Journal of Environmental & Earth Sciences

A Systematic Review of the Space Industry’s Environmental Burden within Earth System Limits

Nahed Bahman, Naser Naser, Mohammad Shadab Hussain — Thu, 09 Apr 2026 00:00:00 +0800

The environmental impacts of the modern space industry have expanded rapidly with the rise of commercial launch services, satellite mega constellations, and reusable spacecraft. Despite growing global interest, these impacts remain poorly understood and largely unregulated. This paper systematically reviews the environmental footprint of contemporary space activities, synthesizing evidence across five domains: rocket emissions, orbital debris, atmospheric reentry, light pollution, and material resource use. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology, over 80 peer-reviewed studies and international agency reports were analyzed. Findings reveal significant, yet underregulated, impacts on atmospheric chemistry, orbital sustainability, and terrestrial resources. While mitigation efforts, such as green propellants, debris removal technologies, and sustainability rating systems, are emerging, their adoption remains fragmented and largely voluntary. The review identifies persistent research and policy gaps, including the lack of transparent life cycle assessments and robust global standards. It further highlights the accelerating pace of space commercialization and the increasing involvement of private actors, which intensify governance challenges and complicate accountability mechanisms across jurisdictions. Additionally, disparities in technological capacity between nations raise concerns about unequal environmental burdens and access to orbital resources. It calls for the integration of space activities into comprehensive environmental governance frameworks and the advancement of interdisciplinary, systemic solutions to ensure the long-term sustainability of both orbital and terrestrial environments.

Machine-Learning-Enhanced Transient Electromagnetic Signal Processing for Advanced Mineral Exploration

Changchun Wang; Maohong You, Fei Qin — Fri, 17 Apr 2026 00:00:00 +0800

This review synthesizes recent progress in machine-learning-enhanced transient electromagnetic signal processing for advanced mineral exploration, with emphasis on methods that improve reliability under realistic field conditions. Transient Electromagnetic (TEM) data provide strong sensitivity to subsurface conductivity, yet practical interpretation is often limited by non-stationary interference, platform- and instrument-dependent artifacts, wide dynamic range decay, and ill-posed inversion. We organize the literature using a pipeline perspective spanning automated quality control, denoising and interference suppression, system-response correction and normalization, representation learning, Machine learning (ML) assisted inversion (including surrogate forward models and hybrid physics ML inference), and target detection and ranking. Particular attention is given to the exploration-specific constraints that shape evidence quality, including label scarcity and bias, the synthetic-to-field gap, spatial leakage in evaluation splits, and the need for cost-aware metrics tied to drill decisions rather than pointwise regression error. Across reported studies, the strongest and most transferable benefits are observed in quality control (QC) automation and interference-aware denoising that improve repeatability and stabilize downstream inversion. More ambitious end-to-end inversion and target-ranking models remain promising but are highly sensitive to domain shift across waveforms, gate schedules, noise regimes, and geology, making calibrated uncertainty estimation and out-of-distribution detection central requirements for deployment. We conclude by outlining reproducibility and reporting practices suitable for SCI-standard evidence and by identifying priority research directions, including realistic synthetic data generation, hybrid inversion with error control, and benchmark tasks aligned with exploration value.

Autonomous Multi-Robot Systems for Real-Time Environmental Monitoring and Disaster Response

