Search Results (2,403)

The livestock sector underpins food security, employment, and rural livelihoods across the Southern African Development Community (SADC), contributing up to 50% of agricultural GDP and supporting more than 60% of rural households. Yet climate change poses escalating threats through heat stress, declining pasture productivity, water scarcity, and vector-borne diseases that compromise productivity and economic resilience. This review identifies and locates effective climate change mitigation strategies along the livestock value chain, spanning production, processing, transport, and consumption, to promote sustainable, low-emission, and inclusive growth in the SADC region. A broad review of 46 peer-reviewed and institutional sources (2000–2024) was undertaken, focusing on livestock-related mitigation within SADC and comparable agro-ecological systems. Strategies were thematically categorized by value-chain stage and assessed for their emission-reduction and livelihood-enhancement potential. Local strategies include genetic improvement for low-methane and heat-tolerant breeds, adaptive rangeland and feed management, renewable-energy adoption in processing, climate-resilient transport infrastructure, and consumer awareness of low-emission products. Evidence suggests potential GHG-emission reductions of 18–30%, coupled with productivity gains and improved smallholder incomes. Coordinated implementation through the SADC Regional Agricultural Investment Plan (2021–2030) and national policies can transform the livestock sector into a climate-resilient driver of inclusive growth. Further research should quantify the socioeconomic feasibility and scaling potential of these strategies across production systems. Successful integration of climate change mitigation imperatives must be tailored to local biophysical conditions (e.g., rainfall, soil type) and socioeconomic contexts (e.g., market access, cultural practices). Full article

Globally, greenhouse gas (GHG) emissions have risen dramatically due to accelerated industrialization, excessive fossil fuel extraction, and agricultural activities, leading to global warming and ecosystem collapse. Achieving net-zero carbon emissions has therefore become a crucial global priority. Despite substantial international efforts, only a small number of countries have achieved carbon neutrality so far, with the majority aiming to do so by 2050 or 2060. Progress remains hindered by fragmented international coordination and inadequate integration of mitigation and adaptation co-benefits. However, agriculture is a major carbon emitter with significant mitigation potential. Attaining local carbon neutrality in agricultural landscapes is highly costly and strongly impacted by the spatial heterogeneity of GHG emissions and the diversity of available mitigation possibilities. This sector remains a major contributor to methane (CH₄) and nitrous oxide (N₂O) emissions, mainly through enteric fermentation and fertilizer use, and thus must be prioritized in global carbon neutrality strategies. Tactics such as improved livestock management, reduced use of synthetic fertilizers, conservation agriculture, afforestation, and renewable energy adoption can reduce emissions. These technical approaches should be supported by effective policy instruments, like carbon taxes, cap-and-trade schemes, low-carbon practice subsidies, and regulatory frameworks. Together, these measures can enable a transition toward long-term sustainability in agriculture by balancing emissions with removals through enhanced carbon sinks and credible offset mechanisms. Full article

