Atmospheric Carbon Dioxide Research Articles

Drought in a warmer, CO 2 -rich climate restricts grassland water use and soil water mixing

Soil water sustains terrestrial life, yet its fate is uncertain under a changing climate. We conducted a deuterium labeling experiment to determine whether elevated atmospheric carbon dioxide (CO 2 ), warming, and drought impact soil water storage and transport in a temperate grassland. Elevated CO 2 created a wetter rootzone compared with ambient conditions, whereas warming decreased soil moisture. Soil water remained well mixed in all global change treatments except for summer drought combined with warming and elevated CO 2 . These combined treatments caused the grassland to conserve water and restricted soil water flow to large, rapidly draining pores without mixing with small, slowly draining pores. Our results suggest that drought in a warmer, more CO 2 -rich climate can severely alter grassland ecohydrology by constraining postdrought soil water flow and grassland water use.

Meta-Analysis of Larval Bivalve Growth in Response to Ocean Acidification and its Application to Sea Scallop Larval Dispersal in the Mid-Atlantic Bight

Ocean acidification, caused by increasing atmospheric carbon dioxide and coastal physical, biological, and chemical processes, is an ongoing threat to carbonate-utilizing organisms living in productive coastal shelves. Bivalves exposed to acidification have shown reduced growth, reproduction, and metabolic processes, with larval stages exhibiting the greatest susceptibility. Here, we compile results from published studies on larval bivalve growth responses to acidification to estimate a relationship between larval growth and seawater aragonite saturation state. We then apply this relationship to a larval dispersal individual-based model for Atlantic sea scallops (Placopecten magellanicus), an economically vital species in the Mid-Atlantic Bight that is historically under-studied in acidification research. To date, there have been no published studies on sea scallop larval response to ocean acidification. Model simulations allowed the identification of potential impacts of acidification on scallop success in the region. Results show that larval sea scallops that are sensitive to ocean acidification had a 17% lower settlement success rate and over 50% reduction in larval passage between major Mid Atlantic Bight fisheries habitats than those that are not sensitive to acidification. Additionally, temperature and ocean acidification interact as drivers of larval success, with aragonite saturation states > 3.0 compensating for temperature-induced mortality (> 19 ˚C) in some cases. This balance between drivers influences larval settlement success across spatial and interannual scales in the Mid Atlantic Bight.

Effects of Elevated CO2 on Maize Physiological and Biochemical Processes

Maize (Zea mays) is a critical global crop, serving as a source of food, livestock feed, and industrial raw materials. Climate changes, driven by rising atmospheric carbon dioxide (CO2) levels, have substantial effects on maize physiology, growth, and nutrient content. This review investigates the impact of elevated CO2 on maize, with a particular focus on photosynthesis enhancement as it improves water use efficiency (WUE), which can lead to increased biomass production. Despite this, elevated CO2 results in a decreased concentration of essential nutrients, including nitrogen, phosphorus, potassium, and folate. The reduction in folate, which is vital for both plant development and human nutrition, poses challenges, especially for population heavily reliant on maize. Additionally, biofortification through traditional breeding and genetic engineering is proposed as a strategy to enhance folate level in maize to mitigate nutritional deficiencies. Elevated CO2 stimulates lignin production, improving stress resistance and carbon sequestration capacity. However, the increase in guaiacyl-rich lignin may negatively affect biomass degradability and efficiency in biofuel production. The findings emphasize the importance of balancing maize’s stress resilience, nutrient profile, and lignin composition to address future climate challenges. This balance is essential for optimizing maize cultivation for food security, biofuel production, and environmental sustainability.