Xiaolan Li, Xinrong Ma, Yanwei Xu — Fri, 17 Apr 2026 00:00:00 +0800

Autonomous multi-robot systems (MRS) are revolutionizing environmental monitoring and disaster response by enabling real-time data collection, enhanced situational awareness, and efficient task execution in hazardous environments. They are made up of autonomous and collaborative groups of robots that are fitted with high-tech sensors, machine learning algorithms, and communication technologies that enable them to handle a host of tasks, including environmental surveillance and search and rescue missions. The MRS has major strengths compared to the conventional approaches, which are increased response rates, operation in hazardous or even inaccessible locations, and scalability when dealing with high-volume operations. This review examines the core technologies of MRS, which are sensor integration, autonomous navigation, and coordination algorithms, and how they are used in environmental monitoring and managing disasters. Such issues as environmental variability, power constraints, reliability of communication, scalability, and ethical issues are also analyzed. Nevertheless, the problems do not deter the further development of AI, energy systems, and communication standards, which support the functionality of MRS and allow more efficient, adaptable, and effective systems. The next generation of autonomous MRS has huge potential of enhancing disaster resilience, environmental conservation, and management of resources. MRS can be instrumental in reducing the impact of natural disasters, tracking ecosystems, and protecting human life by working around the current constraints.

Microbial and Plant-Based Bioremediation of Petroleum Hydrocarbons: Mechanisms, Strategies and Environmental Applications

Wed, 08 Apr 2026 00:00:00 +0800

Petroleum hydrocarbon (PH) pollution poses a persistent threat to terrestrial and aquatic ecosystems, with wide‑ranging implications for soil fertility, water quality, and human health. Conventional physicochemical remediation methods, although effective in some contexts, often entail high operational costs, generate secondary waste, and fail to achieve complete mineralization of complex hydrocarbon mixtures. In contrast, microbial bioremediation has emerged as a sustainable, cost‑effective, and ecologically compatible strategy that harnesses the metabolic versatility of indigenous and exogenous bacteria to degrade a broad spectrum of aliphatic, aromatic, and heterocyclic hydrocarbons. Recent advances in biostimulation, bioaugmentation, phytoremediation, and engineered bioreactors have demonstrated field‑scale removal efficiencies of total petroleum hydrocarbons (TPH) exceeding 70–90% within weeks to months, depending on site‑specific conditions and pollutant load. Nevertheless, incomplete degradation, environmental variability, and the potential accumulation of intermediate metabolites constrain the robustness and predictability of bioremediation at scale. Emerging technologies such as nanobioremediation, bioelectrochemical systems, and “omics” driven microbial community engineering offer promising avenues to enhance degradation kinetics, extend substrate range, and mitigate antibiotic resistance gene (ARG) dissemination associated with exposure to contaminated matrices. This review synthesizes current knowledge on the classification, sources, and ecological impacts of petroleum hydrocarbons, critically evaluates the mechanisms and techniques underpinning microbial bioremediation, and identifies key research gaps and regulatory challenges. The article further outlines future perspectives for integrating multi‑process, data‑driven remediation strategies into national and international frameworks for environmental restoration.

Assessing APEC's Role in Urban Energy Transitions and the Environmental Impact: A Comparative Analysis of China, Japan, and Singapore

Wendkuuni Steve Harold Kaghembega, Zhu Li, Pengfei Xie, Yujiao Huo — Sun, 14 Apr 2024 00:00:00 +0800

This study evaluates the role of the Asia-Pacific Economic Cooperation (APEC) in shaping urban energy transitions through a comparative analysis of China, Japan, and Singapore. Although regional cooperation has become an important complement to global climate governance, empirical evidence of APEC's substantive influence on urban decarbonization remains limited. The research integrates qualitative institutional analysis with quantitative assessment using a panel dataset and the Shared Socioeconomic Pathways framework, employing Shared Socioeconomic Pathway 5 (SSP5) to examine environmental trajectories under fossil-fuel-intensive growth conditions. The findings show that APEC operates primarily through soft governance mechanisms policy coordination, knowledge diffusion, and technical cooperation rather than binding regulatory instruments. Its influence appears in the strategic alignment of national and municipal energy policies with regional low-carbon frameworks, though implementation pathways diverge according to domestic institutional configurations. China adopts a centralized, state-led model of clean energy urbanization; Japan advances technologically driven smart energy systems within a decentralized governance structure; and Singapore applies an integrated, data-driven sustainability framework emphasizing regulatory coherence and performance benchmarking. Scenario results under SSP5 reveal persistent structural coupling between economic growth and carbon emissions across all three economies. China's economic scale generates substantial emissions from coal- and oil-intensive sectors, while Japan's continued reliance on fossil fuels and liquefied natural gas constrains deeper decoupling despite lower energy intensity and Singapore's CO₂ emissions, strong dependence on imported fossil fuels, making its carbon footprint largely embedded in regional supply chains.