Essential oil-based feed additives have been proposed as a practical strategy to mitigate enteric methane emissions in ruminants, but their effects are not always consistent. The objective of this study was to evaluate the effects of dietary supplementation with an essential oil blend on in vitro methane production, rumen fermentation, nutrient digestibility, growth performance, carcass traits, and meat quality in Lithuanian Blackface lambs. We hypothesized that supplementation would induce measurable changes in in vitro methane production and selected rumen fermentation variables, while growth performance and technological meat quality would remain comparable between treatments. Sixty Lithuanian Blackface lambs were allocated to control (C) and treatment (T) groups (30 lambs per group). The C group received a basal diet, and the T group received the same diet supplemented with an essential oil blend, Agolin Ruminant, at a dose rate of 0.1 g/animal/day, consisting of linalool, eugenol, geranyl acetate, and geraniol. An in vitro rumen fermentation assay was performed using rumen fluid pooled within both dietary groups from multiple lambs and incubated as a single batch with four replicate fermentation flasks per treatment (n = 4 fermenters per group) to quantify methane production and in vitro nutrient digestibility. In vivo apparent nutrient digestibility was evaluated in a dedicated sub-trial (n = 6 animals per group). Growth performance in the main trial was analyzed using the pen as the experimental unit (n = 3 pens per group), and slaughter-based measurements—including slaughter and carcass traits, rumen volatile fatty acids and protozoal counts, and Longissimus dorsi meat quality and intramuscular fatty acids—were determined in 10 lambs per treatment (n = 10 animals per group). In vitro methane production did not differ between groups (p = 0.366); in vitro crude fiber digestibility showed a tendency to increase with supplementation (p = 0.066). Fermentation end-products were largely unchanged, although propionate tended to be higher (p = 0.063), and the acetate:propionate ratio was lower (p = 0.043) in the supplemented group; protozoal counts were not different between groups. In vivo apparent nutrient digestibility was comparable between treatments. Growth performance was lower in the supplemented group, resulting in an overall mean ADG 19.0% lower. Slaughter and carcass traits were comparable between treatments. Meat proximate composition, cholesterol concentration, pH, color, water losses, and instrumental texture/shear parameters were not affected by supplementation. Intramuscular lauric (C12:0), myristic (C14:0), and pentadecanoic (C15:0) fatty acids were lower (p < 0.05), while C14:1 n-7 tended to decrease (p = 0.050); however, total saturated, monounsaturated, and polyunsaturated fatty acids and nutritional ratios were unchanged. Overall, under the study conditions and dose used, the essential oil blend did not significantly reduce in vitro methane production and elicited only limited rumen fermentation responses; ADG was 19.0% lower in the supplemented group, whereas carcass traits and technological meat quality were unaffected, and only specific intramuscular fatty acids were altered. Full article

Cruise ships and superyachts have experienced significant global expansion throughout the 21st century. Although the growth in cruise passenger numbers was temporarily disrupted by the COVID-19 pandemic, occupancy rates have since rebounded and even exceeded pre-pandemic levels. This study highlights the significant environmental impact of cruise ships and luxury yachts, particularly in terms of air emissions and marine pollution. Emission levels associated with different fuel types and marine engines are analysed, including the average emissions generated by the Norwegian Cruise Line fleet while docked in ports, as well as the estimated emission reductions achievable through the implementation of onshore power supply systems. To identify environmentally preferable fuel options, a hybrid ANN/MCDM framework is applied. The weighting coefficients of eight evaluation criteria are determined using the Artificial Neural Network/Extreme Learning Machine (ANN/ELM) model, ensuring an objective and data-driven assessment of their relative importance. The ANN/ELM model was trained using emission and fuel-related data collected from the literature and industry reports, and its performance was validated using standard validation procedures, achieving satisfactory predictive accuracy for determining the weighting coefficients. The final ranking of eight fuel alternatives is subsequently performed using the Ranking Alternatives by Weighting of Evaluated Criteria (RAWEC) method. The considered alternatives include conventional and emerging marine fuels currently used in practice or under technological development (A₁–A₈), while the optimization criteria (C₁–C₈) encompass major air pollutants (CO₂, NOx, SOx, CO, PM, CH₄), the fuel cost-to-consumption ratio, and the potential impact on water pollution. The water pollution criterion is assessed qualitatively using the Saaty scale. The integrated ANN/ELM–RAWEC approach enables a systematic comparison of marine fuels and supports the identification of options with the lowest overall environmental impact. Full article

