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Agriculture contributes to global climate change by producing 20–25% of greenhouse gases (GHGs). CO 2 is released from deforestation and land conversion, methane from rice paddy fields, and nitrous oxides from overfertilization. An increasing world population requires a change in the agro food systems, including a reduction in chemical fertilizers and pesticides as well as the production and access to food. Greenhouse gas (GHG) emissions have created a global climate crisis which requires immediate interventions to mitigate the negative effects on all aspects of life on this planet. As current agriculture and land use contributes up to 25% of total GHG emissions, plant scientists take center stage in finding possible solutions for a transition to sustainable agriculture and land use. In this article, the PlantACT! (Plants for climate ACTion!) initiative of plant scientists lays out a road map of how and in which areas plant scientists can contribute to finding immediate, mid-term, and long-term solutions, and what changes are necessary to implement these solutions at the personal, institutional, and funding levels. [ABSTRACT FROM AUTHOR]

Cocoa production is a leading driver of deforestation in the humid-tropics of West Africa. Reconciling climate change mitigation with livelihoods of farmers requires identification of production strategies to concurrently improve yield and profit while curtailing emissions of greenhouse gases (GHG). Using a 2021 plot-survey conducted in Ghana's Eastern region, we evaluated yields, GHG emissions, and value of production (VOP) (a profit indicator) across a typology representing the diversity of systems at plot-level. The typology was constructed by first stratifying plots according to shade levels and variety (hybrid vs. Amazonia) which resulted in three systems: Hybrid sun , hybrid variety under full-sun (little to no shade); Hybrid shade , hybrid and moderate shade (13–25 shade trees ha−1); and Amazonia, Amazonia under predominantly moderate shade. Next, factor analysis and clustering were used to group plots within each system according to cocoa yield, vegetation, management, and (local) climate conditions. Cluster analysis showed that fertiliser, weeding, pruning, hand pollination, cocoa tree density, and shade tree densities of differing heights were most influential for determination across systems. Hybrid shade had the highest net GHG removal rate at −6.8 ± 1.7 (± 95% CI) Mg CO 2 eq ha−1 yr−1: 48% and 127% higher (emissions more negative) respectively over Amazonia and Hybrid sun. Hybrid shade additionally had the highest average and least variable VOP among production systems at 669 ± 564 USD ha−1 yr−1, compared to Hybrid sun and Amazonia at 404 ± 442 and 213 ± 280 USD ha−1 yr−1 respectively. These results point to hybrid cocoa grown under moderate shade of 13–25 shade trees ha−1 as optimal for reconciling climate change mitigation with development in West African cocoa. • Study concurrently evaluates financial profits and GHG balances (N 2 O & CH 4 emissions, CO 2 removals) in West African cocoa. • Plot-level indicators are evaluated across a typology obtained from sample-stratification and clustering. • Hybrid cocoa under moderate shade (13-25 shade trees ha-1) had GHG removal increment of 127% over same variety without shade. • This system too had higher mean profits, thus best reconciling GHG mitigation and economic development for the region. [ABSTRACT FROM AUTHOR]

The continuous rise in global temperatures is an evidence of climate change. CO 2 emissions have caused major problems owing to its contribution to climate change. In particular, the construction industry has a considerable carbon footprint. Therefore, investigations into climate change mitigation are indeed a priority. All steps in the construction process, from raw materials preparation to cement production, contribute to CO 2 emissions. This can be mitigated to a certain extent by incorporating bio-based constituents into construction materials. However, bio-based materials may negatively affect cement reaction and structural performance, despite their positive environmental impacts. Biochar, a carbon-rich product of biomass pyrolysis, is considered a potential substitute for cement replacement that can enhance structural properties if used in appropriate amounts. Although biochar has conventionally been used as a soil amendment in the agricultural industry, researchers have recently investigated its applicability in concrete. Importantly, the results thus far have reported its contribution to the enhancement of the mechanical, thermal, and physical properties of cement. This review provides a comprehensive overview of the physicochemical properties of biochar added cementitious materials, including the fresh and hardened properties of biochar-cement mixtures considering both environmental and economic aspects. • The structure of biochar exhibits excellent compatibility with the cement matrix. • Biochar addition can modify the physical and mechanical properties. • Biochar improves concrete durability, sequesters carbon, and mitigates climate change. • Biochar can be used for carbon sequestration in cement applications. • Economic benefits of biochar-cement composites are not well elaborated in the literature. [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 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]