Declines in carbon and nitrogen release from decomposing litter under elevated CO2 in terrestrial ecosystems

Abstract Atmospheric carbon dioxide (CO2) concentrations have been increasing dramatically due to human activities and land use changes, and the CO2 fertilization effect significantly increases global net primary productivity (NPP). However, whether the decomposition of surplus litter input on the soil surface is facilitated by elevated CO2 (eCO2) across a broad range of terrestrial ecosystems is not fully understood. We compiled 227, 85 and 131 paired observations (with and without eCO2) for litter mass loss, carbon (C) and nitrogen (N) release, respectively, during litter decomposition to assess the fate of decomposing litter and C and N release under eCO2 across terrestrial ecosystems. Litter mass loss was decreased by 4.46%, and C and N release were significantly reduced by 6.70% and 3.36%, respectively, under eCO2. This eCO2 effect on litter mass loss was greater in forests (decreased by 7.22%) than in croplands and grasslands. In forests, eCO2 had a greater effect on the decomposition rate of broadleaved than coniferous litter, and root litter was more sensitive than leaf and stem litter. Changes in litter lignin concentration and edaphic factors under eCO2 contributed to these differences in litter decomposition. Greater decreases in litter mass loss and C and N release were found after longer time (6-12 months) than short-term (less than 6 months) CO2 enrichment. A possible consequence is that more litter accumulates on soil surface without being decomposed due to eCO2 in terrestrial ecosystems over longer time periods, resulting in a negative loop in biogeochemical cycles with increasing atmospheric CO2 concentration.

Built to remove carbon.

Building materials could facilitate long-term removal of atmospheric carbon dioxide.

Development of a superhydrophobic and superoleophilic halloysite nanotube/phenyltriethoxysilane-coated melamine sponge sorbent material with high performance in supercritical CO2 atmosphere for the selective and effective oil spill cleanup and oil-water separation.

In this study, activated halloysite nanotube (HNT) and phenyltriethoxysilane (PTES) were utilized for the first time to fabricate modified HNT materials and coat them onto melamine sponge (MS) substrate in the supercritical carbon dioxide (scCO2) atmosphere. The successful coating of MS substrate was confirmed using SEM, EDS, XPS, and contact angle measurements. The drainage technique applied in the CO2 medium achieved the uniform coating of both the inner and outer surfaces of the MS. Water and oil contact angles of the fabricated sorbent material (MS-PTES) were measured as 167.1° and 0°, respectively. MS-PTES sorbent having superhydrophobic and superoleophilic properties demonstrated sorption capacities ranging from 47.6g/g to 132.2g/g for 13 different pollutants, including various petroleum products, oils, and organic solvents. Moreover, the MS-PTES sorbent material showed outstanding separation efficiency (99.99%) for the diesel-water mixture using a continuous separation process. It also displayed high selectivity for oil and organic solvent pollutants under acidic, saline, and alkaline conditions, along with excellent reusability, chemical stability, robustness, and mechanical flexibility. MS sorbent material coated with HNT-modified PTES nanoparticles, produced in the scCO2 atmosphere using the drainage technique, represents a promising solution for the removal of petroleum derivatives, oils, and organic solvents from water.

Statistical power and the detection of global change responses: The case of leaf production in old‐growth forests

AbstractForests sequester a substantial portion of anthropogenic carbon emissions. Many open questions concern how. We address two of these questions. Has leaf and fine litter production changed? And what is the contribution of old‐growth forests? We address these questions with long‐term records (≥10 years) of total, reproductive, and especially foliar fine litter production from 32 old‐growth forests. We expect increases in forest productivity associated with rising atmospheric carbon dioxide concentrations and, in cold climates, with rising temperatures. We evaluate the statistical power of our analysis using simulations of known temporal trends parameterized with sample sizes (in number of years) and levels of interannual variation observed for each record. Statistical power is inadequate to detect biologically plausible trends for records lasting less than 20 years. Modest interannual variation characterizes fine litter production, and more variable phenomena will require even longer records to evaluate global change responses with sufficient statistical power. Just four old‐growth forests have records of fine litter production lasting longer than 20 years, and these four provide no evidence for increases. Three of the four forests are in central Panama, also have long‐term records of wood production, and both components of aboveground production are unchanged over 21–38 years. The possibility that recent increases in forest productivity are limited for old‐growth forests deserves more attention.