This study evaluated the effects of sodium monensin or a blend containing condensed tannins and yeast products on intake, digestibility, performance, and methane emissions in lactating Holstein cows. Nine cows (three rumen-fistulated and six non-fistulated) were assigned to three 3 × 3 Latin squares. The treatments were: a control (CON), sodium monensin (MON; 12 mg/kg of dry matter [DM]), condensed Acacia tannins and Saccharomyces cerevisiae yeast blend (SUP; 2 g/kg of DM). The trial lasted 84 days, with three 28-day periods. Neutral detergent fiber (NDF) intake was higher in CON and SUP (p = 0.029). Milk yield, energy-corrected milk, and milk composition did not differ (p > 0.05). The total methane emissions were not affected by treatments (p > 0.05). Methane yield/Kg of DM intake (DMI), organic matter intake (OMI), and digestible OM tended to be lower in SUP (p = 0.091, p = 0.093, p = 0.086). SUP increased the DM, crude protein (CP), and NDF ingestion rates (p = 0.049, p = 0.028, p = 0.013) and decreased the CP rumen pool (p = 0.014). Rumen pH tended to be higher in SUP (p = 0.067). The potentially digestible NDF digestion rate decreased in MON (p = 0.007). Finally, SUP-treated animals showed a tendency to reduce their methane yield relative to DMI, OMI, and digestible OM. Further studies should investigate the long-term impacts of supplementation, rumen microbiome changes, and underlying mechanisms driving methane mitigation. Full article

The objective of this study was to assess the contribution of oat (Avena sativa L.) and common vetch (Vicia sativa) hay supplementation as a forage-based strategy to improve the environmental and productive performance of grazing systems in the high Andean zone through its effects on enteric methane (CH₄) emissions and live weight gain. Twenty heifers grazed native grasses, and only half of the group received the supplement. The experiment was conducted as a crossover design. Methane emissions were quantified through sulfur hexafluoride methodology. Native pastures were characterized by low protein content, while lignin was lower in the oat hay plus common vetch hay than in the native grass mixture. On average, heifers consumed 7 kg dry matter per day (p ≥ 0.05) and ingested 24% more crude protein when supplemented (p = 0.0001). Digestible and metabolizable energy intakes were also significantly higher in supplemented animals (p ≤ 0.05). Live weight change was positive for supplemented animals (245 g/d). Net CH₄ production ranged from 179.6 to 196.3 g/d (p = 0.183). However, when CH₄ emissions were expressed relative to crude protein or acid detergent lignin intake, supplemented diets were found to emit less than native grass-based diets (p ≤ 0.05). These results suggest that supplementation with oat hay plus vetch is a feeding alternative for heifers during the dry season in the Peruvian Andean region to increase animal productivity without affecting CH₄ emissions. Full article

Methane (CH₄) is a potent greenhouse gas, and accurately estimating its global budget is essential for climate change mitigation. This review provides a comparative synthesis of top-down, bottom-up, and integrated approaches for quantifying methane emissions and sinks, with a particular focus on the role of remote sensing. Top-down methods, leveraging satellite observations from instruments like GOSAT and TROPOMI within atmospheric inversion frameworks (Bayesian, 4D-Var), provide observationally constrained, spatially integrated fluxes, reducing global budget uncertainty to ±5–10%. However, they face challenges in source attribution and rely heavily on transport model accuracy. Conversely, bottom-up approaches, including process-based models (e.g., CLM, DNDC) and emission inventories (e.g., EDGAR), offer detailed, sector-specific insights but are prone to underestimating emissions from super-emitters and diffuse sources like wetlands, with uncertainties often exceeding ±20–40% for individual sectors. Key persistent discrepancies between the two approaches are largest for natural sources (e.g., a 20–40 Tg yr⁻¹ gap for tropical wetlands). Integrated approaches, which synergize top-down atmospheric constraints with bottom-up inventory data, are emerging as the most robust methodology, effectively narrowing the global budget gap and improving confidence. Recent advancements in satellite missions (e.g., MethaneSAT), machine learning algorithms for plume detection, and high-resolution inversion models are transforming monitoring capabilities. However, challenges remain in harmonizing datasets, representing complex microbial processes in models, and expanding observational coverage in data-scarce tropical regions. This review concludes by outlining a future path centered on hybrid inversion frameworks, AI-driven source attribution, and cross-disciplinary collaboration to deliver the actionable methane budgets needed for effective climate policy. Full article

