Global Warming Research Articles

Heat-stable protein PGSL1 enhances pollen germination and tube growth at high temperature

Global warming intensifies extreme heat events, threatening crop reproduction by impairing pollen development, germination, and tube growth. However, the mechanisms underlying pollen heat responses remain elusive. The actin cytoskeleton and actin-binding proteins (ABPs) are crucial in these processes, yet their roles under heat stress are poorly understood. Here, we identify a mutant, pollen germination sensitive to LatB (pgsl1), via forward genetic screening. PGSL1 encodes a heat-stable, plant-specific ABP that binds and stabilizes actin filaments (F-actin), preventing heat-induced denaturation. High temperatures reduce F-actin content but promote bundling in pollen tubes. Notably, pgsl1 mutants exhibit decreased F-actin abundance and bundling under heat stress compared to wild-type plants. These findings highlight PGSL1 as a key regulator of actin dynamics, essential for pollen heat tolerance, offering potential strategies to enhance crop resilience in a warming climate.

Climate Change, Extreme Weather Events, Food Security, and Nutrition: Evolving Relationships and Critical Challenges.

Climate change, also known as global warming, poses significant challenges for both the planet and humanity. With further warming, every region across the world is projected to increasingly experience concurrent and multiple changes in climate, compounding overall risk. Long-term climate change and near-term extreme weather events have multiple negative effects on food security, diets, and nutrition via complex, multidirectional pathways through food, health, water, and social protection systems. However, measuring climate-attributable malnutrition impacts, especially among the most vulnerable populations, remains challenging. Changes in climate across a range of geographies have been modeled, projected, and observed showing detrimental associations with dietary and nutrition outcomes, particularly undernutrition. Many of these undernourished populations are climate vulnerable due to a variety of determinants challenging their ability to adapt to impending risks. While nutrition integration within climate adaptation plans have lagged, there is momentum for robust collaboration between climate and nutrition communities to fill data gaps that are critical for joint decision-making.

Global warming expectations of German firm representatives are overly optimistic, uncertain, and easily influenced

What expectations do firm representatives hold regarding future climate change, and how certain are they in their expectations? We analyze German firm representatives’ expectations and effects of the firms’ policy affectedness and engagement, and firm representatives’ knowledge using an information treatment experiment. We find modest economic sector differences and a positive association of engagement (i.e., energy and emission metering and reduction target setting) with expected global warming. The information treatment increases the global warming expectations in the optimistic (low warming) scenarios and decreases expectations in the pessimistic (high warming) scenarios. Moreover, representatives from less engaged firms appear rather uncertain and overly optimistic and tend to be pushed upwards in their expectations by the information treatment, while a downward shift is observed among the more engaged firms. Our results imply that the majority of respondents have a high degree of uncertainty and limited knowledge regarding climate change and appear easily influenceable.

Recent intensified riverine CO2 emission across the Northern Hemisphere permafrost region

Global warming causes permafrost thawing, transferring large amounts of soil carbon into rivers, which inevitably accelerates riverine CO2 release. However, temporally and spatially explicit variations of riverine CO2 emissions remain unclear, limiting the assessment of land carbon-climate feedback. Using new and published 5685 riverine CO2 partial pressure data in the Arctic and Tibetan Plateau, we show that current riverine CO2 emission across the Northern Hemisphere permafrost zone is 200 ± 15 Tg C yr⁻1. The emission offsets 28.1 ± 2.1% of the land carbon uptake in the Northern Hemisphere permafrost zone, with large regional variability of 13.1 to 63.1%. Our findings suggest that CO2 emissions increased at a rate of 0.42 ± 0.16 Tg C yr⁻1 during 2000 to 2020, and this is primarily driven by increased precipitation and accelerated permafrost thawing under climate change. This study highlights increased riverine carbon emission and strengthening of the permafrost carbon feedback to climate after incorporating carbon release from rivers.

