Anthropogenic Global Warming Research Articles

In thermotolerance tests of tropical tree leaves, the chlorophyll fluorescence parameter Fv/Fm measured soon after heat exposure is not a reliable predictor of tissue necrosis.

Tropical rainforests are hot and may be particularly sensitive to ongoing anthropogenic global warming. This has led to increased interest in the thermotolerance of tropical trees. Thermotolerance of leaves of two tropical tree species, Terminalia catappa and Coccoloba uvifera, was determined by exposing leaf samples to 15-min heat treatments, followed by measurements of potential photosystem II quantum yield (dark-adapted value of variable/maximum chlorophyll a fluorescence, Fv/Fm) after 24 h and 14 days, and visible damage (necrosis) after 14 days. T50 (24 h), the temperature at which Fv/Fm declined by 50% 24 h after heat treatments, was associated with only ~10% leaf area damage in C. uvifera and no damage in T. catappa. In neither species was leaf necrosis observed at T5 (24 h), the temperature at which Fv/Fm declined by 5%. In both species, temperatures significantly higher than T50 (24 h) were required for 50% leaf area necrosis to occur. T50 (14 days) was a better proxy of visible leaf damage than T50 (24 h). The relationship between heat-induced Fv/Fm decline and tissue necrosis varies among species. In species surveys of leaf thermal tolerances, calibration of the Fv/Fm assay against the necrosis test is recommended for each species under investigation. Fv/Fm measurements soon after heat exposure do not reliably predict irreversible heat damage and may thus not be suitable to model and predict the thermostability of tropical forest trees.

Impacts of long-term climate change on human health: a global scoping review

Abstract Introduction Research output on climate change and human health is growing rapidly. This can make it difficult to find and use relevant information to develop public health action. Methods We present a global scoping review of the rapidly growing quantitative research output on long-term climate change and human health. We searched Scopus, Embase, and PubMed for quantitative, English language literature published between January 2000 and June 2021 that referenced climate change and human health in titles, abstracts, or keywords. Results From 36,956 publications we identified 754 relevant studies. Europe, the Americas, and the Western Pacific were studied much more often than other WHO regions. Research on temperature and vectors accounted for 70% of all included publications. Malaria, diarrheal diseases, and cardiovascular diseases were the most studied specific health outcomes. We found very few studies on non-communicable diseases in low- and middle-income countries. Retrospective publications (153) showed effects of climate change are already occurring worldwide. Most studies on tick-borne encephalitis, malaria, and lower respiratory infections associated with air pollution found impacts caused by climate change have increased. The strongest attribution of climate change was found for heat-related impacts. In prospective publications (626) diarrheal diseases, and impacts associated with heat and chemical air pollution were most consistently projected to increase. Future vector-borne disease impacts were projected to be highly location specific. Some studies demonstrated adaptation can effectively reduce impacts, while noting that capacity to adapt differs greatly between population groups. Conclusions Our findings underline climate change impacts are diverse and complex. Future research should prioritize the relatively understudied regions most vulnerable to climate change, such as Africa, and impacts beyond those related to temperature and vector-borne diseases.

A Report on the Tabanus Species Tabanus rufofrater in Mithun (Bos frontalis)

Background: Mithun (Bos frontalis) experience infestations from various ectoparasites, including several types of flies that cause painful bites, stress, blood loss and transmit a range of microorganisms. In the Mithun-inhabited forested regions of Phek, Nagaland, the Tabanus fly is particularly prevalent. Methods: Researchers studied Tabanus flies infesting free-range mithun in Phek District, Nagaland. The flies were collected and processed at the ICAR-NRC on Mithun in Nagaland. Both morphological (using stereoscopic microscopes) and molecular methods (employing ribosomal and mitochondrial gene markers) were utilized for identification. Additionally, DNA barcoding was done at Eurofins Genomics India Pvt. Ltd. to further ascertain the flies’ identities. Climate attributes (Temperature, Rainfall and Humidity) was recorded during the study. Result: Through morphological and molecular investigations, it was conclusively determined to be Tabanus rufofrater. The highest occurrence of Tabanus rufofrater encounters takes place between May and August, aligning with the pre-monsoon and monsoon seasons, before gradually declining thereafter. The prevalence of Tabanus rufofrater attacks peaks from May to August, coinciding with the pre-monsoon and monsoon periods and subsequently decreases.