Antarctica’s extreme cryospheric conditions impose severe thermodynamic constraints on the natural attenuation of hydrocarbon pollutants. Despite the Antarctic Treaty System’s protections, the footprint of human logistics has left persistent reservoirs of petroleum hydrocarbons that threaten endemic biodiversity. This review critically synthesizes the state-of-the-art in Antarctic bioremediation, moving beyond traditional culture-dependent studies to integrate recent multi-omics breakthroughs (2020–2025). We analyze the molecular mechanisms limiting bioavailability in frozen soils and highlight the adaptive strategies of psychrophilic consortia, including the modification of membrane fluidity and the expression of cold-active enzymes (e.g., RHDs, AlkB). Notably, we discuss emerging findings on novel long-chain alkane degradation genes (almA, ladA) identified in 2025, which challenge previous assumptions about recalcitrance. Furthermore, the review evaluates the engineering bottlenecks of in situ versus ex situ strategies, emphasizing the synergistic potential of bacterial–fungal co-cultures and the ecological necessity of “climate-smart” remediation to mitigate methane emissions from thawing permafrost. By bridging the gap between fundamental microbial genetics and applied field engineering, we propose a roadmap for the next generation of biotechnological solutions in the warming polar environment. Full article

This study aims to evaluate the blanching process of wasted Undaria pinnatifida as a ruminant feed source by assessing chemical compositions, in vitro nutrient digestibility, rumen fermentation characteristics, greenhouse gas emissions, and rumen microbes. The blanching process was conducted at different temperatures (15 vs. 80 vs. 90 °C) and times (2 vs. 4 min) to assess the chemical and mineral contents. Supplementation levels of U. pinnatifida (0 vs. 0.5 vs. 1 vs. 2%) were observed with the blanching process (non-blanching (NBL) vs. blanching (LOS)). Increasing blanching temperature and time decreased (p < 0.05) dry matter, crude ash, and the mineral contents, including sodium, phosphorus, and arsenic. Moreover, LOS treatment increased (p < 0.01) in vitro dry matter and neutral detergent fiber digestibility, ruminal pH, and the acetate-to-propionate ratio, but reduced (p < 0.01) CH₄ (mL/g NDFD). Additionally, 2% of LOS treatment reduced the abundance of protozoa, fungi, fibrolytic microbes, methanogenic archaea, Methanobrevibacter ruminantium, Methanosarcina barkeri, and Methanosphaera stadtmanae (p < 0.01). Therefore, blanching at 80 °C for 2 min improved the nutritional profile by reducing antinutritional minerals. Subsequent in vitro fermentation suggested that supplementing the diet with 0.5–1% of LOS improved digestibility and altered fermentation, potentially reducing methane yield (per NDFD). Full article

This study estimates China’s methane (CH₄) emissions from 43 specific emission sources in 2020 and projects future trends through 2050 under two scenarios: Current Legislation (CLE) and Maximum Technically Feasible Reduction (MFR). The analysis utilises the Greenhouse gas and Air pollution Interactions and Synergies (GAINS) model methane framework, incorporating updated province-level activity data to capture the pronounced regional heterogeneity inherent in emission profiles and mitigation capacities. The results reveal a national CH₄ budget of 1114 MtCO₂e in 2020, with the energy sector (59%) and agriculture (28%) emerging as the primary contributors. A substantial technical mitigation potential is identified; by 2050, emissions could be curtailed by up to 48% relative to the CLE scenario, representing a 46% reduction from 2020 levels. The energy and waste sectors emerge as the primary contributors to this potential. Specifically, coal mining CH₄ abatement constitutes 58% of the energy sector’s total reduction potential, while enhanced solid waste management accounts for 97% of the mitigation within the waste sector. Key measures include ventilation air methane (VAM) oxidation and pre-mining degasification, as well as anaerobic digestion and recovery and utilization for energy use. Owing to regional disparities in hydrothermal conditions (representing the combined influence of temperature and moisture), demographic status, economic development, the most effective mitigation strategies vary across provinces. For example, pre-mining degasification and VAM oxidation are most impactful in major coal-producing regions such as Shanxi, Inner Mongolia, and Shaanxi. In contrast, anaerobic digestion, recovery and utilization, and waste incineration play a dominant role in more economically developed and densely populated provinces such as Jiangsu, Shandong and Zhejiang. By delineating region-specific technological priorities, this study quantifies the maximum technical mitigation potential for China and offers guidance for other nations facing similar mitigation challenges. Full article

