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Carbon capture and storage (CCS) is a critical technology for mitigating greenhouse gas emissions and combating climate change. CCS involves capturing CO2 emissions from industrial processes and power plants and injecting them deep underground for long-term storage. The success of CCS projects is influenced by various factors, including the regional pressure dissipation effects in subsurface geological formations. The safe and efficient operation of CCS projects depends on maintaining the pressure in the storage formation. Regional pressure dissipation, often resulting from the permeability and geomechanical properties of the storage site, can have significant effects on project integrity. This paper provides a state-of-art of the impact of regional pressure dissipation on CCS projects, highlights its effects, and discusses ongoing investigations in this area based on different case studies. The results corroborate the idea that the Sleipner project has considerable lateral hydraulic connectivity, which is evidenced by pressure increase ranging from <0.1 MPa in case of an uncompartmentalized reservoir to >1 MPa in case of substantial flow barriers. After five years of injection, pore pressures in the water leg of a gas reservoir have increased from 18 MPa to 30 MPa at Salah project, resulting in a 2 cm surface uplift. Furthermore, artificial CO2 injection was simulated numerically for 30 years timespan in the depleted oil reservoir of Jurong, located near the Huangqiao CO2-oil reservoir. The maximum amount of CO2 injected into a single well could reach 5.43 × 106 tons, potentially increasing the formation pressure by up to 9.5 MPa. In conclusion, regional pressure dissipation is a critical factor in the implementation of CCS projects. Its impact can affect project safety, efficiency, and environmental sustainability. Ongoing research and investigations are essential to improve our understanding of this phenomenon and develop strategies to mitigate its effects, ultimately advancing the success of CCS as a climate change mitigation solution. [ABSTRACT FROM AUTHOR]

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Purpose: Bioenergy with carbon dioxide removal (CDR) is increasingly proposed as an efficient way to mitigate climate change. This study examined the circumstances and methodological choices in which two CDR bioenergy systems were preferable to a reference bioenergy system from a climate change mitigation perspective. The CDR systems were also compared. Methods: Three systems were modelled: two CDR systems (Biochar, bioenergy with carbon capture and storage (BECCS)), with a combined heat and power (CHP) system as reference. A parameterised life cycle inventory (LCI) model was developed and computed for all systems and four different functional units (FUs), resulting in different distributions of climate impacts. Contribution analysis was performed, followed by pair-wise comparison of all scenarios to establish their ranking. First-order Sobol indices were computed to assess the contribution of each parameter to total variance. When ranking of scenarios was strongly dependent on parameter values, decision tree analysis was applied. Results and discussion: The CDR systems had a lower climate impact than CHP in most computations, across all FUs. On comparing the two CDR systems, the preferable system changed with FU. With heat or carbon sequestration as FU the Biochar system was preferable in general, while with electricity or biomass use as FU, the BECCS system had the lowest climate impact in most computations. For most system configurations, energy substitutions had a large influence and contributed most to the variance in results. The system ranking also depended on the reference activities in the background energy system. Conclusions: The Biochar and BECCS systems were generally preferable to the reference CHP system from a climate mitigation perspective, particularly when the reference energy systems had a relatively low climate impact. However, FU and parameters affected the system ranking. For comparing BECCS and biochar, case-specific climate impacts will be decisive, but not always conclusive, as the choice of FU has such large impact on the results. Recommendations: When conducting LCA of multi-functional systems, the use of several FUs, parameterised LCI, and contribution analysis allows for deeper investigation than conventional sensitivity analyses. When analysing the climate impact of bioenergy with or without carbon removal, it is especially important to perform sensitivity analysis on the energy background system, since it strongly affects the results. [ABSTRACT FROM AUTHOR]