Weather Prediction with Machine Learning

Weather forecasting is the technical process of predicting atmospheric conditions at a location. Many scientists have also been trying to predict the weather, both formally and informally, for years. Weather forecasting is done by collecting data from specific locations with different climate attributes. Traditional numerical weather prediction models have made significant progress, but there are still limitations in their accuracy, especially in detecting local weather events. In recent years, machine learning techniques have become a powerful tool for improving weather forecasts by exploiting the large amounts of data and complex patterns inherent in atmospheric systems. We propose a machine- learning model that uses historical data to train the model. The model is then used to predict weather with better accuracy than traditional models.

EXPRESS: Chaxu climate as a double-edged sword: a moderated mediation model of organizational justice, hierarchy level on turnover intention

Research on chaxu climate, a prevalent organizational phenomenon in China, has captured significant academic attention in recent years. This study aims to explain why some employees who experience chaxu climate in hospitality organizations contemplate leaving, while others do not. We propose a moderated mediation model to examine the double-edged sword impact of chaxu climate on turnover intention. Through one qualitative study and two scenarios-based experimental studies, we reveal that organizational justice plays a crucial role as a contextual cue, influencing employees’ attribution of chaxu climate and subsequent turnover intention. Perceived insider status is identified as a mediator. Furthermore, we establish a second-level moderating effect of the hierarchy level, distinguishing between supervisor and front-line employees. Theoretical and practical implications are discussed accordingly.

Attribution of environmental outcomes to climate change: Perceptions of coastal communities in the Caribbean

Attribution of environmental outcomes to climate change is a live debate in scholarly and policy circles. Non-scientific attribution by the lay public has value for enriching the discourse, engagements, and decisions on loss and damage, adaptation and mitigation, communication strategies, and the science-policy interface from local to international levels. There is a need for context-specific studies on perceived climate attribution by the lay public. Unlike the few previous studies that focused on attribution of extreme events to climate change by the lay public, the current paper assessed the key compositional and contextual factors that influence the attribution of environmental outcomes with slow onset to climate change. This study surveyed 441 households in eight small coastal communities in three Caribbean countries and applied a generalized linear regression model with a complementary log-log link to assess the relationship between compositional and contextual factors that influence perceived linkage between climate change and environmental outcome. At the bivariate level, the results showed that ethnicity, marital status, household head highest education, household income, and community of living were significant predictors of the likelihood of the perceived linkage between climate change and worsening environmental outcome. At the multivariate level, when all factors have been accounted for, we found that respondents with higher education were 160% more likely to indicate that climate change has adverse effects on environmental outcomes. Respondents with 10 or more years of experience in their present occupation were 73% more likely to suggest a linkage between climate change and worse environmental outcomes. Other strong predictors included income, ethnicity and community of residence. The perceived relationship between climate change and environmental outcomes differed systematically based on the compositional and contextual attributes of respondents. Several significant relationships at the bivariate level persisted at the multivariate level, indicating that the perceived linkages are robust and entrenched. It is concluded that there are heterogeneities in the perceived relationship between climate change and environmental outcomes based on the compositional and contextual factors of the households. Higher education and longer experience in the same occupation contribute significantly to climate attribution by the lay public.

Rising global temperatures and its impact on sleep behavior of male redheaded bunting (Emberiza bruniceps).