Random Forest model for precise cooling load estimation in optimized and non-optimized form

Abstract Energy is vital for life and human development, with global warming due to activities such as the combustion of fossil fuels and deforestation emitting dangerous greenhouse gases, changing the climate of the Earth. Global energy demand is increasing, with developed nations viewing buildings as major energy consumers. Due to the long lifespan of buildings, it is important to evaluate their suitability to future climate change and possible changes in energy consumption. Appraisal of the cooling loads in each building is now required due to rising energy costs and the need to reduce the impacts of climate change caused by energy consumption from fossil fuels in buildings. This paper aims to apply Random Forest Regression (RF) and Support Vector Regression (SVR), well-known machine learning algorithms to predict building cooling loads. It utilizes the Jellyfish Search Optimizer (JSO) and Transit Search Optimization Algorithm (TSOA) to enhance accuracy and minimize overall error in Cooling Load (CL) estimation. The investigation suggests two high-performance schemes, applies two optimizers for hybrid schemes, and utilizes an ensemble approach for accurate appraisal. Moreover, the SHAP method is utilized to compare the effectiveness of the parameters. The research proves to be insightful in constructing CL projection and suggests that a RFJS-based model is the most effective way to optimize energy consumption. The hybrid model attained an R 2 of 0.994 at its best and RMSE of 0.744. Other than this, the following effective ensemble approach was RSJS, whose R 2 and RMSE were 0.989 and 0.985, accordingly. The third best-performing model was SVJS with R 2 and RMSE values of 0.972 and 1.583, accordingly.

EPO Enhances Adaptation to Hypoxic Environment in the Freshwater Teleost (Micropterus salmoides) through the PI3K/AKT Pathway.

Hypoxia has become one of the most common environmental stress events in the life history of aquatic organisms due to accelerated global warming. Exploring the adaptation mechanisms of aquatic organisms in hypoxic environments is important to deepen our understanding of environmental toxicology and to design breeding programs. In this study, the largemouth bass Micropterus salmoides exhibited greater hypoxic adaptability after 4 weeks of intermittent hypoxic exposure (IHE), with the O2 tension for loss of equilibrium decreased from 1.17 ± 0.20 to 0.66 ± 0.10 mg/L. Combined transcriptomics, biochemical detection, and immunostaining results revealed that the hypoxia-tolerant phenotype driven by IHE was strongly correlated with the activation of erythropoietin (EPO). EPO promoted phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) signaling to alleviate hepatic damage under acute hypoxic exposure (AHE) by selectively regulating the expression of genes related to antioxidant defense, antiapoptosis, and cell proliferation, which plays an important role in regulating hypoxic adaptation. The inhibition of EPO impaired cell survival in hypoxic environments, but intervention with the PI3K agonist 740 Y-P reversed this process. This novel finding provides insights into exploring how aquatic organisms cope with the challenges of hypoxia under increasing environmental risks.

Contrail Cirrus Climate Impact: From Radiative Forcing to Surface Temperature Change

Abstract Contrail cirrus has been regarded as the most important individual component of aviation-induced global climate impact, a conclusion prompted by radiative forcing estimates from a variety of models. However, there have been indications of a reduced effective radiative forcing of contrail cirrus with respect to its instantaneous radiative impact, as well as indications of a reduced contrail efficacy to force surface temperature changes. Here, we present a set of global climate model simulations driven by either upscaled contrail cirrus or a CO2 increase, first with prescribed and then with interactive sea surface temperature, yielding self-consistent results for forcings, feedbacks, and climate sensitivity. If contrail cirrus and CO2 induce the same classical (stratosphere adjusted) radiative forcing, we find the contrail cirrus effective radiative forcing reduced to about 55% compared to that from CO2, qualitatively confirming previous results. The surface temperature response per unit effective radiative forcing (the climate sensitivity parameter) is also smaller (reduced to about 40%) for contrail cirrus. In total, the simulations indicate an efficacy value as low as 0.21 for contrail cirrus, with an estimated statistical uncertainty between 0.10 and 0.32, while consolidated knowledge to quantify the respective systematic uncertainty is currently lacking. Our results indicate a much smaller relative contrail cirrus impact on global warming than classical or even effective radiative forcing estimates suggest. The analysis of radiative adjustments and feedbacks reveals a major role of natural clouds in driving the differences in the response behavior. We discuss consequences of the results for aviation climate impact assessments and promising further research directions. Significance Statement To date, the impact of contrail cirrus on global surface temperature change is largely unknown. Based on a set of climate model simulations, this study provides a first determination of respective key parameters explaining global surface warming (climate sensitivity and efficacy). The obtained climate sensitivity is lower for contrail cirrus than for CO2. The simulations were further examined by feedback analysis to identify the radiative processes which are most relevant for the exceptionally low efficacy of contrail cirrus radiative forcing to induce surface temperature changes.

