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The term carbon (C) sequestration has not just become a buzzword but is something of a siren's call to scientific communicators and media outlets. Carbon sequestration is the removal of C from the atmosphere and the storage, for example, in soil. It has the potential to partially compensate for anthropogenic greenhouse gas emissions and is, therefore, an important piece in the global climate change mitigation puzzle. However, the term C sequestration is often used misleadingly and, while likely unintentional, can lead to the perpetuation of biased conclusions and exaggerated expectations about its contribution to climate change mitigation efforts. Soils have considerable potential to take up C but many are also in a state of continuous loss. In such soils, measures to build up soil C may only lead to a reduction in C losses (C loss mitigation) rather than result in real C sequestration and negative emissions. In an examination of 100 recent peer‐reviewed papers on topics surrounding soil C, only 4% were found to have used the term C sequestration correctly. Furthermore, 13% of the papers equated C sequestration with C stocks. The review, further, revealed that measures leading to C sequestration will not always result in climate change mitigation when non‐CO2 greenhouse gases and leakage are taken into consideration. This paper highlights potential pitfalls when using the term C sequestration incorrectly and calls for accurate usage of this term going forward. Revised and new terms are suggested to distinguish clearly between C sequestration in soils, SOC loss mitigation, negative emissions, climate change mitigation, SOC storage, and SOC accrual to avoid miscommunication among scientists and stakeholder groups in future. [ABSTRACT FROM AUTHOR]

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]

Blue carbon has been proposed as a nature-based solution for climate change mitigation; however, a limited number of published works and data and knowledge gaps hinder the development of small island developing states' (SIDS) national blue carbon resources globally. This paper reviews the blue carbon ecosystems of Seychelles as a case study in the context of SIDS, comparing estimations by the Blue Carbon Lab and recent blue carbon (mangrove and seagrass) evaluations submitted to the Seychelles national government. Mangroves (2195 ha, 80% in Aldabra Atoll) and seagrasses (142,065 ha) dominate in Seychelles, with coral reefs having the potential for carbon sequestration (169,000 ha). Seychelles is on track to protecting its blue carbon, but these systems are threatened by rising sea levels, coastal squeeze, erosion, severe storms, and human activities. The importance of carbon inventories, accounting institutions, and continuous monitoring of blue carbon systems is discussed. Blue accounting is necessary for accurate accounting of carbon sequestration and carbon storage, generating carbon credits, and representing impactful reductions in greenhouse gases for NDCs. Challenges and opportunities include policy legislation regarding ownership rights, accreditation and certification for carbon credits, sustainable financing mechanisms like natural asset companies and blue tokens, local engagement for long-term success, and carbon market dynamics following COP27. The restoration and regulation of blue carbon resources for optimal ecosystem services delivery, carbon inventories, and blue carbon policy are recommended development priorities. Blue carbon ecosystems have the potential to contribute to NDCs of SIDS while simultaneously offering sustainable development pathways for local communities through the multiple ecosystem services they provide. [ABSTRACT FROM AUTHOR]

Calcium oxalate (CaOx) crystals, ubiquitous in numerous plant families, have emerged as fascinating and complex structures with far-reaching implications in plant physiology, ecology, and human health. This paper encapsulates a comprehensive exploration of CaOx crystals, beginning with their formation and physiological role within plants, to their larger ecological implications, and finally, their impact on human society. Recent research has elucidated key genes involved in CaOx crystal formation, as well as the crystals' diverse physiological roles, including their function in calcium regulation, defense against herbivory, and potential contributions to carbon sequestration. We also highlight the ecological significance of CaOx crystals in nutrient cycling and plant-soil interactions, and the potential hazards posed by these crystals in human nutrition, particularly in the context of oxalate-rich diets and kidney stone formation. Despite significant advances, many aspects, particularly their ecological impacts and potential role in climate change mitigation, remain under-explored, necessitating future research. [ABSTRACT FROM AUTHOR]

Enhanced CO2 mineralization and geologic CO2 storage have received increasing attention as two prominent approaches in combating climate change and fostering sustainable development of human society. This paper aims to explore three emerging areas of research within the realm of enhanced CO2 mineralization and geologic CO2 storage, including enhanced rock weathering, numerical modeling and validation of CO2 storage accounting for the interplay of various trapping mechanisms, and the examination of how reservoir heterogeneity influences the migration of CO2-brine multiphase flow. Discussions highlight the effectiveness of the spectrum induced polarization for monitoring changes in petrophysical and geochemical properties of rocks during enhanced rock weathering. Additionally, the multi-scale heterogeneity of geological formations needs to be carefully characterized, due to the fact that it plays a vital role in CO2 migration. Further research is required to achieve accurate and reliable simulations of convective mixing for field-scale applications. [ABSTRACT FROM AUTHOR]

Countries have pledged to different national and international environmental agreements, most prominently the climate change mitigation targets of the Paris Agreement. Accounting for carbon stocks and flows (fluxes) is essential for countries that have recently adopted the United Nations System of Environmental-Economic Accounting - ecosystem accounting framework (UNSEEA) as a global statistical standard. In this paper, we analyze how spatial carbon fluxes can be used in support of the UNSEEA carbon accounts in five case countries with available in-situ data. Using global multi-date biomass map products and other remotely sensed data, we mapped the 2010–2018 carbon fluxes in Brazil, the Netherlands, the Philippines, Sweden and the USA using National Forest Inventory (NFI) and local biomass maps from airborne LiDAR as reference data. We identified areas that are unsupported by the reference data within environmental feature space (6–47% of vegetated country area); cross-validated an ensemble machine learning (RMSE=9–39 Mg C ha - 1 and R 2 =0.16–0.71) used to map carbon fluxes with prediction intervals; and assessed spatially correlated residuals (<5 km) before aggregating carbon fluxes from 1-ha pixels to UNSEEA forest classes. The resulting carbon accounting tables revealed the net carbon sequestration in natural broadleaved forests. Both in plantations and in other woody vegetation ecosystems, emissions exceeded sequestration. Overall, our estimates align with FAO-Forest Resource Assessment and national studies with the largest deviations in Brazil and USA. These two countries used highly clustered reference data, where clustering caused uncertainty given the need to extrapolate to under-sampled areas. We finally provide recommendations to mitigate the effect of under-sampling and to better account for the uncertainties once carbon stocks and flows need to be aggregated in relatively smaller countries. These actions are timely given the global initiatives that aim to upscale UNSEEA carbon accounting. [ABSTRACT FROM AUTHOR]

Countries have pledged to different national and international environmental agreements, most prominently the climate change mitigation targets of the Paris Agreement. Accounting for carbon stocks and flows (fluxes) is essential for countries that have recently adopted the United Nations System of Environmental-Economic Accounting - ecosystem accounting framework (UNSEEA) as a global statistical standard. In this paper, we analyze how spatial carbon fluxes can be used in support of the UNSEEA carbon accounts in five case countries with available in-situ data. Using global multi-date biomass map products and other remotely sensed data, we mapped the 2010–2018 carbon fluxes in Brazil, the Netherlands, the Philippines, Sweden and the USA using National Forest Inventory (NFI) and local biomass maps from airborne LiDAR as reference data. We identified areas that are unsupported by the reference data within environmental feature space (6–47% of vegetated country area); cross-validated an ensemble machine learning (RMSE=9–39 Mg C ha - 1 and R 2 =0.16–0.71) used to map carbon fluxes with prediction intervals; and assessed spatially correlated residuals (<5 km) before aggregating carbon fluxes from 1-ha pixels to UNSEEA forest classes. The resulting carbon accounting tables revealed the net carbon sequestration in natural broadleaved forests. Both in plantations and in other woody vegetation ecosystems, emissions exceeded sequestration. Overall, our estimates align with FAO-Forest Resource Assessment and national studies with the largest deviations in Brazil and USA. These two countries used highly clustered reference data, where clustering caused uncertainty given the need to extrapolate to under-sampled areas. We finally provide recommendations to mitigate the effect of under-sampling and to better account for the uncertainties once carbon stocks and flows need to be aggregated in relatively smaller countries. These actions are timely given the global initiatives that aim to upscale UNSEEA carbon accounting. [ABSTRACT FROM AUTHOR]

