Carbon Storage Research Articles

Feasible deployment of carbon capture and storage and the requirements of climate targets

Climate change mitigation requires the large-scale deployment of carbon capture and storage (CCS). Recent plans indicate an eight-fold increase in CCS capacity by 2030, yet the feasibility of CCS expansion is debated. Using historical growth of CCS and other policy-driven technologies, we show that if plans double between 2023 and 2025 and their failure rates decrease by half, CCS could reach 0.37 GtCO2 yr−1 by 2030—lower than most 1.5 °C pathways but higher than most 2 °C pathways. Staying on-track to 2 °C would require that in 2030–2040 CCS accelerates at least as fast as wind power did in the 2000s, and that after 2040, it grows faster than nuclear power did in the 1970s to 1980s. Only 10% of mitigation pathways meet these feasibility constraints, and virtually all of them depict <600 GtCO2 captured and stored by 2100. Relaxing the constraints by assuming no failures of CCS plans and growth as fast as flue-gas desulfurization would approximately double this amount.

Influence of Tree Geometry on Growth and Yield of Mungbean (Vigna radiata L.) under Gamhar (Gmelina arborea Roxb.) based Agroforestry System

The experiment was conducted during kharif (June to September) 2022–23 at Rani Lakshmi Bai Central Agricultural University, Jhansi, Uttar Pradesh, India to evaluate effect of Gmelina arborea geometry on the growth and yield of mungbean, tree growth, biomass, carbon storage and assessing the economic feasibility of the agroforestry systems. The experiment was designed for intercropping of one mungbean high yielding varieties viz., IPM 205-7 (Virat) sown in June with Gmelina arborea. The treatments for gamhar and mungbean are as follows: T1-Vigna radiata sole crop; T2-Gmelina arborea sole tree (5×5 m2); T3-Gmelina arborea sole tree (5×4 m2); T4-Gmelina arborea sole tree (5×3 m2); T5-Gmelina arborea (5×5 m2)+Vigna radiata; T6-Gmelina arborea (5×4 m2)+Vigna radiata; T7-Gmelina arborea (5×3 m2)+Vigna radiata. Experiment was designed in randomized block design (RBD) with seven treatments and five replications. The effect of different spacing patterns viz., S1-5×5 m2, S2-5×4 m2, S3-5×3 m2 in 2 year old Gamhar plantation with seven treatments combinations on mungbean was studied at the Forestry Research Farm, RLBCAU, Jhansi. The maximum number of branches plant-1 (8.04), number of trifoliate leaves plant-1 (11.96), number of seeds pod-1 (12.32), grain yield (0.73 t ha-1) and straw yield (2.13 t ha-1) was recorded in mungbean sole crop. The plant height (62.51 cm) was recorded highest in mungbean intercrop in 5×3 m2 gamhar spacing. The maximum girth (27.38 cm) of trees was recorded in 5×5 m2 gamhar spacing mungbean intercrop. The tree height (6.01 m) and benefit cost ratio (2.67) was observed maximum in 5×4 m2 gamhar spacing with mungbean intercrop.

Research advances of microbial transformation of CO2 in geological sequestration

Carbon capture, utilization and storage is the vital technology for China to achieve the goals of carbon peaking and carbon neutrality. Microbial activities in situ are an indispensable part in the process of geological CO2 sequestration. Some microorganisms can convert CO2 into methane and organics as the resource for utilization or into carbonate to achieve long-term sequestration. These activities contribute to the stable storage of CO2 and even negative carbon emission. This paper focuses on the processes of bio-methanation, bio-liquefaction, and bio-precipitation that may be involved in CO2 sequestration in deep stratum and discusses the research progress in the bio-transformation pathways. Bio-methanation and bio-liquefaction can convert CO2 into methane or high-value organic compounds to realize resource reuse. The two technologies can be used alone or coupled to expand the application range of CO2 biotransformation. Bio-mineralization can convert CO2 into calcite by microorganism-induced carbonate precipitation, being a technology of great potential in fixing CO2 and limiting CO2 escape. At present, this field is still in the infancy stage, and there is an urgent need to establish and improve the theoretical and technical systems of CO2 in-situ biotransformation from transformation principle, influencing factors, conversion efficiency, economy, environmental protection, and technological conditions. Moreover, it can be combined with CCUS to establish a technical system integrating capture, transport, displace, storage, transfer, and exploit, so as to promote the value-added application of CCUS and the achievement of carbon peaking and carbon neutrality.