Global-Scale Multidecadal Variability in Climate Models and Observations. Part I: Forced Response

Abstract Twentieth-century climate variations exhibit, on top of a secular global warming trend, multidecadal variability with globally coherent patterns. Identifying and attributing such patterns requires one to combine modern reanalyses of atmospheric and oceanic observations with estimates of climate response to variable forcings based on ensemble simulations of the twentieth-century climate by the state-of-the-art global coupled models. This contribution is the first installment of the series of papers in which an identical sequence of pattern-recognition methods is applied to a 38-model ensemble of historical simulations within phases 5 and 6 of the Coupled Model Intercomparison Project (CMIP5/6) and to two twentieth-century reanalysis datasets to succinctly describe their global-scale multidecadal variability. The focus here is on characterizing the globally distributed forced response in near-surface air temperature (SAT) and sea level pressure (SLP) using a combination of the signal-to-noise-maximizing pattern (S/NP) filtering and linear-regression-based rescaling. A particular novel aspect of this work lies in isolating the forced-response structures common across the entire model ensemble versus the residual responses of individual models, thus setting the stage for exploring whether the latter responses can serve as a viable explanation of the observed multidecadal climate teleconnections. CMIP5/6 models’ common forced response is dominated by two S/NP modes, whose amplitudes differ from model to model. The S/NP-1 describes polar and land-intensified global warming with a slower warming rate prior to mid-60s and a faster warming afterward. The S/NP-2 component is characterized by a pronounced multidecadal variability without much of a centennial-scale trend and exhibits antisymmetric temperature response between the hemispheres. The two mode’s SLP signature is associated with the downward trend over the Southern Ocean and Antarctica after mid-60s and is much weaker than the SLP background internal variability elsewhere. The CMIP models that have large contributions from S/NP-1 and small contribution from S/NP-2 to their forced response tend to exhibit large twentieth-century global-mean SAT trend and vice versa. The residual forced responses of individual models unexplained by S/NPs 1 and 2 do exhibit multidecadal variations with the appearance of long-range teleconnections, albeit with a much smaller amplitude than the observed climate’s globally connected deviations from the model estimated forced trends. Significance Statement Understanding the discrepancies between the observed and simulated multidecadal climate variability constitutes one of the pressing problems in climate science. These discrepancies manifest a coherent global signal which may reflect biases in the simulated response to external forcings or point to the observed internal variability unmatched by the climate models. This study provides a compact characterization of the global-scale forced responses in terms of just a few dominant patterns common across an ensemble of state-of-the-art climate models and the residual forced variability of individual models. The relative amplitudes of these patterns gauge climate sensitivity of individual models, while the residual signals have by far insufficient magnitude to explain the observed multidecadal climate undulations on top of the secular warming trend.

Single-cell transcriptomic dynamics of scallop heart reveals the heterogeneous response to heat stress

BackgroundAnimals with open circulatory systems are highly vulnerable to environmental temperature fluctuations, making them particularly threatened by global warming. However, research on the cellular heterogeneity of heart responses to elevated temperatures in animals with open circulatory systems remains limited.ResultsHere, we conducted a comprehensive investigation of the morphology, metabolism and scRNA-seq of the heart in a molluscan model, Argopecten irradians, under heat stress. Our results unraveled that the severity of cardiac structure damage increased progressively with rising temperature, accompanied by widespread mitochondrial dysfunction and neurohumoral response. We identified two subpopulations within cardiomyocytes (CMs), including ventricular myocytes (VMs) and atrial myocytes (AMs), which exhibited specialized functional roles in response to thermal stress. Specifically, AMs enhanced cell–cell communications with the immune-like cells and fibroblasts to contribute to maintaining cardiac homeostasis under heat stress. Whereas, VMs displayed enhanced energy supply and differentiation potential to withstand thermal challenges. Furthermore, RNA interference targeting the most heat-responsive gene, PLRP2-like, resulted in a significant reduction in heat tolerance and triglyceride accumulation in scallops.ConclusionsOur study investigated the heterogeneous response of the scallop heart to high temperatures, revealing distinct response patterns between VMs and AMs. We further identified a key gene, AiPLRP2-like, which exhibits unique cellular localization patterns compared to its mammalian counterpart and may play a pivotal role in regulating cardiac thermotolerance in organisms with open circulatory systems. These findings provide novel insights into the theoretical framework and evolutionary adaptations of marine invertebrate hearts in response to environmental temperature fluctuations.