Agriculture represents about 11% of global anthropogenic greenhouse gas emissions (GHGe). Many climate change mitigation strategies have been evaluated in Mediterranean agroecosystems, including their soil organic carbon sequestration potential. High residue yielding old varieties could constitute a useful alternative, especially for organic farming, which lacks specific genetic material. In this study, old and modern wheat varieties were evaluated under organic (ORG) and conventional (CON) management during a 3-year field experiment under rainfed Mediterranean conditions. Field measurements of biomass components, literature emission factors, and soil organic carbon modeling were combined in an attributional Life Cycle Assessment, in order to estimate GHGe from “cradle to farm gate”. The resulting yield-based carbon footprints of old wheat varieties were significantly lower than those of modern varieties both under CON management, decreasing from 263 to 144 g CO 2 e kg −1 , and under ORG management, decreasing from 29 to −43 g CO 2 e kg −1 . Our results indicate that climate change mitigation strategies in Mediterranean rainfed cereal cropping systems should focus on diminishing GHGe from machinery and fertilizer use, and promoting carbon sequestration. The combination of organic management and old cereal varieties can constitute a promising climate change mitigation strategy in these systems, as low area-scaled GHGe of organic management are combined with enhanced carbon sequestration and a good yield performance of old varieties under these conditions. [ABSTRACT FROM AUTHOR]

Policymakers and businesses in Southeast Asia are increasingly interested in using carbon markets to encourage adoption of regenerative agriculture practices by farmers. These practices are thought to mitigate climate change by reducing soil carbon loss and enhancing soil carbon sequestration. However, there is uncertainty in the ability of regenerative agriculture practices to increase soil organic carbon (SOC) stocks of croplands. We reviewed 92 empirical studies that investigated the effects of 17 regenerative farming practices across 11 broad categories of crops on SOC stock or content in Southeast Asia. Our synthesis found supporting evidence for the use of organic amendments like biochar, compost, and manure, as well as cover cropping, crop rotation, and conservation tillage to increase SOC. However, studies for practices like addition of compost and manure reported increases in greenhouse gas emissions like methane (CH 4) and nitrous oxide (N 2 O), demonstrating that increases in SOC may be offset by increases in greenhouse gas emissions. Only a few studies measured both the changes in SOC stocks and greenhouse gas emissions and none of the studies completed full greenhouse gas inventories. Estimating the net impact of SOC gains and increase of greenhouse gas emissions will be necessary to understand the overall effect of practices like compost, manure and crop residue incorporation on net atmospheric greenhouse gas concentrations. If these practices are implemented for soil carbon projects, practitioners should anticipate increases in greenhouse gas emissions from soils and implement additional practices, such as alternate wetting and drying, to optimize the climate change mitigation effects of regenerative agriculture. We encourage future research on practices, such as agroforestry and changes in crop residue management, where there are few studies and little variation in experimental design and environmental conditions. Given the interest in scaling up regenerative agriculture through voluntary carbon markets to boost SOC stocks in croplands, policymakers and businesses can support research in this area by making field-collected data from their projects accessible to researchers to further the study of the impact of these practices across different abiotic conditions and soil managements. This data sharing would alleviate the paucity and improve the quality of empirical data on regenerative agricultural practices in Southeast Asian croplands, facilitate practice-specific meta-analyses, and help to optimize climate change mitigation effects of regenerative agriculture. • Regenerative agriculture practices can increase soil carbon in Southeast Asia. • These practices can also increase cropland greenhouse gas emissions like methane. • More empirical data is needed to quantify the practices' effects on soil carbon [ABSTRACT FROM AUTHOR]