Carbon neutrality strategies have a significant role in climate mitigation efforts. As global concerns regarding climate change continue to increase, achieving carbon neutrality has emerged as a paramount objective for reducing greenhouse gas emissions and limiting the adverse impacts of anthropogenic activities on the environment. This research investigates a wide range of scholarly works to conduct an in-depth analysis and synthesis of the relevant information about carbon neutrality strategies. The review introduces carbon neutrality principles and terminologies, highlighting their importance in climate mitigation. It then proceeds to explore the wide range of strategies employed across different sectors and industries, investigating their effectiveness, scalability, and potential challenges. A multidimensional analysis contrasts the United States Nationally Determined Contributions pathway 2023, China's Nationally Determined contributions 2023, and the EU Directive 2023/2413, assessing their economic, environmental, political, and social impacts. The study evaluates strategies' effectiveness, scalability, and innovation for transitioning to a sustainable, low-carbon future. It fills a gap by analyzing global approaches across the US, China, and the EU, which account for about 50% of the world's total GHG emissions. It evaluates the novel application of diverse strategies, from renewable energy transitions to innovative policy measures, highlighting their potential to mitigate climate change effectively. By providing a multidimensional analysis of these strategies' impacts, the research not only enhances understanding of effective carbon neutrality tactics but also underscores the importance of international cooperation in realizing a sustainable, low-carbon future. • Identifies and analyzes carbon neutrality strategies, emphasizing the need for diverse US, Chinese, and EU approaches. • Evaluate renewable energy, carbon capture, and policy tools for carbon reduction effectiveness, scalability, and innovation. • Highlights the study's novelty in synthesizing current knowledge on carbon neutrality, addressing a significant research gap. • Concludes with strategic ideas for international collaboration and policy development for low-carbon futures. [ABSTRACT FROM AUTHOR]

In order to achieve greenhouse gas neutrality, hydrogen generated from renewable sources will play an important role. Additionally, as underlined in the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), new technologies to remove greenhouse gases from the atmosphere are required on a large scale. A novel concept for hydrogen production with net negative emissions referred to as HyBECCS (Hydrogen Bioenergy with Carbon Capture and Storage) combines these two purposes in one technological approach. The HyBECCS concept combines biohydrogen production from biomass with the capture and storage of biogenic carbon dioxide. Various technology combinations of HyBECCS processes are possible, whose ecological effects and economic viability need to be analyzed in order to provide a basis for comparison and decision‐making. This paper presents fundamentals for the techno‐economic and environmental evaluation of HyBECCS approaches. Transferable frameworks on system boundaries as well as emission, cost, and revenue streams are defined and specifics for the application of existing assessment methods are elaborated. In addition, peculiarities concerning the HyBECCS approach with respect to political regulatory measures and interrelationships between economics and ecology are outlined. Based on these considerations, two key performance indicators (KPIs) are established, referred to as levelized cost of carbon‐negative hydrogen (LCCNH) and of negative emissions (LCNE). Both KPIs allow deciding whether a specific HyBECCS project is economically viable and allows its comparison with different hydrogen, energy provision, or negative emission technologies (NETs). Carbon‐negative hydrogen production referred to as HyBECCS (Hydrogen Bioenergy with Carbon Capture and Storage) combines hydrogen production from biomass with the capture and storage of biogenic carbon dioxide. Various technology combinations of HyBECCS processes are possible, whose ecological effects and economic viability need to be analysed. This paper presents fundamentals for the techno‐economic and environmental evaluation of HyBECCS approaches. Transferable frameworks on system boundaries as well as emission, cost and revenue streams are defined and specifics for the application of existing assessment methods are elaborated. [ABSTRACT FROM AUTHOR]

• A CGE model elaborately depicting six CCS technologies was developed. • Impacts of four CCS incentive scenarios on decarbonization pathways were simulated. • CCS can sequester 960 ∼ 1,604 MtCO 2 annually in China by 2060 with policy incentives. • CCS incentives can reduce China's future primary energy demand by 7.7 ∼ 17.4 %. • CCS incentives can increase GDP by 5.64 ∼ 6.59 % compared to no policy scenario. Carbon capture and storage (CCS) technology, considered as a pivotal tool in mitigating climate change within the fossil energy system, particularly in China, has experienced slower development than expected. The exploration of direct incentive policies to facilitate its growth remains relatively underdeveloped. This study developed a hybrid dynamic computable general equilibrium (CGE) model to simulate the substantial impacts of CCS incentive policies on China within the context of carbon neutrality target. Two potential incentive policies, carbon emission trading system (ETS) and 45Q tax credit, were simulated, with different sectoral coverage. The results indicate that CCS technologies can reduce carbon emissions by 960 ∼ 1,604 MtCO 2 annually by 2060 through the strategic implementation of these incentive policies. The 45Q tax credit demonstrates its effectiveness in promoting early-stage research and development (R&D) and demonstration of CCS, while the ETS policy facilitates the commercial development of CCS in the later stage of development. By 2060, the implementation of CCS incentive policies could potentially result in 7.7 ∼ 17.4 % reduction in China's primary energy consumption, 71.2 ∼ 82.7 % decrease in the carbon price of ETS and 5.64 ∼ 6.59 % increase in the GDP compared with the no-policy scenario. In addition, the sectoral output in various sectors and the welfare of urban and rural households also increase. This paper provides an important reference for the realization of China's carbon neutrality goal and the model framework can be applied to other countries. [ABSTRACT FROM AUTHOR]

