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CO 2 concentration in the atmosphere has crossed an unprecedented level of 420 ppm, causing catastrophic events like climate change. Climate change mitigation via carbon capture is crucial for reducing CO 2 emissions. Among various CO 2 capture technologies, adsorption is considered one of the most efficient and promising techniques. In recent times, substantial research has been conducted on producing cost-effective and efficient adsorbents for CO 2 capture via the thermal and chemical treatments of biomass. In this review, we discuss key scientific results to give broad insight into the recent progress in biomass conversion to activated porous carbon (APC). The effects of various chemical and thermal treatments on the textural properties and CO 2 adsorption capacity of APC are comprehensively discussed. CO 2 adsorption mechanism based on interaction with the surface functionality is thoroughly explained. The economic aspects of APC synthesis and post-combustion CO 2 capture using APC are systematically reviewed. [Display omitted] • Use of biomass based activate porous carbon (APC) for CO 2 capture is reviewed. • CO 2 adsorption mechanism on APC surface is thoroughly explained. • APC surface functionalization via metal doping and heteroatom doping is discussed. • Economics of APC synthesis & large-scale CO 2 capture on APC is critically reviewed. [ABSTRACT FROM AUTHOR]

This research aims to explore the current evidence on the sustainability of Bioenergy with Carbon Capture and Storage under a life cycle approach and to understand how research on this topic has evolved in the last decade. A systematic literature review was performed, and the main focus was identifying methodological shortcomings and analysing Global Warming Potential results. Forty-seven studies were selected for in-depth revision. Results show that the number of Life Cycle Assessment (LCA) studies on BECCS has increased in the last couple of years and that most of these studies report near-carbon neutral or carbon-negative results for electricity, biofuel energy, and other products. However, in many cases, some aspects have been omitted from the discussion, such as proper accounting of land use impacts, impact allocation procedure, accounting of leakage from storage sites, and impacts related to carbon utilisation. Despite this methodological variability, Global Warming Potential results are mostly carbon-negative and carbon-neutral for both power BECCS and industrial BECCS systems. Consequently, current scientific evidence suggests climate change mitigation benefits from BECCS despite methodological variability. However, it is still insufficient to reach a consensus on the sustainability of this technology as a solution for a global energy transition. It is recommended that further LCA research deals carefully with methodological and product systems variability, which may affect environmental impact results. Moreover, carbon capture approaches with high potential benefits should be further analysed, and the most optimal BECCS typologies should be identified. Finally, additional life cycle impact categories should be reported, along with the assessment of the economic and social dimensions of BECCS. [Display omitted] • Life Cycle Assessment (LCA) of Bioenergy with Carbon Capture and Storage (BECCS) was reviewed. • LCA methodology choices were discussed. • Global Warming Potential ranges between −3.873 and 0.366 kg CO 2 eq per MJ. • Current evidence is insufficient to confirm that BECCS is a sustainable solution for climate change mitigation. [ABSTRACT FROM AUTHOR]

Recently, electric fuels (E-fuel), which are the chemicals produced from the conversion of renewable-based hydrogen (H 2), are actively being developed as a sustainable energy carrier. Renewable methane is particularly a promising alternative to fossil-based natural gas, which can be produced from CO 2 or syngas methanation. In this work, techno-economic assessment (TEA) and life-cycle assessment (LCA) for renewable methane production are performed through syngas methanation, where CO 2 is collected using direct air capture (DAC) and syngas is produced by solid oxide electrolysis (SOE) with renewable-based electricity. This research considers the different technical, economic, and environmental performances of the systems for renewable methane production. A favorable reduction in a maximum of 23.3% of CH 4 production cost is observed by the scale-up effects of SOE system from 1 MW to 10 MW. TEA draws the conclusion that economic infeasibility is proved at the current level, but additional research and improvement of SOE system and a plunge in renewable electricity prices can lead to the economic equivalent of conventional natural gas. Furthermore, given that certain energy resources with low energy intensity (0.0394 kg CO 2 -eq MJ−1) are integrated with SOE system for methane production, the LCA results that renewable methane production at a large scale has a potential to access negative CO 2 emissions and accelerate climate change mitigation. Consequently, it is concluded that syngas methanation with renewable-based energy systems and DAC can make a considerable opportunity for climate change mitigation under the assumption that SOE system and renewable energy are significantly improved. [Display omitted] • Feasibility of renewable methane production from syngas methanation is investigated • Solid oxide electrolysis for syngas production with renewable energy is covered • Direct air capture as CO 2 capture technology is considered for renewable methane • Possibility of negative CO 2 emission is confirmed by utilizing direct air capture • Mitigating climate change is proved by renewable methane with direct air 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]