A Comparative Review of Post-Combustion Capture and Direct Air Capture of CO2

Mitigating anthropogenic CO2 emissions has been a subject of incredible urgency in recent years. Carbon capture and storage (CCS) has emerged as a promising means of cutting emissions, with post-combustion capture and direct air capture (DAC) both gaining traction as methods of offsetting emissions from point sources and the ambient atmosphere. Each of these carbon capture methods rely on absorbent or adsorbent materials to function, whose properties can vastly impact capture performance. In this work, 14 materials are analyzed, with qualitative descriptions and performance data of each material based on existing review papers and representative case studies being presented. The review highlights limitations in the field in standardizing the reporting of experimental data, complicating the direct comparison of different materials’ efficacies. While no single CCS technology is found to be unequivocally superior, the promising performances of certain materials in earlier stages of development emphasize the importance of investing further in emerging post-combustion capture materials. This study concludes that CCS technologies are a necessary tool in ultimately reaching net zero emissions due to their role in neutralizing sectors resistant to decarbonization, but they should not be relied upon to substitute the transition to renewable energy, as the prevention of emissions should take priority over the abatement of emissions.

Response: Commentary: Large Trees Dominate Carbon Storage in Forests East of the Cascade Crest in the United States Pacific Northwest

Response: Commentary: Large Trees Dominate Carbon Storage in Forests East of the Cascade Crest in the United States Pacific Northwest

Economic valuation of carbon sequestration in Quito’s Metropolitan Park using Sentinel-2 and neural networks

This study introduces an innovative method for assessing the economic value of carbon stored by the urban park forest in Quito, Ecuador. The method uses Sentinel-2 remote sensing data and advanced deep learning techniques. A large forest study area was chosen, and detailed field measurements were taken to gather biomass and carbon data. Sentinel-2 satellite images were processed to correct for radiation and atmospheric conditions, and vegetation indices such as NDVI and EVI were calculated. To model forest biomass, a convolutional neural network (CNN) was created and trained using Sentinel-2 spectral bands and vegetation indices. The model was validated with independent field data and demonstrated high accuracy in estimating biomass and carbon, as indicated by evaluation metrics like RMSE and R². The findings include detailed maps showing the spatial distribution of biomass and carbon in the study area, which can be a valuable tool for forest management and the implementation of policies for valuing stored carbon. This approach combines the high resolution of Sentinel-2 data with the predictive power of neural networks, providing a robust and scalable method for estimating carbon across large forest areas. The study's conclusions emphasize the feasibility and accuracy of this approach and its potential for application in various forestry and geographical contexts.

Synthesis of Cyclobutanes and Cyclobutenes by Strain-Release-Driven Ring-Opening of Bicyclo[1.1.0]butanes

AbstractCyclobutanes and cyclobutenes exhibit intriguing structures and demonstrate significant biological activities and diverse synthetic applications. This review aims to summarize recent progress in strain-release-driven ring-opening reactions of bicyclo[1.1.0]butanes (BCBs) to synthesize these four-membered carbon rings. It outlines the strategies, regio- and stereoselectivity, the synthetic scope of reactions, and the mechanistic implications of the catalytic ring-opening process, providing a supplementary perspective to existing reviews.1 Introduction2 Thermally Driven Nucleophilic Ring-Opening3 Thermally Driven Rearrangement and Isomerization Reaction4 Light-Driven Ring-Opening5 Transition-Metal/Lewis Acid Catalyzed Ring-Opening6 Conclusion and Outlook