Several prediction equations have been created, based on various dietary composition variables, to predict dairy cattle enteric methane emissions (EMEs). Inconsistencies in measuring EMEs have created difficulties comparing dairy cattle emissions between farms and inhibits certain in efforts to reduce emissions and work towards Net Zero. The aims of the current study were to gather existing EME prediction equations and evaluate the variability in their prediction results. An additional aim was to create a combined prediction equation, based on the dietary components with the highest predictive ability, representing the average prediction across existing equations, which accounted for the variation amongst existing equations. The 32 equations produced large variation in the prediction of EMEs for each of the 15 example diets, ranging from 12.49 to 34.27 g CH₄/kg DM. To create a combined EME prediction equation, twelve combinations of dietary variables were evaluated using a mixed-effects model. An equation based on metabolised energy (ME) and neutral detergent fibre (NDF) was chosen (methane (CH₄) = 0.33 × ME + 0.31 × NDF + 3.47), due to the significance of the predictor variables and low prediction error (RMSE = 1.47 g CH₄/kg DM), with a random-effects residual variance of 2.32. The combined equation may act as a suitable compromise to compare emissions between studies accounting for unexplained variation. Full article

Methane (CH₄) is a major component of natural gas and a potent greenhouse gas. Increasing atmospheric methane concentrations are attributed to emissive anthropogenic activities by an average of 13 ppb per yr since 2020 and are linked to a changing global climate. Mitigating CH₄ emissions from oil and gas production sites has recently become a target to reduce overall greenhouse gas emissions; however, monitoring the efficacy of mitigation strategies depends on accurate quantification of CH₄ emissions at the facility-level. Near-field quantification of methane (CH₄) emissions from oil and gas (O&G) facilities remains challenging due to the effects of atmospheric variability and sensor configuration on atmospheric dispersion models. This study evaluates the performance of two atmospheric dispersion models, the Gaussian plume (GP) and backward Lagrangian stochastic (bLS), by comparing calculated CH₄ emissions to controlled single-point emissions between 0.4 and 5.2 kg CH₄ h⁻¹. Emissions were calculated by both models using 121 individual sets of measurements comprising five-minute averaged downwind methane mixing ratios and matching meteorological data. The comparison shows that the bLS approach achieved a higher proportion of emission estimates within a factor of two (FAC2) of the known emission rates compared to the GP approach. The emissions calculated by the bLS model also had a lower multiplicative error and reduced bias relative to GP. Other error-based metrics further confirmed the bLS model performed better, as it yielded lower RMSE and MAE than GP. Statistical analysis of the emission data shows that the lateral and vertical alignment of the source and the sensor plays a critical role in emission estimations, as measurements made closer to the plume centerline and at a distance between 40 and 80 m downwind yielded the best FAC2 agreement. High wind meander degraded the ability of both approaches to generate representative emissions, particularly with the GP approach, as it violates the modeling approach’s assumption of steady-state emissions. Data suggest emissions calculated by the bLS model are comprehensively in better agreement, but the computational demands of the modeling approach and integration into fenceline systems limit real-time applicability. While these results provide insight into model performance under controlled near-field conditions, their applicability to more complex or heterogeneous oil and gas production environments (e.g., the regions Marcellus or Unita Basins) remains limited and uncertain. Full article