Produced through pyrolysis, biochars are used as a soil amendment. Differences in feedstock and processing result in differentiated products which impact their values in different soil conditions. Despite the enormous potential, biochars have not been widely used. This paper overviews the benefits and potential demand for biochar and features of supply chain, and identifies opportunities for viable introduction of biochars. The value of biochars should be evaluated as a part of the pyrolysis system that coproduces biochars and biofuels. Biochars can improve agricultural productivity and soil functioning and contribute to climate change mitigation through carbon sequestration. Furthermore, it can provide extra benefit by contributing to fire prevention. The cost of biochar system depends on the costs of feedstock acquisition, transportation, and processing. Biochar is most likely to be adopted in locations with marginal land and high‐value crop, and near low‐cost feedstock sources. The adoption of biochar can be enhanced by compensation for carbon sequestration, further investment in research, and learning of producers to enhance efficiency of the supply chain. Biochar is a charcoal that has been used to improve soil quality. It is obtained through heating organic materials such as crop and forest residues without oxygen. Diverse types of biochar can be coproduced with biofuels. The paper reviews the benefits and potential demand of biochar, and features of the supply chain that would be used to produce and market it. Biochar can improve agricultural productivity and mitigate climate change. Current adoption is low but will be improved with compensation for carbon sequestration, placing processing facilities closer to the biomass sources, and investment in research to reduce cost of production. [ABSTRACT FROM AUTHOR]

Combining biomass-fired power generation with CO2 capture and storage leads to so-called negative CO2 emissions. Negative CO2 emissions can already be obtained when coal is co-fired with biomass in a power plant with CCS technology. The need for bioenergy with CO2 capture and storage has been identified as one of the key technologies to keep global warming below 2 °C, as this is one of the large-scale technologies that can remove CO2 from the atmosphere. According to the definition of bioenergy with CO2 capture and storage, capturing and storing the CO2 originating from biomass, along with the biomass binding with carbon from the atmosphere as it grows, will result in net removal of CO2 from the atmosphere. Another technology option for CO2 removal from the atmosphere is direct air capture. The idea of a net carbon balance for different systems (including bioenergy with CO2 capture and storage, and direct air capture) has been presented in the literature. This paper gives a background on carbon dioxide removal solutions—with a focus on ecology, economy, and policy-relevant distinctions in technology. As presented in this paper, the bioenergy with CO2 capture and storage is superior to direct air capture for countries like Poland in terms of ecological impact. This is mainly due to the electricity generation mix structure (highly dependent on fossil fuels), which shifts the CO2 emissions to upstream processes, and relatively the low environmental burden for biomass acquisition. Nevertheless, the depletion of non-renewable natural resources for newly built bioenergy power plant with CO2 capture and storage, and direct air capture with surplus wind energy, has a similar impact below 0.5 GJ3x/t of negative CO2 emissions. When the economic factors are a concern, the use of bioenergy with CO2 capture and storage provides an economic justification at current CO2 emission allowance prices of around 90 EUR/t CO2. Conversely, for direct air capture to be viable, the cost would need to be from 3 to 4.5 times higher. [ABSTRACT FROM AUTHOR]

This is a commentary on the paper in GCB by Moinet et al. (2023) entitled "Carbon for soils, not soils for carbon". The paper challenges two claims often made for soil carbon sequestration: (1) Sequestration of C in agricultural soils can make a substantial contribution to climate change mitigation. (2) Increasing SOC will routinely lead to increased crop yields and contribute to global food security. [ABSTRACT FROM AUTHOR]

Herein, 7,308 relevant documents on biochar application for the remediation of heavy metal (HM)-contaminated soil (BARHMCS) from 1991 to 2020 were extracted from the Web of Science Core Collection and subjected to bibliometric and knowledge mapping analyses to provide a global perspective. The results showed that (1) the number of publications increased over time and could be divided into two subperiods, i.e., the slow growth period (SGP) and rapid growth period (RGP), according to whether the annual publication number was ≥300. (2) A total of 126 countries, 741 institutions, and 1,021 scholars have contributed to this field. (3) These studies are mainly published in Science of the Total Environment, Chemosphere, etc., and are mainly based on the categories of environmental science, soil science, and environmental engineering. (4) The top five keyword clusters for the SGP were biochar, biochar, sorption, charcoal, and HMs, and those for the RGP were adsorption, black carbon, nitrous oxide, cadmium, and pyrolysis. (5) The main knowledge domains and the most cited references during the SGP and RGP were discussed. (6) Future directions are related to biochar application for plant remediation, the mitigation of climate change through increased carbon sequestration, biochar modification, and biochar for HMs and multiple organic pollutants. Biochar application in the remediation of heavy metal-contaminated soil (BARHMCS) has become a popular research topic worldwide. Many excellent papers on this topic have been published, including some valuable reviews. However, there are no reviews including bibliometric and visual analyses. In the present study, bibliometric and visual analyses of relevant literature in the field of BARHMCS based on the Web of Science Core Collection were carried out to outline the development process of this field at a macro level, clarify the research hotspots, identify the knowledge domains that support this field, and explore future research directions. These efforts will no doubt help readers fully understand BARHMCS from a global perspective and provide a reference for future research. An overall global perspective of biochar remediation of heavy metal (HM)-contaminated soil was provided. The main popular research topics of each period were discussed. Knowledge domains were discussed. Five main future research directions were identified based on burst keyword analysis. Biochar modification and its effect on HMs and coexisting organic pollutants should be studied in the future for soil remediation purposes. [ABSTRACT FROM AUTHOR]

Agriculture is the second-highest, after energy use, source of greenhouse gas emissions, which are released from soils and animal digestion processes and as a result of energy consumption at various stages of agricultural production. However, changes in the management of agricultural systems may mitigate the negative impact of this sector on the atmosphere and climate. This paper presents a literature review on energy consumption in agriculture and the potential of agricultural crop production to assist in mitigation of global warming by increasing absorption of CO2 from the atmosphere. The issue was considered in the context of managing the cultivation of main, catch and cover crops. The potential of carbon sequestration in the above- and below-ground biomass of selected crops was analyzed. It was stated that, depending on the species, main crops can sequester up to 113 CO2 ha−1 yr−1 in whole biomass, while catch or cover crops can sequester up to 14.80 CO2 ha−1 yr−1 and 0.17 CO2 ha−1 yr−1 in the above- and below-ground biomass, respectively. The benefits of the spread of catch or cover crops, such as improvement of soil quality (leading to an increase in primary crop yield by even as much as 65%) and a phytosanitary effect, as well as the barriers that limit the use of catch crops, including the problems with matching crop species to climate and soil conditions and the risk of reducing farmers' income, were considered. The results of the review show that catch crops can assimilate an additional amount of 4 to 6 tonnes CO2 ha−1 yr−1, and thus, spreading of catch crops is an effective way to reduce the climate impact of agriculture. [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]