Increasing evapotranspiration in peatlands from the monsoon regions of East China with the rapid warming during the early Holocene

Peatlands are one of the largest natural terrestrial carbon store, which evolve closely with the hydrological functioning. Evapotranspiration serves as a nexus of the carbon and water cycles in peatlands. Its long-term changes in the geological past are essential to gain a complete understanding of its response to global warming. Here, the evapotranspiration changes in peatlands from the monsoon regions of East China during the significant warming period of ∼ 11.5–10 ka in the Early Holocene are investigated, based on a new leaf wax δD record from the Hani peatland in Northeast China along with the previously reported representative records across monsoonal eastern China. All of the leaf wax δD records exhibit less depleted values during this episode, which follow neither with the changes in precipitation isotopes nor the vegetation compositions. They are thus interpreted as enhanced evapotranspiration. Further comprehensive comparisons based on paleoenvironmental records reveal that evapotranspiration changes are highly sensitive to rising temperatures but are intricately linked with precipitation variations. The strong evapotranspiration appears to be potentially linked to water table drawdown on longer timescales, which further actively interacts with peat-forming plants. Our results suggest that evapotranspiration is expected to increase in peatlands as the climate warms, but its changes might be complicated by accompanying hydrological and vegetational shifts.

Coupled water-habitat-carbon nexus and driving mechanisms in the Tarim River Basin: A multi-scenario simulation perspective

Human activity has transformed natural land use patterns and exerted a significant impact on the mechanisms underlying ecosystem service (ES) provisioning. This has disrupted the equilibrium between human development and ecological protection and hasled to further degradation of desert ecosystems endemic to arid regions. In this study, we employed the three SSP-RCP scenarios provided by CMIP6 to represent varying rates of development within the Tarim River Basin (TRB) and modeled land use in 2050 based on the coupled system dynamics (SD) + patch-generating land use simulation (PLUS) + InVEST model. A dynamic simulation of the trade-off/synergy between key land use types and ESs in the ecologically vulnerable areas of the TRB was performed to identify the impacts of the individual effects of single factors and the scale effects of multiple factors on ESs. The results showed that (1) in the SSP126, SSP245, andSSP585 scenarios, the ratio of outflows to inflows of converted unused land gradually increased in the following periods:79.28 %, 79.42 %, 79.54 %in 2020–2030; 96.19 %, 91.62 %, 66.07 %in 2030–2040; and 93.76 %, 91.65 %, 60.96 %in 2040–2050, respectively.(2) A high water yield (WY) was observed in the highland mountains; high habitat quality (HQ) was observed in the highland mountains, along the Tarim River, and around cities; high carbon storage (CS) was observed in the highland mountains, along the Tarim River, and in urban areas. (3) Under the three scenarios, WY, HQ, and CS were mainly affected by environmental factors, with the highest single-factor tests represented by temperature (0.594; 0.595; 0.596), precipitation(0.582; 0.589; 0.590); NDVI(0.312; 0.295; 0.299), soil erosion(0.227; 0.221; 0.219); and NDVI(0.298; 0.282; 0.310), soil erosion(0.122; 0.125; 0.132), respectively. Additionally, the interaction factors with the highest explanatory power for WY, HQ, and CS were precipitation ∪ NDVI (0.73); elevation ∪ NDVI (0.37); and soil ∪ NDVI (0.31), respectively. Moreover, the human aggregation level exerted positive (0.117), negative (−0.173), and negative (−0.286) impacts on WY, HQ, and CS, respectively. The results show that the combination of GeoDetector and the partial least squares structural equation modeling (PLS-SEM) provides a complementary and creative framework for investigating the driving mechanisms of ecosystems.