In the face of escalating global climate challenges, effective carbon dioxide (CO₂) capture techniques remain at the forefront of mitigating anthropogenic greenhouse gas emissions. This comprehensive review elucidates the latest advancements in CO₂ capture, emphasizing two predominant methodologies: absorption and adsorption. We delve into the mechanisms underlying each process, highlighting the novel materials and technologies that have emerged over recent years. For absorption, the focus is placed on the material design strategy, and identifying new materials in the class of amines, ionic liquids (ILs) and nanofluids for enhanced CO 2 capture capacities and reduced energy requirements. In the realm of adsorption, the synthesis of innovative adsorbents, such as metal organic framework (MOF), organic polymers, inorganic adsorbents, silicon-based adsorbents, and biochar and byproducts from biomass with superior selectivity and stability, is explored. Additionally, the review addresses the challenges associated with each method, offering insights into potential avenues for further research. By providing a holistic overview of the current landscape of CO₂ capture, this article serves as a pivotal resource for researchers and industry professionals aiming to advance sustainable solutions to combat climate change. [Display omitted] • Absorption and adsorption materials are at the forefront of CO 2 capture technologies. • Ionic-liquids and nanofluids can be comparable to amines with improvements in scalability and stability. • Biomass byproducts as adsorbents offers a sustainable solution to CO 2 capture. [ABSTRACT FROM AUTHOR]

In the post-industrial age, the realisation of inherent technical innovation potentials requires that stakeholders develop flexible, cooperation-based frameworks if first mover opportunities and advantages are to be realised. In the Paris Agreement5 implementation context, carbon capture and storage technologies have emerged as a complementary adjunct to climate change mitigation and a diversified energy mix. However, developing the technology is not without technical and financial risks. The challenge for key stakeholders, primarily (but not exclusively) government and industry counterparts is to develop mutually reinforcing strategies, regulations and policies for testing and commercialising Carbon Capture and Storage ("CCS") technologies and networks, as that will be determinative of their fate. In the Paris Agreement implementation period, the UK, for example, has indicated a commitment to bold greenhouse gas reductions (57% by 2030), and investment in CCS, as part of the ambitious emissions reductions targets set forth by the European Union, the deployment of which is meant to count for 20% of the greenhouse gas emissions captured by 2030. This has subsequently resulted in plans for several pilot CCS plants on UK soil. The up-scaling of CCS to the demonstration level, however, is dependent not only on the presence of sufficient interest and funding - an ongoing issue in the UK both pre- and post-Brexit - but also on the existence of appropriate regulatory conditions and options for additional private financing by industrial stakeholders. Furthermore, it is important to note that the up-scaling of projects from pilot to demonstration, and further on to a commercial-scale, is materializing in the context of a global financial crisis and a dip in investment trust in high-risk ventures. The development of CCS projects in individual states, is not only influenced by national regulatory regimes, policy developments, and fluctuations in financial markets, but is also dependent upon the legislative signals given from supra-national bodies and binding international agreements. In Europe, the CCS Directive's approach to long term environmental and related financial risk has led to the current state of regulatory and financial uncertainty, thereby, giving rise to potentially uninsurable liabilities which dis-incentivise private sector investment in CCS technology. This is in contrast with legislation in competing states including the United States, Norway, Canada and Australia. There is every indication that the paramount issue standing in the way of CCS is uncertainty over regulated financial security requirements for site operators and the nature and attribution of liability arising from leakage. This uncertainty could be addressed by a combination of insurance for storage sites and a robust permitting process, which would minimize the likelihood of leakage to virtually zero. There are, therefore, excellent reasons for national and international law and policymakers to seriously consider a more careful and tailored legislative and policy mix, so that regulatory oversight is in balance with innovative financial, insurance and liability mechanisms. In addition to exploring this subject matter, the article offers a number of recommendations for flexible, stakeholder partner-based advancement of CCS technology potentials in climate change and related environmental regulation. [ABSTRACT FROM AUTHOR]

