associated with mega‐ENSO. Key Points: The recently‐observed poleward shift of tropical cyclone (TC) genesis is related strongly to mega‐ENSOChanges in modeled TCs and a TC proxy in a warming climate show a consistent northward TC genesis migrationExtra‐tropical sea surface temperature warming associated with mega‐ENSO appears responsible for poleward TC genesis movement [ABSTRACT FROM AUTHOR]

Silver is a highly toxic element for marine organisms. However, its controlling factor in marine sediments remains largely unknown, limiting our understanding of its biogeochemical cycling. Based on a sediment core from the Vietnam upwelling area in the South China Sea, it is found that Ag is significantly enriched in sediments of this area (as high as 0.39 μg/g), and it shows a very similar geochemical behavior to Ca and Sr. Our study supports the theory that Ag could be a marine paleo‐productivity indicator. Burial of Ag over the past 3,200 years shows an abrupt increase at around 1850 CE, in concordance with the global atmospheric CO2 record. It is hypothesized that elevated CO2 and global warming enhance marine productivity in the Vietnam coastal upwelling area, favoring the burial of Ag. Human‐induced global warming thus significantly impacts its biogeochemical cycling. Plain Language Summary: Cycling of elements in Earth systems is fundamental to Earth vitality. Examining biogeochemical cycling of elements is thus important in geoscience research. Global warming in recent time has exerted significant impact on the cycles of some elements, including carbon (C), nitrogen (N), and phosphorus (P). This imposes challenges to the integrity and security of Earth ecosystems. However, little is known about some other bio‐active elements. For example, silver (Ag) is highly toxic to marine organisms, but its occurrence, distribution, and fate under a warming background is largely unknown. We analyzed a marine core from the South China Sea, Western Pacific. It was found that concentrations of Ag in the sediments were pretty high, and its burial rate showed an abrupt increase at around 1850 CE. This is probably associated with increased marine productivity as Earth warmed. This study advances our understanding of the Ag cycle. Key Points: High concentrations of and significant variations in Ag were found in marine sedimentsAg in marine sediments is a marker for ocean paleoproductivityGlobal warming favors the burial of Ag in oceans [ABSTRACT FROM AUTHOR]

The Great Lakes Region (GLR) of North America is at the intersection of multiple extratropical cyclone (ETC) tracks, and the region's cold‐season climate is heavily influenced by the large temperature gradients and intense precipitation associated with these cyclones. The goal of this study is to understand how ETCs are changing within a warming climate. Historical GLR cyclone characteristics from 1959 to 2021 are examined using a storm tracking algorithm and the ERA‐5 atmospheric reanalysis. Of the 886 cyclones identified, half are the large long‐track cyclones that are typically included in ETC studies, and half are smaller short‐track cyclones that, while not always considered in ETC studies, still have an important impact on the GLR with significant precipitation trends. While all cyclones exhibit strong interannual variability, storm trajectories appear to be migrating northward and, most notably, the cyclones are becoming warmer and wetter at a rate faster than the background climate. Plain Language Summary: Winter weather patterns in the Great Lakes Region of the United States are driven by large‐scale weather systems known as "extratropical cyclones." Even with a warming climate, the Great Lakes Region experiences highly variable winters, with cold‐air outbreaks, extreme snowfall, and mild temperatures all possible from year to year. This study uses historical analyzed atmospheric data to identify and track extratropical cyclones that pass through the Great Lakes Region in order to understand how the cyclones have changed along with our changing climate. We find that the airmasses within the cyclones have increased in moisture and warmed up faster than the overall climate. We also find that the cyclone tracks have shifted northward, implying that the frequency of warm temperatures and heavy rainfall in the wintertime is increasing for the lower portion of the Great Lakes. Key Points: Cold season extratropical cyclones that pass through the Great Lakes region are shifting to more northern tracksThe number and intensity of Great Lakes cyclones do not show an increasing trendGreat Lakes extratropical cyclones are warming and are increasing in moisture at a rate faster than the background climate [ABSTRACT FROM AUTHOR]