Applicability Evaluation of Himawari-9 Downward Surface Shortwave Radiation (DSSR) Product under Complex Weather Conditions: A Case Study of Guangxi

Yiming Qin, Jiaqiu Hu, Lu Zhang, Kui Huang, Houjian Zhan, Jian Tang — Thu, 09 Apr 2026 00:00:00 +0800

The Advanced Himawari Imager (AHI) aboard Himawari-8/9 can provide downward surface shortwave radiation (DSSR) with 5 km and a high temporal resolution of 10 min. To evaluate its applicability under complex meteorological and topographic conditions, this study systematically assesses the overall quality of the Himawari-9 DSSR product in Guangxi region and its performance under different cloud and aerosol conditions, based on ground-observed observations from photovoltaic and meteorological stations in 2023. The overall comparison of hourly AHI DSSR and ground DSSR shows a high correlation coefficient (R = 0.85); however, there is also a large bias (RPE (relative prediction error) = 46.71%, RMSE (root mean square error) = 162.99 W/m²). Errors are larger in spring and summer, and spatially, errors are significantly higher in the hilly and mountainous areas of northwestern Guangxi compared to the flatter southern and central regions. Satellite retrieval accuracy degrades markedly as cloud cover and aerosol level intensify, with the correlation coefficients dipping from 0.90 (clear sky) to the lowest values of 0.11 (COD (cloud optical depth) > 50) and slightly decreasing from 0.84 (0 ≤ AOD (aerosol optical depth) ≤ 0.1) to 0.79 (AOD >2), respectively. These findings reveal critical limitations of satellite DSSR products under specific atmospheric conditions, providing essential guidance for photovoltaic resource assessment and power forecasting applications in Guangxi. It also serves as an important reference for the evaluation and application of satellite-derived surface radiation products at the national scale.

Landforms Evolution and Formation of Pseudo Karst-Related Geotourism Sites of Al Ula Depression, Northwest Saudi Arabia

Ali Abdellatif Mesaed, Ammar Abdulmonem Amin — Fri, 03 Apr 2026 00:00:00 +0800

Al Ula depression is an oval-shaped oasis of a general NW-SE trend with a maximum length of 50 km and a maximum width of 25 km. Geologically, the area comprises four main rock units, from base to top: Arabian shield rocks, Paleozoic clastic sedimentary cover, Tertiary basic volcanics (Harrat), and Quaternary wadi deposits. The depression was formed by the integration of climatic, lithologic, and structural elements. These elements were dominant during humid rainy periods that operate in highly fractured and faulted clastic sedimentary rocks and the underlying Arabian shield igneous and metamorphic rocks. The processes of weathering and denudation begin from the west and the east along two main NE faults that delineate the western and eastern scarps of the depression. The presence of isolated landforms, inselbergs, and highly weathered Arabian shield supports the formation of the Al Ula depression throughout prolonged periods of etchplanation, pedimentation, and peneplanation. The presence of a black basaltic sheet overlying the Paleozoic clastics led to progressive erosion by scarp retreat and a constant height of the resulting landforms. The presence of vast peneplain areas reflects the attainment of the final stage of the erosional cycle. The present-day landforms and their spatial distribution reflect the final manifestation of arid climatic conditions.