Artificial Intelligence-Enhanced Green Building Design for Environmental Sustainability

Green buildings are those that use sustainable methods of construction to either maintain or improve the local quality of life. Decisions affecting a project's quality, safety, profitability, and timetable are made using Artificial Intelligence (AI) in Green Construction by analyzing data gathered from monitoring the construction site and using predictive analytics. For instance, increased accuracy in weather predictions might lead to more production, less waste, lower costs, and less greenhouse gas emissions. Green building construction is a significant source of carbon dioxide released through the breakdown of carbonates. Researchers have concluded that integrating industrial wastes is crucial in green concrete making due to its benefits, such as reducing the requirement for cement. When planning with concrete, its compressive strength must be considered. Due to their high predictive power, AI algorithms may be used to determine the compressive strength of concrete mixtures. Existing artificial intelligence (AI) models may be evaluated for their modeling process and accuracy to inform the creation of new models that more accurately represent the comprehensive evaluation of setting parameters on model performance and boost accuracy. Potential sources of conflict in this anthropocentric future include climate change and the availability of renewable energy sources. Scientists think there is a connection between the increased emission of greenhouse gases like carbon dioxide (Co2) from the combustion of fossil fuels and the acceleration of climate change and global warming. Research has demonstrated that the building sector is a significant source of atmospheric carbon dioxide (Co2). Construction, building activities, and subpar energy sources have all significantly increased atmospheric CO2. The proposed research set out to measure how well AI in Green Building Construction (AI-GBC) might reduce carbon emissions and utility bills. Artificial intelligence uses SVM and GA to reduce energy use and carbon dioxide emissions. Several statistical metrics, such as Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Root Mean Squared Log Error (RMSLE), are used to evaluate the AI-GBC's precision. Both Machine Learning (ML) models yielded positive results, with prediction accuracies above 95%. Regarding predicting Co_2, GA models were close to the mark, with an R2 of 0.95. Ninety-six percent will complete a performance analysis, and 97% will conduct a k-fold cross-validation analysis. Cross-validation is used to ensure that the findings of the extended modeling technique are accurate and prevent overfitting.

Effect of Loading and Carbonation on the Compressive Strength and Hydraulic Conductivity of Solidified Sand

Abstract Cement-based solidification/stabilization (S/S) techniques have been widely used to produce stable forms of contaminated soils and reduce the mobility of contaminants into the environment. However, information on the long-term performances of S/S under environmental conditions (i.e., variable loading and atmospheric carbon dioxide) remains sparse. In this study, a triaxial test setup was modified to simulate environmental conditions. The permeability and compressive strength of silica sand solidified with portland cement were measured at different stages of four scenarios involving carbonation only, axial strain only, carbonation followed by axial strain, and axial strain followed by carbonation. X-ray computed tomography (CT) was used to characterize the internal structure of the samples. Permeability and compressive strength results indicate that the axial strain accelerated the damage to the S/S specimens and increased their permeability. The deterioration due to the mechanical strain decreased in the presence of carbon dioxide. Consistent changes in microstructure were observed with the CT scan. The results indicate that the influence of stressors on the void size distribution, compressive strength, and permeability is complex and characterized by interactions between the stressors.

Impacts of Antarctic Sea Ice Change on Global Warming Pattern Inferred From CMIP6 Intermodel Spread

AbstractGlobal climate models generally project a robust decline in Antarctic sea ice (ASI) under increased atmospheric carbon dioxide (CO2) while an ASI expansion has been observed over the recent four decades. Motivated by the apparent model‐observation discrepancy, this study investigates the influences of ASI change on global warming pattern by exploiting the spread across models from Phase 6 of the Coupled Model Intercomparison Project (CMIP6). The results indicate a close intermodel relationship between ASI change and global sea surface warming pattern. Models with less ASI loss tend to produce a weaker warming globally, especially in the Southern Ocean, subtropical southeastern Pacific Ocean, and tropical Pacific Ocean. This extratropical teleconnection to the tropics agrees with the theory of cross‐equator energy transport. By correcting the modeled ASI change with observations, we can bring the SST warming pattern closer to observations, especially in the Southern Hemisphere and tropics.