Green roofs can mitigate climate change through various mechanisms, including carbon sequestration, thermal process regulation, and building energy savings. While those mechanisms have been well studied, it remains unclear how to quantify carbon dioxide reduction and design green roofs properly for optimal performance. This review summarizes the processes, factors, and quantitative methods for carbon dioxide reduction from peer-reviewed literature. Firstly, the processes that account for how green roofs reduce carbon dioxide directly (by absorbing ambient CO 2 and storing it in biomass and substrate) and indirectly (thermal process regulation reduces energy consumption) are focused. The factors affecting CO 2 reduction (i.e., vegetation, substrate, building environment, and maintenance) are then discussed to investigate how these factors impact the performance of green roofs. Lastly, quantitative methods, including field experiments and simulation models to evaluate direct and indirect CO 2 reductions from green roofs, are discussed considering different spatial scales. The review found that a better understanding of green roofs' carbon reduction mechanisms is needed. Recommendations also should be developed on customized green roof system designs for various climate conditions. Lastly, there is a lack of green roof decarbonization evaluation at multiple spatial and temporal scales to effectively implement green roofs in urban areas. Overall, this comprehensive review facilitates an understanding of how green roofs reduce CO 2 , the driving factors, and quantitative methods, which will advance research on designing and building green roofs as effective climate mitigation solutions in urban areas. • Analysis of the carbon sequestration and energy savings processes of green roofs. • Evaluation of factors affecting carbon sequestration and thermal performance. • Summarizing methods to quantify the carbon dioxide reduction services of green roofs. [ABSTRACT FROM AUTHOR]

Abstract Biochar-based carbon management networks (CMNs) offer a means of achieving negative net greenhouse gas (GHG) emissions. Such systems rely on relatively mature technologies for biochar production, distribution and application by tillage; thus, the prospects for near-term scale-up, especially in developing countries with agriculture-intensive economies, are promising. The main technological gap lies in the capability to predict, optimize and monitor the actual climate change mitigation benefits. Computer-aided planning of biochar-based CMNs will be needed to maximize GHG reductions while minimizing any potential adverse environmental impacts. Such models can help decision-makers to understand and optimize the cost/benefit aspects of such systems to accelerate their commercial deployment. This paper gives a brief review of the available scientific literature, and discusses prospective areas for further research to facilitate the large-scale use of biochar as a negative emissions technology (NET). Highlights • Biochar application to soil is a potentially scalable negative emissions technology. • Biochar-based carbon management networks can be operated based on this concept. • Computer-aided planning, optimization and monitoring are required. • An integrated modelling framework should be developed for effective decision support. [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 addition to carbon capture and storage, efforts are also being focussed on using captured CO 2 , both directly as a working fluid and in chemical conversion processes, as a key strategy for mitigating climate change and achieving resource efficiency. These processes require large amounts of energy, which should come from sustainable and, ideally, renewable sources. A strong value chain is required to support the production of valuable products from CO 2 . A value chain is a network of technologies and infrastructures (such as conversion, transportation, storage) along with its associated activities (such as sourcing raw materials, processing, logistics, inventory management, waste management) required to convert low-value resources to high-value products and energy services, and deliver them to customers. A CO 2 value chain involves production of CO 2 (involving capture and purification), technologies that convert CO 2 and other materials into valuable products, sourcing of low-carbon energy to drive all of the transformation processes required to convert CO 2 to products (including production of hydrogen, syngas, methane etc.), transport of energy and materials to where they are needed, managing inventory levels of resources, and delivering the products to customers, all in order to create value (economic, environmental, social etc.). Technologies underpinning future CO 2 value chains were examined. CO 2 conversion technologies, such as urea production, Sabatier synthesis, Fischer-Tropsch synthesis, hydrogenation to methanol, dry reforming, hydrogenation to formic acid and electrochemical reduction, were assessed and compared based on key performance indicators such as: CAPEX, OPEX, electricity consumption, TRL, product price, net CO 2 consumption etc. Technologies for transport and storage of key resources are also discussed. This work lays the foundation for a comprehensive whole-system value chain analysis, modelling and optimisation. [ABSTRACT FROM AUTHOR]