Ecosystem‐scale photosynthetic efficiency (EPE) is proposed as an effective indicator to quantify gross primary productivity (GPP), but how the coupling between EPE and GPP varies as vegetation resilience decreases has not been evaluated. Here, we quantified forest resilience with optimized Bayesian models. With the use of multisource satellite and modeling data, our study revealed that forests on the Loess Plateau and in the Qinba Mountains in China are experiencing rapid resilience loss and are already facing mortality warnings after 2010. Reductions in resilience also drove the marked decoupling of GPP from EPE. Notably, the decline in resilience was accompanied by a decrease in EPE in about 74% of the forests while GPP increased. The mechanism underlying this decoupling could be attributed to enhanced atmospheric water demand and soil water constraints. The dynamic relationships found here could help to improve forest mortality models and enhance photosynthesis‐based GPP evaluation. Plain Language Summary: The persistence and functionality of forest ecosystems highly depend on their resilience. Low‐resilience forests may be unable to absorb changes and achieve system variable stabilization under perturbations in external drivers and may undergo irreversible system shifts. Reduced resilience is often caused by impaired physiological functions, which inevitably affects forest photosynthetic processes and carbon sinks. Our study on fragile ecosystems in China revealed that forests are rapidly losing resilience and are already facing mortality warnings after 2010. This phenomenon has also led to significant decoupling of carbon sinks from photosynthesis, driven by an elevated atmospheric water demand and soil water deficits. These findings demonstrate that forests will exhibit greater risk of mortality across broad scales under global warming and that photosynthetic proxies cannot be consistently used for evaluating carbon sequestration in ecosystems. Key Points: Early mortality warning signals have been detected for different forest types since 2010A reduction in forest resilience weakens the relationship between the gross primary productivity and photosynthetic efficiencyThe decoupling of forest photosynthesis from carbon sinks exhibits different response patterns to soil water and atmospheric drying [ABSTRACT FROM AUTHOR]

Idealized general circulation models (GCMs) suggest global‐mean precipitation ceases to increase with warming in hot climates because evaporation is limited by the available solar radiation at the surface. We investigate the extent to which this generalizes in comprehensive GCMs. We find that in the Community Atmosphere Model, global‐mean precipitation increases approximately linearly with global‐mean surface temperatures up to about 330 K, where it peaks at 5 mm day−1. Beyond 330 K, global‐mean precipitation decreases substantially despite increasing surface temperatures because of increased atmospheric shortwave absorption by water vapor, which decreases the shortwave radiation available for evaporation at the surface. Precipitation decreases in the tropics and subtropics but continues to increase in the extratropics because of continuously strengthening poleward moisture transport. Precipitable water increases everywhere, resulting in longer water‐vapor residence times and implying more episodic precipitation. Other GCMs indicate global‐mean precipitation might exhibit a smaller maximum rate and begin to decrease at lower surface temperatures. Plain Language Summary: Earth's climate has experienced substantial changes over its history, including periods of extremely cold temperatures where most regions contained ice, and periods of extremely warm temperatures where most regions contained no ice. In this study, we explore how precipitation changed in extremely cold and warm climates using a unique set of coupled climate model simulations. We find that global‐mean precipitation increases linearly with global‐mean surface temperatures up to 330 K, where it peaks at 5 mm day−1 and then decreases as surface temperatures further increase. This occurs because in hot climates, global‐mean precipitation is almost entirely balanced by absorbed shortwave radiation at the surface. As the climate warms, the atmosphere contains more water vapor, resulting in increased absorption of shortwave radiation within the atmosphere and decreased absorption of shortwave radiation at the surface. This decreases the energy available for surface evaporation. We show that other climate models exhibit qualitatively similar behavior but indicate global‐mean precipitation might exhibit a smaller maximum rate and begin to decrease at lower surface temperatures. These results demonstrate the need to better understand Earth's hydrological cycle in hot climates. These results also have large implications for understanding weathering in past climates and the habitability of other Earth‐like planets. Key Points: In CAM4, global‐mean precipitation increases linearly with surface temperatures up to 330 K, then decreases with higher temperaturesPrecipitation decreases at high temperatures due to increased atmospheric shortwave absorption by water vapor, decreasing surface absorptionAt high temperatures, precipitation decreases in most regions, but continues to increase in the extratropics due to eddy moisture transport [ABSTRACT FROM AUTHOR]