We have read with interest an opinion paper recently published in the European Journal of Soil Science (Berthelin et al., 2022). This paper presents some interesting considerations, at least one of which is already well known to soil scientists working on soil organic carbon (SOC), that is, a large portion (80%–90%) of fresh carbon inputs to soil is subject to rapid mineralization. The short‐term mineralization kinetics of organic inputs is well‐known and accounted for in soil organic matter models. Thus, clearly, the long‐term predictions based on these models do not overlook short‐term mineralization. We point out that many agronomic practices can significantly contribute to SOC sequestration. If conducted responsibly whilst fully recognising the caveats, SOC sequestration can lead to a win‐win situation where agriculture can both contribute to the mitigation of climate change and adapt to it, whilst at the same time delivering other co‐benefits such as reduced soil erosion and enhanced biodiversity. Highlights: Rapid mineralization of organic inputs is an important factor for soil carbon sequestration.Mineralization kinetics of organic inputs are well‐known and accounted for in soil organic matter models.Many agronomic practices can contribute significantly to SOC sequestration.SOC sequestration can lead to a win‐win situation where agriculture can both contribute to the mitigation of climate change and adapt to it. [ABSTRACT FROM AUTHOR]

Paying Indigenous communities to conserve land for carbon sequestration is a controversial way of tackling climate change. Critics argue that paying for ecological services (or 'PES') in the form of carbon offset programmes reduces land and social relations to an economic transaction that devalues Indigenous livelihoods and communities. At the same time, empirical studies have shown that Indigenous communities have accepted and even embraced the idea of being paid to conserve land for climate change mitigation. This paper explores this apparent contradiction by investigating the implementation of Programa Socio Bosque (PSB), a PES carbon sequestration programme in Ecuador. Drawing upon primary fieldwork in the highland province of Chimborazo, it makes the case that PES programmes need to be understood as form of state power that reconfigures and reinforces the ways in which Indigenous peoples engage with the state. Particularly important in this regard is the role of the state in reinforcing the agrarian conditions under which Indigenous communities use and interpret PES payments while at the same time reconfiguring new forms of land conservation. Empirically, the research reveals important complementarities between the goals of carbon sequestration PES programmes and Indigenous land‐use practices. Methodologically, it highlights the importance of situating the study of PES programmes in a context of land struggles, community–state relations and agrarian change. [ABSTRACT FROM AUTHOR]

The main hurdle in instrumentalizing agricultural soils to sequester atmospheric carbon is the development of methods to measure soil carbon stocks which are robust, scalable, and widely applicable. Our objective is to develop an approach that can help overcome these hurdles. In this paper, we present the Wageningen Soil Carbon STOck pRotocol (SoilCASTOR). SoilCASTOR uses a novel approach fusing satellite data, direct proximal sensing-based soil measurements, and machine learning to yield soil carbon stock estimates. The method has been tested and applied in the USA on fields with agricultural land use. Results show that the estimates are precise and repeatable and that the approach could be rapidly scalable. The precision of farm C stocks is below 5% enabling detection of soil organic carbon changes desired for the 4 per 1000 initiative. The assessment can be done robustly with as few as 0.5 sample per hectare for farms varying from 20 to 150 hectares. These findings could enable the structural implementation of carbon farming. [ABSTRACT FROM AUTHOR]

Future carbon dioxide capture and storage (CCS) will be impacted by the new scenario in which the energy supply rapidly shifts from oil-based to natural gas-based means, but this shift also presents an opportunity to utilize natural gas hydrates (NGHs). This review discusses the present state of CCS research and development, the advantages of the various approaches, and the barriers to commercialization that exist today. It also provides an evaluation of certain practical small- and large-scale CCS applications. The high initial investment, as well as ongoing maintenance costs, plague today's commercially accessible CO2 capture technologies, including absorption, adsorption, membranes, and cryogenic separation. Gas hydrate-based capture has the potential to become the dominant method for CO2 separation because of the high recovery rates and purity it provides. Hydrate-based technologies, including CO2 capture, CO2 separation, and transportation, can also be used to reduce greenhouse gas emissions and have excellent application potential. Despite this, the potential of technology based on gas hydrates to help reduce the effects of climate change in the future has received little attention. This study discusses cosmopolitan energy provision and environmental challenges and conversions, and the role of gas hydrates in the carbon cycle. This paper summarizes the state-of-the-art developments in hydrate-based reactors, thereby providing a perspective on the roles of NGHs in the future energy supply and climate change mitigation. In all these areas, we focus on identifying future CCS challenges and the technological development risk in gas hydrate-based systems, which should be highlighted in the next several decades. [ABSTRACT FROM AUTHOR]

The atmospheric concentration of CO2 is steadily increasing and causing climate change. To achieve the Paris 1.5 or 2°C target, negative emission technologies must be deployed in addition to reducing carbon emissions. The ocean is a large carbon sink but the potential of marine primary producers to contribute to carbon neutrality remains unclear.Here we review the alterations to carbon capture and sequestration of marine primary producers (including traditional 'blue carbon' plants, microalgae and macroalgae) in the Anthropocene, and, for the first time, assess and compare the potential of various marine primary producers to carbon neutrality and climate change mitigation via biogeoengineering approaches.The contributions of marine primary producers to carbon sequestration have been decreasing in the Anthropocene due to the decrease in biomass driven by direct anthropogenic activities and climate change. The potential of blue carbon plants (mangroves, saltmarshes and seagrasses) is limited by the available areas for their revegetation. Microalgae appear to have a large potential due to their ubiquity but how to enhance their carbon sequestration efficiency is very complex and uncertain. On the other hand, macroalgae can play an essential role in mitigating climate change through extensive offshore cultivation due to higher carbon sequestration capacity and substantial available areas. This approach seems both technically and economically feasible due to the development of offshore aquaculture and a well‐established market for macroalgal products.Synthesis and applications. This paper provides new insights and suggests promising directions for utilizing marine primary producers to achieve the Paris temperature target. We propose that macroalgae cultivation can play an essential role in attaining carbon neutrality and climate change mitigation, although its ecological impacts need to be assessed further. [ABSTRACT FROM AUTHOR]