Whilst carbon capture and storage (CCS) has been promoted as a direct countermeasure against global warming, there remains much debate about what its final role as a climate change mitigation strategy will be. One key criticism directed towards CCS has been its inability to gain public support. This study compares public attitudes to the range of low carbon energy sources and technologies across Australia and China, and is the first study to compare primary data across these two countries on this topic. An online survey encompassing a broad set of questions was used to identify the factors that are associated with support for CCS compared to other energy technologies. Data were collected from a nationally representative Australian sample (n = 2383) and from Chinese urban residents across six regions (n = 1266). The survey confirmed low levels of knowledge and support for CCS in both countries. However, male respondents, those who perceived themselves to have higher knowledge of CCS, and those who valued economic outcomes over environmental protection were more likely to support CCS - as long as the risks were not perceived to outweigh the benefits. The results found that for Australians who believed in human-induced climate change they were likely to be unsupportive of CCS. This opposition appears to be linked to no tolerance for extending fossil fuels as in our factor analysis CCS was aligned to fossil fuels in Australia. In both countries, support for renewable energy technologies remains strong. Given the International Energy Agency's future energy demand projections, combined with slow progress towards meeting the Paris Climate Agreement, the lack of knowledge and support for CCS is concerning. While there have been some technological advances, without parallel improvements in public acceptance of CCS, it will be difficult to see any commercial projects going forward in the near future. Although, the Chinese government's success in educating on climate science, as evidenced in these results, suggests that they may be more effective at informing the public of the benefits of CCS and take the lead on its deployment for climate change mitigation. Based on the latest climate models, it is almost crunch time for governments to decide if CCS has a role to play as part of an energy transition to a low carbon future or perhaps it may be time to turn their focus to climate adaptation. [ABSTRACT FROM AUTHOR]

Abstract Amine-based CO 2 capture (ACC) has become one cost-effective method for reducing carbon emissions in order to mitigate climate changes. The amine-rich wastewater (ARWW) generated from ACC may contain a series of degradation products of amine-based solvents (ABSs). These products are harmful for ecological environment and human health. Effective and reliable ARWW treatment methods are highly required for mitigating the harmfulness. However, there is a lack of a comprehensive review of the existing limited methods that can guide ARWW-related technological advancements and treatment practices. To fill this gap, the review is achieved in this study. All available technologies for treating the ARWW from washwater, condenser, and reclaimer units in ACC are examined based on clarification of degradation mechanisms and ARWW compounds. A series of significant findings and recommendations are revealed through this review. For instance, ARWW treatment methods should be selected according to degradation conditions and pollution concentrations. UV light can be only used for treating wastewater from washwater and condenser units in ACC. Biological activated carbon is feasible for removing nitrosamines from washwater and condenser units. Sequence batch reactors, microbial fuel cells, and the other techniques for removing amines and similar degradation products are applicable for treating ARWW. This review provides scientific support for the selection and improvement of ARWW treatment techniques, the mitigation of ACC's consequences in environment, health and other aspects, and the extensive development and applications of ACC systems. Highlights • Investigation of degradation mechanisms and hazardousness of amine-rich wastewater. • Analyzing techniques for treating wastewater generated from washwater, condenser, and reclaimer units. • Providing support for the selection and improvement of wastewater treatment techniques. • Mitigation of wastewater has consequences in the environment and health during CO 2 capture. [ABSTRACT FROM AUTHOR]

The Intergovernmental panel on climate change raised awareness on the urgent need for action to limit climate change. Answers include bioenergy with carbon capture and storage (BECCS), which could theoretically generate negative emissions. The life cycle assessment (LCA) method needs to be applied to BECCS systems to assess their negative emission potential and prevent transfers from one environmental impact category to another. To allow for informed decision-making, the quality of LCA results should be evaluated. The quality of results is related to the quality of the data used. The purpose of this article is thus to review the life cycle inventory data that are used for BECCS LCA. To this end, 35 recent BECCS LCA were selected and the inventory data they used was collected. Synthesis inventory tables were then compiled, including the observed range of variability for each data item. These tables cover biomass harvesting, pre-treatment, combustion, gasification, and carbon dioxide capture with a monoethanolamine (MEA) based solvent. Data quality is also reviewed, through the representativeness, reproducibility and completeness of the life cycle inventories highlighted in the selected articles. Only a third of the articles (13/35) provide life cycle inventory tables. Only half of the articles assess the impact on climate change leading to inventory cut-offs. BECCS systems including combustion followed by MEA-based capture have been most referenced (12/35 articles). More transparency on data quality is recommended. Certain promising BECCS systems should also be further studied. This applies, for instance, to BECCS systems that involve second-generation solvents. • A review of the data quality used in life cycle assessment (LCA) of BECCS is assessed. • Only a third of the studied articles provide their life cycle inventory tables. • Inventory data currently used in LCA of BECCS is compiled into synthesis tables. • BECCS systems including MEA-based capture are most frequently referenced. • BECCS systems that should be further assessed with LCA are identified. [ABSTRACT FROM AUTHOR]