Wood and other bio-based building materials are often perceived as a good choice from a climate mitigation perspective. This article compares the life cycle assessment of the same multi-residential building from the perspective of 16 countries participating in the international project Annex 72 of the International Energy Agency to determine the effects of different datasets and methods of accounting for biogenic carbon in wood construction. Three assessment methods are herein considered: two recognized in the standards (the so-called 0/0 method and −1/+1 method) and a variation of the latter (−1/+1* method) used in Australia, Canada, France, and New Zealand. The 0/0 method considers neither fixation in the production stage nor releases of biogenic carbon at the end of a wood product's life. In contrast, the −1/+1 method accounts for the fixation of biogenic carbon in the production stage and its release in the end-of-life stage, irrespective of the disposal scenario (recycling, incineration or landfill). The −1/+1 method assumes that landfills offer only a temporary sequestration of carbon. In the −1/+1* variation, landfills and recycling are considered a partly permanent sequestration of biogenic carbon and thus fewer emissions are accounted for in the end-of-life stage. We examine the variability of the calculated life cycle-based greenhouse gas emissions calculated for a case study building by each participating country, within the same assessment method and across the methods. The results vary substantially. The main reasons for deviations are whether or not landfills and recycling are considered a partly permanent sequestration of biogenic carbon and a mismatch in the biogenic carbon balance. Our findings support the need for further research and to develop practical guidelines to harmonize life cycle assessment methods of buildings with bio-based materials. [Display omitted] • Life cycle assessments of the same multi-residential building were carried out by experts from 16 countries. • Effects of methods and datasets of biogenic carbon accounting in wood construction were identified. • Different end-of-life scenarios (incineration, landfill, recycling) cause variations in the results. • Different interpretations of the permanence of storing biogenic carbon in landfills also cause variations in the results. • The input and output flows of biogenic carbon must be balanced to correctly assess its climate change impacts. [ABSTRACT FROM AUTHOR]

Crop production and soil fertility management implies a multitude of decisions and activities on crop choice, rotation design and nutrient management. In practice, the choices to be made and the resulting outcomes are subject to a wide range of objectives and constraints. Objectives are economic as well as environmental, for instance sequestering carbon in agricultural soils or reducing nitrogen losses. Constraints originate from biophysical and institutional conditions that may restrict the possibilities for choosing crops or using specific cultivation and fertilization practices. To explore the consequences of management interventions to increase the supply of organic C to the soil on income and N losses, we developed the linear programming model NutMatch. The novelty of the model is the coherent description of mutual interdependencies amongst a broad range of sustainability indicators related to soil fertility management in arable cropping, enabling the quantification of synergies and trade-offs between objectives. NutMatch was applied to four different crop rotations subjected to four fertiliser strategies differing in the use of the organic fertilisers cattle slurry, pig slurry or compost, next to mineral fertiliser. Each combination of rotation and fertiliser strategy contributed differently to financial return, N emissions and organic matter inputs into the soil. Our model calculations show that, at the rotational level, crop residues, cattle slurry and compost each substantially contributed to SOC accumulation (range 200-450 kg C ha -1 yr -1 ), while contributions of pig slurry and cover crops were small (20-50 kg C ha -1 yr -1 ). The use of compost and pig slurry resulted in increases of 0.61-0.73 and 3.15-3.38 kg N 2 O-N per 100 kg extra SOC accumulated, respectively, with the other fertilizers taking an intermediate position. From a GHG emission perspective, the maximum acceptable increase is 0.75 kg N 2 O-N per 100 kg extra SOC accumulated, which was only met by compost. Doubling the winter wheat area combined with the cultivation of cover crops to increase SOC accumulation resulted in a net GHG emission benefit, but was associated with a financial trade-off of 2.30-3.30 euro per kg SOC gained. Our model calculations suggest that trade-offs between C inputs and emissions of greenhouse gases (notably N 2 O) or other pollutants (NO 3 , NH 3 ) can be substantial. Due to the many data from a large variety of sources incorporated in the model, the trade-offs are uncertain. Our model-based explorations provide insight in soil carbon sequestration options and their limitations vis-a-vis other objectives. [ABSTRACT FROM AUTHOR]