Anthropogenic global warming is one of the most pervasive threats to nature and biodiversity. The magnitude with which earths' temperature is rising is affecting every lifeform uniquely; however, the studies highlighting the impacts of global warming on avian sleep are scarce. To this end, the present study was aimed at analyzing the impact of global warming on sleep behavior of a nocturnal migrant, Emberiza bruniceps. For this purpose, the birds were divided into two groups (N = 15 each), subjected to high (35 ± 1°C) and low (19 ± 1°C) temperature schedule with concurrent exposure to 8L:16D (short day; SD) photoperiod followed by 13L:11D (long day; LD). The experiment continued till 7 cycles of zugunruhe (LD) in birds. The results reveal significant impact of temperature treatment on initiation and quality of zugunruhe. Temporal distribution of activity and rest varied according to the temperature provided. Focusing on rest and specifically on sleep of birds, high ambient temperatures resulted in greater sleep fragmentation (evident by increased awakenings during night), whereas low temperature created a sleep conducive environment (evident by abundance of back sleep). Besides postural differences, high temperature resulted in reduced sleep duration, sleep onset latency and circulating plasma melatonin levels in comparison with low temperature suggesting the negative impact of high temperature on different sleep attributes. Not only sleep, seasonal physiology of birds such as hyperphagia, gain in body mass, and fat stores showed significant reduction in high temperature condition. Besides behavioral and physiological alterations, high ambient temperature led to elevated expression of temperature sensitive (trpv4, trpm8, hspa8, and hsp70) genes. Enhanced expression of chrm3 (responsible for wakefulness) also affirms sleep fragmentation in response to high temperature. Thus, the study highlights the negative impact of high temperature on birds' sleep behavior and seasonal physiology.

Drying trend in land and sea in East Asia during the warm season over the past four decades

Abstract The East Asian region is typically characterized by warm and humid conditions from late spring to summer. However, in recent decades, this region has experienced an increase in severe drying conditions, deviating from historical climatological patterns. This study investigated the precipitation-evaporation (P-E) trends across land and sea regions in East Asia (EA) during the extended summer season (April to September) from 1980 to 2022, and the key physical processes driving these trends through moisture budget decomposition and numerical experiments. The results reveal pronounced drying trends in southeastern China and the Yellow Sea and parts of the Korea Strait and Korean Peninsula over the past 43 years. The underlying physical processes driving these drying conditions differ between land and sea in EA. In southeastern China, the drying is driven by dynamic processes, particularly moisture divergence related to wind changes. This is linked to anomalous strengthening of descending motion due to the Indo-Pacific warm pool warming induced by both anthropogenic global warming and natural Pacific Decadal Oscillation-like sea surface temperature (SST) patterns. Conversely, drying in the Yellow Sea and adjacent areas is influenced by thermodynamic moisture advection. The altered humidity distribution due to global warming-induced SST patterns, which are higher over the Northwest Pacific marginal sea and lower in inland China, drives dry air transport from inland China to the Yellow Sea via background southwesterly wind. These findings enhance our understanding of the drying trend and their distinct processes in EA’s land and sea areas during the extended summer.

Attribution of climate change and human activities to spatiotemporal changes of ecological service value in Yunnan Province of China

Quantifying the influence of climate change and human activities on spatiotemporal changes of regional ecological service value (ESV) can provide key information for regional ecosystem protection. However, few studies have distinguished the contributions of climate change and human activities to the total ESV. In this study, Yunnan Province in Southwest China with high biodiversity and ESV was selected as a representative region for the attribution analysis of ESV changes. The Carnegie-Ames Stanford Approach (CASA) was used to calculate the vegetation net primary productivity (NPP), and improved equivalent factor method was used to calculate ESVs of different ecosystem service functions directly from NPP. Then, the multi-factor attribution analysis method was used to quantify the contribution rates of climate change and human activities to changes in ESV. Results show that the ESV in Yunnan Province increased by 12.9 % in 2000–2019 compared to 1980–1999 without considering economic development. Land use and cover change (LUCC) is the main cause for the increase in ESV with the contribution rate of 92.3 %, while that of climate change is only 7.7 %. Major components of ESV change are ESV changes in forests, grasslands, and farmland, which are all mainly caused by LUCC with the contribute rates of over 80 %. ESVs in different cities differ greatly, where the ESV and ESV per unit area in Pu'er City are 5.3 and 2.6 times as those in Zhaotong City, respectively. LUCC is also the main cause of ESV changes in all cities, with contributions rates generally exceeding 80 %. When considering economic development, the ESV in Yunnan has increased by 336.2 % in these two periods. Contribution rate of economic development to ESV increase in Yunnan is 80.3 %, while that of climate change and LUCC is only 19.7 %. The speed of ecological construction in Yunnan Province is far slower than that of economic development, and appropriate measures should be taken to improve the ecological services in the future.