Landfills are a significant source of atmospheric emissions associated with the decomposition of organic waste; however, conventional monitoring methods typically have limited spatial coverage. This study evaluates the use of an UAV-based system for the spatial characterization of gases associated with biogas emissions at a municipal landfill. A DJI Matrice 350 RTK platform equipped with a Sniffer4D Mini2 multi-gas station and a Zenmuse H20T thermal camera were used. Four flight campaigns were conducted at an altitude of 20 m, with an acquisition frequency of approximately 1 Hz, recording total hydrocarbons (C_xH_y) as an indirect indicator of methane (CH₄), carbon dioxide (CO₂), carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₂), oxygen (O₂), temperature, and relative humidity. The results showed a marked transition around 13:10 h, characterized by a simultaneous increase in CH₄ equivalent and CO₂, along with a decrease in NO₂, O₃, and SO₂. Furthermore, CH₄ equivalent and CO₂ showed the highest positive correlation among the variables (r = 0.96). Spatial maps generated using ordinary kriging revealed more heterogeneous patterns, while the qualitative thermal orthophoto confirmed the site’s surface variability. Overall, the results demonstrate that the integration of multi-gas sensors and aerial thermography on UAVs is viable for the spatial monitoring of landfills. Full article

Ruminants significantly contribute to global methane (CH₄) emissions, necessitating the development of dietary mitigation strategies. This study evaluated five Bangladeshi seaweeds (brown, red, and green types) from Saint Martin Island for their anti-methanogenic potential through phenotypic identification, proximate analysis, and in vitro fermentation assessment. Significant interspecies variation was (p < 0.001) observed in dry matter (DM: 82.1–99.9%), acid detergent fiber (ADF: 17.4–24.9%), neutral detergent fiber (NDF: 29.6–43.6%), and dry matter degradability (DMD: 43.9–58.7%), while crude protein (CP) remained consistent (p = 0.574). After 48 h of fermentation, total gas (1.3–22.1 mL/g DM) and CH₄ yield (0.04–1.6 mL/g DM) varied markedly (p < 0.01). DMD was strongly correlated with total gas and CH₄ production. Crucially, both ADF and NDF showed a positive correlation with total gas and CH₄ production. However, NDF displayed a weak positive correlation with DMD. These findings suggest atypical fiber fraction dynamics, contrasting with terrestrial forages. Supplementation effects of two red seaweeds, SW-4 (Gracilaria parvispora) and SW-5 (Asparagopsis taxiformis), on Napier grass were assessed at 5% and 10% inclusion levels. SW-5 reduced CH₄ by 52.7% when co-fermented with Napier grass at a 10% inclusion level for 48 h, whereas SW-4 showed no significant effect. These results highlight SW-5 as a promising dietary supplement to reduce enteric CH₄ in ruminants, suggesting further in vivo validation for optimal use. Full article

Ecosystem disruption is a significant challenge of the contemporary age, arising from substantial CO₂/CO emissions resulting from dependence on fossil fuels as a primary energy source. Scholars across several fields are striving to mitigate these severe greenhouse gas emissions. The most promising method is to adsorb carbon and convert it into sustainable energy. We sought to diminish CO levels by electrocatalytic reduction using innovative catalytic surfaces, namely transition metal phosphides (TMPs). During this work, VP is recognized as a very effective surface for CO reduction and the synthesis of formaldehyde, methanol, and methane at −0.68 V. Further, hydrogen evolution reaction (HER) does not pose a challenge for any surface, despite all TMPs facilitating CO reduction. In summary, predictions derived from this density functional theory (DFT)-guided analysis provide experimentalists with insights to validate experiments and synthesize active catalysts for CO conversion and green energy generation. Full article