Pastoral farming systems have always adapted to the seasonal availability of forage resources and climate variability by moving animals. However, the role of animal mobility as a possible mitigating strategy in response to climate change has not been clearly documented. To understand this role, we investigated (i) the major methodological challenges linked to the diversity of grazing areas and other forage resources exploited by these systems and enteric emissions of methane; (ii) the impacts of grazing practices (carbon sequestration/emission) on soil and biomass carbon fluxes. We developed an approach based on two existing models (OSTRAL: Outil de Simulation du TRoupeau ovin ALlaitant and CASA: Carnegie Ames Stanford Approach) that we adapted and used in combination. This approach was applied to three French Mediterranean sheep and crop farming systems with different degrees of flock mobility (sedentary, single transhumance and double transhumance). The preliminary results produced by the whole farm model OSTRAL showed that two systems (sedentary and double transhumance) causing low carbon emissions. In the sedentary system, higher animal productivity offsets the increase in GHG emissions (in CO 2 eq) caused by feed production. In the pastoral system, grazing reduced total GHG emissions (in CO 2 eq). The CASA model proved to be useful to simulate the carbon balance under dynamic land cover in natural environments, whether used for grazing or not. This model can help assess the impact of grazing practices and carbon fluxes in systems linked to natural environments. The results of the first application showed that seasonal mobility of livestock increases the contribution of rangeland to feeding systems and improves the non-renewable energy balance of the system. It is thus extremely important to include the specificities of animals grazing in rangelands outside the structural limits of the farm when evaluating GHG emissions. [ABSTRACT FROM AUTHOR]

• A thorough analysis on variations of CO 2 fluxes and carbon budget was conducted. • Nitrogen and water conditions were primary factors controlling maize seasonal NEE. • NBP for the winter wheat-maize rotation system ranged from -239.1 to 237.0 gCm−2. • Net ecosystem GHG emissions ranged from -39.23 to 325.23 gCm−2 for the wheat system. • Nitrogen and water application should be optimized for climate smart agriculture. Investigating CO 2 fluxes and carbon budget in agro-ecosystems is essential to develop climate smart agriculture. Here, we conducted a thorough analysis on the daily, seasonal and inter-annual variations in CO 2 fluxes and carbon budget in a winter-wheat and summer-maize rotation system in the North China Plain (NCP) to better understand the CO 2 flux exchange and the underlying mechanisms of carbon budget dynamics. During 2003-2010, the inter-annual variability of monthly gross primary productivity was significantly correlated with leaf area index (LAI), temperature and net radiation. The inter-annual variability of monthly ecosystem respiration was significantly correlated with LAI, soil temperature and moisture. Daily and monthly variability in net ecosystem exchange (NEE) was significantly correlated with LAI. At a seasonal scale, soil moisture was one of the primary factors controlling carbon sequestration of wheat system. Nitrogen application rate and water conditions were the primary factors controlling carbon sequestration of maize system. The NEE for winter wheat system, maize system, and winter wheat-maize rotation system in the NCP ranged from -418 to -29, -448 to -119, and -857 to -274 gCm−2, respectively. The net biome productivity (NBP) for winter wheat system, maize system, and winter wheat-maize rotation system in the NCP ranged from -223 to 151, -236 to 94, and -239 to 237 gCm−2, respectively. Taking greenhouse gas (GHG) emissions from irrigation, fertilization, herbicides, fungicide, insecticide, and field operations, the associated net GHG emissions ranged from -39 to 325 gCm−2 for wheat system and -22 to 287 gCm−2 for maize system. Wheat and maize systems in the region were a medium source of GHG emissions in most of years, mainly due to the large application rates of fertilization and irrigation. Our findings gain new insights into the mechanisms underlying the inter-annual variations in CO 2 fluxes and carbon budget, highlighting the optimization of genotype, environment and management interactions to realize climate smart agriculture. [ABSTRACT FROM AUTHOR]