With the growing literature related to climate change mitigation measures and policy interventions, a systematic review of the application of computable general equilibrium (CGE) model is inevitable. Therefore, this article aims to characterise the relevant studies, define a comparative framework to identify the current state-of-the-art and the gaps in applied general equilibrium models. Firstly, the systematic review found a total of 301 research articles from Scopus and Web of Science databases and finally analysed 154 articles based on inclusion and exclusion criteria from 67 refereed journals. The review analysis found that application of CGE model is very vital in addressing climate change mitigation issues at the national, regional and global levels. However, China attracted the most substantial research interests followed by the USA, India and Australia, among others, which are in line with their share of greenhouse gas emissions in the world. Most of the research themes focus on the carbon tax, emission reduction target, emission trading, renewable energy, energy efficiency, and carbon capture and storage as primary drivers of low carbon economy. Nevertheless, there is a trend of employing more static CGE model compared to the dynamic CGE, although application of the latter has a limitation of providing right inputs to the macroeconomic policy. Finally, research directions and gaps envision other complementary models such as dynamic stochastic general equilibrium (DSGE) and agent-based model (ABM) for proper policy interventions. [ABSTRACT FROM AUTHOR]

Driven by the desire to mitigate climate change and reduce overdependence on fossil fuels, biofuels have been actively pursued in recent years because they are believed to be inherently environmentally friendly. In the past few years, however, critics have objected to the basis for which it should be adopted due to potential negative trade-offs. Sustainable Development Goals (SDG) number seven seeks to substantially increase contribution of renewable energy to global energy supply, as well as double the rate of improvement in efficiency of energy. Biofuels are likely to play a key role in the pursuit of these goals being one of the most advanced alternative energy sources. This review assesses the potential of biofuels to contribute to the set SDGs by presenting an appraisal of their development over the years. It sheds light on some main arguments surrounding biofuels from the perspective of proponents and critics alike. Even though biofuels have a great potential in aiding climate change mitigation, its large scale adoption is regarded as problematic in its current state. This is because of its potential negative trade-offs in terms of land use change and emissions, especially for first and second generation biofuels. However, a combination of plant biology, carbon capture techniques and novel bioconversion processes provided by third and fourth generation biofuel technologies have set open an era of fuels that will be abundant, energy efficient and clean to support the seventh SDG. [ABSTRACT FROM AUTHOR]

Despite the recognition of carbon capture and sequestration (CCS) as a credible technology for reducing emissions, its implementation has been stalled, partly due to the public's perception of the technology. The literature on CCS technology diffusion points to negative public perception of the technology as a barrier to implementation, and the role of media in that framing. Yet, there remains a gap in the knowledge of media framing of a successful CCS project. This study analyzes the Saskatchewan case, the first successful commercial scale CCS technology deployment in the world and finds that the media framing of CCS technology in Saskatchewan applied a narrative/storytelling approach by deploying metaphors that connected to local values, beliefs, and norms. Also, it notes certain conditions in Saskatchewan made it possible for some frames to be advanced while others were minimized, discounted, or absent altogether in the discussion. Applying the Socio-Political Evaluation of Energy Deployment (SPEED) framework, the study highlights the role of authoritative voices, mostly within Saskatchewan's political system in reframing CCS technology from uncertainty and risk into opportunity; minimizing and sometimes discounting or ignoring the negative frames that have been identified in previous studies as a barrier. It concludes that in Saskatchewan there was a trade-off in framing, where opportunities to advance frames that emphasize how CCS technology can support long term low carbon energy transition and climate change mitigation were missed. This study adds to the literature in that it analyzes a successful case of CCS technology deployment. • The social context shaping technology deployment is created, shaped, and reinforced through communicative practices that are channeled through the media. • Compared to the literature on the social context of CCS technology deployment, this study found similar themes with different articulation and synthesis (communicative practices). • Two major frames found in this study to have enabled the successful deployment of CCS technology in Saskatchewan are: 'World Energy Leader' and 'Managed Risks'. • An effort to understand the key role of actors as they engage in communicative practices that frame innovative and contentious technology is critical to understanding how social context informs technology deployment. [ABSTRACT FROM AUTHOR]