Pore-Controllable Synthesis of Phthalic Acid-Derived Hierarchical Activated Carbon for Dilute CO2 Capture.

Carbon capture and storage (CCS) from dilute sources is an important strategy for stabilizing the concentration of atmospheric carbon dioxide and global temperature. However, the adsorption process is extremely challenging due to the sluggish diffusion rate of dilute CO2. Herein, p-phthalic acid (PTA)-derived hierarchical porous activated carbon (PTA-C) with abundant micro- and mesopores was successfully prepared for dilute CO2 (2 vol %) capture at ambient conditions. The optimal PTA-C sample exhibits an improved BET surface area and total pore volume of 1012.527 m2/g and 2.257 cm3/g, respectively, which endowed a dilute CO2 (2 vol %) adsorptive capacity of 0.89 mmol/g at 25 °C and atmospheric pressure. The dilute CO2 adsorptive capacity is increased to 2.71 mmol/g under the same conditions on amine-modified PTA-C (PTA-NC), which is much higher than that of amine-modified commercial coconut husk AC. In addition, the crude p-phthalic acid as feedstocks for production of PTA-C is widely available from polyester fabrics, which makes these PTA-C cost-effective for large-scale CCS from dilute CO2 sources in industry.

Temporal variability of atmospheric carbon dioxide emissions in the port of Veracruz, Mexico

Temporal variability of atmospheric carbon dioxide emissions in the port of Veracruz, Mexico

Carbon sequestration by ecosystems of cold territories of Transbaikalia

In the Baikal region, the continuous cryolithozone occupies ≈15, the transitional intermittent zone with Talikov islands – 30, the transitional island zone – 45, taliki with a continuous area – 10%. Attention is drawn to the dominance of the transition band, which is characterized by unstable thermodynamic equilibrium. High-temperature permafrost is easily degraded by technoconversion of external heat exchange conditions: removal of ground covers (organogenic layer and snow cover), deforestation, plowing, fires, etc. These circumstances increase the natural hazards and risks in the region. In this regard, the territory of Transbaikalia is of great interest, being in the permafrost zone and near its southern border, on the one hand, and with increased warming rates in recent decades, on the other. The continentality and severity of the climate in Buryatia are much more pronounced than in neighboring single-latitude regions of Russia. The southern boundary of the cryolithozone stretches almost throughout the entire territory of the republic, within which a whole range of landscapes is distinguished – from automorphic forest ecosystems to widespread, due to the high proportion of lakes and swamps, hydromorphic landscapes formed under the active influence of permafrost, as well as dry-steppe. The implementation of the Kyoto Protocol on Stabilization of Greenhouse Gas (GHG) Concentrations in the Atmosphere requires a quantitative assessment of spatiotemporal changes in terrestrial carbon sinks. Identifying areas with high potential and strategies for managing sequestration of atmospheric carbon dioxide by ecosystems is an important task and there is great uncertainty about the actual estimates of carbon reservoirs and how they may be affected by climate change. In the current conditions, we consider the study of the patterns of functioning of the soil and plant carbon reservoir in Transbaikalia to be timely and relevant.