• Integrating the source to sink BECCS chain into an energy system optimization model. • CCS cost-storage curves are created to analyze cost-competitiveness of BECCS. • Assess the dynamic relation between negative emissions and land use change emissions. • Total system costs decrease when BECCS is modelled endogenously. • Source-sink matching shows higher CO 2 injection rates (250 Mt CO 2) can be reached than mentioned in scientific literature (up to 135 Mt CO 2). • Unrestricted modeling of BECCS increases demand for biomass. Even though this comes with a higher EF due to LUC emissions, still net GHG benefits are larger. Bioenergy with carbon capture and storage (BECCS) can lead to negative emissions, and is seen as an important option to decarbonize energy systems. Its potential decarbonization contribution depends on low-carbon resource availability, its ability to meet end-use demand and the geological storage potential to safely trap CO 2. Here an energy system model is used to assess the BECCS decarbonization potential in Brazil, considering uncertainty in low-carbon biomass resources, and storage potential, injection rates and costs of CO 2 storage, assessed in eight scenarios. A spatial explicit analysis is done to make improved estimates on the storage potential, injection rates, and costs for CO 2 storage in the Rio Bonito saline aquifer of the Paraná basin. Although there are large differences in storage potential (12–117 Gt CO 2) and costs (on average 5–15 $/t CO 2), the accumulated volume of CO 2 stored between 2010 and 2050 is 2.9 Gt CO 2 for all scenarios, with injection rates around 240 Mt CO 2 in 2050. This shows that BECCS is a cost-competitive option to decarbonize the Brazilian energy system, even under pessimistic estimates of CO 2 storage potential and costs, and low biomass availability. The cheapest sink locations are selected, in the high development scenario. When CCS development is low, injection rates are the limiting factor. Locations are selected with the highest injection rates, even though sometimes more expensive. When CO 2 storage is limited, total system costs increase, mainly because decarbonization of the industry and freight transport sector relies on more expensive decarbonization options such as green hydrogen. [ABSTRACT FROM AUTHOR]

• Cities' contribution to global emissions reductions is essential yet uncertain. • A novel dataset is analysed to unveil their progress and expected impact. • Most cities have modest mitigation achievements varying with size and geography. • Cities strongly rely on natural carbon sinks to reach net-zero emissions. • Gaps, barriers, and assistance needs are numerous and call for capacity building. Cities are increasingly becoming critical climate actors. However, their preparedness and ambition in forging climate-neutral futures is hard to ascertain. In this study, we analyse the Expressions of Interest in the Mission on 100 Climate-Neutral and Smart Cities by 2030, an unprecedented dataset of city inputs to 374 different questions on the transition to (net) zero. We i) delineate emissions baselines, accounting methodologies, and inventories' completeness (sectors/sources, carriers, gases), ii) analyse emission trends and cities' capacity to deliver on their climate mitigation commitments, iii) examine the estimated magnitude and origin of residual emissions by 2030 together with the envisioned offsetting strategies, and iv) elucidate gaps, methodological deficiencies, and forms of assistance. Data suggest that if all 362 eligible cities were to reach climate neutrality, approximately 650 MtCO 2 eq would be removed. However, this would require at least a quadruple effort in half the time compared to current mitigation achievements. Beyond the challenge of emissions baselining, cities lack adequate data collection and monitoring systems and show little familiarity with non-technological and technological avenues to tackle harder-to-eradicate emissions. Capacity building will be key across multiple (e.g., technical, financial, operational) domains to turn ambitious mayoral commitments into factual contributions to climate mitigation. [ABSTRACT FROM AUTHOR]