Subsurface cooling trend in the Southern Tropical Indian Ocean (1958-2023) linked with global warming and the Interdecadal Pacific Oscillation

Subsurface cooling trend in the Southern Tropical Indian Ocean (1958-2023) linked with global warming and the Interdecadal Pacific Oscillation

Improved Optimal Fingerprinting Based on Estimating Equations Reaffirms Anthropogenic Effect on Global Warming

Abstract The optimal fingerprinting approach is central to detecting and attributing climate change. It utilizes a regression model with covariates that have measurement errors, linked by a shared covariance matrix with the regression error up to a known scale. The inferences about the regression coefficients are vital for making reliable detection and attribution statements, as well as for quantifying uncertainties in outcomes like attributable warming. Traditionally, this has involved the total least squares (TLS) method, which depends on accurately estimating the covariance matrix of the regression error. However, inaccuracies in this matrix’s estimation can lead to skewed scaling factor estimators and overly optimistic confidence intervals, potentially misrepresenting the accuracy of detection and attribution statements. The recent advent of an estimating equations approach, which offers more efficient point estimation with smaller possible variance and precise uncertainty quantification, prompts a critical reassessment of past climate change detection and attribution analyses. By applying this advanced method to HadCRUT5 observational data and CMIP6 multimodel simulations, our study reevaluates temperature detection and attribution at global and regional levels, strengthens the existing detection and attribution conclusions at the global scale, and provides evidence of the effect of anthropogenic forcings in various regions. Significance Statement Optimal fingerprinting plays an essential role in quantifying human impacts on climate change by facilitating the statistical analysis of estimated scaling factors, which is fundamental for detecting and attributing climate change to external forces. A well-acknowledged challenge in this process is the estimation of the covariance matrix of the regression error, which is critical in correcting the bias due to errors in variables and quantifying the uncertainty of the resulting estimator. The challenge remained unsolved until the recent advancement of an estimating equations approach, which ensures efficient unbiased point estimators and reliable confidence intervals. Using this method, this work reassesses the previous climate change detection and attribution studies with the latest datasets, HadCRUT5 and CMIP6. This reevaluation confirms earlier findings on the global scale and unveils human impacts in various regions.

How governments address climate change through carbon pricing intensity

AbtractCarbon pricing policies are central climate policy instruments to limit global warming, but the instrument design in terms of price and emission coverage varies widely. Governments can set instrument designs that essentially make carbon pricing ineffective. To understand when serious measures against climate change are taken, we need to go beyond the question of which governments price carbon and focus on the specific design of the implemented instruments. Based on the literature of partisan theory in the context of climate policy, I analyze 21 OECD countries with implemented carbon pricing policies between 1990 and 2022. Results indicate that the government’s position constitutes a decisive element for climate policy measures in addition to institutional frameworks, economic conditions and situational pressures that can limit or expand a government’s ability to act. The structure of the temporal delay, though, is of central importance for policy analyses using first difference estimation.

Fungal contamination in residential water systems: A comparative study between hot and cold water samples

Some fungal species are known to have adverse health effects for humans and their presence in water systems may lead to alterations in the taste and odour of the water they occupy. Although a few country-based regulations are known, no universal legal restriction on the presence of fungi in drinking or utility water is present currently. Waterborne fungi have been a neglected part of microbial studies worldwide, and more sudies are needed in the current era of global warming. This study was performed to evaluate (i) the fungal load in randomly selected residential water systems connected to the municipal water supply in Istanbul, Türkiye, and (ii) the possible impact of water temperature on the number and biodiversity of fungi. Additionally, the relationship between bacterial loads, some water parameters and the determined fungi were investigated. Cold and hot water samples were taken from 20 randomly selected buildings in Istanbul and inoculated into SDA using the membrane filtration method for fungal isolation, and onto R2A and Candida Agar using the spread plate method for bacterial and Candida isolation, respectively. More microorganisms were detected in cold water samples than in hot water. The mean fungal and bacterial numbers in cold and hot water samples were 2.4, 1.47, 702.3 and 79.5 cfu/100 mL, respectively. No Candida was found. It was determined that temperature affected the biodiversity and frequency of fungi. Penicillium (41%) and Aspergillus (43.75%) were the dominant fungal genera in cold and hot water, respectively. Aspergillus versicolor was the most common fungal species found in both water samples. 9 of fungi were identified that are known to have the potential to cause allergies and/or opportunistic infections. No relationship was detected between fungal growth and pH and chlorine.