Biochar amendment has been proposed as a promising solution to mitigate greenhouse gas (GHG) emissions from agriculture and sustainably enhance crop yield. However, the net GHG mitigation potential of biochar remains uncertain, especially the controversial results from field and laboratory experiments. Using 9970 published observational data derived from 592 peer-reviewed papers, this study highlighted the effects of biochar in field experiments on crop yield, soil organic carbon (SOC) stocks, carbon dioxide (CO 2) and methane (CH 4) fluxes, and soil nitrogen (N) dynamics (i.e., soil inorganic N stocks, nitrous oxide [N 2 O] emissions, ammonia [NH 3 ] volatilization, and inorganic N leaching). Overall, field data indicated that biochar significantly increased gross SOC stocks (26.6%) and crop yield (15.7%), reduced soil CH 4 (−14.8%) and N 2 O (−23.1%) emissions, and ammonium (−24.9%) and total inorganic N leaching (−23.2%) but had no effect on soil CO 2 emissions. Whereas laboratory data generally showed greater effect sizes of biochar on these indictors. Global warming potential was decreased only in field experiments, but both experiments showed similar reductions in GHG intensity. Both experiments suggested that soil and biochar cation exchange capacity, pH, biochar application rate, and nitrogen fertilization interactively regulated biochar effects on crop yield and GHG emissions. The unrealistically high rates of biochar in laboratory experiments may overestimate its benefit on soil C sequestration and/or underestimate its mitigation potential. These findings provide a comprehensive view that biochar amendment may serve as a viable climate-smart agricultural practice that can help in partial achievement of multiple sustainable development goals. • Biochar is an effective strategy for climate-smart agriculture. • Biochar added to field (∼20 Mg ha−1) can increase gross SOC stock by ∼27%. • Biochar can decrease global warming potential and greenhouse gas intensity. • Unrealistically high biochar rates in lab overestimated soil carbon sequestration. [ABSTRACT FROM AUTHOR]

Biochar has received increasing attention in agricultural and environmental fields as an integrated solution to agricultural waste recycling, soil amendment, carbon sequestration, and greenhouse gas (GHG) reduction. However, obtaining the environmental benefits of biochar is limited by an inadequate number of soil applications. Currently, the willingness to use biochar in soil management is relatively low, which results from the insufficient understanding and promotion of the roles of biochar in soil management and climate change mitigation. This review article presents biochar applications based on carbon-neutral strategies in agricultural soil systems. The primary roles of biochar in soil improvement and remediation are discussed and the main soil application methods are introduced. The focus of this article is on biochar-based soil management strategies for contributing to carbon neutrality. Carbon sequestration using biochar is an application-dependent strategy, as the key to obtaining this ecological benefit is to store biochar products in soil via effective agricultural management. This article offers insights into biochar-based soil management strategies and their contribution to carbon neutrality in agricultural soil systems, with recommendations for appropriate government involvement in promoting biochar-based soil management and for incorporating biochar into the carbon trading market. • The non-CO 2 GHGs account for the majority of carbon emission via agricultural soil. • Incorporating biochar into the global carbon trading market is recommended. • Using biochar to help achieve carbon neutrality is an application-dependent strategy. [ABSTRACT FROM AUTHOR]