The decarbonization of industry and industrial systems is a pressing challenge given the relative lack of low-carbon options available for "hard to decarbonize" sectors such as steelmaking, cement manufacturing, and chemical production. Carbon capture utilization and storage (CCUS) represents a promising and crosscutting solution to this formidable problem. This review takes a systematic and sociotechnical perspective to examine how CCUS can support industrial decarbonization and relevant associated technical, economic, and social factors. This includes a focus on the energy and climate impacts of carbon emitting activities, the role, and options for CCUS in global responses to climate change, technical aspects of capture, transport, storage, and utilization, as well as policy implications and areas requiring further research. In doing so, the Review examines hundreds of published studies on the topic over the previous twenty years to offer a state-of-the-art investigation on technical options for capture (including direct air capture), transportation (including pipelines, ships, and rail), storage (including biotic and abiotic), and utilization (including enhanced oil recovery and biochar). The Review also investigates the evidence base within the literature on enablers and barriers to CCUS, policy mechanisms, and international frameworks as well as themes such as geopolitics, trade, and future research gaps. We conclude with insights about future CCUS pathways and sociotechnical systems dynamics. [Display omitted] • Carbon Capture Utilization and Storage can play a critical role in climate change mitigation. • Ample emerging technologies are available with adequate capture capacities and biotic and abiotic forms of storage. • Utilization processes include enhanced oil recovery and biochar. • Carbon Capture Utilization and Storage deployment has been largely limited by social and economic barriers. • Policy driven solutions may help drive costs down, engender social acceptance, and increase CCUS deployment. [ABSTRACT FROM AUTHOR]

In this study, we use an integrated assessment model – GCAM, whose results were included in the IPCC Fifth Assessment Report – to explore the ways in which CCS could be used in a future carbon-constrained world. We focus on possible roles for CCS applications across different sectors – electricity, liquid fuels (predominantly, biofuels for transportation), and industry – and coupled to different primary fuels (oil, gas, coal, and biomass). To generate scenarios, we assume an increasing economy-wide global price on GHG emissions high enough to match several prescribed radiative forcing targets, approximating a least-cost mitigation pathway for a given target. Results show that the deployment of CCS technologies is not limited to fossil fuels, nor to power plants. There is potential for significant long-term climate change mitigation from application of CCS in the use of biomass to produce both electricity and liquid fuels. Moreover, in many climate change mitigation scenarios examined with GCAM, most biofuels and bio-electricity over the 21 st century use CCS to reduce their emissions. These results can be explained in terms of the relative cost competition between technologies in GCAM. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) is broadly understood to be a key mitigation technology, yet modeling analyses provide different results regarding the applications in which it might be used most effectively. Here we use the Global Change Assessment Model (GCAM) to explore the sensitivity of CCS deployment across sectors and fuels to future technology cost assumptions. We find that CCS is deployed preferentially in electricity generation or in liquid fuels production, depending on CCS and biofuels production cost assumptions. We consistently find significant deployment across both sectors in all of the scenarios considered here, with bioenergy with CCS (BECCS) often the dominant application. As such, this study challenges the view that CCS will primarily be coupled with power plants and used mainly in conjunction with fossil fuels, and suggests greater focus on practical implications of significant CCS and BECCS deployment to inform energy system transformation scenarios over the 21st century. [ABSTRACT FROM AUTHOR]

Storing CO 2 in sub-seabed sediments is a promising CO 2 sequestration method to reduce atmospheric CO 2 concentrations and mitigate climate change. Leaked CO 2 from the sequestration site can form CO 2 hydrates in the sediment and reduce the effective permeability of the sediment layer, developing a self-sealing cap above the storage site. Previous studies usually treat the CO 2 hydrate layer similarly to a methane hydrate reservoir. However, unlike methane, CO 2 has a larger solubility that increases significantly with depth, leading to high gas saturation levels in the sediment. Near the base of the CO 2 hydrate stability zone, CO 2 free gas, CO 2 hydrate and dissolved CO 2 coexist, and elevated surface energies of the curved surfaces of bubbles and hydrate crystals in pores shift the phase equilibria. The bubbles entrapped in the three-phase zone help to reduce the effective permeability besides accumulate CO 2 hydrates. We simulate the three-phase zone in a shallow seabed using Monte Carlo methods in packed synthetic mono-dispersed spherical sediment grains, taking into account of the surface curvatures of the gas–liquid and hydrate–liquid interfaces in irregular pore spaces constrained by the sediment grains, and estimate the permeability reduction caused by entrapped CO 2 bubbles. Finer sediment grains, larger geothermal gradients and shallower seawater all tend to broaden the zone, and the effective permeability in the three-phase zone can be further reduced by up to an order of magnitude than that with hydrates only. We also analyze the sensitivity of the three-phase zone due to temperature and pressure perturbations, and the results suggest possible thickness and depth variations of the zone due to cyclic temperature and sea level changes. This work demonstrates the difference between the CO 2 hydrate-bearing sediment layer and the methane hydrate reservoir, and provides insight into the formation mechanism of the self-sealing cap above the sequestration sites. • Significant CO 2 gas exists in marine sediments due to decreased CO 2 solubility. • Aqueous, gaseous and hydrate CO 2 can coexist in a finite zone in irregular pores. • Finer grains, larger geothermal gradients and shallower seawater broaden the zone. • CO 2 bubbles further reduce the effective permeability and enhance the self-sealing. [ABSTRACT FROM AUTHOR]