Unlocking High CO2 Gas Fields in the Central Song Hong Basin, Vietnam: Implication for Carbon Storage

Vo Thi Hai Quan — Tue, 07 Apr 2026 00:00:00 +0800

CO₂-dominated gases in the A, B, C pools were resulted from gas chromatography analysis in the central Song Hong basin. These data were integrated with additional information on regional geology, properties of source rocks and reservoirs from Rock-Eval pyrolysis and petrology data in the Pliocene and Pleistocene formations that were used to imply the impacts of geological features on the origin of gases. Compositions of gases comprise the dominance of CO₂, followed by C₁, small contents of N₂, minor contents of C₂ and absence of C₃–C₈, H₂S, He, Ar, H₂, and CO. These gases could be generated from deeper sources and probably small amounts of them released from shallow sources that are strongly impacted by the rapid sedimentation rate, biochemical and geothermal alteration phases. The main period of gas migration and entrapment in the A, B, C fields could be in the period of Pliocene–Pleistocene. The dominance of CO₂ contents in these gas reservoirs mainly came from the dissolving carbonate in sandstone reservoirs, interacting between feldspar and clay minerals with carbonate cement, the process of CH₄ generation in the early stage of sediment diagenesis at shallow depths. Understanding where the CO₂ comes from and regional geological activities are useful for unlocking these high CO₂ accumulations and finding out suitable geological formations for CO₂ storage. Stratigraphic correlation shows the consistent properties of the reservoirs including geological units, high pore spaces, carbonate cements, and high pressures, which are suitable geological formations for potential CO₂ storage.

Assessing the Impacts of Cemetery on Soil and Groundwater around the St. Peter Anglican Church’s Cemetery, Ikere-Ekiti, Southwestern Nigeria

Abel Ojo Talabi, Christopher Ayodele Ajayi , Oluwatoyin O. Akinola — Mon, 13 Apr 2026 00:00:00 +0800

This study evaluated the effects of St. Peter Anglican Church’s Cemetery, Ikere-Ekiti, Southwestern Nigeria, on surrounding soils and groundwater using a Two-Dimensional (2-D) Electrical Resistivity Tomography (ERT), measured physical characteristics of selected 25 wells’ water and a standardized sanitary survey checklist of the wells. Wells’ locations were captured employing an eTrex 12 Channel Global Positioning System (GPS). Subsequently, in-situ parameters (temperature (℃), electric conductivity (EC (µS/cm)) and pH) were measured using a multiparameter portable meter (model Testr-35). Sanitary inspection revealed substantial variation in protective infrastructures. Thirteen of the twenty-five wells lacked cement bases, only one well (Well 25) was fenced, and a few wells near the cemetery exhibited marshy surroundings and inadequate covering, resulting in risk scores ranging from 20% to 50%. Measured in-situ parameters revealed that the pH ranged from 6.49–7.21, EC from 88–687 μS/cm, and Total Dissolved Solids (TDS) from 44–343 mg/L. All physical parameters had values within the approved World Health Organization (WHO) standard for drinking water. The result of the ERT revealed that the leachate from the cemetery has accumulated within stations 15 and 19 (distances 75–95 m) to a depth of about 2.5 to 25 m around the South-Western part of Traverse 1. Traces of the leachates were observed around stations 7 to 9 within a depth range of 0–7.5 m along the North-Eastern part of Traverse 2. Overall, the results showed that the quality of groundwater is suitable for domestic use, as most wells have good infrastructure built up that prevented percolation of leachates.

Evaluating the Generalization of an Ensemble Learning Model for Global Horizontal Irradiance Estimation in Guangxi Province Using FY-4A Satellite Data

Wed, 15 Apr 2026 00:00:00 +0800

This study investigates the application of the Extreme Gradient Boosting (XGBoost) ensemble learning algorithm for estimating global horizontal irradiance (GHI) based on satellite data in Guangxi Province, China. By synergistically integrating top-of-atmosphere (TOA) reflectance and brightness temperature data from 14 spectral bands of the Fengyun-4A (FY-4A) Advanced Geosynchronous Radiation Imager (AGRI) and European Centre for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) reanalysis meteorological variables—including relative humidity, planetary boundary layer height, and surface pressure—we developed an all-sky model to predict hourly surface solar radiation. The model was trained on data from 159 ground stations across China in 2018 and incorporates 31 features covering satellite observations, geographical parameters, and meteorological variables. Validation was conducted using independent observational data from three additional ground stations in Guangxi (Guilin, Nanning, and Beihai) that were withheld from training, yielding Root Mean Square Error (RMSE) of approximately 126–150 W/m² and Correlation Coefficient (CC) of 0.80–0.84, confirming strong spatial generalization. Seasonal analysis revealed that the model performed best in winter and least accurately in summer, attributable to the complexity of convective cloud dynamics in the subtropical monsoon climate of Guangxi. Feature importance analysis identified brightness temperature at 7.42 μm, solar zenith angle, relative humidity, and TOA reflectance at 0.47 μm as the most influential predictors, consistent with the physical mechanisms governing atmospheric transmissivity. These findings demonstrate that the direct data-driven satellite–machine learning framework offers a computationally efficient and scalable alternative to semi-empirical approaches for regional solar resource assessment.

