Potent Greenhouse Gas Research Articles

Abstract Trifluoromethane (HCF 3 , HFC‐23) is a byproduct of fluoropolymer production that has limited applications. It is often stored or destroyed at the point of production, but if released into the environment is a potent greenhouse gas with a global warming potential of 14 600 times that of CO 2 . State‐of‐the‐art chemical technologies for upgrading HCF 3 typically occur with conservation of the CF 3 group. These approaches will come under increased scrutiny as concern over the environmental impact of perfluoroalkyl substances (PFAS) continues to grow. A more sustainable approach involves synthetic transformations that repurpose the atomic content of HCF 3 while also destroying the CF 3 group. In this paper, we report a rare example of the transformation of HCF 3 into a fluoroalkene functional group through defluoroalkylation. We rationalise product formation through DFT calculations, scale‐up the synthesis through continuous flow methods, and show that a fluoroalkene reagent derived from HCF 3 is a competent nucleophile for the fluoroethenylation of a range of aldehydes.

Trifluoromethane (HCF3, HFC-23) is a byproduct of fluoropolymer production that has limited applications. It is often stored or destroyed at the point of production, but if released into the environment is a potent greenhouse gas with a global warming potential of 14600 times that of CO2. State-of-the-art chemical technologies for upgrading HCF3 typically occur with conservation of the CF3 group. These approaches will come under increased scrutiny as concern over the environmental impact of perfluoroalkyl substances (PFAS) continues to grow. A more sustainable approach involves synthetic transformations that repurpose the atomic content of HCF3 while also destroying the CF3 group. In this paper, we report a rare example of the transformation of HCF3 into a fluoroalkene functional group through defluoroalkylation. We rationalise product formation through DFT calculations, scale-up the synthesis through continuous flow methods, and show that a fluoroalkene reagent derived from HCF3 is a competent nucleophile for the fluoroethenylation of a range of aldehydes.

Effects of bedding materials and composting methods on gaseous emissions and compost quality across the whole chain of sheep husbandry and manure management.

Methane is a potent but short-lived greenhouse gas and rapid reductions of its anthropogenic emissions could help decrease near-term warming1. Solid waste emits methane through the decay of organic material, which amounts to about 10% of total anthropogenic methane emissions2. Satellite instruments3 enable monitoring of strong methane hotspots4, including many strongly emitting urban areas that include solid waste disposal sites as most prominent sources5. Here we present a survey of methane emissions from 151 individual waste disposal sites across six continents using high-resolution satellite observations that can detect localized methane emissions above 100 kg h-1. Within this dataset, we find that our satellite-based estimates generally show no correlation with reported or modelled emission estimates at facility scale. This reveals major uncertainties in the current understanding of methane emissions from wastedisposal sites, warranting further investigations to reconcile bottom-up and top-down approaches. We also observe that managed landfills show lower emission per area than dumping sites, and that detected emission sources often align with the open non-covered parts of the facility where waste is added. Our results highlight the potential of high-resolution satellite observations to detect and monitor methane emissions from the waste sector globally, providing actionable insights to help improve emission estimates and focus mitigation efforts.

Impact of freeze-thaw cycle on metagenomics in subsurface wastewater infiltration systems: Ecological implications for greenhouse gas emissions.

Methane is a potent greenhouse gas that requires its emissions to be mitigated. A significant source for methane emissions is in the form of the biogas that is produced from anaerobic digestion in wastewater reclamation and landfill facilities. Biogas has a high valorization potential in the form of its bioconversion into ectoines, an active ingredient in skin care products, by halotolerant alkaliphilic methanotrophs. Cultures of Methylotuvimicrobium alcaliphilum 20Z were grown in bench scale stirred-tank reactors to determine factors to improve methane uptake and removal. Tangential flow filtration was also implemented for a bio-milking method to recover ectoine from culture media. Methane uptake and reactor productivity increased, with a temperature of 28 °C compared with 21 °C. Decreasing the methane gas bubble diameter by decreasing the sparger pore size from 1 mm to 0.5 µm significantly improved methane removal and reactor productivity by increasing mass transfer. Premixing methane and air before sparging into the reactor saw a higher removal of methane, while sparging methane and air separately created an increase in reactor productivity. Maximum methane removal efficiency was observed to be 70.56% ± 0.54 which translated to a CH4-EC of 93.82 ± 3.36 g CH4 m−3 h−1. Maximum ectoine yields was observed to be 0.579 mg ectoine L−1 h−1.