Changes in Vegetation Cover and the Relationship with Surface Temperature in the Cananéia–Iguape Coastal System, São Paulo, Brazil

The objective of this article is to investigate the possible correlations between vegetation indices and surface temperature in the Cananéia–Iguape Coastal System (CICS), in São Paulo (Brazil). Vegetation index data from MODIS orbital products were used to carry out this work. The Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) were acquired from the MODIS/Aqua sensor (MYD13Q1) and the leaf area index (LAI) from the MODIS/Terra (MOD15A2H). Surface temperature data were acquired from MODIS/Aqua (MYD11A2). The data were processed using Google Earth Engine and Google Colab. The data were collected, and spatial and temporal correlations were applied. Correlations were applied in the annual and seasonal period. The annual temporal correlation between vegetation indices and surface temperature was positive, but statistically significant for the LAI, with r = 0.43 (90% significance). In the seasonal period, positive correlations occurred in JFM for all indices (95% significance). Spatially, the results of this research indicate that the largest area showed a positive correlation between VI and LST. The hottest and rainiest periods (OND and JFM) had clearer and more significant correlations. In some regions, significant and clear correlations were observed, such as in some areas in the north, south and close to the city of Iguape. This highlights the complexity of the interactions between vegetation indices and climatic attributes, and highlights the importance of considering other environmental variables and processes when interpreting changes in vegetation. However, this research has significantly progressed the field, by establishing new correlations and demonstrating the importance of considering climate variability, for a more accurate understanding of the impacts on vegetation indices.

Pengenalan Satwa Papua dan Status Konservasinya melalui Sosialisasi di Sekolah SMA Bintuni Papua Barat

Papua has a high level of species diversity and endemism. This community service activity (PKM) is motivated by the decreasing of Papua's biodiversity due to anthropogenic activities and global warming, so it is necessary to make efforts to increase public awareness, especially among the children about the concept of protection, management, and use wisely and sustainably for Papua's diversity. Therefore, we carried out socialization about the Papuan animals and their conservation status to students at SMA Negeri 1 and SMA YPPK St. Arnoldus Jansen in Bintuni Bay District, West Papua Province on 10-11 December 2021. Socialization activities involve lectures, questions, and answers, filling out questionnaires, and giving rewards. The results showed that 61.54% of participants did not know the conservation status of animals in Papua based on Indonesian and international regulations. In addition, as many as 87.18% of participants stated that some animals in Papua were sold in the market and participants also consumed some of these animals. However, the participants' desire to protect Papua's animals is quite high (94.87%).