Prospective Life Cycle Assessment (pLCA) is useful to evaluate the environmental performance of current and emerging technologies in the future. Yet, as energy systems and industries are rapidly shifting towards cleaner means of production, pLCA requires an inventory database that encapsulates the expected changes in technologies and the environment at a given point in time, following specific socio-techno-economic pathways. To this end, this study introduces premise , a tool to streamline the generation of prospective inventory databases for pLCA by integrating scenarios generated by Integrated Assessment Models (IAM). More precisely, premise applies a number of transformations on energy-intensive activities found in the inventory database ecoinvent according to projections provided by the IAM. Unsurprisingly, the study shows that, within a given socio-economic narrative, the climate change mitigation target chosen affects the performance of nearly all activities in the database. This is illustrated by focusing on the effects observed on a few activities, such as systems for direct air capture of CO 2 , lithium-ion batteries, electricity and clinker production as well as freight transport by road, in relation to the applied sector-based transformation and the chosen climate change mitigation target. This work also discusses the limitations and challenges faced when coupling IAM and LCA databases and what improvements are to be brought in to further facilitate the development of pLCA. [Display omitted] • Prospective LCA can benefit from projections of models such as IAM. • Premise streamlines the production of LCA databases based on prospective scenarios. • Emissions and energy efficiencies of major industries are aligned with IAM scenarios. • Stricter greenhouse gas targets result in larger transformations in the LCA database. • However, such targets result in increased LCA impacts other than global warming. [ABSTRACT FROM AUTHOR]

Crop residue management remains a major problem in the Indian agriculture sector. The in-situ firing of crop residues has been linked to air pollution, global warming, soil fertility decline and others. Biochar conversion through slow pyrolysis could be one of the techniques for the safe disposal of crop residues. 212.04 ± 44.27 MT biochar could be produced from 517.82 MT crop residues in India. Biochar conversion of crop residues can address agriculture production, safe drinking water, livelihood, energy security and environmental protection. Soil amendment with biochar sequestrate about 376.11 ± 78.52 MT CO 2 e carbon and help retain about 1.66 ± 0.46 MT of soil nutrients. Also, crop residues derived biochar has an estimated market value of approximately $500 billion in India. Biochar applications in the cosmetics, pharma and chemical industries offer market and employment opportunities. This review discusses the impact of in-situ crop residue burning and its biochar conversion through slow pyrolysis as part of sustainable crop residue management. Also, biochar applications and socio-economic aspects of crop residues – biochar system has been deliberated to fulfil several sustainable development goals (SDGs). [Display omitted] • Impacts of crop residues in-situ firing in India were quantified and discussed. • Biochar conversion of crop residues for its strategic management was discussed. • Impact of pyrolysis process parameters on biochar yield & properties was reviewed. • Biochar as a conventional & upcoming value-added product was comprehensively analysed. • Crop residues – biochar system for the attainment of SDGs has been mapped. [ABSTRACT FROM AUTHOR]

Abstract: Global climate change is a change in the long-term weather patterns that characterize the regions of the world. Scientists state unequivocally that the earth is warming. Natural climate variability alone cannot explain this trend. Human activities, especially the burning of coal and oil, have warmed the earth by dramatically increasing the concentrations of heat-trapping gases in the atmosphere. The more of these gases humans put into the atmosphere, the more the earth will warm in the decades and centuries ahead. The impacts of warming can already be observed in many places, from rising sea levels to melting snow and ice to changing weather patterns. Climate change is already affecting ecosystems, freshwater supplies, and human health. Although climate change cannot be avoided entirely, the most severe impacts of climate change can be avoided by substantially reducing the amount of heat-trapping gases released into the atmosphere. However, the time available for beginning serious action to avoid severe global consequences is growing short. This paper reviews assessing of such climate change impacts on various components of the ecosystem such as air, water, plants, animals and human beings, with special emphasis on economy. The most daunting problem of global warming is also discussed. This paper, further reviews the mitigation measures, with a special focus on carbon sequestration and clean development mechanism (CDM). The importance of synergy between climate change mitigation and adaptation has been discussed. An overview of the relationship between economy and emissions, including Carbon Tax and Emission Trading and the policies are also presented. [Copyright &y& Elsevier]

