Editorial: Advances and Challenges in Geological CO₂ Sequestration

Muhammad Hammad Rasool^1*Arshad Raza²Maqsood Ahmad¹

• ¹Universiti Teknologi PETRONAS, Seri Iskander, Malaysia
• ²King Fahd University of Petroleum & Minerals College of Petroleum Engineering & Geosciences, Dhahran, Saudi Arabia

The global scientific community continues to confront the urgent need to reduce atmospheric carbon dioxide (CO₂) concentrations through large-scale, durable sequestration in geological formations. As international decarbonization targets intensify, geologic CO₂ storage has emerged as a cornerstone technology bridging energy security with climate mitigation. Yet, progress depends on improving understanding of geochemical trapping, basin-scale capacity estimation, and the technical-economic feasibility of developing safe and efficient storage value chains.The Research Topic "Advances and Challenges in Geological CO₂ Sequestration" brings together multidisciplinary contributions that capture state-of-the-art progress and enduring knowledge gaps in subsurface CO₂ storage. The collection spans structural characterization of storage complexes, development of regional carbon capture, utilization, and storage (CCUS) frameworks, and novel resource-optimization strategies. Collectively, these papers highlight that while regional geological heterogeneity, policy maturity, and monitoring readiness differ across continents, the technical principles governing injectivity, containment, and scalability remain universally critical. The featured articles in this Research Topic highlight advances from subsurface characterization and regional CCUS screening to value-chain deployment and dynamic modelling, collectively shaping the evolving landscape of geological CO₂ sequestration. Summary of these articles have been outlined in subsequent sub-sections and illustrated in Figure 1. In 3D seismic structural characterization of faulted subsurface reservoirs in the northern East Cameron Block, Gulf of America continental shelf: implications for CO₂ sequestration (O'Donnell et al., 2025;10.3389/feart.2025.1577336), high-resolution seismic interpretation and well-log integration were applied to the Miocene-Pliocene successions offshore Louisiana. The authors mapped rollover anticlines, salt-related growth faults, and regional sealing units that control plume migration and containment efficiency. Their study identified more than twenty structural closures capable of storing ~70 Mt of supercritical CO₂, emphasizing the significance of detailed fault geometry and seal integrity for safe long-term injection. This work demonstrates how 3D seismic data can bridge the gap between hydrocarbon exploration heritage and new CCUS potential in mature basins, providing a transferable workflow for other continental shelf provinces. A broader regional perspective is provided by A framework for regional high-level technical screening of promising CCUS value chains (Lothe et al., 2025;10.3389/feart.2025.1641951). Within the EUfunded CCUS ZEN project, this study developed a harmonized screening workflow integrating emission mapping, transport infrastructure, and storage readiness across the Baltic and Mediterranean regions. Using open-source geospatial datasets, the authors delineated industrial clusters, transport corridors, and storage units in saline aquifers and depleted fields, culminating in eight prototype CCUS value chains. Their analysis revealed that the Baltic region holds roughly triple the storage capacity of the Mediterranean, underscoring both geological potential and the need for coordinated transnational infrastructure. The framework offers a replicable methodology for other emerging CCUS regions to evaluate source-sink matching and storage maturity efficiently. Complementing the continental framework, CO₂ storage options in development of CCUS value chain scenarios in northern Poland (Wójcicki, 2025;10.3389/feart.2025.1679609) applies the CCUS ZEN principles to a specific Central European corridor. The study harmonized reservoir and caprock parameters from domestic and European datasets to evaluate both onshore and offshore saline aquifers of the Central European Basin System and Baltic Sea. Using Monte Carlo simulations and the CSLF methodology, it quantified volumetric storage capacity and uncertainty while identifying regulatory and logistical challenges to implementation. The findings advocate integrating local storage opportunities with planned CO₂ transport infrastructure such as the Port of Gdańsk terminal to create a regional CCUS hub that could interconnect with future pan-European networks. The fourth contribution, Estimation of dynamic geologic CO₂ storage resources in the Illinois Basin, including effects of brine extraction, anisotropy, and hydrogeologic heterogeneity (Plampin et al., 2025, in press), advances numerical optimization for basin-scale storage management. Employing the iTOUGH2 simulation-optimization framework, the authors explored coupled CO₂ injection, brine extraction, and reinjection scenarios to enhance injectivity across multi-layered saline formations. Their results indicate that formation thickness, permeability, and depth exert dominant control on CO₂ injectivity, and that strategic brine extraction can locally augment storage efficiency though reinjection logistics remain a key constraint. This dynamic perspective highlights how computational modelling can inform reservoir-specific decisions and maximize storage utilization within complex hydrogeologic systems. Together, these studies reinforce the evolving paradigm of CO₂ storage research: from static capacity estimates toward dynamic, system-wide optimization that integrates geology, engineering, and policy. Across diverse geological settings; from the Gulf of America's faulted margins to Europe's sedimentary basins; authors emphasize the need for reliable monitoring frameworks, accurate capacity validation, and early alignment of infrastructure with regulatory readiness. Common threads include the value of open-access geospatial datasets, harmonized screening methodologies, and cross-border collaboration for CCUS deployment. Importantly, the studies illustrate that advancing sequestration technologies demands not only technical innovation but also socio-legal adaptation to regional contexts. As carbon management transitions from conceptual planning to operational scaling, geological sequestration must continue evolving toward integrated, data-driven decision frameworks. Emerging directions include coupling geophysical monitoring with physics-informed modelling, exploring costorage of CO₂ with geothermal or hydrogen operations, and refining geochemical mineralization strategies for long-term security. The contributions in this Research Topic provide both foundational workflows and forward-looking insights, emphasizing that robust storage design is inseparable from public acceptance, legal certainty, and environmental stewardship.The editors extend sincere appreciation to all authors, reviewers, and the Frontiers in Earth Science editorial office for their invaluable efforts. The collective work showcased here highlights not only scientific progress but also the collaborative spirit driving global CO₂ sequestration research.