Estimating potential greenhouse gas emissions from degraded seagrass meadows: A case study from Thailand's seagrass ecosystems

ABSTRACT Methane is a potent greenhouse gas that causes nearly one-third of global warming, but its spatial and temporal dynamics are inadequately understood. This study addresses this gap by providing an integrated methane monitoring strategy for Western Canada for 2019–2024. We implement a quality-screened concentration-mapping strategy using multi-temporal Sentinel-5P methane concentration (XCH₄) and GIS-based Jenks classification to obtain reproducible hotspot and persistence maps. We add a unit-agnostic satellite – inventory concordance screen including Spearman’s ρ and bootstrapped Pearson’s r for prioritization that goes beyond the scope of the traditional air quality monitoring. Our results identify a persistent XCH₄ increase (1801–1878 ppb), with concentrations at their maximum during the autumn and winter months consistent with local activities like industrial and agricultural operations and heat demand. Hotspots recurring in the south of the four western provinces, that is, British Columbia, Alberta, Saskatchewan, and Manitoba, pose potential hazards to residents, while northeastern Manitoba hotspots threaten vulnerable ecosystems. To enhance interpretability and reproducibility, we include non-parametric variability envelopes that transparently convey temporal sampling uncertainty and improve comparability across provinces as descriptive summaries for decision support. Therefore, we recommend the incorporation of Sentinel-5P data into province-level methane monitoring and reporting frameworks to complement the emission inventories published by the Environment and Climate Change Canada. This will bridge policy gaps by complementing inventory-based models with concentration-based hotspot prioritization, thereby directing mitigation to high-risk locations. This information is crucial to achieve a global methane emission reduction of 75% by 2030 and Sustainable Development Goals 3, 13, and 15.

Methane dry reforming not only utilizes two potent greenhouse gases of methane and carbon dioxide, but also provides a valuable feedstock for the production of chemicals. However, this process has been heavily hindered by high operating temperature and coke formation with catalyst deactivation over the last century. Herein, we propose an approach whereby concentrated-solar catalytic methane dry reforming addresses these longstanding issues. By leveraging focused light as the sole energy source and utilizing a well-designed catalyst, the catalyst with Ni-O4 coordination active center achieves high conversion rates of 93.6% for CH4 and 93.7% for CO2, meanwhile sustaining stability for over 800 hours. Particularly noteworthy is the light-to-chemical energy conversion efficiency reaching 25.9%. This research represents a significant leap forward in integrating renewable energy sources with chemical production, offering a viable and sustainable alternative to traditional thermochemical processes for generating valuable chemicals.

In response to the imperative to mitigate methane—one of the most potent greenhouse gases—this study proposes and tests an integrated workflow for designing methane drainage boreholes targeting post-mining areas in an active underground coal mine (Pniówek, Poland). The workflow combines the following: (1) forecasting methane emissions from goafs and active longwalls for 2024–2040; (2) 3D geological characterization (structural and lithofacies models); (3) selection and sealing of goaf zones; and (4) optimization of well placement, drilling, and performance evaluation of drainage boreholes, including an assessment of energy use from the recovered gas. Applying the method delineated priority capture zones and estimated recoverable rates under multiple scenarios. Preliminary field data from a borehole near seam 362/1 indicate stable methane inflow to the drainage system and a concomitant reduction in methane load within the ventilation network. The integrated design improves targeting efficiency and provides a quantitative basis for scheduling, risk management, and sizing of surface-to-underground infrastructure. The results suggest that systematic drainage of post-mining voids can enhance safety, limit fugitive emissions, and create opportunities for on-site power generation. The approach is transferable to other active mines with legacy workings, provided site-specific calibration and monitoring are implemented.