Evaluation and Optimization of Landscape Spatial Patterns and Ecosystem Services in the Northern Agro-Pastoral Ecotone, China

The alteration of landscape spatial patterns (LSPs) and ecosystem services (ESs) in watersheds can have detrimental effects on the local environment and community. However, a comprehensive understanding of the current state of LSPs and ESs in watersheds around Winter Olympic venues in China is limited. Here, we assessed current LSPs and ESs and developed optimization strategies for the Xigou watershed around Winter Olympic venues in the northern agro-pastoral ecotone of China. The results indicated that the main land use type was grassland in the Xigou watershed, and landscape types were relatively homogenous. All three ESs (water yield, sediment retention, and carbon storage) generally improved from 2004 to 2020. For ESs, there was the lowest total volume of water yield in 2004 (637.44 × 104 m3). But sediment retention (10.54 × 106 t, 18.13 × 106 t, 13.28 × 106 t, and 16.85 × 106 t) had an upward, then downward, then upward trend before and after ERP. Carbon storage grew steadily. Correlation analysis suggested that the three ESs were closely related to the landscape spatial indices of average patch area (AREA_MN), contagion index (CONTAG), and Shannon’s evenness index (SHEI). AREA_MN, CONTAG, and SHEI in the eastern part of the study area promoted sediment retention and carbon storage, while in the southwestern part of the study area, they inhibited water yield and sediment retention. The results suggest that improving sediment retention by optimizing land use and cover change (LUCC) and LSPs is the main approach to further enhance ESs in the study area. Our study suggests that the inclusion of multiple landscape pattern indices can provide a more comprehensive representation of regional ecosystem service.

A data-driven dual-optimization hybrid machine learning model for predicting carbon dioxide trapping efficiency in saline aquifers: Application in carbon capture and storage

Geological carbon sequestration (GCS) is a promising method to reduce global carbon emissions. To better understand the CO2 trapping mechanism, the CO2 sequestration process was simulated through a physics-based reservoir simulator, and the residual trapping (RTI) and solubility trapping (STI) efficiencies were analyzed. Through the experiments, a database containing 4543 data points with reservoir physical parameters and rock properties was established. In this study, a kernel extreme learning machine (KELM) model based on variational mode decomposition (VMD) and dung beetle optimization optimizer (DBO) was proposed to perform the prediction task. Through the VMD, the original data sequences were decomposed and combined, and the obtained subsequences were executed modeling prediction and reconstruction respectively. The reliability of the prediction model was confirmed to be greater than 97.71% through domain analysis. In addition, it was applied to a tight gas reservoir in China in to confirm its validity in field applications. Comparative results indicated a high agreement between the prediction results and the simulation results, suggesting that the proposed method can complement numerical simulations and help users understand the application of machine learning in carbon capture and storage (CCS).

Performance analysis of refuse‐derived fuel gasification plant with carbon capture and storage for power, heating, and hydrogen production

AbstractAmong various waste‐to‐energy technologies, gasification is one of the most promising, because of high efficiency, feedstock flexibility, and carbon capture potential. This case study is focused on comprehensive analysis of integrated gasification combined cycle‐based plant with refuse‐derived fuel (RDF) as feedstock and carbon capture. As there are hardly any studies focused on simulation of waste gasification with carbon capture, most of which are lacking important process specifics, this study addresses existing research gap. Process flowsheets are developed in detail according to literature data for various process configurations and simulated in AspenPlus software, while obtained results on material and energy balance were used for estimation of plant efficiency and performance indicators. Waste generation data in Novi Sad, Serbia, were used for determination of RDF flowrate. Configurations include different syngas cleaning pathways, final products (power, heating, and hydrogen) and co‐gasification with coal. Cogeneration increases overall plant efficiency from 27%–36% (power production only) to 63%–76%. High net hydrogen efficiencies, around 58%, compensate lower power and thermal energy production in hydrogen‐based configurations. Overall, co‐gasification produces better results due to higher feedstock heating value. Obtained results will be used in further research for environmental and economic evaluation to provide multi‐level assessment of proposed processes.