Abstract: Climate change is fast becoming the major environmental and energy concern worldwide. There is a major dilemma between the continued reliance on fossil fuel for our energy supply and the pressing need to address the problem of greenhouse gas (GHG) emissions from combustion process. This paper reviews the potential for carbon capture and storage (CCS) as a part of the climate change mitigation strategy for the Malaysian electricity sector using a technology assessment framework. The nation''s historical trend of high reliance on fossil fuel for its electricity sector makes it a prime candidate for CCS adoption. The suitability and practicality of the technology was reviewed from a broad perspective with consideration of Malaysia-specific conditions. It is apparent from this assessment that CCS has the potential to play an important role in Malaysia''s climate change mitigation strategy provided that key criteria are fulfilled. [Copyright &y& Elsevier]

Carbon Capture, Utilization and Storage (CCUS) is considered a critical carbon dioxide reduction technology for climate change mitigation. More recently, it has been attracting significant attention from the Chinese government, industry and academia in relation to its research, development and deployment. This paper screens 1,202 unique scientific articles from Web of Science related to China's CCUS and employs Citespace to conduct a knowledge mapping of the domain. The results show that the number of publications have increased and CCUS has become a multidisciplinary area of study. The paper visually demonstrates the most productive institutions, main authors, and primary sources of China's CCUS research domain. Moreover, the paper explains how the research topics have changed over time and discovers the current research frontiers including "pipeline", "shale gas" and "steel". Of significant interest is the finding that China's CCUS research progress appears to be directly related to the increasing policy support through China's five-year planning process. However, research regarding public perception, financial mechanisms and appropriate business models for CCUS deployment is found to be less prevalent. Recommendations to improve research in these areas are provided from the perspective of government intervention. This paper also highlights the importance of continued government support for CCUS as part of the national development strategy for carbon emissions reduction and transitioning towards a low carbon future. • The evolution of China's CCUS research is identified using a bibliometric method. • Outlines research foci, most productive organizations, main authors and top-tier journals. • Government intervention appears the most significant driver for CCUS development in China. • Three research areas−"pipeline", "shale gas" and "steel"− are receiving strongest policy support. • The topics "public perception", "financial mechanisms", and "business models"− lack sufficient focus in China. [ABSTRACT FROM AUTHOR]

Carbon capture and sequestration (CCS) is an important technology to reduce fossil CO 2 emissions and remove CO 2 from the atmosphere. Scenarios for CCS deployment consistent with global climate goals involve gigatonne-scale deployment of CCS within the next several decades. CCS technologies typically involve large water consumption during their energy-intensive capture process. Despite potential concerns, the water footprint of large-scale CCS adoption consistent with stringent climate change mitigation has not yet been explored. This study presents the water footprints (m3 water per tonne CO 2 captured) of four prominent CCS technologies: Post-combustion CCS, Pre-combustion CCS, Direct Air CCS, and Bioenergy with CCS. Depending on technology, the water footprint of CCS ranges from 0.74 to 575 m3 H 2 O/tonne CO 2. Bioenergy with CCS is the technology that has the highest water footprint per tonne CO 2 captured, largely due to the high water requirements associated with transpiration. The widespread deployment of CCS to meet the 1.5 °C climate target would almost double anthropogenic water footprint. Consequently, this would likely exacerbate and create green and blue water scarcity conditions in many regions worldwide. Climate mitigation scenarios with a diversified portfolio of CCS technologies have lower impacts on water resources than scenarios relying mainly on one of them. The water footprint assessment of CCS is a crucial factor in evaluating these technologies. Water-scarce regions should prioritize water-efficient CCS technologies in their mitigation goals. In conclusion, the most water-efficient way to stabilize the Earth's climate is to rapidly decarbonize our energy systems and improve energy efficiency. • Carbon capture and storage involve large green and blue water consumption. • Large-scale deployment of carbon capture and storage could double the water footprint of humanity. • Trade-offs between climate mitigation benefits and water resources should be weighed. • Carbon capture and storage should be prioritized in regions not affected by water scarcity. • Water sustainability should be accounted for in carbon dioxide removal policies. [ABSTRACT FROM AUTHOR]