A 37 years [1984–2021] Landsat/Sentinel-2 derived snow cover time-series for Switzerland

Switzerland, renowned for its mountainous landscapes, holds nearly 10% of Europe’s water reserves, with 40% of its running waters originating from snowmelt. Snow plays a crucial role in the country’s water management, hydroelectric power, and alpine ecosystems. It supports freshwater supply, agriculture, and tourism, making accurate snow monitoring vital for resource management and environmental preservation. Climate change, however, threatens snow cover, impacting water availability, biodiversity, and ecosystem services. Remote sensing technologies have emerged as key tools for monitoring snow cover, providing critical data for climate models, hazard prediction, and resource planning. In Switzerland, snow cover is monitored using ground-based measurements, remote sensing, and climate models, with datasets from satellites like Landsat and Sentinel-2 offering valuable insights despite challenges such as cloud obstruction. Such data are essential for hydrological modelling, agricultural monitoring, and climate studies, contributing to our understanding of global warming and aiding in natural hazard assessment. Hereafter, we present a 37-year monthly time-series of snow cover derived from Landsat and Sentinel-2 data using the Snow Observations from Space algorithm and processed in the Swiss Data Cube that facilitates the analysis, production and reuse of this Essential Climate Variable, enhancing environmental monitoring efforts at national scale.

Global warming drives a threefold increase in persistence and 1 °C rise in intensity of marine heatwaves

Marine heatwaves are extreme climatic events consisting of persistent periods of warm ocean waters that have profound impacts on marine life. These episodes are becoming more intense, longer, and more frequent in response to anthropogenic global warming. Here, we provide a comprehensive and quantitative assessment on the role of global warming on marine heatwaves. To do so, we construct a counterfactual version of observed global sea surface temperatures since 1940, corresponding to a stationary climate without the effect of long-term increasing global temperatures, and use it to calculate the contribution of global air temperature rise on the intensity and persistence of marine heatwaves. We determine that global warming is responsible for nearly half of these extreme events and that, on a global average, it has led to a three-fold increase in the number of days per year that the oceans experience extreme surface heat conditions. We also show that global warming is responsible for an increase of 1 °C in the maximum intensity of the events. Our findings highlight the detrimental role that human-induced global warming plays on marine heatwaves. This study supports the need for mitigation and adaptation strategies to address these threats to marine ecosystems.

Overshoot: A Conceptual Review of Exceeding and Returning to Global Warming of 1.5°C

Limited progress with mitigation makes it almost inevitable that global warming of 1.5°C will be exceeded. This realization confronts Parties to the United Nations Framework Convention on Climate Change (UNFCCC) with a choice either to stabilize warming above but as close as possible to 1.5°C or to reverse global warming back to this level. We review core concepts and current knowledge relating to overshoot: an exceedance and subsequent decline back below a specified global warming level. We clarify the concept and origins of overshoot in science and climate policy, discuss the key drivers of climate-related risks and how they might evolve under overshoot trajectories to foster more systematic research into those risks, and consider the role of adaptation. We then consider the feasibility of overshoot in terms of mitigation across the six feasibility dimensions introduced by the Intergovernmental Panel on Climate Change (IPCC) in its sixth Assessment Report. We conclude by discussing critical barriers, challenges, and knowledge gaps related to overshoot.

Recycled CO2 in Consumer Packaged Goods: Combining Values and Attitudes to Examine Europeans’ Consumption Intentions

The main objective of this study was to investigate European consumers’ intentions to purchase cosmetics and detergents with green ingredients made from recycled CO2. Aiming to better understand both moral and practical criteria of consumers’ intentions, a combination of the Values-Beliefs-Norms and the Theory of Planned Behaviour models served as the basis of this study’s theoretical framework. The combination was extended with risk perception about global warming, scepticism and media influence. Online interviews were conducted with stratified samples based on gender and age distributions in France, Germany, Greece and Spain. Structural equation modelling and moderation analyses were employed to analyse the data. The results indicated that consumption intentions are generated by consumers’ biospheric values and a sequence of risk perception, awareness of consequences, and ascription of responsibility while they are directly determined (in declining order) by perceived behavioural control, personal norms, attitudes and subjective norms. Subjective norms indicated additional indirect impacts on consumption intentions through personal norms and ascription of responsibility. Moderation also indicated that the relationship between perceived behavioural control and consumption intentions is stronger in consumers, who are less sceptical towards ecological claims on packaging, while the relationship between personal norms and consumption intentions is stronger in consumers, who are less influenced by advertisements. Theoretical, managerial and social implications were derived from the results.