Nanoconfinement effect on the miscible behaviors of CO2/shale oil/surfactant systems in nanopores: Implications for CO2 sequestration and enhanced oil recovery

Currently, CO2 flooding is the most promising carbon capture, utilization, and storage (CCUS) technology in the energy industry. Understanding the nanoconfinement effect on the CO2-oil miscible process is crucial for accurately determining the minimum miscibility pressure (MMP) of CO2/oil in shale reservoirs. In this study, we conducted molecular dynamics (MD) simulations to investigate the effects of pore size, surfactants, and pore type on the MMP of nanoconfined CO2/shale oil/surfactant systems. Validations against experimental data show a deviation of 2.98 % in the CO2 MMP. The MMPs under nanoconfinement are found to be significantly lower than those in bulk phase conditions (up to 22.94 %). The simulation results reveal that decreasing pore size can enhance the miscibility of CO2 and oil by increasing the CO2 adsorption ratio, improving CO2-surfactant interactions, and inhibiting the tendency of CO2 molecules to self-aggregate. The enhancement of CO2-oil miscibility caused by surfactants is ranked by CFP > SF > SDS according to the mixing degrees (Dmix) and the spatial distribution of CO2 around surfactant molecules. In addition, pore type exhibits various abilities in influencing the MMP, owing to their different mineral surface properties and ability to influence CO2-surfactant interactions. Nanopores with stronger hydrophobicity and a denser CO2 distribution around surfactant molecules have lower MMPs. The results show that the order of MMP in terms of pore types is Quartz < Kaolinite < I/M clay. This study elaborates the micro-mechanisms of surfactant-assisted CO2-oil miscibility under nanoconfinement, offering valuable insights for effectively designing CO2 miscible flooding in shale oil reservoir development.

Unexpected sustained soil carbon flux in response to simultaneous warming and nitrogen enrichment compared with single factors alone.

Recent observations document that long-term soil warming in a temperate deciduous forest leads to significant soil carbon loss, whereas chronic soil nitrogen enrichment leads to significant soil carbon gain. Most global change experiments like these are single factor, investigating the impacts of one stressor in isolation of others. Because warming and ecosystem nitrogen enrichment are happening concurrently in many parts of the world, we designed a field experiment to test how these two factors, alone and in combination, impact soil carbon cycling. Here, we show that long-term continuous soil warming or nitrogen enrichment when applied alone followed the predicted response, with warming resulting in significant soil carbon loss and nitrogen fertilization tending towards soil carbon gain. The combination treatment showed an unanticipated response, whereby soil respiratory carbon loss was significantly higher than either single factor alone, but without a concomitant decline in soil carbon storage. Observations suggest that when soils are exposed to both factors simultaneously, plant carbon inputs to the soil are enhanced, counterbalancing soil carbon loss and helping maintain soil carbon stocks near control levels. This has implications for both atmospheric CO2 emissions and soil fertility and shows that coupling two important global change drivers results in a distinctive response that was not predicted by the behaviour of the single factors in isolation.

Urban Soil Dynamics: The Relationship Between Soil Health and Urbanization

Urbanization, combined with unsustainable agricultural practices, climate change, and pollution, poses a significant threat to soil health, leading to degradation with far-reaching impacts on ecosystems and human well-being. This article explores these challenges and specifically focuses on how urbanization affects soil health by degrading its quality and limiting its ability to sustain life. The study examines the dynamics of soil humification, the potential of urban soils to store carbon, and the critical impacts on food production and public health. Through a comprehensive analysis that includes geographical perspectives on soil-related issues, the article highlights innovative management strategies that can enhance the productivity and sustainability of urban soils. It emphasizes the urgent need to integrate soil science into environmental and urban planning to mitigate these negative impacts and promote a sustainable future.