The Cretaceous world: plate tectonics, palaeogeography and palaeoclimate

The tectonics, geography and climate of the Cretaceous world were very different from the modern world. At the start of the Cretaceous, the supercontinent of Pangaea had just begun to break apart and only a few small ocean basins separated Laurasia, West Gondwana and East Gondwana. Unlike the modern world, there were no significant continent–continent collisions during the Cretaceous, and the continents were low-lying and easily flooded. The transition from a Pangaea-like configuration to a more dispersed continental arrangement had important effects on the global sea level and climate. During the Early Cretaceous, as the continents rifted apart, the new continental rifts were transformed into young ocean basins. The oceanic lithosphere in these young ocean basins was thermally elevated, which boosted sea level. Sea level, on average, was c. 70 m higher than that of the present day. Sea level was highest during the mid-Cretaceous (90–80 Ma), with a subsidiary peak occurring c. 120 Myr ago (early Aptian). Overall, the Cretaceous was much warmer than the present-day climate (>10°C warmer). These very warm times produced oceanic anoxic events (OAEs), and the high temperatures in equatorial regions sometimes made terrestrial and shallow-marine ecosystems uninhabitable (temperatures >40°C). This is unlike anything we have seen in the last 35 Myr and may presage the eventual results of man-made global warming. This mostly stable, hot climate regime endured for nearly 80 Myr before dramatically terminating with the Chicxulub bolide impact 66 Myr ago. Temperatures plummeted to icehouse levels in the ‘impact winter’ as a result of sunlight-absorbing dust and aerosols being thrown into the atmosphere. As a consequence of the collapse of the food chain, c. 75% of all species were wiped out. The effect of this extinction event on global ecosystems was second only to the great Permo-Triassic Extinction.

Hazardous Waste Litigation and Mapping: A template for designing maps of climate change attribution

Hazardous Waste Litigation and Mapping: A template for designing maps of climate change attribution

Tropical and mid-latitude causal drivers of the eastern Mediterranean Etesians during boreal summer

During boreal summer, large scale subsidence and a persistent northerly flow, known as the Etesians, characterize the tropospheric circulation over the eastern Mediterranean. The Etesians bring clear skies and alleviate the impact of heat waves over the region. The intraseasonal variability of the Etesians and subsidence over the eastern Mediterranean has been thought to be influenced by the South Asian monsoon and atmospheric processes over the North Atlantic. Here, we employ causal effect networks and causal maps, obtained by applying the Peter and Clark Momentary Conditional Independence (PCMCI) causal discovery algorithm, to identify causal precursors of Etesians. We find that both wave train activity over the North Atlantic/North American region and convective activity over South Asia associated with the Indian summer monsoon (ISM) are causally related to the Etesians at 3-day time scale. Thus, intraseasonal ISM variability affects the eastern Mediterranean circulation, though its influence is conveyed via a Middle East ridge. On longer weekly time scale, the mid-latitude influence weakens, while the influence of the tropical convective activity via the Middle East ridge remains stable. Moreover, the heat low over the Arabian Peninsula, a feature strongly responsible for the development of the Etesians, is caused by a stronger Middle East ridge and not by North Atlantic wave activity. Finally, we discuss potential implication for circulation changes in the eastern Mediterranean due to anthropogenic global warming.

Field evaluation and characterization of a novel biostimulant for broccoli (Brassica oleracea var. italica) cultivation under drought and salt stress which increases antioxidant, glucosinolate and phytohormone content

Anthropogenic global warming is affecting crop yield and thus compromising food security. Drought and salinization of the irrigation water or soil are increasingly frequent in most arable land, specifically in arid and semiarid areas such as the Mediterranean basin. Many crops have been displaced or their yield has plummeted in recent years, causing food shortages and price increases. In a context of global population growth and reduction in the availability of natural resources used in agriculture, finding novel tools that help farmers to maintain yield in an increasingly arid and saline scenario is of pivotal importance. This is particularly important in organic agriculture, where the number of available tools is very limited. Biostimulants are substances or microorganisms of natural origin whose function is to stimulate plant processes related to nutrient absorption, nutrient use efficiency, tolerance to abiotic stress or the quality of the agricultural products obtained. In the present work, we have evaluated, in field, the agronomic effectiveness of a novel biostimulant formulation in a cruciferous crop of great interest in the Mediterranean basin (broccoli) under control conditions, water and salt stress. Our research has shown that our product had a positive effect on broccoli production and in delaying flowering time. We have also found that the application of our biostimulant increased enzymatic and non-enzymatic antioxidant defense under drought conditions. Similarly, when exposed to salinity, the biostimulant increased the concentration of different phytohormones and glucosinolates. Taken together, our biostimulant increases the tolerance of broccoli to salt stress and water limitation by increasing the antioxidant response, the level of glucosinolates and eliciting the hormonal response.