Spatiotemporal Evolution of Air–Sea CO2 Flux in the South China Sea and Its Response to Environmental Factors

Increasing atmospheric carbon dioxide (CO2) from human activities underscores the need to understand air–sea CO2 flux in marine environments, particularly in marginal seas like the South China Sea (SCS). This research analyzes the spatial and temporal patterns of air–sea CO2 flux across four typical regions of the SCS: the northern SCS, western SCS, SCS basin, and northeastern SCS. Our results show that the SCS serves as a carbon source from spring to autumn and shifts to a carbon sink in winter. The northern SCS exhibits strong carbon sink behavior during winter, transitioning to a source in warmer months, while the western SCS and SCS basin consistently act as carbon sources year-round, with summer peaks. The northeastern SCS acts as a source in warmer months, becoming a weak sink in winter. Partial correlation analysis reveals that temperature and wind speed significantly influence air–sea CO2 flux, though regional differences exist. Notably, chlorophyll-a in the northern SCS is negatively correlated with air–sea CO2 flux, indicating that high primary productivity enhances CO2 absorption, whereas other regions show contrasting relationships. These findings provide valuable insights into the complex carbon cycle mechanisms in the SCS.

Bio-Inspired Eco-Composite Materials Seaweed Waste Integration for Sustainable Structural Applications

The increasing levels of atmospheric carbon dioxide (CO2) and plastic waste in marine environments demand immediate action to mitigate their effects. A promising solution lies in enhancing algal cultivation in marine environments, which not only absorbs CO2 and produces oxygen (O2) but also contributes to carbon sequestration. This study aims to develop biodegradable substrates for algae cultivation, facilitating their gradual degradation in marine environments and eventual deposition on the ocean floor, thereby addressing both plastic pollution and CO2 emissions. We selected various degradable polymers and incorporated differing proportions of algae residue powder (10%, 20%, and 30% by weight) into these substrates. The compositions were processed through extrusion and molded into test samples for hot compression molding. Characterization included assessments of mass loss, morphology, chemical composition, and mechanical strength under both dry conditions and after immersion in seawater for up to two months. The results indicate that the incorporation of algae residue significantly accelerates the degradation of the samples, particularly under extended exposure to seawater. Mass loss measurements indicated that samples with a 30 wt% algae addition experienced mass losses of up to 12% after two months of immersion. Mechanical strength tests demonstrated a reduction of up to 57% in strength due to the incorporation of algae, with seawater immersion further exacerbating this loss. These findings highlight the potential of biopolymer substrates infused with algae residue for effective carbon sequestration through enhanced algae cultivation.

Volatilization of elements during clinker formation in a carbon dioxide atmosphere

Volatilization of elements during clinker formation in a carbon dioxide atmosphere

Will Climate Change Alter the Swimming Behavior of Larval Stone Crabs?: A Guided-Inquiry Lesson

The ocean has absorbed ~one third of the excess atmospheric carbon dioxide (CO2) released since the Industrial Revolution. When the ocean absorbs excess CO2, a series of chemical reactions occur that result in a reduction in seawater pH, a process called ocean acidification. The excess atmospheric CO2 is also resulting in warmer seawater temperatures. These stressors pose a threat to marine organisms, especially during earlier life stages (i.e., larvae). The larvae of species like the Florida stone crab (Menippe mercenaria) are free swimming, allowing a population to disperse and recruit into new habitats. After release, stone crab larvae undergo vertical swimming excursions in response to abiotic stimuli (gravity, light, pressure) allowing them to control their depth. Typically, newly hatched larvae respond to abiotic cues that would promote a shallower depth distribution, where surface currents can transport them offshore to complete development. As larvae develop offshore, they become less sensitive to certain abiotic stimuli, which promotes a deeper depth distribution that may expose them to variable current speeds, thus influencing the direction of advection (horizontal movement). Environmental stressors like ocean acidification and elevated seawater temperatures may also impact the larvae’s natural response to these abiotic stimuli throughout ontogeny (development). Changes in their natural swimming behavior due to climate stressors could, therefore, influence the transport and dispersal of the species. This guided-inquiry lesson challenges introductory marine biology and oceanography students to determine how future ocean pH and temperature projections could impact the swimming behavior of Florida stone crab larvae.