Despite increasing interest, a lack of comprehensive knowledge regarding the efficient design and implementation of carbon farming schemes remains. These schemes must efficiently achieve higher carbon sequestration, incentivize farmers, and increase farmers' participation in global carbon markets. Our study systematically reviews, describes, and maps available evidence related to carbon farming contracts to assess different incentive mechanisms for carbon farming. We conduct a systematic mapping review of articles extracted from various databases employing the Collaboration for Environmental Evidence method. We shortlist 52 articles and analyze about 40 global case studies, identifying three main incentive mechanisms of carbon farming contracts, namely, result-based, action-based, and hybrid payments. We examine how these incentive mechanisms are designed, in addition to associated payment types, monitoring approaches, and barriers to implementation. Result-based payments include stringent monitoring and can be implemented through auctions, carbon credits, product labels or certificates. Action-based payments are found to be simpler, with lower monitoring requirements for farmers and can be paid upfront or after contract implementation. Hybrid payments combine both techniques, offering low-risk and guaranteed payments for farmers and definite environmental mitigation impacts. Result-based and hybrid payments motivate farmers to innovate to meet environmental objectives while also connecting them to carbon markets. The major challenges to developing a successful carbon farming project include lack of permanence, non-additionality, and the absence of stringent monitoring, reporting, and verification standards, all of which affect farmers' incentives. This study determines that carbon farming contract design and efficiency can be improved by analyzing the lessons learned from previous experiences. By examining and improving the attributes that define different incentive mechanisms, farmers can be better motivated to enroll in carbon farming schemes and benefit from increased access to carbon markets to potentially transform agriculture into a viable tool for climate action. • Systematic mapping reviewed 52 papers, which encompassed 40 global cases. • Three incentive mechanisms: result-based, action-based, and hybrid payments. • Results-based payments: stringent MRV, high risk but high profitability to farmers. • Action-based payments: simple MRV, low risk but low profitability to farmers. • Hybrid payment: low-risk and high profitability; connect farmers to carbon markets. [ABSTRACT FROM AUTHOR]

Despite numerous prior studies regarding public acceptance of climate change mitigation technologies, most academic papers focus on individual technologies in their analyses. Little is known about the acceptance of multiple low-carbon energy technologies. This study bridges this research gap and explores the cross-technology acceptance of various energy solutions at different locations. Thus, we provide a comprehensive understanding of public acceptance patterns by analysing a broader range of technologies concurrently, focusing on: (a) nuclear power, (b) district heating, (c) energy-saving technologies, (d) onshore, nearshore, and offshore wind power (WP), (e) photovoltaics (PV) installed on agricultural land, industrial roofs, and private roofs, and (f) carbon capture and storage (CCS) in offshore, nearshore, rural onshore, and urban onshore locations. Based on Danish nationally representative survey data, our results give strong policy indications that PV on industrial rooftops is accepted at the highest level. In contrast, nuclear power, onshore rural and urban CCS, and nearshore CCS are the least accepted technologies to combat climate change among the Danish public. Additionally, we discover that the acceptance of a specific technology is contingent on locations. Specifically, the public acceptance of PV, WP, and CCS depends on the place of living and the potential location of technology placement. Finally, this study explores subgroup analyses to compare acceptance differences according to gender, age, education, income, and location of residence. [Display omitted] [ABSTRACT FROM AUTHOR]

Agroforestry is land-use systems and technologies where woody perennials are deliberately used on equivalent land management units as crops and/or animals. Its systems combine tree growing with the assembly of different crops or animals. Hence, developing positive ecological and economic interactions between components, agroforestry systems aim to produce a variety of environmental, economic and social advantages to farming communities. It plays a major role in soil conservation and global climate change mitigation particularly due to its tree component. Trees control soil degradation through their roots and accumulate greenhouse emission (GHG) in their biomass. What is more, it conjointly helps in global climate change adaptation. It's a long-time undeniable fact that despite our gift effort at global climate change mitigation (GHG reduction), there is an additional pressing ought to address the impact of global climate change (adaptation). Peoples ought to be acutely aware regarding the scope and advantages of agroforestry and that they ought to participate in the implementation and development of agroforestry within the country. Thus, this paper reviews different analysis findings on the opportunities and challenges for scaling up agroforestry practices. Therefore, the agroforestry system is economically and ecologically sound practices with an improvement of overall farm productivity, soil enrichment through litterfall, maintaining environmental services like international global climate change mitigation (carbon sequestration), phytoremediation, watershed protection and biodiversity conservation. [ABSTRACT FROM AUTHOR]

This paper explores economic opportunities of Opuntia cultivation in Spain regarding fresh food production (comparing production structures of Mexico, Italy and Spain), cactus pear non-food uses (exploiting its bio-functional, medicinal, nutraceutical and cosmetic properties) and environmental issues related to climate change mitigation through soil carbon sequestration. Cactus pear production structures and costs are different in the three countries: Mexico (939.77 €), Italy (4.055.1 €) and Spain (9453.77 €). Spain does not present a real productive sector but only isolated farms. Opuntia is an interesting opportunity for non-food production due to the amount of its bioactive compounds. Main components (μg g−1 dried weight) are: kaempferol (34), myrcetin (65), isorhamnetin and derivatives (590), luteolin (8.4), ferulic acid and derivatives (1,050), and catechin (50). Obtaining these compounds could be a way of increasing cactus pear production profitability and creating jobs and value in rural areas. Cactus pear cultivation is a successful tool to mitigate climate change in arid and semiarid regions considering adequate farm and cultivation practices and systems. This crop is often located in high rurality areas, cultivated by small and micro-farmers. Cactus pear cultivation can be an effective tool for rural development in European arid and semiarid areas regarding production, job creation and environmental issues. • Opuntia is cultivated by micro-farmers in areas of high rurality. • Cactus pear cultivation could be a success to mitigate climate change in arid regions. • Opuntia can be an effective tool for rural development in European arid regions. • Italy presents a developed Opuntia sector and is the model to be followed. [ABSTRACT FROM AUTHOR]

Climate change is not only manifested by high temperatures, but means perverse, cascading effects that must be viewed in interaction. Climate change solutions can not only be cost-effective, but also improve the level and quality of life of the population while protecting the environment. In order to improve the situation, at the moment, the following actions are necessary: reducing emissions, adapting to the effects of climate change and financing the necessary adaptation measures. Photosynthesis, respiration, transpiration, stomatal conductance, assimilation, etc. can be used in the plant breeding process, with the aim of identifying plant genotypes with an increased potential for capturing CO2 from the atmosphere, thus contributing to maintaining the global average temperature within the limits, which would not lead to the intensification of the greenhouse effect and the change of factors climatic. In order to carry out the study, grapevine genotypes of intraspecific origin from the V. vinifera L. and genotypes of interspecific origin (V. vinifera L. x M. rotundifolia Michx.) were used. The measurements were made in the period up to flowering, the formation (growth) of berries and in the period of mature berries (formed). Phytomonitoring was carried out with the help of the PTM-48A monitor, which is an automatic CO2 exchange monitoring system. Studies have shown that the interspecific grapevine genotypes are characterized by much better adaptive features than intraspecific genotypes in relation to climate change. The respective methodology can also be applied in the improvement process of different plant crops. [ABSTRACT FROM AUTHOR]

Perennial vegetables are a neglected and underutilized class of crops with potential to address 21st century challenges. They represent 33–56% of cultivated vegetable species, and occupy 6% of world vegetable cropland. Despite their distinct relevance to climate change mitigation and nutritional security, perennial vegetables receive little attention in the scientific literature. Compared to widely grown and marketed vegetable crops, many perennial vegetables show higher levels of key nutrients needed to address deficiencies. Trees with edible leaves are the group of vegetables with the highest levels of these key nutrients. Individual "multi-nutrient" species are identified with very high levels of multiple nutrients for addressing deficiencies. This paper reports on the synthesis and meta-analysis of a heretofore fragmented global literature on 613 cultivated perennial vegetables, representing 107 botanical families from every inhabited continent, in order to characterize the extent and potential of this class of crops. Carbon sequestration potential from new adoption of perennial vegetables is estimated at 22.7–280.6 MMT CO2-eq/yr on 4.6–26.4 Mha by 2050. [ABSTRACT FROM AUTHOR]