2023 temperatures reflect steady global warming and internal sea surface temperature variability

2023 was the warmest year on record, influenced by multiple warm ocean basins. This has prompted speculation of an acceleration in surface warming, or a stronger than expected influence from loss of aerosol induced cooling. Here we use a recent Green’s function-based method to quantify the influence of sea surface temperature patterns on the 2023 global temperature anomaly, and compare them to previous record warm years. We show that the strong deviation from recent warming trends is consistent with previously observed sea surface temperature influences, and regional forcing. This indicates that internal variability was a strong contributor to the exceptional 2023 temperature evolution, in combination with steady anthropogenic global warming.

High‐Resolution Ice‐Core Analyses Identify the Eldgjá Eruption and a Cluster of Icelandic and Trans‐Continental Tephras Between 936 and 943 CE

AbstractThe Eldgjá eruption is the largest basalt lava flood of the Common Era. It has been linked to a major ice‐core sulfur (S) spike in 939–940 CE and Northern Hemisphere summer cooling in 940 CE. Despite its magnitude and potential climate impacts, uncertainties remain concerning the eruption timeline, atmospheric dispersal of emitted volatiles, and coincident volcanism in Iceland and elsewhere. Here, we present a comprehensive analysis of Greenland ice‐cores from 936 to 943 CE, revealing a complex volatile record and cryptotephra with numerous geochemical populations. Transitional alkali basalt tephra matching Eldgjá are found in 939–940 CE, while tholeiitic basalt shards present in 936/937 CE and 940/941 CE are compatible with contemporaneous Icelandic eruptions from Grímsvötn and Bárðarbunga‐Veiðivötn systems (including V‐Sv tephra). We also find four silicic tephra populations, one of which we link to the Jala Pumice of Ceboruco (Mexico) at 941 ± 1 CE. Triple S isotopes, Δ33S, spanning 936–940 CE are indicative of upper tropospheric/lower stratospheric transport of aerosol sourced from the Icelandic fissure eruptions. However, anomalous Δ33S (down to −0.4‰) in 940–941 CE evidence stratospheric aerosol transport consistent with summer surface cooling revealed by tree‐ring reconstructions. Tephra associated with the anomalous Δ33S have a variety of compositions, complicating the attribution of climate cooling to Eldgjá alone. Nevertheless, our study confirms a major S emission from Eldgjá in 939–940 CE and implicates Eldgjá and a cluster of eruptions as triggers of summer cooling, severe winters, and privations in ∼940 CE.

Working towards a Green Economy – Meaning, Measures, Policies & Implementation

The transition towards a Green Economy is a critical human response to the imminent threat of climate change, driven primarily by anthropogenic global warming. This paper explores the multifaceted aspects of Green Economy, encompassing sustainable development and economic growth that mitigates environmental degradation. The concept is grounded in the UNEP definition of a Green Economy, emphasizing improved human well-being and social equity while reducing environmental risks. Key areas include renewable energy, sustainable transport, green building, water and waste management, and land management. Measurement of progress towards a Green Economy is examined through various indices like the Global Green Economy Index (GGEI) and methodologies proposed by OECD. The challenges faced by developing countries in monitoring and achieving Green Growth are discussed, highlighting the need for enhanced statistical capacities and integrated policy frameworks. Policies for transitioning to Green Economic Growth are analyzed, with a focus on developing countries and strategic sectors. The paper also delves into specific policy instruments such as environmental labeling, green subsidies, payments for ecosystem services, environmental taxes, and promotion of green energy investments. Additionally, it discusses strategic trade policies and innovation indicators, using China as a case study to illustrate the potential benefits and challenges. The conclusion underscores the necessity of harmonizing economic growth with sustainability, advocating for a model where Green Economic Growth serves as both a driver of economic development and a solution to environmental challenges. This holistic approach is essential to prevent economic regress and ensure a sustainable future for all.