Investigation of mechanical and thermal behaviors of dual fibre loaded reinforced vinylester composites.

Due to ecological imbalances and global warming caused by synthetic fibres and petrochemical polymers, researchers are increasingly focusing on the study and fabrication of natural fibre-reinforced polymer composites. To date, no reports have been found on the synergistic effect of abaca and sisal fibre on vinylester (VE). In this research, a novel composite based on VE matrix containing sisal and abaca, ranging from 10 to 30 wt% loadings was developed. After fabrication of different composite samples, their physico-chemical properties were evaluated and examined. The results indicated that the dual fibre loaded vinyl ester composite with 30 wt% revealed maximum mechanical strength (29 MPa) compared to the pure VE (6 MPa). Similarly, the values of flexural (855 MPa), impact (10.77 kJ/mm2) and hardness strengths (86 HRB) of 30 wt% dual fibre loadings were increased compared to the neat VE (Flexural - 238 MPa, Impact - 6 kJ/mm2, Hardness - 9 HRB). The thermogravimetric analysis (TGA) depicted that the addition of sisal and abaca fibre decreases the initial onset degradation temperature of VE, respectively, but their weight residues were higher than those of pure VE indicating higher thermal stability. Further, the water absorption studies depicted decreased moisture absorption for the developed VE composites containing sisal and abaca fibre. Hence, the enhanced physico-chemical properties of newly developed composites were suitable for various applications ranging from aerospace to sports equipment.

Nutrient inversion but not warming drive changes in periphyton biomass and composition in shallow lake mesocosms

AbstractPeriphyton plays an important functional role in shallow lakes and is sensitive to variation in nutrient availability and global warming. Understanding the responses of periphyton to changes in nutrient availability in contrasting warming scenarios can contribute to the development of more efficient techniques for the restoration of lakes in a future warmer world. We analyzed the periphyton response to early eutrophication and oligotrophication under three different warming scenarios and explored the associated environmental drivers of periphyton in 24 shallow lake mesocosms. These were initially set up in 2003 with two nutrient treatments (with or without nutrient addition) and three temperatures (ambient, A2 IPCC scenario and A2 increased by 50%) following a full factorial design. In 2023, the nutrient treatment was inverted, starting nutrient addition in low nutrient mesocosms (nutrient increase) and stopping nutrient addition (nutrient decrease) in the remaining. Artificial plants were placed in each mesocosm to allow periphyton to develop for 21 d, both before and after the inversion of the nutrient treatments. We found marked changes in periphyton biomass and composition to the nutrient inversion, but no response to warming. Nutrient decrease induced lower periphyton biomass and compositional changes at species and group levels. Nutrient increase had no effect on biomass accrual or species composition but altered the group composition. Our results suggest that lower nitrate availability was a crucial factor driving biomass and compositional changes with the cessation of nutrient addition, while a combination of environmental variables explained the altered periphyton group composition in the nutrient increase treatment.

Predictors of the Argumentative Writing Based on Multiple Texts: Individual and Process Variables

This study aims to determine individual and process differences that influence argumentative writing with multiple texts. The participants of this study, which used a predictive correlational design, were 101 high school graduates and undergraduate students from two provinces in southeastern Turkey who voluntarily participated in the study. The data were obtained from argumentative essays written by the participants after reading source texts, as well as from a topic interest scale. The participants read five different source texts with different claims related to climate change and global warming, and then they wrote argumentative essays evaluating the claims in these texts. Pearson correlation and hierarchical regression were used to analyze the data. Generally, findings indicated that students were not sufficiently successful in argumentative writing with multiple texts; both demographic characteristics and certain individual variables affected composition length. Topic interest, composition length, source content citation, and addition frequency variables accounted for approximately 41% of the variance in text-based argumentative writing. The findings of the study highlight the variables that are effective in text-based argumentative writing tasks and discuss them within the framework of the multiple-text literature.