Abstract. This study investigates the effects of tropospheric ozone (O3), a potent greenhouse gas and air pollutant, on European forests, an issue lacking comprehensive analysis at the site level. Unlike other greenhouse gases, tropospheric O3 is primarily formed through photochemical reactions, and it significantly impairs vegetation productivity and carbon fixation, thereby affecting forest health and ecosystem services. We utilise data from multiple European flux tower sites and integrate statistical and mechanistic modelling approaches to simulate O3 impacts on photosynthesis and stomatal conductance. The study examines six key forest sites across Europe – Hyytiälä and Värriö (Finland), Brasschaat (Belgium), Fontainebleau-Barbeau (France), and Bosco-Fontana and Castelporziano 2 (Italy) – representing boreal, temperate and Mediterranean climates. These sites provide a diverse range of environmental conditions and forest types, enabling a comprehensive assessment of O3 effects on gross primary production (GPP). We calibrated the Joint UK Land Environment Simulator (JULES) model using observed GPP data to simulate different O3 exposure sensitivities. Incorporating O3 effects improved the model's accuracy across all sites, although the magnitude of improvement varied depending on site-specific factors such as vegetation type, climate and ozone exposure levels. The GPP reduction due to ozone exposure varied considerably across sites, with annual mean reductions ranging from 1.04 % at Värriö to 6.2 % at Bosco-Fontana. These findings emphasise the need to account for local environmental conditions when assessing ozone stress on forests. This study highlights key model strengths and limitations in representing O3–vegetation interactions, with implications for improving forest productivity simulations under future air pollution scenarios. The model effectively captures the diurnal and seasonal variability of GPP and its sensitivity to O3 stress, particularly in boreal and temperate forests. However, its performance is limited in Mediterranean ecosystems, where pronounced O3 peaks and environmental stressors such as high vapour pressure deficit exacerbate GPP declines, pointing to the need for improved parameterisation and representation of site-specific processes. By integrating in situ measurements, this research contributes to developing targeted strategies for mitigating the adverse effects of O3 on forest ecosystems.

Nitrous oxide (N2O) is a potent greenhouse gas with a global warming potential > 310 times that of CO2. Owing to its rapid increase in atmospheric concentrations from industrial emissions, N2O poses increasing environmental concerns. Among the various N2O abatement technologies, catalytic decomposition can directly convert N2O into harmless N2 and O2 without generating secondary pollutants. In this study, Co3O4 spinel catalysts were synthesized using a polymer-assisted precipitation method, using polyvinyl alcohol, polyvinylpyrrolidone, or polyethylene glycol (PEG) as N2O decomposition catalysts. The PEG-mediated synthesis method yielded the most active catalyst with superior N2O decomposition efficiency. Structural and surface analyses confirmed that PEG facilitated the formation of Co2+-enriched surface sites and abundant oxygen vacancies, which are crucial active sites for N2O adsorption and activation. Moreover, these features improved the redox properties and electron transfer behavior of the resulting catalyst. In particular, the PEG-derived 5Co3O4/CeO2 catalyst exhibited enhanced N2O decomposition activity and stability even in the presence of coexisting N2O and O2, highlighting its potential for real-world applications. This study provides an effective synthetic route for Co3O4-based catalysts and potential opportunities for wide applications in industrial N2O removal.

Increase in the concentration of carbon dioxide (CO2) in the atmosphere due to anthropogenic activities has become an enormous problem in recent years. As CO2 is one of the most potent greenhouse gases, increase in its concentration will lead to increase in the average temperature of the atmosphere, which is referred to as global warming. Global warming leads to unpredictable change in weather and climate, sea-level rise, decline in arctic ice caps, only to name a few. To get rid of this problem, carbon capture and sequestration has become one promising technological breakthrough. Porous materials have shown considerable advantages in the adsorption of CO2. Among many porous materials like metal organic frameworks (MOFs), porous carbon-based materials, zeolites, etc., zeolites have shown certain advantages like tuning pore sizes and properties by ion exchange, easy regeneration, greater selectivity, etc. This review article explores the application of zeolites in the field of CO2 separation, with a particular emphasis on recent advancements and emerging trends in their development and performance.

BackgroundInhalers are essential for managing asthma and chronic obstructive pulmonary disease; however, their environmental effects vary significantly. Pressurised metered-dose inhalers (pMDIs) contain potent greenhouse gases (GHGs), resulting in a much higher carbon footprint (CF) than non-propellant inhalers (NPIs). Consequently, reducing the use of pMDIs is seen as an important contribution to reduce the healthcare sector’s effect on climate change. This study analyses inhaler dispensing trends in Germany, estimates their resulting CF and quantifies the potential GHG savings from increased NPI use.MethodsDispensing data at the expense of statutory health insurances, covering nearly 90% of the German population, were analysed from 2013 to 2022 across three age groups. Annual dispensing shares and CF estimates based on life cycle assessment-derived CF values were calculated for four inhaler types: pMDIs with hydrofluorocarbon (HFC)-134a, pMDIs with HFC-227ea, dry powder inhalers (DPIs), and soft mist inhalers (SMIs). Two scenario calculations estimated the potential GHG savings.ResultsBetween 2013 and 2022, the total number of dispensed defined daily doses of inhalers increased by 14%, with no significant shift towards lower-emission inhalers (2013, 55% NPIs; 2022, 52% NPIs). Consequently, the total CF increased from 459 kilotonnes of carbon dioxide equivalent (kt CO2eq) in 2013 to 525 kt CO2eq in 2022 (+14%). More than 95% of the inhaler-related CF was attributable to pMDIs. A GHG-saving scenario assuming 85% NPI use among patients aged 10–79 years projected an annual CF reduction of 55% (288 kt CO2eq).ConclusionDespite climate neutrality goals, inhaler-related CF has continued to rise because of stable pMDI usage rates. The substantial potential for GHG reduction highlights the necessity and feasibility of a sustainable change in clinical prescription practice. Our insights could support the promotion of climate-friendly inhalers across other European countries with similar prescription patterns.

