Search Results (533)

Google Earth Engine (GEE) is a cloud-based platform revolutionizing geospatial analysis by providing access to vast satellite datasets and computational capabilities for monitoring environmental and societal issues. It incorporates machine learning (ML) techniques and algorithms as part of its tools for analyzing and processing large geospatial data. This review explores the diverse applications of GEE in monitoring and mitigating greenhouse gas emissions and uptakes. GEE is a cloud-based platform built on Google’s infrastructure for analyzing and visualizing large-scale geospatial datasets. It offers large datasets for monitoring greenhouse gas (GHG) emissions and understanding their environmental impact. By leveraging GEE’s capabilities, researchers have developed tools and algorithms to analyze remotely sensed data and accurately quantify GHG emissions and uptakes. This review examines progress and trends in GEE applications, focusing on monitoring carbon dioxide (CO₂), methane (CH₄), and nitrous oxide/nitrogen dioxide (N₂O/NO₂) emissions. It discusses the integration of GEE with different machine learning methods and the challenges and opportunities in optimizing algorithms and ensuring data interoperability. Furthermore, it highlights GEE’s role in pinpointing emission hotspots, as demonstrated in studies monitoring uptakes. By providing insights into GEE’s capabilities for precise monitoring and mapping of GHGs, this review aims to advance environmental research and decision-making processes in mitigating climate change. Full article

The quest for renewable energy sources has resulted in alternative fuels like ammonia, which offer promising carbon-free fuel for combustion engines. Ammonia has been demonstrated to be a potential fuel for decarbonizing power generator, marine, and heavy-duty transport sectors. Ammonia’s infrastructure for transportation has been established due to its widespread primary use in the agriculture sector. Ammonia has the potential to serve as a zero-carbon alternative fuel for internal combustion engines and gas turbines, given successful carbon-free synthesis and necessary modifications to legacy heat engines. While its storage characteristics surpass those of hydrogen, the intrinsic properties of ammonia pose challenges in ignition, flame propagation, and the emissions of nitrogen oxides (NOx) and nitrous oxide (N₂O) during combustion in heat engines. Recent noteworthy efforts in academia and industry have been dedicated to developing innovative combustion strategies and enabling technologies for heat engines, aiming to enhance efficiency, fuel economy, and emissions. This paper provides an overview of the latest advancements in the combustion of neat or high-percentage ammonia, offering perspectives on the most promising technical solutions for gas turbines, spark ignition, and compression ignition engines. Full article

The responses of nitrous oxide (N₂O) emissions to nitrogen (N) application in acidic, perennial agricultural systems, and the factors driving these emissions, remain poorly understood. To address this gap, a 12-year field experiment was conducted to investigate the effects of different N application rates (0, 112.5, 225, and 450 kg N ha⁻¹ yr⁻¹) on N₂O emissions, tea yield, and the associated driving factors in a tea plantation. The study found that soil pH significantly decreased with long-term N application, dropping by 0.32 to 0.85 units. Annual tea yield increased significantly, by 148–243%. N application also elevated N₂O emission fluxes by 33–277%, with notable seasonal fluctuations observed. N₂O flux was positively correlated with N rates, water-filled pore space (WFPS), soil temperature (T_soil), and inorganic N (NH₄⁺-N and NO₃⁻-N), while showing a negative correlation with soil pH. Random forest (RF) modeling identified WFPS, N rates, and Tsoil as the most important variables influencing N₂O flux. The cumulative N₂O emissions for N112.5, N225, and N450 were 1584, 2791, and 45,046 g N ha⁻², respectively, representing increases of 1.33, 2.34, and 3.77 times compared to N0. The N₂O-N emission factors (EF) were 0.35%, 0.71%, and 0.74%, respectively, and increased with higher N rates. These findings highlight the importance of selecting appropriate fertilization timing and improving water and fertilizer management as key strategies for mitigating soil acidification, enhancing nitrogen use efficiency (NUE), and reducing N₂O emissions in acidic tea-plantation systems. This study offers a theoretical foundation for developing rational N fertilizer management practices and strategies aimed at reducing N₂O emissions in tea-plantation soils. Full article