Soil Organic Carbon Dynamics: Drivers of Climate Change-induced Soil Organic Carbon Loss at Various Ecosystems

At roughly 2500 Peta gram (Pg) C, soil organic carbon (SOC) is the biggest carbon store in terrestrial ecosystems and is a crucial contributor to vital soil functions and ecosystem services, such as agricultural soil productivity. SOC stocks are in a dynamic equilibrium between C inputs, primarily from crop residues and organic manures, and C loss owing to decomposition and mineralization of soil organic matter (SOM) under long-term constant land management and environmental circumstances. In addition, the rate of C addition in native ecosystems is governed by the nature and productivity of the local flora, which is mostly influenced by climatic conditions. However, being a complex system, various factors, such as soil management and land-use change influence the soil C pool. Along with temperature gradients from temperate to tropical regions, SOC supplies were shown to be shrinking on a global and regional basis. This reflects the rates of SOM decomposition as a function of temperature, which fluctuates more rapidly than net primary production (NPP). SOM decomposition rates are also influenced by several parameters, including soil temperature and moisture, soil respiration and pH, and soil physical properties including texture and clay mineralogy. Nonetheless, increased temperatures as a result of climate change are thought to be the primary driver of accelerated decomposition, which results in considerable reductions in SOC supplies and sequestration. Furthermore, climatic change contributes to soil deterioration by increasing the mineralization of the SOC pool and causing desertification (irreversible expansion of desert landforms). Similarly, erosion is a degrading process that affects C dynamics and leads to terrestrial carbon loss through the breakdown of structural aggregates, as well as lower productivity in eroding areas due to a lack of soil nutrients. Thus, for an in-depth understanding of worldwide soil C dynamics and to provide support to C management and decision support systems to policymakers and land managers in the face of changing climates, comprehensive research on the influence of multiple climate-induced drivers on soil C is required.

Spatiotemporal Variation and Prediction of Carbon Storage in Terrestrial Ecosystems at Multiple Development Stages in Beijing City Based on the Plus and Integrated Valuation of Ecosystem Services and Tradeoffs Models

Terrestrial ecosystems play a critical role in the global carbon cycle, and their carbon sequestration capacity is vital for mitigating the impacts of climate change. Changes in land use and land cover (LULC) dynamics significantly alter this capacity. This study scrutinizes the LULC evolution within the Beijing metropolitan region from 1992 to 2022, evaluating its implications for ecosystem carbon storage. It also employs the Patch-Generating Land Use Simulation (PLUS) model to simulate LULC patterns under four scenarios for 2035: an Uncontrolled Scenario (UCS), a Natural Evolution Scenario (NES), a Strict Control Scenario (SCS), and a Reforestation and Wetland Expansion Scenario (RWES). The InVEST model is concurrently used to assess and forecast ecosystem carbon storage under each scenario. Key insights from the study are as follows: (1) from 1992 to 2022, Beijing’s LULC exhibited a phased developmental trajectory, marked by an expansion of urban and forested areas at the expense of agricultural land; (2) concurrently, the region’s ecosystem carbon storage displayed a fluctuating trend, peaking initially before declining, with higher storage in the northwest and lower in the central urban zones; (3) by 2035, ecosystem carbon storage is projected to decrease by 1.41 Megatons under the UCS, decrease by 0.097 Megatons under the NES, increase by 1.70 Megatons under the SCS, and increase by 11.97 Megatons under the RWES; and (4) the study underscores the efficacy of policies curtailing construction land expansion in Beijing, advocating for sustained urban growth constraints and intensified afforestation initiatives. This research reveals significant changes in urban land use types and the mechanisms propelling these shifts, offering a scientific basis for comprehending LULC transformations in Beijing and their ramifications for ecosystem carbon storage. It further provides policymakers with substantial insights for the development of strategic environmental and urban planning initiatives.