The decline of carbon intensive technologies is a key element in the ongoing energy transition and our attempts to tackle climate change. At the same time, our understanding of technology decline and of the associated policies and politics is still limited. This paper builds on the sustainability transitions perspective, a novel approach to analyze socio‐technical transformation, including the complex interplay of policy and technology change. We study the decline of coal‐fired power generation in the United Kingdom from 2000 to 2017 by analyzing the discourse in The Guardian. We find scientists and environmental NGOs criticizing coal for climate and health reasons. Government and incumbent businesses tried to re‐legitimate coal but eventually, their resistance collapsed and coal was almost completely abandoned in just a few years. Particularly devastating for coal were failed promises around carbon capture and storage, rapid diffusion of wind energy, and pressure from various policies. This study contributes to better understanding the contested nature of decline, and the interplay of discursive struggles, technology change, and public policy in sustainability transitions. [ABSTRACT FROM AUTHOR]

The increasing fossil fuel supply to meet the rapidly growing electricity demand is resulting in rising carbon dioxide (CO2) emissions in Cambodia. The purpose of this paper is to analyze CO2 mitigation options from the power sector under the cleaner supply-side options beyond the Intended Nationally Determined Contribution (INDC) of Cambodia. The Long-range Energy Alternative Planning (LEAP) model is used to analyze the share of electricity generation and CO2 emissions during 2015 to 2050 under four main scenarios, namely Business-as-Usual (BALI), Renewable Energy' (RE), Carbon Capture and Storage (CCS), and Carbon Tax (CT). Results illustrate that in the BAU scenario, electricity generation and CO2 emissions from the power sector would be increased by almost 16 and 42 limes respectively in 2050 when compared io 2015. Results also show with CO2 emission reduction potential of about 32.94% in 2050. The imposition of carbon tax amounting to USD500/tC02 has the highest CO2 emission reduction potential in the power sector when compared with other scenarios. Results depict that except the RE scenarios considering lower shares of solar and biomass, all scenarios would help in attainting the 27% CO2 emission reduction target of Cambodia's INDC by 2030. [ABSTRACT FROM AUTHOR]

Annual carbon estimation of the most diverse ecosystems is a recurring theme in meetings that address climate change mitigation, as it is essential to have a realistic inventory of carbon stock in the biosphere and the ability to assimilate atmospheric carbon. Measurements of CO2 flux over ecosystems after being taken undergo rigorous post-processing to remove spurious and unrealistic data. In addition, a correction for low turbulence situations, where the eddy-covariance technique may be underestimated, is to take the friction velocity (u *) as a threshold to establish valid measurements, especially at night. This method, although widely used by the scientific community, is not unanimous. Especially since u * is itself a flow and consequently its value correlates with the time scale used for the analysis. This paper presents the annual carbon estimate of a natural pasture ecosystem, Pampa biome, in an experimental site established in Santa Maria - RS. We evaluated three distinct situations in the annual carbon estimate (NEP): i) without au * filter; ii) with a fixed filter u * for all evaluated years and; iii) with the filter u * varying seasonally. The methodology used to estimate u * is the same as that used by Papale et al. (2006). The results show a total annual carbon sequestration variability of up to 10% depending on the methodology employed. The ecosystem in question, regardless of the method used, proved to be a carbon sink. However, the use of one methodology or another in ecosystem situations that are close to carbon assimaltion neutral should be closely scrutinized for an accurate annual balance. Pampa biome, in an experimental site established in Santa Maria - RS. We evaluated three distinct situations in the annual carbon estimate (NEP): i) without au * filter; ii) with a fixed filter u * for all evaluated years and; iii) with the filter u * varying seasonally. The methodology used to estimate u * is the same as that used by Papale et al. (2006). The results show a total annual carbon sequestration variability of up to 10% depending on the methodology employed. The ecosystem in question, regardless of the method used, proved to be a carbon sink. However, the use of one methodology or another in ecosystem situations that are close to carbon assimaltion neutral should be closely scrutinized for an accurate annual balance. Pampa biome, in an experimental site established in Santa Maria - RS. We evaluated three distinct situations in the annual carbon estimate (NEP): i) without au * filter; ii) with a fixed filter u * for all evaluated years and; iii) with the filter u * varying seasonally. The methodology used to estimate u * is the same as that used by Papale et al. (2006). The results show a total annual carbon sequestration variability of up to 10% depending on the methodology employed. The ecosystem in question, regardless of the method used, proved to be a carbon sink. However, the use of one methodology or another in ecosystem situations that are close to carbon assimaltion neutral should be closely scrutinized for an accurate annual balance. We evaluated three distinct situations in the annual carbon estimate (NEP): i) without au * filter; ii) with a fixed filter u * for all evaluated years and; iii) with the filter u * varying seasonally. The methodology used to estimate u * is the same as that used by Papale et al. (2006). The results show a total annual carbon sequestration variability of up to 10% depending on the methodology employed. The ecosystem in question, regardless of the method used, proved to be a carbon sink. However, the use of one methodology or another in ecosystem situations that are close to carbon assimaltion neutral should be closely scrutinized for an accurate annual balance. We evaluated three distinct situations in the annual carbon estimate (NEP): i) without au * filter; ii) with a fixed filter u * for all evaluated years and; iii) with the filter u * varying seasonally. The methodology used to estimate u * is the same as that used by Papale et al. (2006). The results show a total annual carbon sequestration variability of up to 10% depending on the methodology employed. The ecosystem in question, regardless of the method used, proved to be a carbon sink. However, the use of one methodology or another in ecosystem situations that are close to carbon assimaltion neutral should be closely scrutinized for an accurate annual balance. The methodology used to estimate u * is the same as that used by Papale et al. (2006). The results show a total annual carbon sequestration variability of up to 10% depending on the methodology employed. The ecosystem in question, regardless of the method used, proved to be a carbon sink. However, the use of one methodology or another in ecosystem situations that are close to carbon assimaltion neutral should be closely scrutinized for an accurate annual balance. The methodology used to estimate u * is the same as that used by Papale et al. (2006). The results show a total annual carbon sequestration variability of up to 10% depending on the methodology employed. The ecosystem in question, regardless of the method used, proved to be a carbon sink. However, the use of one methodology or another in ecosystem situations that are close to carbon assimaltion neutral should be closely scrutinized for an accurate annual balance. [ABSTRACT FROM AUTHOR]

There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international '4p1000' initiative and the FAO's Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long‐term experiments and space‐for‐time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils. [ABSTRACT FROM AUTHOR]

Terrestrial ecosystems store more carbon (C) than the atmosphere and provide ecosystem services (ES) such as global climate regulation, by sequestering carbon within biomass and soil. Land use land cover (LULC) change is considered a key factor, playing an important role in the dynamic variations of carbon storage. The aim of this paper is to assess the effects that LULC has had on carbon stocks and consequently on climate change regulation in north-western Morocco over 21 years. To achieve this aim, the Integrated Valuation of ES and Trade-offs (InVEST) model is used to assess status and variation in the net amount of carbon stored by the different types of LULC, and the economic value of the carbon sequestered in the remaining stock. The results show that the total carbon stock increased from 4.81TgC in 1996 to 4.98TgC in 2017. Over the 21 years, the LULC changes had the greatest effect on carbon storage - an increase of 6.87% with 0.17TgC of carbon sequestered, since the majority of unused land was changed to forest and cultivated land. Based on the global costs of atmospheric carbon, we estimate the economic value of carbon storage services to be between US$1,800,000 and US$3,570,000 for the whole period, with an average yearly increment of between US$86,000 and US$170,000. The results show that the ecosystem management has had a substantial climate mitigation effect. Also, the possibility of paying for ES could inform policy on the adoption of LULC to support livelihood and management choices. [ABSTRACT FROM AUTHOR]