Straw returning (R) combined with the application of a decomposition agent (RD) can increase crop yield and soil carbon (C) storage. However, the effect of RD on soil nitrous oxide (N₂O) emissions in tropical areas remains poorly understood. In this study, an in situ experiment was performed under different water management strategies (long-term flooding or alternate wetting and drying) with the R and RD treatments to evaluate soil N₂O emissions and rice yield. The SOC and TN contents were significantly lower under the RD treatment than under the R treatment. The R treatment significantly increased rice yield; however, the yield was further significantly increased under the RD treatment. The soil N₂O emissions and yield-scaled N₂O emissions were higher under the R treatment than under the no-straw-returning treatment. However, the RD treatment greatly reduced soil N₂O emissions and yield-scaled N₂O emissions under various water management strategies compared with those under the R treatment. Moreover, yield-scaled N₂O emissions were lower in the RD treatment than in the control. The soil N₂O emissions and yield-scaled N₂O emissions were distinctly higher under alternate wetting and drying than under long-term flooding. Our results indicated that long-term flooding and straw returning with decomposition agents can effectively increase rice yield and reduce soil N₂O emissions in tropical areas. Full article

To evaluate the estimation and spatiotemporal variation characteristics of nitrous oxide emissions from agricultural sources in Anhui Province, the nitrous oxide emissions generated during crop cultivation and manure management were assessed based on the recommended methods in the “Guidelines for Provincial Greenhouse Gas Inventories” and official statistical data. The results showed that the overall emission of nitrous oxide from agricultural land showed a downward trend, reaching a valley value in 2019 with an emission of 2.83 × 10⁴ tons. The annual average emissions of nitrous oxide from agricultural land and manure management account for 80.98% and 19.02% of the total annual average emissions of nitrous oxide from agricultural activities in Anhui Province, respectively. Both agricultural land emissions and livestock manure management show a trend of nitrous oxide emissions decreasing from the northern region of Anhui > central region of Anhui > southern region of Anhui. In this paper, we explored and discussed the intrinsic driving factors behind the spatiotemporal changes in nitrous oxide emissions, and analyzed the potential for future emission reductions. It is suggested that the emissions of nitrous oxide from agricultural sources can be reduced through measures such as reasonable nitrogen application, adjustment of aquaculture structures, and the improvement of manure treatment methods, providing a theoretical reference for the estimation of greenhouse gas emissions from agricultural sources. Full article

Rivers and estuaries are recognized as significant sources of atmospheric greenhouse gas nitrous oxide (N₂O), primarily through diffusive pathways. Anthropogenic nitrogen contributions to surface water bodies can alter the baseline emissions from natural sources; however, due to high spatial variability and limited datasets, the specific sources and sinks contributing to N₂O remain poorly understood. This study investigates the sources and sinks of nitrous oxide (N₂O) in river systems located in Sanya, Hainan Province, China. In April 2023, we collected 48 samples of river water and seawater, measuring hydrochemical parameters in situ while analyzing N₂O concentrations in the laboratory. The results indicate that N₂O concentrations vary significantly across different river systems within Sanya. Specifically, N₂O concentrations ranged from 0.33 to 307.18 nmol/L for samples from the Sanya River, 2.28 to 3113.46 nmol/L for samples from Damaoshui River, 5.72 to 122.75 nmol/L for Tengqiao River waters, and between 11.08 and 18.07 nmol/L for Ningyuan River waters; coastal seawater exhibited concentrations ranging from 2.42 to 21.96 nmol/L. Notably, we observed that riverine N₂O levels near sewage discharge points were oversaturated—indicating a peak concentration—which subsequently declined towards levels more consistent with those found in natural river systems as one approaches the mouths of estuaries. Both Sanya River and Damaoshui River appear to be significant sources of N₂O; conversely, coastal seawater is not considered a substantial source. Our data suggest that wastewater discharges may play a critical role in influencing N₂O levels within river waters by directly introducing oversaturated effluents into these ecosystems. Full article