Elevated sea surface temperature and enhanced primary productivity during Ocean Anoxic Event 1d in the eastern Tethys: Calcareous nannofossil evidence from southern Tibet, China

Mid-Cretaceous oceanic anoxic events (OAEs) are characterized by major disturbances to the global carbon cycle and are considered ancient analogs for anthropogenic global warming. Among these events, OAE 1d, occurring around the Albian-Cenomanian boundary, remains understudied in the eastern Tethys region, leaving a critical palaeogeographic gap that hampers a global understanding of its impacts. In this paper, we present a detailed record of calcareous nannofossil assemblages from the lower to middle part of the Lengqingre Formation in the Chaqiela section of Gamba, southern Tibet, China. The study interval contains abundant, moderately to well preserved calcareous nannofossil assemblages, with Watznaueria barnesiae, Discorhabdus ignotus, Biscutum constans, and Zeugrhabdotus erectus as the dominant species constituting >50% of the assemblages. These nannofossil assemblages allow the study interval to be constrained to Upper Cretaceous (UC) Biozones UC0 through UC2, with the Albian-Cenomanian boundary located in the lower part of the Lengqingre Formation, and the middle part assigned to Cenomanian in the study area. As such, the position of OAE 1d in this section is accurately determined. Calculated nutrient and temperature indices based on nannofossil species with preferred ecologies reveal significant palaeoceanographic changes across the OAE 1d. These changes show increased abundance of warm-water taxa (e.g., Rhagodiscus asper and Zeugrhabdotus diplogrammus) and high-productivity taxa (e.g., D. ignotus, B. constans, and Z. erectus), suggesting increased sea surface temperature and enhanced productivity during OAE 1d in the southwestern shelf sea of the eastern Tethys Ocean.

The combination of a microbial and a non-microbial biostimulant increases yield in lettuce (Lactuca sativa) under salt stress conditions by up-regulating cytokinin biosynthesis.

Salinization poses a significant challenge in agriculture, exacerbated by anthropogenic global warming. Biostimulants, derived from living microorganisms or natural extracts, have emerged as valuable tools for conventional and organic agriculture. However, our understanding of the molecular mechanisms underlying the effects of biostimulants is very limited, especially in crops under real cultivation conditions. In this study, we adopted an integrative approach to investigate the effectiveness of the combined application of plant growth-promoting bacterium (Bacillus megaterium strain BM08) and a non-microbial biostimulant under control conditions (normal watering) and salt stress. After confirming the yield increase under both conditions, we investigated the molecular mechanisms underlying the observed effect by measuring a number of physiological parameters (i.e., lipid peroxidation, antioxidants, chlorophylls, total phenolics and phytohormone content), as well as RNA sequencing and primary metabolite analyses. Our findings reveal that the combined effect of the microbial and non-microbial biostimulants led to a decrease in the antioxidant response and an up-regulation of genes involved in cytokinin biosynthesis under salt stress conditions. This, in turn, resulted in a higher concentration of the bioactive cytokinin, isopentenyladenosine, in roots and leaves and an increase in γ-aminobutyric acid, a non-proteic amino acid related to abiotic stress responses. In addition, we observed a decrease in malic acid, along with an abscisic acid (ABA)-independent up-regulation of SR-kinases, a family of protein kinases associated with abiotic stress responses. Furthermore, we observed that the single application of the non-microbial biostimulant triggers an ABA-dependent response under salt stress; however, when combined with the microbial biostimulant, it potentiated the mechanisms triggered by the BM08 bacterial strain. This comprehensive investigation shows that the combination of two biostimulants is able to elicit a cytokinin-dependent response that may explain the observed yield increase under salt stress conditions.