Regulating ecosystem services provided by urban forests are of great importance for the quality of life among city dwellers. To reach a maximum contribution to well-being in cities, the urban regulating ecosystem services (URES) must match with the demands in terms of space and time. If we understand the matches or mismatches between the current urban dwellers’ desired quality conditions (demand) and the supply of URES by urban forests (UF) in the cities, this will facilitate integrating the concepts of ecosystem services in urban planning and management, but such an assessment has suffered from major knowledge limitations. Since it is complex and problematic to identify the direct demands for URES and the spatiotemporal patterns therein, improving the demand indicators can help to determine the actual requirements. In this paper, a methodological approach based on indicators is presented and demonstrated for two important URES: air quality improvement and global climate change mitigation provided by urban trees and shrubs. Four air quality standards and greenhouse gas reduction targets were used and compared to supplies of the URES in Tabriz, Iran. Our results show that the mean contribution of the URES supply to air quality standards and greenhouse gas reduction targets is modest. Hence, in Tabriz, there is a strong mismatch between demand and supply. Mismatches at the city scale will have to be reduced by both a reduction in pollutant emissions and an increased provisioning of URES supply through urban greenery. The presented assessment approach and the results for Tabriz make it explicit how different the demands and supplies of the two studied URES are, and we expect similar mismatches in many other cities. Therefore, our approach, relatively simple but still realistic and easy-to-apply, can raise awareness about, and the utility of, the ecosystem services concepts for urban planning and policymaking. [ABSTRACT FROM AUTHOR]

Highlights • LAC GHG efficiency in agricultural sector using within and across country metrics. • 5 Countries offset agriculture emissions with land-use-related carbon sequestration. • Small Caribbean island-states report the worst-case decoupling elasticity scenario. • Top decoupling countries are not equivalent to high factor productivity countries. Abstract The paper explores the relationship between production and greenhouse gas (GHG) emissions in the agricultural sector of Latin America and the Caribbean (LAC) between 1990 and 2015. By appraising how GHG emissions have changed with respect to agricultural production (elasticity), we are able to classify countries into six decoupling states. While the decoupling elasticity provides information for assessing the evolution within countries, we introduce a performance ratio for country comparison by calculating GHG emissions over agricultural production for 2015 and using the global distribution as benchmark. The information from both measurements serves to identify various country and sub regional situations. The findings illustrate that countries with performance ratios in the top 25% and under the best-case elasticity scenario (of strong decoupling) are not necessarily the same as the ones usually identified under factor productivity analyses, suggesting that environment-specific policy incentives and tools play a key role in enhancing sustainable agricultural production. Another major finding is that very few countries in the region (and worldwide) are able to offset agriculture emissions with land use-related carbon sequestration practices. Lastly, the evidence on small Caribbean island-states reporting the worst-case elasticity scenario (of strong negative decoupling) and performance ratios close to the world median, further supports the need for development plans related to climate change mitigation and adaptation in this sub region. [ABSTRACT FROM AUTHOR]

The effects of tillage on soil properties, crop productivity, and global greenhouse gas emissions have been discussed in the last decades. Global ecosystem models have limited capacity to simulate the various effects of tillage. With respect to the decomposition of soil organic matter, they either assume a constant increase due to tillage or they ignore the effects of tillage. Hence, they do not allow for analysing the effects of tillage and cannot evaluate, for example, reduced tillage or no tillage (referred to here as "no-till") practises as mitigation practices for climate change. In this paper, we describe the implementation of tillage-related practices in the global ecosystem model LPJmL. The extended model is evaluated against reported differences between tillage and no-till management on several soil properties. To this end, simulation results are compared with published meta-analyses on tillage effects. In general, the model is able to reproduce observed tillage effects on global, as well as regional, patterns of carbon and water fluxes. However, modelled N fluxes deviate from the literature values and need further study. The addition of the tillage module to LPJmL5 opens up opportunities to assess the impact of agricultural soil management practices under different scenarios with implications for agricultural productivity, carbon sequestration, greenhouse gas emissions, and other environmental indicators. [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]

Reforesting and managing ecosystems have been proposed as ways to mitigate global warming and offset anthropogenic carbon emissions. The intent of our opinion piece is to provide a perspective on how well plants and ecosystems sequester carbon. The ability of individual plants and ecosystems to mine carbon dioxide from the atmosphere, as defined by rates and cumulative amounts, is limited by laws of physics and ecological principles. Consequently, the rates and amount of net carbon uptake are slow and low compared to the rates and amounts of carbon dioxide we release by fossil fuels combustion. Managing ecosystems to sequester carbon can also cause unintended consequences to arise. In this paper, we articulate a series of key take‐home points. First, the potential amount of carbon an ecosystem can assimilate on an annual basis scales with absorbed sunlight, which varies with latitude, leaf area index and available water. Second, efforts to improve photosynthesis will come with the cost of more respiration. Third, the rates and amount of net carbon uptake are relatively slow and low, compared to the rates and amounts and rates of carbon dioxide we release by fossil fuels combustion. Fourth, huge amounts of land area for ecosystems will be needed to be an effective carbon sink to mitigate anthropogenic carbon emissions. Fifth, the effectiveness of using this land as a carbon sink will depend on its ability to remain as a permanent carbon sink. Sixth, converting land to forests or wetlands may have unintended costs that warm the local climate, such as changing albedo, increasing surface roughness or releasing other greenhouse gases. We based our analysis on 1,163 site‐years of direct eddy covariance measurements of gross and net carbon fluxes from 155 sites across the globe. The ability of individual plants and ecosystems to mine carbon dioxide from the atmosphere, as defined by rates and cumulative amounts, is limited by laws of physics and ecological principles. Consequently, the rates and amount of net carbon uptake are slow and low compared to the rates and amounts of carbon dioxide we release by fossil fuels combustion. [ABSTRACT FROM AUTHOR]

The Government of Botswana has pledged a nationally determined contribution (NDC) as a commitment to the Paris Agreement. For the power sector, the NDC states that the government expects renewable energy (RE) to meet 25% of peak electricity demand by 2030. However, due to high initial cost of RE technologies, the government plans to maintain a coal-based power system in the future. Therefore, the purpose of this paper is to examine Botswana's national plan from an economic perspective, using scenario and cost analysis, to explore the possibility of the power sector's low carbon transition in the light of Botswana's NDC. Five scenarios are designed to reflect a range of investment cost changes of RE technologies. While most scenarios only achieve 19% (P3, P4 and P5) and 54% (P6) of the NDC's power sector target, the P7 scenario far exceeds the goal by achieving 188% of the NDC target. Furthermore, as the difference of levelized cost of electricity among the scenarios is minimal, the P7 scenario is the most attractive pathway for the government. Even for other scenarios, the government should still deploy the suggested capacity of solar photovoltaic (PV) as it is both economically and socially beneficial in the long term. However, in these cases, the government's political will to meet the NDC's power sector target and to promote the solar PV industry will be critical in designing future power sector policies. [ABSTRACT FROM AUTHOR]