Dairy manure is an important nitrogen (N) source for crops, but its role in greenhouse gas (GHG) emissions and farm sustainability is not fully understood. We evaluated the effects of application of two dairy manure sources (bedded pack heifer, BP, and separated dairy solids, SDS) on corn silage yield and GHG emissions (carbon dioxide, CO₂; methane, CH₄; nitrous oxide, N₂O) compared to a urea-fertilizer-only control (80 kg N ha⁻¹ yr⁻¹). The BP and SDS were applied at 18.4 and 19.4 Mg dry matter ha⁻¹ in fall 2020 in the final year of ryegrass production. No-till corn was planted from 2021 to 2023, and GHG emissions were measured each season (from May to November). The results showed significantly greater CO₂-C emissions for BP in 2021 and no differences in 2022 or 2023. A small N₂O-N emission increase for BP occurred in the spring after application; however, seasonal fluxes were low or negative. Mean CH₄-C emissions ranged from 2 to 7 kg ha⁻¹ yr⁻¹ with no treatment differences. Lack of soil aeration appeared to be an important factor affecting seasonal N₂O-N and CH₄-C emissions. The results suggest that GHG models should account for field-level nutrient management factors in addition to soil aeration status. Full article

Reservoirs are hotspots for emissions of the greenhouse gas nitrous oxide; however, the nitrite cycling processes associated with nitrous oxide production therein remain poorly understood, limiting a better assessment of the potential for reservoirs to emit nitrous oxide. Accordingly, this study presents the application of the natural abundance isotope technique combined with a geochemical model to elucidate the nitrite cycling in the freshwater aquaculture and non-aquaculture zones of a large artificial reservoir in eastern China. We employed nitrite dual isotopes to identify nitrite transformation processes. Additionally, a steady-state model was used to estimate the rates of these processes as well as the residence time of nitrite. Our findings indicate that nitrite production in this reservoir may be primarily driven by ammonia oxidation. However, the pathways of nitrite removal differ notably between the aquaculture and non-aquaculture zones, suggesting a significant impact of the aquaculture activities. The steady-state model calculations revealed that nitrification may be more pronounced in the aquaculture zones compared to the non-aquaculture zones, which may be related to the altered balance of competition for substrates between phytoplankton and microbes induced by aquaculture activities. Moreover, we observed a latitude-dependent increase in the significance of nitrite oxidation in natural environments, highlighting potential implications for regional and global nitrogen cycling. Our study highlights the complexity of the nitrite cycle and emphasizes the roles of both natural and anthropogenic factors in shaping nitrogen dynamics within freshwater reservoirs. This understanding contributes to a more accurate assessment of the greenhouse gas emission potential of reservoirs, offering valuable implications for the adoption of sustainable aquaculture practices to mitigate climate impacts and support global sustainable development goals. Full article

Straw is widely incorporated into conservation agriculture around the world. However, its effects on greenhouse gas emissions (GHGs) and nitrogen dynamics under soils formed by the long-term application of different amounts of nitrogen (N) fertilizer are still unclear. An incubation experiment was conducted on soils collected from a field study after 6 years of contrasting N fertilization of 0 (low N), 187 (medium N), and 337 kg N ha⁻¹ (high N), with and without maize straw. Straw amendment significantly stimulated both nitrous oxide (N₂O) and carbon dioxide (CO₂) fluxes (p < 0.05), and increased cumulative emissions by 0.8 and 19.0 times on average compared to those without straw incorporation. Medium-N soil observably weakened N₂O emissions (23.8 μg kg⁻¹) compared to high-N soil (162.7 μg kg⁻¹), and increased CO₂ emissions (1.9 g kg⁻¹) compared to low-N soils (2.3 g kg⁻¹) with straw amendment. Soil NH₄⁺-N and NO₃⁻-N invariably increased with rising soil N level, whereas straw promoted the turnover of mineral N by enhancing soil N fixation capacity. From the first day until the end of incubation, NH₄⁺-N decreased by 79.0% and 24.7%, while NO₃⁻-N showed a decrease of 58.8% or an increase of 75.2%, depending on whether straw was amended or not, respectively. Moreover, partial least squares path modeling and random forest mean predictor importance were used to find that straw affected GHGs by altering the N turnover capacity. Straw amendment increased GHGs and diminished the risk of losing mineral N by enhancing its turnover. Combining straw with medium-N soil could mitigate the greenhouse effect and improve the N and carbon (C) balance in farming systems compared to low- and high-N soils. This is recommended as a farmland management strategy in Northeast China. Full article