Methane hydroxylation presents a promising approach to produce high-energy methanol from potent greenhouse gases, thereby contributing to a more sustainable future. Despite its environmental importance, current research on this process remains challenging due to the harsh operating conditions for the activation of inert C-H bond in methane. In nature, methane monooxygenase converts methane by activating the C-H bonds through its hydroxylase, under ambient conditions, receiving electrons from NADH via a reductase. Beyond the traditional biological approach, the development of NADH-independent biocatalytic systems could open new avenues for cost-effective and sustainable methane conversion. Herein, we report an NADH-free biosolar platform that activates hydroxylase for eco-friendly methanol production. The xanthene-based light harvester spontaneously associates with hydroxylase and directly transfers its photoexcited electrons to the diiron active site, eliminating the need for a cofactor or reductase. Halogenation of xanthene accelerates direct electron transfer to the active site by increasing the polarizability and spin-orbit coupling of the light harvesters. Accordingly, the direct photobiocatalytic platform achieved a methanol time yield of 7.52 mmol gcat−1 h−1. This work provides the design concept of solar-driven biocatalytic methane hydroxylation under ambient conditions, suggesting a promising approach for implementing methanol biomanufacturing.

Nitrous oxide (N2O), a potent greenhouse gas (GHG) and major contributor to climate change, is primarily released through agricultural activities. To better understand and quantify how land management practices, local climate conditions, and soil physicochemical properties affect these agricultural N2O emissions, we conducted a review of the peer-reviewed literature on N2O emission from corn [Zea mays L.] and soybean [Glycine max (L.) Merr.] fields. We evaluated the seasonal, cumulative effects of three nitrogen fertilizer rates—no fertilizer (0), low (<188 kg N ha−1), and high (188–400 kg N ha−1)—tillage practices, local climate (precipitation and temperature), soil texture, and soil pH on soil N2O emissions. This meta-analysis included 77 articles for corn and 22 articles for soybean fields. Average N2O emissions during the corn rotation were 2.34 and 2.45 kg N2O-N ha−1 season−1 under low and high N fertilizer rates, respectively, and were both substantially (p < 0.0001) greater than those of non-fertilized corn fields (0.91 kg N2O-N ha−1 season−1). Non-fertilized soybean fields showed seasonal N2O emissions of 0.74 kg N2O-N ha−1, while low fertilizer application triggered a sharp increase (1.87 kg N2O-N ha−1) in N2O emissions by roughly 2.5 times (p < 0.028). Increased temperature did not significantly (p > 0.05) affect the emission of N2O from fertilized or non-fertilized corn fields. Regardless of fertilization and tillage practices, our analysis, including Principal Component Analysis, revealed that in corn fields, precipitation and soil pH are the dominant factors influencing soil N2O emissions. This study uniquely quantifies the influence of climate–soil factors, such as precipitation and soil pH, alongside agronomic practices, on N2O emissions, offering new insights beyond previous reviews focused primarily on fertilizer rates or tillage effects.