This paper provides pathways of the carbon content of electricity extracted from the Intergovernmental Panel on Climate Change’s fifth Assessment Report scenarios database. It demonstrates three policy-relevant aspects of the carbon content of electricity that are implicit in most integrated assessment model results but under-discussed in academia and the policy debate. First, climate stabilization at any level from 1.5 °C to 3 °C requires the carbon content of electricity to decrease quickly and become almost carbon-free before the end of the century. As such, the question for policy makers is not whether to decarbonize electricity but when and how to do so. Second, decarbonization of electricity is still possible and required if some of the key zero-carbon technologies—such as nuclear power or carbon capture and storage—turn out to be unavailable. Third, progressive decarbonization of electricity is part of every country’s cost-effective means of contributing to climate stabilization. The pathways of the carbon content of electricity reported here can be used to benchmark existing decarbonization targets, such as those set by the European Energy Roadmap or inform new policies in other countries. They can also be used to assess the desirable uptake rates of electric and plug-in hybrid vehicles, electric stoves and heat pumps, industrial electric furnaces, or other electrification technologies. [ABSTRACT FROM AUTHOR]

The effective implementation of sustainable forest management depends largely on carrying out forest operations in a sustainable manner. Climate change, as well as the increasing demand for forest products, requires a re-thinking of forest operations in terms of sustainability. In this context, it is important to understand the major driving factors for the future development of forest operations that promote economic, environmental and social well-being. The main objective of this paper is to identify important issues concerning forest operations and to propose a new paradigm towards sustainability in a changing climate, work and environmental conditions. Previously developed concepts of forest operations are reviewed, and a newly developed concept – Sustainable Forest Operations (SFO), is presented. Five key performance areas to ensure the sustainability of forest operations include: (i) environment; (ii) ergonomics; (iii) economics; (iv) quality optimization of products and production; and (v) people and society. Practical field examples are presented to demonstrate how these five interconnected principles are relevant to achieving sustainability, namely profit and wood quality maximization, ecological benefits, climate change mitigation, carbon sequestration, and forest workers' health and safety. The new concept of SFO provides integrated perspectives and approaches to effectively address ongoing and foreseeable challenges the global forest communities face, while balancing forest operations performance across economic, environmental and social sustainability. In this new concept, we emphasize the role of wood as a renewable and environmentally friendly material, and forest workers' safety and utilization efficiency and waste management as additional key elements of sustainability. [ABSTRACT FROM AUTHOR]

The “4 per Thousand” initiative was launched at the 21st Conference of Parties (COP21) in December 2015 to address global climate change through the aspirational goal of increasing soil organic carbon (SOC) stock of the world to 40-cm depth by an average annual rate of 4%. Small landholders (SLHs), often faced with difficult bio-physical and socio-economic conditions, are the principal managers of soil in India. There are 117 million SLHs representing 85% of the total operational holdings, cultivating over 72 million ha of land, and meeting 50–60% of India's food requirement. The agricultural soils of SLHs are strongly depleted of SOC and nutrient reserves. Therefore, the challenge of feeding 1.7 billion people in India by 2050 will depend on increasing the current productivity levels by restoring the depleted soils of SLHs. According to our estimates, soils of SLHs currently contain 1370–1770 Tg C and, which can be increased to 2460–2650 Tg C by 2050 through large-scale adoption of best management practices (BMPs) including balanced application of nutrients, compost, agroforestry, and conservation agriculture. A wide spread adoption of these practices can enhance C sequestration by 70–130 Tg CO 2 e per annum and produce 410–440 million Mg of food grains accounting for 80–85% of the total requirement by 2050. In this paper we propose strategies for achieving the dual objectives of advancing food security, the “4 per Thousand” target and mitigating climate change in India. [ABSTRACT FROM AUTHOR]

Besides being an opportunity to valorize biomass residues, biochar (i.e., the solid product of biomass pyrolysis) has many potential environmental benefits, such as climate change mitigation and reduced nutrient leaching. Even though the academic interest in biochar has increased, it is not being used at a large scale yet, mainly because of its economic infeasibility compared to fertilizers and because farmers are either unaware of or skeptical about its effects. In this paper, the economics of biochar are examined by performing a systematic review, following the guidelines of the Collaboration for Environmental Evidence. Specifically, it has been examined to which extent the production and application of biochar are yet profitable from an investor's perspective and desirable from a societal perspective. For the first time, this review investigates the extent to which previous studies have included external costs and benefits. We find that profitability and desirability of biochar production and use are highly uncertain and case-specific, depending on factors like location, feedstock, scale, pyrolysis conditions, biochar price, cultivated crop, and the potential internalization of externalities, which hampers private investment. To advance biochar development and deployment, those factors must be considered carefully for each case. Although externalities are included in the literature to some extent, the focus is mostly on external benefits rather than external costs, often focusing on its carbon sequestration potential. The inclusion of externalities in economic assessments is necessary to provide solid arguments to develop policies for the acceleration of market uptake of biochar technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • Key CCUS technologies are comprehensively reviewed in terms of the technology readiness level (TRL). • Critical limitations of implementing industrial CCUS system elements are identified. • Unique data for the CCUS facilities, and latest global R&D projects are summarized. • Crucial need to establish CCUS worldwide databases of the most recent research is highlighted. • Future outlook for CCUS is suggested. The latest tremendously rapid expansion of the energy and industrial sector has led to a sharp increase in stationary sources of CO 2. Consequently, a lot of concerns have been raised about the prevention of global warming and the achievement of climate mitigation strategies by 2050 with a low-carbon and sustainable future. In view of this, the current state of various aspects of carbon capture, utilization, and storage (CCUS) technologies in general technical assessment were concisely reviewed and discussed. We concentrated on precisely identifying the technology readiness level (TRL), which is beneficial to specifically defining the maturity for each key element of the CCUS system with a commercialization direction paths. In addition, we especially presented and emphasized the importance of CO 2 capture types from flue gases and CO 2 separation methods. Then, we determined valuable data from the largest R&D projects at various scales. This paper provides a critical review of the literature related to challenges of the CCUS system that must be overcome to raise many low TRL technologies and facilitate their implementation on a commercial scale. Finally, our work aims to guide the further scaling up and establishment of worldwide CO 2 emission reduction projects. [ABSTRACT FROM AUTHOR]

The world's energy needs have been continually growing over the past decade, yet fossil fuels are limited. Renewable energies are becoming more prevalent, but are still a long way from being commonplace worldwide. Literature mining is applied to review carbon capture and storage (CCS) development trends and to develop and examine a novel carbon capture and storage technological paradigm (CCSTP), which incorporates CCSTP competition, diffusion and shift. This paper first provides an overview of the research and progress in CCS technological development, then applies a techno-paradigm theory to analyze CCSTP development and to provide a guide for future CCS technological trends. CCS could avoid CO2 being released into the atmosphere. Moreover, bioenergy with CCS (BECCS) can make a significant contribution to a net removal of anthropogenic CO2 emissions. In this study, we compare the different CCSTP developmental paths and the conventional techno-paradigm by examining the S-curves. The analyses in this paper provide a useful guide for scholars seeking new inspiration in their research and for potential investors who are seeking to invest research funds in more mature technologies. We conclude that political barriers and public acceptance are the major distinctions between the CCSTP and the conventional techno-paradigm. It is expected that policy instruments and economic instruments are going to play a pivotal role in the accomplishment of global carbon reduction scenarios. [ABSTRACT FROM AUTHOR]