Anesthetic gases represent a small but significant portion of the environmental impact of health care in many countries. These compounds include several fluorocarbons commonly referred to as “fluranes”. The fluranes are greenhouse gases (GHG) with global warming potentials in the hundreds to thousands and are also PFAS compounds (per- and polyfluorinated alkyl substances) according to at least one definition. Nitrous oxide (N₂O) is sometimes used as an adjunct in anesthesia, or for sedation, but has a significant stratospheric ozone depletion potential as well as GHG effects. Reducing emissions of these compounds into the environment is, therefore, a growing priority in the health care sector. Elimination or substitution of the highest impact fluranes with alternatives has been pursued with some success but limitations remain. Several emission control strategies have been developed for fluranes including adsorption onto solids, which has shown commercial promise. Catalytic decomposition methods have been pursued for N₂O emission control, although mixtures of fluranes and N₂O are potentially problematic for this technology. All such emission control technologies require the effective scavenging and containment of the anesthetics during use, but the limited available information suggests that fugitive emissions into the operating room may be a significant route for unmitigated losses of approximately 50% of the used fluranes into the environment. A better understanding and quantification of such fugitive emissions is needed to help minimize these releases. Further cost–benefit and techno-economic analyses are also needed to identify strategies and best practices for the future. Full article

This study focuses on assessing the indoor air quality in a storage room (SR) belonging to Museo Nazionale Scienza e Tecnologia Leonardo da Vinci in Milan (MUST), covering pollutants originating from outdoor sources and emissions from historical plastic objects made from cellulose acetate (CA), cellulose nitrate (CN), and urea–formaldehyde (UF) stored in metal cabinets. The concentrations of SO₂ (sulphur dioxide), NO₂ (nitrogen dioxide), NOx (nitrogen oxides), HONO (nitrous acid), HNO₃ (nitric acid), O₃ (ozone), NH₃ (ammonia), CH₃COOH (acetic acid), and HCOOH (formic acid) were determined. The concentrations of SO₂, O₃, and NOx measured inside the metal cabinets were consistently lower compared to the other sampling sites. This result was expected due to their reactivity and the lack of internal sources. The SR and metal cabinets showed similar concentrations of NO and NO₂, except for CA, where a high NO concentration was detected. The interaction between the CA surfaces and NO₂ altered the distribution of NO and NO₂, leading to a significant increase in NO. The presence of HNO₃ potentially led to the formation of ammonium nitrate, as confirmed by ER-FTIR measurements. High levels of HONO and HNO₃ in CN and NH₃ in the UF indicate object deterioration, while elevated concentrations of CH₃COOH in CA and HCOOH in the SR suggest specific degradation pathways for cellulose acetate and other organic materials, respectively. These results could direct conservators towards the most appropriate practical actions. Full article

Considerable attention has recently been given to the contribution of the greenhouse gas (GHG) emissions of the healthcare sector to climate change. GHGs used in medical practice are regularly released into the atmosphere and contribute to elevations in global temperatures that produce detrimental effects on the environment and human health. Consequently, a comprehensive assessment of their global warming potential over 100 years (GWP) characteristics, and clinical uses, many of which have evaded scrutiny from policy makers due to their medical necessity, is needed. Of major interest are volatile anesthetics, analgesics, and inhalers, as well as fluorinated gases used as tamponades in retinal detachment surgery. In this review, we conducted a literature search from July to September 2024 on medical greenhouse gases and calculated estimates of these gases’ GHG emissions in metric tons CO₂ equivalent (MTCO₂e) and their relative GWP. Notably, the anesthetics desflurane and nitrous oxide contribute the most emissions out of the major medical GHGs, equivalent to driving 12 million gasoline-powered cars annually in the US. Retinal tamponade gases have markedly high GWP up to 23,500 times compared to CO₂ and long atmospheric lifetimes up to 10,000 years, thus bearing the potential to contribute to climate change in the long term. This review provides the basis for discussions on examining the environmental impacts of medical gases with high GWP, determining whether alternatives may be available, and reducing emissions while maintaining or even improving patient care. Full article