We show that the winter Beaufort High (BH) index defined by sea level pressure (SLP) has a robust negative trend under the scenarios SSP5‐8.5 and SSP2‐4.5, with a reduction by about 5 hPa and 2 hPa, respectively, by the end of the 21st century. The negative trends in the BH SLP are associated with the changes in the background SLP over the Arctic basin. However, the vorticity of the winter BH tends to intensify under SSP5‐8.5, but shows no robust increase under SSP2‐4.5. The intensification is associated with the enhanced ridge over the Western Arctic. Therefore, it is necessary to take into account the dynamic aspects of the BH, such as vorticity. Based on this assessment, under the most likely emissions scenario, the winter BH is likely to weaken through the 21st century, in terms of SLP, but shows no robust changes in term of vorticity. Plain Language Summary: We used the latest IPCC global climate model outputs to investigate the wintertime changes in the Beaufort High (BH). Under the climate change scenarios, during winter, the sea level pressure (SLP) over the BH region is expected to decrease. The SLP reduction is up to 5 hPa by the end‐of‐the‐century. Thus, the BH seems to become weaker. However, its vorticity tends to increase under SSP5‐8.5, mostly due to the intensification of the ridge over the western North America. Key Points: The Beaufort High (BH) index defined by sea level pressure (SLP) decreases under warming climate scenariosMeanwhile, the BH vorticity tends to intensify due to the change in the ridge over the Western ArcticBesides the SLP, impact studies of the BH on the Arctic Ocean need to consider its dynamics such as vorticity [ABSTRACT FROM AUTHOR]

Carbon storage technology is primarily targeted in saline formations, which is a porous rock matrix filled with brine, sealed with a low permeability caprock. There are significant variations of CO2 wetting properties, typically reported in the literature as contact angle of CO2 and brine interacting with a rock material, suggesting that CO2 could become wetting under geostorage conditions and negatively impact containment effectiveness. Here, we performed the first controlled laboratory measurements of CO2‐brine contact angles on shale rocks from low permeability sealing formations with distinctive mineralogic properties—calcite‐rich, quartz‐rich, and dolomite‐rich. We targeted temperatures at 40° and 100°C, pressures at 8.3, 34.5, and 62.1 MPa, and salinity at 35,000 and 260,000 ppm. Results show no significant change in contact angle with mineralogy, temperature, pressure, salinity, and CO2 bubble size. We conclude that caprocks will remain water‐wet at geologic CO2 storage conditions and will not lose their capillary sealing capacity. Plain Language Summary: Carbon capture and storage technology is gaining momentum to reduce carbon dioxide (CO2) emissions to mitigate global warming by capturing the CO2 produced by stationary industrial sources, transporting it, and then storing it deep underground. CO2 storage is primarily targeted in saline formations, which is a porous rock matrix filled with brine, sealed with a low permeability caprock. Several studies have examined the sealing ability of caprocks and suggested that CO2 could become wetting under geostorage conditions and negatively impact containment effectiveness. Our controlled laboratory experiments show caprocks with different mineral compositions will remain water‐wet at geologic CO2 storage conditions and will not lose their capillary sealing ability. Key Points: Performed first CO2‐brine contact angle experiments on shale rocks from sealing formations with distinctive mineralogic propertiesNo change in contact angle with mineralogy, temperature (100°C), pressure (62 MPa), salinity (260,000 ppm), and bubble size (200–2,500 μm)Caprock minerals will remain water‐wet at geologic CO2 storage conditions and will not lose their capillary sealing capacity [ABSTRACT FROM AUTHOR]

Warming associated with climate change will advance the onset of spring phenology for many forest plants across the Eastern United States. Understory forbs and spring ephemerals that fix a disproportionate amount of carbon during early spring may be negatively affected by earlier canopy closure; however, information on the spatial patterns of phenological change for these communities is still lacking. To assess the potential for changes in spring phenological windows, we synthesized observations from the Appalachian Mountain Club's (AMCs) Mountain Watch (MW) project, the National Phenology Network (NPN), and AMC's iNaturalist projects between 2004 and 2022 (n = 118,250) across the length of the Appalachian Trail (AT) Corridor (34° N–46° N latitude). We used hierarchical Bayesian modeling to examine the sensitivity of spring flowering and leaf‐out for 11 understory species and 14 canopy tree species to mean spring temperature (April–June). We conducted analyses across the AT Corridor, partitioned by regions of 4° latitude (south, mid‐Atlantic, and north). Spring phenologies for both understory plants and canopy trees advanced with warming (~6 and ~3 days/°C, respectively). However, the sensitivity of each group varied by latitude, with the phenology of trees and understory plants advancing to a greater degree in the mid‐Atlantic region (~10 days/°C) than in the southern or northern regions (~5 days/°C). While we find evidence that phenological windows remain stable in the southern and mid‐Atlantic portions of the AT, we observed an expansion of the spring phenological window in the north where there was greater understory forb temperature sensitivity compared with trees (~2.7 days/°C). Our analyses indicate the differential sensitivity of forest plant phenology to potential warming across a large latitudinal gradient in the Eastern United States. Further, evidence for a temperature‐driven expansion of the spring phenological window suggests a potential beneficial effect for understory plants in the northern AT, although phenological mismatch with potential pollinators and increased vulnerability to late winter frosts are possible. Using extensive citizen‐science datasets allows us to synthesize regional‐ and continental‐scale data to explore spatial and temporal trends in spring phenology related to warming. Such data can help to standardize approaches in phenological research and its application to forest climate resiliency. [ABSTRACT FROM AUTHOR]