Tree species diversity impacts on ecosystem services of temperate forests

Tree species diversity is crucial for forest ecosystem services as it relates to ecosystem functions. However, it remains unclear how spatially continuous tree species diversity affects multiple ecosystem services in temperate forests that undergo various management practices. We mapped the spatial pattern of tree species diversity represented by the Shannon diversity index, H’ in the temperate forests of Northeast China using 1,028 in situ observations and 846 Sentinel-2 images. We further analysed the relationships between tree species diversity and ecosystem services including carbon storage, water yield, and soil retention, while controlling for the covarying effects of multiple forest attributes including tree height, leaf area index (LAI), and stand age. Our results showed distinct spatial variations in tree species diversity across different forest management practices, with natural forests exhibiting a higher diversity compared to managed natural forests and planted forests. Tree species diversity was found to be positively associated with improved ecosystem services, particularly water yield and soil retention, while the effects plateaued above diversity of 1.0 (Shannon index values). We also showed that LAI was the most important factor influencing carbon storage, while tree species diversity and stand age were crucial for water yield and soil retention. These results highlight the importance of maintaining diverse tree species to improve ecosystem services in temperate forests, providing a robust framework for effectively monitoring and managing forest ecosystems with regards to sustainable forest functioning.

Lignocellulose Composition of Preparation of Porous Carbon Materials and CO&lt;sub&gt;2&lt;/sub&gt; Adsorption Performance Research

Porous carbon material adsorbents are one of the effective methods for carbon dioxide (CO2) capture and storage (CCS). In order to realize its application, it is urgent to find economical and efficient raw materials for preparing porous carbon materials. In this study, porous carbon materials were successfully prepared using lignocellulosic components as a carbon source and a mild Kac adsorbent. The CO2 adsorption performance of these materials was then tested. LCH-1 exhibited excellent CO2 adsorption performance and stability in all samples. The microporosity of LCH-1 is as high as 84.48%, and its CO2 adsorption capacity under 1 bar at 273K and 298K is 4.94 mmol/g and 3.31 mmol/g, respectively.

Seasonal variability and seagrass traits affect methane fluxes in a subtropical meadow

Abstract Plant traits which vary both within and between species often drive biogeochemical cycling. Understanding the relative role of within‐ and between‐species trait variability in driving carbon cycling is essential to scaling site measurements to global carbon budgets. In seagrass meadows, carbon and nitrogen mineralization rates and associated greenhouse gas emissions are highly variable, impeding our ability to reliably predict whether meadows are net carbon sinks. Evaluating the influence of within‐ and between‐species trait variability on greenhouse gas fluxes will improve our understanding of local‐scale drivers of greenhouse gas production and consumption in seagrass meadows. To test the effects of plant traits on dissolved greenhouse gas fluxes, we performed mesocosm incubations with live, intact seagrass plants. We compared methane (CH4) and nitrous oxide (N2O) fluxes under dark and light conditions from sediments dominated by Halodule wrightii and Thalassia testudinum across dormant, early and peak growing seasons in a subtropical meadow along the west coast of peninsular Florida. We also measured oxygen (O2) fluxes to interpret greenhouse gas fluxes within the context of community metabolism. We measured several seagrass traits, such as above‐ and below‐ground biomass and leaf and root area and assessed their impact as well as the impact of species identity on dissolved gas fluxes. We found that abiotic factors linked to metabolism (i.e. light and temperature) influenced greenhouse gas fluxes across seasons. In addition to light conditions and sampling month, plant size (a composite trait variable) was a significant predictor of O2 consumption and CH4 production under dark conditions, and better predicted fluxes than individual plant traits. CH4 production was slightly higher in H. wrightii‐dominated sediments, but species identity was less important than plant size in driving CH4 production. N2O fluxes were low and not influenced by plant traits or species identity. Synthesis: Our results indicate that within‐species more so than between‐species trait variability drives the direction and magnitude of CH4 fluxes in seagrass meadows. We identified a trade‐off where seagrass biomass is often associated with enhanced sediment carbon storage, but in our study, plant size promoted CH4 production, potentially offsetting the benefits of long‐term storage.