Abstract Dimethylsulfoniopropionate (DMSP) is a globally abundant organosulfur compound produced by marine organisms, where it plays key physiological roles in stress protection and serves as a major source of carbon, sulfur, and energy for microbial communities. Importantly, DMSP degradation contributes to the formation of the climate-active gas dimethyl sulfide (DMS), which can drive the production of potent greenhouse gases, methane and carbon dioxide, in anoxic environments. While aerobic DMSP degradation is well studied, its fate under anoxic conditions remains poorly understood, and the microbial populations and metabolic pathways underlying these biotransformations are virtually unknown. Here, we present the first detailed investigation of microbial DMSP cycling in anoxic saltmarsh sediments. Our sediment samples had high in situ DMSP concentrations (up to 7.7 μmol/g) and the conversion efficiencies of DMSP to DMS under anoxic conditions (~68%) were comparable to those in oxic environments. Furthermore, using 13C-labelled DMSP in stable isotope probing (SIP) experiments, combined with 16S rRNA gene sequencing and metagenomics, we identified Amphritea (Oceanospirillales) as a key active DMSP degrader, likely operating via the dddD-encoded lysis pathway. Additional taxa, including Geopsychrobacter, were implicated as potential secondary consumers, while Arcobacteraceae may contribute to sulfur cycling rather than direct DMSP catabolism. This study uncovers a previously overlooked route for DMSP transformation via anaerobic metabolism, expands the known metabolic roles of saltmarsh microorganisms and highlights the potential for DMSP to drive climate-active gas production in anoxic coastal ecosystems.

Developing technologies to capture, purify, and reuse potent greenhouse gases such as sulfur hexafluoride (SF6) is crucial because of their high global warming potential. Porous solid matrices are promising candidates for this purpose, due to their high surface areas and pore volumes. Herein, two coconut shell-derived activated carbons (AC) (CS-CO2 and CS-ZnCl2), obtained through physical and chemical activation, are evaluated and compared with two commercial adsorbents: an AC monolith (ACM) and a metal-organic framework. The adsorption capacities for SF6 and nitrogen (N2) are measured gravimetrically at three temperatures: 283.15, 303.15, and 323.15 K. The experimental data are fitted using the Toth model, and the impact of temperature and pressure on the adsorption performance is analyzed. The order of SF6 adsorption capacity is: ACM > CS-ZnCl2 > Fe-BTC > CS-CO2, reflecting dependence on surface area. Selectivity for SF6/N2 separation is evaluated using Ideal Adsorbed Solution Theory, with ACM exhibiting the highest adsorption capacity due to its selective separation properties. These findings contribute to the understanding and selection of efficient adsorbent materials for SF6 separation and recovery, providing valuable insights for their future implementation in industrial gas treatment and environmental management applications.

Nitrous oxide (N2O), a potent greenhouse gas and ozone-depleting agent, is produced intensely in oxygen minimum zones (OMZs) predominantly through nitrate reduction . However, mechanisms and controls of this pathway remain unclear. Here, we investigate the microbial ecology governing this pathway using experiments and an ecosystem model. We experimentally confirm a critical hypothesis: most denitrifiers do not utilize extracellular nitrite, an intermediate of the pathway. Model results demonstrate that the pathway is compatible with oxygen, and that its response to oxygen is heterogeneous because it is governed by niche partitioning of distinct microbial types and thus may not follow a smooth curve. Lastly, experiments demonstrate that this pathway is sensitive to the type of organic matter, its electron acceptor, in addition to organic matter availability. These findings advance our mechanistic understanding of the primary N2O production pathway, necessary for predictions of marine N2O emissions.

Nitrous oxide (N2O), a potent greenhouse gas, is an important environmental concern associated with biological nitrogen removal in wastewater treatment plants. Anaerobic ammonium oxidation (anammox), recognized as an advanced carbon-neutral nitrogen removal technology, requires a continuous supply of nitrite, which also serves as a key precursor for N2O generation. However, the regulation of the carbon-to-nitrogen (C/N) ratio to minimize N2O emission in mainstream anammox systems remains insufficiently understood. In this study, we evaluated the long-term nitrogen removal performance and N2O emission potential of an oxygen-limited anammox biofilm reactor treating synthetic municipal wastewater with a typical C/N range of 4.0–6.0. Experimental results demonstrated that the highest nitrogen removal efficiency (95.3%), achieved through coupled anammox and denitrification, and the lowest N2O emission factor (0.73%) occurred at a C/N ratio of 5.0. As the C/N ratio increased from 4.0 to 5.0, N2O emissions decreased progressively, but rose slightly when the ratio was further increased to 6.0. High-throughput sequencing revealed that microbial community composition and the abundance of key functional taxa were significantly influenced by the C/N ratio. At a C/N ratio of 5.0, proliferation of anammox bacteria and the disappearance of Acinetobacter populations appeared to contribute to the significant reduction in N2O emission. Furthermore, gene annotation analysis indicated higher abundances of anammox-associated genes (hzs, hdh) and N2O reductase gene (nosZ) at this ratio compared with others. Overall, this study identifies a C/N-dependent strategy for mitigating N2O emissions in mainstream anammox systems and provides new insights into advancing carbon-neutral wastewater treatment.