Hydration of the stratosphere by tropopause‐overshooting convection has received increasing interest due to the extreme concentrations of water vapor that can result and, ultimately, the climate warming potential such hydration provides. Previous work has recognized the importance of numerous dynamic and physical processes that control stratospheric water vapor delivery by convection. This study leverages recent comprehensive observations from the NASA Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) field campaign to determine the frequency at which each process operates during real events. Specifically, a well‐established analysis technique known as tracer‐tracer correlation is applied to DCOTSS observations of ozone, water vapor, and potential temperature to identify the occurrence of known processes. It is found that approximately half of convectively‐driven stratospheric hydration samples show no indication of significant air mass transport and mixing, emphasizing the importance of ice sublimation to stratospheric water vapor delivery. Furthermore, the temperature of the upper troposphere and lower stratosphere environment and/or overshoot appears to be a commonly active constraint, since the approximate maximum possible water vapor concentration that can be reached in an air mass is limited to the saturation mixing ratio when ice is present. Finally, little evidence of relationships between dynamic and physical processes and their spatial distribution was found, implying that stratospheric water vapor delivery by convection is likely facilitated by a complex collection of processes in each overshooting event. Plain Language Summary: Thunderstorms are capable of transporting air and water up to the second layer of Earth's atmosphere, the stratosphere. Resulting irreversible modifications to greenhouse gases that regulate climate, such as water vapor and ozone, are important to quantify and poorly understood. This study uses recently‐obtained aircraft observations to improve understanding of irreversible transport in thunderstorms and the environmental and storm factors that control it. By examining how multiple trace gases and other quantities co‐vary, it is found that half of observed stratospheric changes by thunderstorms only exhibit increases in water vapor, which is argued to be driven by transported ice. It is also found that the environmental temperature is an important constraint in any storm because it limits the amount of stratospheric water vapor change that can occur. Key Points: Recent airborne observations reveal key dynamic and physical processes controlling the stratospheric delivery of water vapor by convectionIn situ observations suggest that water vapor is delivered routinely via both air transport and ice sublimationTemperature is an important constraint for water vapor delivery in any stratospheric environment [ABSTRACT FROM AUTHOR]

Methane (CH4) is the second most abundant greenhouse gas and affects the Earth's radiative balance. In some regions, the methane burden and budget are still not well understood due to the lack of in situ observations, especially vertical profile observations. Here, we present the first high‐resolution aircraft‐based tropospheric vertical profiles of CH4 across the Indian subcontinent. Observations show significant variability, with the largest variability seen in the Indo‐Gangetic Plain (IGP) during post‐monsoon (September). The IGP also shows the highest concentrations and a peak in the boundary layer. By contrast, observations over western India show lower variability, especially during the Asian Summer Monsoon (ASM) (July). During ASM, when CH4 emissions peak, the vertical updraft of CH4 and other tracers is observed, leading to a peak between 4 and 5 km. During winter, the peak occurs in the boundary layer, and a decrease with altitude is observed. Model simulations slightly overestimate CH4 at the surface during some seasons but underestimate it at higher altitudes during all seasons. Integrated over the observed column, model simulations slightly underpredict CH4 (0.5%–3.1%) during all seasons. Calculations made using the observed CO/CH4 enhancement ratios show that in addition to anthropogenic fossil fuel emissions, other sources, such as rice cultivation and wetlands, need to be considered to reproduce the observed CH4 concentrations. Plain Language Summary: Methane is a potent greenhouse gas, which causes global warming. Aircraft‐based observations of methane were conducted over India to study the vertical variability. Observations show that methane is highly variable with altitude, and these vertical profiles are different according to the region and season in India. Models can reproduce the average vertical profiles but not individual flights. Using these data, estimations of methane emissions were also done, which show that current inventories need to account for all the different sources, including agriculture and wetlands. Key Points: First high‐resolution aircraft‐based tropospheric vertical profiles of methane over India are reportedObservations show a large variability of tropospheric methane across seasons and locationsModel simulations slightly underestimate the observed methane in the free troposphere [ABSTRACT FROM AUTHOR]