Inventory and Characterization of the Artesian Boreholes of Dallol Maouri in the Dosso Region in Niger

Wed, 08 Apr 2026 00:00:00 +0800

This study aims to list and characterize the artesian boreholes of the Dallol Maouri valley, in the Dosso Region (Niger), and to assess their water potential with a view to their development for irrigation. The Dallol Maouri is one of the country's most dynamic agricultural areas, where groundwater is the main source of supply for drinking water, irrigation and pastoral activities. Despite the drilling of many artesian boreholes over several decades, their contribution to agricultural development remains limited due to insufficient knowledge of their hydrogeological characteristics and their operational condition. The methodology is based on an integrated approach combining the analysis of bibliographic and technical data, an exhaustive inventory of artesian boreholes supported by field surveys and in situ measurements (condition of the structures, flows and uses), as well as statistical, hydrogeological and spatial analyses under GIS. Forty-one artesian boreholes were inventoried, 93% of which are still flowing. The structures mainly exploit the aquifers of the Intercalary Continental/Hamadien (CI/H) and the lower Continental terminal (Ct¹). Boreholes tapping the CI/H show high flows, reaching up to 257 m³/h, while those of the Ct¹ display flows below 40 m³/h. The results highlight a significant and easily mobilizable water potential for irrigation, contrasted with an advanced deterioration of the structures, 78% of which are in poor condition and require urgent rehabilitation actions. The demonstration of the morpho-structural control of artesianism constitutes a decision support tool for the siting of hydraulic structures and the integrated management of water resources in the Dallol Maouri sub-basin.

Assessment of Groundwater Quality in Agona East District, Ghana

James Kwame Kusi, Sam Arkoful, Twumasi Ankrah Kwarteng, Jacob Dadzie — Tue, 07 Apr 2026 00:00:00 +0800

Groundwater also remains an important source of domestic water for rural areas in Agona East district, despite its quality being constantly endangered by natural and human-induced conditions. In this study, the physicochemical parameters and heavy metals present in hand-dug wells in eight rural communities in the Agona East District in Ghana were assessed. Water samples were collected and analyzed for tests that included pH, turbidity, colour, total dissolved solids (TDS), and levels of Fe, Pb, and As, and these were compared with standards outlined by the World Health Organization for clean drinking water. Results indicated that most physicochemical parameters were within World Health Organization (WHO) permissible limits. However, Fe concentrations in Asamoakwaa and Tawora exceed acceptable levels, likely due to geological sources such as Fe-rich parent bedrock. Trace levels of Pb were detected in Sakwa-kwa and Kokwaado. While the overall groundwater quality in the district is suitable for domestic use (Water Quality Index (WQI) = 38.99), site-specific contamination by heavy metals calls for targeted mitigation measures. The Hazard Index (HI) value was less than 1, indicating that the groundwater is likely not to pose a noncarcinogenic effect on consumers. Also, adults and children who depend on groundwater in Agona East district are not likely to suffer carcinogenic effects since the Carcinogenic Risk Index (CRI) for these groups was below their threshold value (1 × 10⁻⁴). It is recommended that the Environmental Protection Agency (EPA) officers in Agona East district should frequently monitor the activities of people in the area to protect the groundwater resource.