Many studies have examined deregulation as a market tool for competition and efficiency enhancement, but climate change mitigation has hardly been pursued. This paper utilizes the staggered difference-in-difference(SDID) method on the panel of 17 OECD countries for 1985–2017. Authors progressively compare countries that have deregulated their natural gas sector and otherwise to single out the impact on the innovation related to carbon capture, storage, and sequestration(CCS). The SDID approach enables authors to provide evidence for the entire spectrum of liberalization, which has implications for both developed and developing economies. Focusing on carbon capture and storage(CCS) innovation also helps introduce net-zero emission relevance. The empirical results show following the liberalization of the natural sector, deregulation promotes CCS innovation, implying it can promote climate change action. Authors also find that the deregulation effects on CCS innovation among the OECD countries are driven by those with relatively low natural gas regulation, natural gas net-exporters and high input innovation performance in global innovation ranking. In general, (1) our results highlight the role of the regulatory environment and liberalization process in explaining the disparity conclusion of the influence of energy sector deregulation on innovation in extant literature. (2) show potential for natural gas deregulation-lagging economies to accelerate net-zero emission with the market liberalization. (3) suggest augmenting country policy with a market mechanism to accelerate climate change mitigation technologies, among other policy implications. • We study the effect of deregulation on innovation in the natural gas(Ngas) sector. • We apply the staggered difference-in-difference methodology in the analysis. • Ngas deregulation promotes Carbon capture, storage and sequestration(CCS) innovation. • Implying Ngas deregulation can foster the global net-zero emission goals. • We find several heterogeneous outcomes of the deregulation effect on CCS innovation. [ABSTRACT FROM AUTHOR]

The global methanol industry provides a unique supply chain to a plethora of chemicals and processes while also contributing to high quotas of greenhouse gas (GHG) emissions. Hence, as the world focuses on climate change mitigation, green technologies are emerging, allowing for low carbon operations. However, the timeliness and scalability of these technologies limit the sustainable transition of the current methanol industry. Thus, to promote low carbon operations within business-as-usual methanol production, innovative technologies need to be investigated-boasting high resource and energy efficiencies. Here, we examine the effectiveness of novel gas-heated reforming (GHR) over autothermal (ATR) and steam reforming (SMR)- coupled with carbon capture and storage platforms (CCS), in promoting sustainable methanol operations. Our results highlight the GHR as the most efficient flowsheet- with 11 % overall higher energy efficiency and 17 % increase in resource efficiency over ATR and SMR processes. Furthermore, through coupled CCS and electrification, energy and resource efficiencies were improved with GHR systems- achieving 14–41 % reduced GHG emissions compared to ATR and SMR flowsheets. Lastly, considering process economics, GHR flowsheets outperform- producing minimum selling prices up to 24 % lower than the current market. Ultimately, as the world seeks to promote a sustainable transition through the deployment of low carbon energy sources, GHR systems emerge as the preferred technologies- providing both economic and environmental benefits for future low carbon methanol operations. [Display omitted] • Methanol production through Gas-Heated Reforming (GHR) was investigated. • GHR gives 8 % higher energy efficiency over ATR and SMR systems. • Low-carbon electrification sources reduced GHG emissions by 71 %. • CCS integration further lowers GHG emissions by 44 %. • Overall sustainable operations favours GHR and GHR+CCS systems. [ABSTRACT FROM AUTHOR]