In this paper, a model for the distribution of the Global Carbon Budget between the countries of the world is presented. The model is based on the criteria of equity while also taking into account the different historical responsibilities. The Global Carbon Budget corresponds to the quantity of carbon dioxide emissions that can still be released into the atmosphere while maintaining the increase in the average earth surface temperature below 2 °C, and it is therefore compatible with the long-term objective defined in the Paris Agreement. The results of applying the model are shown both for the 15 emitters that currently top the ranking for world emissions as well as for the other countries, which are grouped together in three main groups: Other African, Other Latin American and Caribbean, and the Rest of the World. Mitigation curves compatible with the carbon budget allocated to the different countries are presented. When comparing each emitter’s historical emissions for the period 1971-2010 with the proposed distribution for the period 2011-2050 obtained using the model, it can be seen that developed countries must face the future with a greatly reduced carbon budget, whereas developing countries can make use of a carbon budget that is higher than their cumulative historical emissions. Finally, there is a discussion about how a model with these characteristics could be useful when implementing the Paris Agreement. [ABSTRACT FROM AUTHOR]

Combatting climate change has risen to the top of the international policy discourse. Effective governance necessitates the generation of concise information on the costs-effectiveness of policy instruments aimed at reducing atmospheric greenhouse gas (GHG) emissions. The marginal abatement cost curve (MACC) approach is a framework commonly used to summarise information of potential mitigation effort, and can help in identifying the most cost-effective managerial and technological GHG mitigation options. Agriculture offers key opportunities to mitigate GHG emissions and utilise carbon (C) sink potentials. Therefore, a number of countries have developed national agricultural MACCs in the last decade. Whilst these MACCs have undoubtedly been catalysers for the information exchange between science and policy, they have also accentuated a range of constraints and limitations. In response, each of the scientific teams developed solutions in an attempt to address one or more of these limitations. These solutions represent ‘lessons learned’ which are invaluable for the development of future MACCs. To consolidate and harness this knowledge that has heretofore been dispersed across countries, this paper reviews the engineering agricultural MACCs developed in European countries. We collate the state-of-the-art, review the lessons learnt, and provide a more coherent framework for countries or research groups embarking on a trajectory to develop an agricultural MACC that assesses mitigations both within the farm gate and to the wider bioeconomy. We highlight the contemporary methodological developments, specifically on 1) the emergence of stratified MACCs; 2) accounting for soil carbon sequestration 3) accounting for upstream and downstream emissions; 4) the development of comprehensive cost-calculations; 5) accounting for environmental co-effects and 6) uncertainty analyses. We subsequently discuss how the mitigation potential summarised by MACCs can be incentivised in practice and how this mitigation can be captured in national inventories. We conclude that the main purpose of engineering MACCs is not necessarily the accurate prediction of the total abatement potential and associated costs, but rather the provision of a coherent forum for the complex discussions surrounding agricultural GHG mitigation, and to visualise opportunities and low-hanging fruit in a single graphic and manuscript. [ABSTRACT FROM AUTHOR]

This paper provides a perspective for comparing trade-offs between harvested wood flows and forest carbon stocks with different forest management regimes. A constant management regime applied to a forest area with an even age-class distribution leads to a steady state, in which the annual harvest and carbon stocks remain constant over time. As both are desirable – carbon stocks for mitigating climate change and harvests for the economic use of wood and displacing fossil fuels – an ideal strategy should be chosen from a set of management regimes that are Pareto-optimal in the sense of multi-criteria decision-making. When choosing between Pareto-optimal alternatives, the trade-off between carbon stock and harvests is unavoidable. This trade-off can be described e.g. in terms of carbon payback times or carbon returns. As numerical examples, we present steady-state harvest levels and carbon stocks in a Finnish boreal forest region for different rotation periods, thinning intensities and collection patterns for harvest residues. In the set of simulated management practices, harvest residue collection presents the most favorable trade-off with payback times around 30–40 years; while Pareto-optimal changes in rotation or thinnings exhibited payback times over 100 years, or alternatively carbon returns below 1%. By extending the rotation period and using less-intensive thinnings compared to current practices, the steady-state carbon stocks could be increased by half while maintaining current harvest levels. Additional cases with longer rotation periods should be also considered, but were here excluded due to the lack of reliable data on older forest stands. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) has been established as a viable technology for the mitigation of climate change caused mainly by anthropogenic greenhouse gas emissions into the atmosphere. Ever since the publication of the special report on CCS by the Intergovernmental Panel on Climate Change in 2005, there has been an increased research and development in all areas of CCS. Some of these research involves use of numerical methods and models for optimizing storage and ensuring effective long term containment. In this paper, we propose a workflow for building and calibrating 3D preinjection and 4D geomechanics modelling to assess caprock and fault integrity for geologic carbon dioxide storage. The workflow presented here describes a seamless end-to-end process which combines a transparent flow of data with an easy-to-use graphical user interface. The workflow can conduct 3D static and 4D flow-, pressure-, and temperature-coupled calculations for rock deformations, failure and stresses. In highly heterogeneous and complex models, the workflow is capable of modelling multiple hundred faults, and multiple thousand discrete fractures. It allows the geological model, despite its high degree of complexity to be maintained throughout the geomechanical analyses process. [ABSTRACT FROM AUTHOR]

Increasing soil organic carbon (SOC) stocks in agricultural soils removes carbon dioxide from the atmosphere and contributes towards achieving carbon neutrality. For farmers, higher SOC levels have multiple benefits, including increased soil fertility and resilience against drought-related yield losses. However, increasing SOC levels requires agricultural management changes that are associated with costs. Private soil carbon certificates could compensate for these costs. In these schemes, farmers register their fields with commercial certificate providers who certify SOC increases. Certificates are then sold as voluntary emission offsets on the carbon market. In this paper, we assess the suitability of these certificates as an instrument for climate change mitigation. From a soils' perspective, we address processes of SOC enrichment, their potentials and limits, and options for cost-effective measurement and monitoring. From a farmers' perspective, we assess management options likely to increase SOC, and discuss their synergies and trade-offs with economic, environmental and social targets. From a governance perspective, we address requirements to guarantee additionality and permanence while preventing leakage effects. Furthermore, we address questions of legitimacy and accountability. While increasing SOC is a cornerstone for more sustainable cropping systems, private carbon certificates fall short of expectations for climate change mitigation as permanence of SOC sequestration cannot be guaranteed. Governance challenges include lack of long-term monitoring, problems to ensure additionality, problems to safeguard against leakage effects, and lack of long-term accountability if stored SOC is re-emitted. We conclude that soil-based private carbon certificates are unlikely to deliver the emission offset attributed to them and that their benefit for climate change mitigation is uncertain. Additional research is needed to develop standards for SOC change metrics and monitoring, and to better understand the impact of short term, non-permanent carbon removals on peaks in atmospheric greenhouse gas concentrations and on the probability of exceeding climatic tipping points. Overview of the challenges associated with using soil carbon certificates as privately traded, voluntary emission offsets. [Display omitted] • Soil-based carbon certificates are sold as voluntary emission offsets. • Private certification schemes provide financial incentives for carbon farming. • However, they are not a suitable tool for climate change mitigation. • Permanence, additionality and monitoring are not ensured; leakage effects may occur. • Accountability in case of re-emissions of stored carbon is low. [ABSTRACT FROM AUTHOR]