As bioenergy produces neutral or even negative carbon emissions, the assessment of biomass resources and associated emissions mitigation is a key step toward a low carbon future. However, relevant comprehensive estimates lack in China. Here, we measure the energy potential of China's domestic biomass resources (including crop residues, forest residues, animal manure, municipal solid waste and sewage sludge) from 2000 to 2016 and draw the spatial-temporal variation trajectories at provincial resolution. Scenario analysis and life cycle assessment are also applied to discuss the greenhouse gas mitigation potentials. Results show that the collectable potential of domestic biomass resources increased from 18.31 EJ in 2000 to 22.67 EJ in 2016 with overall uncertainties fluctuating between (−26.6%, 39.7%) and (−27.6%, 39.5%). Taking energy crops into account, the total potential in 2016 (32.69 EJ) was equivalent to 27.6% of China's energy consumption. If this potential can be realized in a planned way to displace fossil fuels during the period 2020–2050, cumulative greenhouse gas emissions mitigation would be in the range of 1652.73–5859.56 Mt CO 2 -equivalent, in which the negative greenhouse gas emissions due to the introduction of bioenergy with carbon capture and storage would account for 923.78–1344.13 Mt CO 2 -equivalent. Contrary to increasing bioenergy potentials in most provinces, there are declining trends in Tibet, Beijing, Shanghai and Zhejiang. In addition, Yunnan, Sichuan and Inner Mongolia would have the highest associated greenhouse gas mitigation potentials. This study can provide valuable guidance on the exploitation of China's untapped biomass resources for the mitigation of global climate change. • China's bioenergy potential in 2016 accounted for 27.6% of its energy consumption. • The bioenergy potential in Tibet, Beijing, Shanghai and Zhejiang was declining. • GHG mitigation potentials of China's bioenergy would be 1653–5860 Mt CO 2 e by 2050. • China's bioenergy can contribute 6–21% to a global carbon mitigation goal in 2050. [ABSTRACT FROM AUTHOR]

Coal-fired power plays an important role in China's power supply, even though the photovoltaic (PV) power has developed rapidly in recent years. Carbon capture and storage (CCS) technology is essential for achieving anticipated long-term climate change mitigation targets. However, China's government subsidy policies tend to support PV, while incentives for CCS are few. Given this situation, a trinomial tree modeling-based real options approach was developed to evaluate CCS retrofitting investment in coal-fired power plants versus PV power investment. This model includes setting different policy scenarios by considering electricity tariff subsidies and Chinese emission trading scheme (CN-ETS). The results showed that coal-fired power with CCS has a cost advantage over PV power in most provinces in China, if the electricity tariff and other subsidy policies remain the same; however, PV power will be cheaper than coal-fired power with CCS in Yunnan, Tianjin, Hebei, Shanghai and Shanxi provinces in the above cases. Incorporating CCS into CN-ETS could cut the former's application cost, but the incentive effect of CN-ETS is not obvious, because the carbon price in China is currently too cheap, and the incentive effect of a power tariff subsidy (subsidy at the PV power tariff level) is much better for PV than for CN-ETS. Increasing the load factor is an important way to reduce the CCS application cost for power plants. The results of this study provide reference and guidance for the collaborative development of CCS and PV. • Trinomial tree model was used to evaluate CCS and PV investment. • CCS and PV investment were compared in different provinces in China. • Regional factors and policy factors were taken into account. • Suggestions on CCS and PV development in China were put forward. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2) has been proposed to be used as the geothermal working fluid, as it presents enhanced thermodynamic properties for this application when compared with the water-based system. This paper aims to present an overview of the recent research advances on CO 2 -based geothermal systems, particularly CO 2 -enhanced systems and CO 2 -plume geothermal energy technology. The results of the recent operational projects are also described. This emerging technology can improve the efficiency of geothermal systems and their environmental impact, promoting the process sustainability and helping to tackle some of the most important issues that Humanity is facing: (i) global climate change; (ii) energy availability; and (iii) water scarcity. For deployment of this technology at a large scale, some issues and uncertainties were identified. Special attention was focused on the basic findings achieved in operational projects. • CO 2 has enhanced thermodynamic properties for geothermal energy production. • CO 2 -based geothermal systems can offset carbon dioxide capture and storage costs. • The use of CO 2 in these systems improves the energy conversion efficiency. • CO 2 -based systems are a promising technology for climate change mitigation. [ABSTRACT FROM AUTHOR]