Despite growing interest in China’s response to climate change and energy security, studies undertaken at the subnational level are rare. In the context of the multilevel governance paradigm, this article examines the governance of climate change and energy policy in Shanghai, a rapidly growing Chinese megacity highly vulnerable to the effects of climate change. Although the energy and carbon intensity of Shanghai’s economy have fallen significantly since China launched its economic reforms, overall carbon emissions in the municipality continue to rise. Through examining the Shanghai case, this article argues that Chinese subnational climate mitigation policy is dominated by hierarchical governance arrangements. Nevertheless, shifts in national climate and energy policy since 2007 have mandated provincial-level governments, including Shanghai, to develop their own climate and energy policies while offering greater local autonomy for incorporating climate and energy issues into development goals: is this attributable to a decentred form of multilevel governance? The article concludes that Shanghai’s climate mitigation and energy policy is dominated by hierarchical governance whereby policies are ‘downloaded’ from the central government. Perspectives for other cities and insights for policymakers are discussed. [ABSTRACT FROM AUTHOR]

Carbon Capture and Storage (CCS) technology is considered key to mitigating climate change by international institutions and governments around the world. The technology is considered advantageous because it may enable the continued utilization of fossil fuels while curbing carbon emissions. However, development of the technology remains slow on the ground. It is generally argued that large-scale, integrated demonstration projects are needed as a next step toward commercialization. Despite government support in several countries, few projects exist so far worldwide. This paper asks why it is so difficult to get demonstration projects off the ground. The argument is that it is not only project-specific factors that determine the feasibility of demonstration, but given the need for government support, a variety of political economy factors influence decision-making processes by policy makers and companies. The paper introduces an analytical framework developed on the basis of the political economy literature that considers six sets of factors that influence outcomes. It discusses two specific projects, Longannet in the UK and Quest in Canada, and explains why one failed and the other one is under construction. The analysis shows that although climate change has been a more important policy concern in the UK compared to Canada, the specific political economy situation of fossil fuel rich provinces like Alberta has led to the Quest project going forward. [ABSTRACT FROM AUTHOR]

• Carbon Capture and Storage (CCS) technologies are one of the many pathways to climate change mitigation but public awareness of this technology is low in the U.S. • This study experimentally evaluates the impact of benefit- and risk-framed messages on community members' support for CCS deployment. • Results indicate that exposure to the relative benefit or risk of CCS influenced public support for CCS through risk-benefit perception and affective evaluation of the technology. There has been a steep growth in the number of carbon capture and storage (CCS) projects globally. However, Americans remain relatively unfamiliar with this climate change mitigation technology, even in communities where the projects would be sited. Using the technology acceptance model as our theoretical framework, this study examined how benefit- and risk-framed messages about CCS might influence community members' support for CCS deployment. Through a messaging experiment, we found that exposure to the relative benefit or risk of CCS influenced public support for CCS through risk-benefit perception and affective evaluation of the technology. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) has the potential to dramatically reduce GHG emissions in energy supply and industry. However, its high costs mean that uncertainty about the stringency of future climate policy may dissuade firms from investing in this technology. This article explores the relationship between firms expectations of government policy and investment in CCS. First, it synthesizes recent cost estimates for CCS applications in electricity generation and oil sands extraction in Canada. Second, it uses these estimates to investigate the potential impact of policy stringency and uncertainty on CCS adoption in Alberta, a Canadian province with near-ideal CCS potential. The results suggest investment in CCS, and by extension other costly abatement actions, will not occur unless governments create a more stringent and durable climate policy environment than currently exists. Policy relevance This paper has two novel and linked objectives, the first of significant utility to researchers and energy modellers in particular, the second to climate policy analysts and decision makers. First, it synthesizes publicly available carbon capture and storage literature and develops cost estimates for key applications related to thermal electricity generation and oil sands extraction in Canada. Second, it uses these cost estimates to investigate the potential impact of policy stringency and uncertainty on carbon capture and storage adoption in Alberta, Canada. Alberta is a test case for CCS due to its fossil resources and high CO2storage potential, and the technology's success or failure in this jurisdiction should be of interest to policy makers elsewhere. [ABSTRACT FROM PUBLISHER]

This study investigates the evolutionary trends of the international collaborations among the research community of carbon capture and storage (CCS) by looking at the collaboration network of countries publishing on CCS. The study also examines the evolution of major research topics in this field by exploring the co-occurrence network of keywords associated with CCS publications. The analysis is carried out based on the CCS related publications extracted from Scopus.com from 1980 to 2013. From the number of annual CCS publications, it seems that CCS research has closely followed the trend of international negotiations on climate change mitigation. The study elaborates how both international collaboration network and knowledge structure of the field have notably developed and interlinked over the years especially after 2005 during which almost 94% of the publications appeared. [ABSTRACT FROM AUTHOR]