Climate change stands out as a significant environmental issue on a global scale, with greenhouse gases being one of its primary drivers. The greenhouse gas process provides a critical framework for understanding the sources, emissions, and environmental impacts of these gases. This article presents an overview of the fundamental elements of the greenhouse gas process in the textile sector and discusses how it should be managed in line with sustainability goals. Carbon dioxide (CO₂), methane (CH₄), nitrous oxides (N₂O), and fluorinated gases are the most common greenhouse gases, each derived from different sources. The textile sector is particularly associated with high greenhouse gas emissions, especially in areas such as energy consumption, water usage, and waste management. Therefore, measurements taken in factories are crucial for identifying emission sources and developing reduction strategies. This article examines in detail the greenhouse gas emissions resulting from various activities at Kıvanç Textile. Energy consumption, particularly the emissions resulting from the fuels used in electricity and heating processes, is evaluated. Additionally, emissions from other important sources such as refrigerant gas leaks, waste management, and transportation are analyzed. The measurement process was carried out in accordance with national and international standards. The greenhouse gas inventory includes data on energy consumption, fuel consumption, refrigerant gas usage, transportation, production process management, and waste management throughout the factory. Based on these data, the total amount and sources of emissions were determined. This study presents a systematic method for calculating a company’s carbon footprint, with data collected in accordance with national and international standards. Such data can provide a reference point for other companies when making similar calculations. All of the businesses of the facility where the study was conducted were examined and calculations were made on a total of 1350 employees. As a result of the detailed study, Kıvanç Textile’s corporate carbon footprint for 2023 was calculated as a total of 68,746.86 tons ${\mathrm{C}\mathrm{O}}_2\mathrm{e}$. According to this data obtained, Kıvanç Textile emitted 50.92 tons of ${\mathrm{C}\mathrm{O}}_2\mathrm{e}$ greenhouse gases per employee. At the same time, it was determined that the production in 2023 was 4,427,082 tons and a greenhouse gas emission of 15.53 tons of ${\mathrm{C}\mathrm{O}}_2\mathrm{e}$ per production (ton) was calculated. This study also includes proposed strategies for reducing emissions. These strategies include energy efficiency measures, the use of renewable energy sources, waste reduction, and the adoption of efficient production processes. In conclusion, this article emphasizes the importance of efforts to measure and reduce greenhouse gas emissions in textile factories. Kıvanç Textile’s greenhouse gas measurements provide a fundamental reference for achieving sustainability goals in the sector. The data obtained will support the factory’s efforts to reduce its carbon footprint and minimize its environmental impacts. Full article

Agricultural land in China represents a major source of nitrous oxide (N₂O) emissions, and as population growth and technological advancements drive agricultural intensification, these emissions are projected to increase. A thorough understanding of historical trends and future dynamics of these emissions is critical for formulating effective mitigation strategies and advancing progress toward the Sustainable Development Goals. This study quantifies N₂O emissions across 31 provinces in China from 2000 to 2021, employing the IPCC coefficient method alongside China’s provincial greenhouse gas inventory guidelines. The spatiotemporal evolution of emission intensities was examined, with the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model employed to assess the influence of population, technological development, economic growth, and energy structure. The findings confirm that agricultural land remains the primary source of N₂O emissions, with significantly higher levels observed in eastern coastal regions compared to western inland areas. Implementing targeted mitigation strategies, such as enhanced agricultural- and manure-management practices and region-specific interventions, is imperative to effectively curb the rising emission trends. Full article

High nitrogen (N) losses and low nitrogen utilisation efficiency (NUE) of conventional-nitrogen fertilisers (CNFs) are due to a mismatch between N-delivery and plant demand; thus, slow-release N fertilisers (SRNFs) are designed to improve the match. A quantitative synthesis is lacking to provide the overall assessment of SRNFs on pasture. This meta-analysis analyses application rate and type of SRNFs on N losses and agronomic performances with 65 data points from 14 studies in seven countries. Standardized mean difference of SRNFs for nitrate leaching losses and N₂O emission were −0.87 and −0.69, respectively, indicating their effectiveness in controlling losses. Undesirably, SRNFs had a more negative impact on dry matter (DM) yield and NUE than CNFs. Subgroup analysis showed that SRNF type and application rate had an impact on all tested parameters. The biodegradable coating-type of SRNF outperformed other types in controlling N losses and improving agronomic performances. High application rates (>100 kg N ha⁻¹) of SRNFs are more effective in controlling N losses. In conclusion, SRNFs are more conducive to controlling N losses, but they showed a negative impact on yield and NUE in pasture. Further studies are recommended to assess the efficacy of SRNFs developed using advanced technologies to understand their impact on pastoral agriculture. Full article