Turfgrass species and sward age influence soil carbon pools near the soil surface

AbstractEnhancing soil carbon (C) sequestration helps reduce atmospheric carbon dioxide concentrations. Turfgrasses are important crops in the urban environment and have shown potential for C sequestration. However, little is known about how turfgrass species selection affects soil C concentration or how this varies over time. The objectives of this research were to evaluate the effect of three turfgrass species, sward age, and soil sampling depth on total soil C and N, soil organic matter (SOM), and labile soil C. A total of 25 locations throughout Indiana were sampled from established swards of Kentucky bluegrass (Poa pratensis L.), tall fescue [Festuca arundinacea Schreb.; syn. Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.], and zoysiagrass (Zoysia japonica Steud.) with varying sward age. Turfgrass species affected soil total C and labile C concentrations but had no effect on soil total nitrogen (N) or SOM. Differences between the C pools of soils under turf 0–10 years in age compared to those 11–25 years in age only occurred near the soil surface. As turf swards age, total soil C, total soil N, and SOM increased near the soil surface (0‐ to 7.5‐cm depth) and little beyond the 7.5 cm in depth. The strong relationship (p ≤ 0.0001, R2 > 0.57) between total N, SOM, and labile C highlighted their interplay in the mineralization of N from SOM and changes in the short‐term C pool of a turfgrass system.

Global lake phytoplankton proliferation intensifies climate warming

In lakes, phytoplankton sequester atmospheric carbon dioxide (CO2) and store it in the form of biomass organic carbon (OC); however, only a small fraction of the OC remains buried, while the remaining part is recycled to the atmosphere as CO2 and methane (CH4). This has the potential effect of adding CO2-equivalents (CO2-eq) to the atmosphere and producing a warming effect due to the higher radiative forcing of CH4 relative to CO2. Here we show a 3.1-fold increase in CO2-eq emissions over a 100-year horizon, with the effect increasing with global warming intensity. Climate warming has stimulated phytoplankton growth in many lakes worldwide, which, in turn, can feed back CO2-eq and create a positive feedback loop between them. In lakes where phytoplankton is negatively impacted by climate warming, the CO2-eq feedback capacity may diminish gradually with the ongoing climate warming.

A Machine Learning Approach to Produce a Continuous Solar‐Induced Chlorophyll Fluorescence Over the Arctic Ocean

AbstractPhytoplankton primary production is a crucial component of Arctic Ocean (AO) biogeochemistry, playing a pivotal role in carbon cycling by supporting higher trophic levels and removing atmospheric carbon dioxide. The advent of satellite observations measuring chlorophyll a concentration (Chl_a) has provided unprecedented insights into the distribution of AO phytoplankton, enhancing our ability to assess oceanic net primary production (NPP). However, the optical properties of AO waters differ significantly from those of the lower‐latitude waters, complicating remotely sensed Chl_a retrievals. To mitigate these deficiencies, solar‐induced chlorophyll fluorescence (SIF) has emerged as a valuable tool for gaining physiological insights into the direct photosynthetic processes of the AO. However, the temporal coverage of satellite SIF data makes long‐term analysis of Chl_a photosynthetic activity challenging. In this study, we leverage satellite‐based SIF measurements from 2018 to 2021 to assess their correlation with a set of predictive factors influencing phytoplankton photosynthesis. Generally, observed SIF over the AO showed a higher correlation with normalized fluorescence line height (NFLH) compared to Chl_a. We extended the temporal coverage of the original SIF data to encompass the period from 2004 to 2020. The extended record revealed noticeable differences between SIF, and satellite‐based Chl_a, and NFLH observations. Our novel data set offers a pathway forward to monitor the physiological interactions of phytoplankton with climate changes, promising to significantly improve our understanding of Arctic waters productivity. The application of this data is expected to provide new insights into how phytoplankton respond to environmental shifts, contributing to a more nuanced understanding of their role in high‐latitude marine ecosystems.