• A thorough analysis on variations of CO 2 fluxes and carbon budget was conducted. • Nitrogen and water conditions were primary factors controlling maize seasonal NEE. • NBP for the winter wheat-maize rotation system ranged from -239.1 to 237.0 gCm−2. • Net ecosystem GHG emissions ranged from -39.23 to 325.23 gCm−2 for the wheat system. • Nitrogen and water application should be optimized for climate smart agriculture. Investigating CO 2 fluxes and carbon budget in agro-ecosystems is essential to develop climate smart agriculture. Here, we conducted a thorough analysis on the daily, seasonal and inter-annual variations in CO 2 fluxes and carbon budget in a winter-wheat and summer-maize rotation system in the North China Plain (NCP) to better understand the CO 2 flux exchange and the underlying mechanisms of carbon budget dynamics. During 2003-2010, the inter-annual variability of monthly gross primary productivity was significantly correlated with leaf area index (LAI), temperature and net radiation. The inter-annual variability of monthly ecosystem respiration was significantly correlated with LAI, soil temperature and moisture. Daily and monthly variability in net ecosystem exchange (NEE) was significantly correlated with LAI. At a seasonal scale, soil moisture was one of the primary factors controlling carbon sequestration of wheat system. Nitrogen application rate and water conditions were the primary factors controlling carbon sequestration of maize system. The NEE for winter wheat system, maize system, and winter wheat-maize rotation system in the NCP ranged from -418 to -29, -448 to -119, and -857 to -274 gCm−2, respectively. The net biome productivity (NBP) for winter wheat system, maize system, and winter wheat-maize rotation system in the NCP ranged from -223 to 151, -236 to 94, and -239 to 237 gCm−2, respectively. Taking greenhouse gas (GHG) emissions from irrigation, fertilization, herbicides, fungicide, insecticide, and field operations, the associated net GHG emissions ranged from -39 to 325 gCm−2 for wheat system and -22 to 287 gCm−2 for maize system. Wheat and maize systems in the region were a medium source of GHG emissions in most of years, mainly due to the large application rates of fertilization and irrigation. Our findings gain new insights into the mechanisms underlying the inter-annual variations in CO 2 fluxes and carbon budget, highlighting the optimization of genotype, environment and management interactions to realize climate smart agriculture. [ABSTRACT FROM AUTHOR]

Carbon capture (CC), along with the efforts to reduce carbon emissions at the source, is a major action toward the mitigation of climate change and global warming due to emissions of greenhouse gases (GHGs). Carbon emissions amount to 36.3 Gt-CO 2 in 2021 from 31.5 Gt-CO 2 in 2022, with a drop of about 1.5 Gt-CO 2 in 2020 relative to 2019 due to the COVID-19 pandemic. The carbon emissions originate from heat and power, transportation, process industries, and residential activities constitute 47.7, 24.9, 18.9, and 8.5% of the total emissions, respectively. The process industries represent the second large-scale point-source of carbon emissions next to heat and power. Additionally, the process industries have high-intensity carbon emissions up to 0.6–0.8 t-CO 2 /t-cement, 1.4–2 t-CO 2 /t-steel, and 2.7–99.2 kg CO 2 /bbl, with flue gas streams having high CO 2 concentration up to 30%. In comparison to 0.4 t-CO 2 /MWh and 3–16% CO 2 in the flue gas from heat and power facilities, these process industries present a highly effective target for CC application. This work reviews and critically discusses the large-scale application of CC to different process industries, namely, cement, iron and steel, oil refinery, and chemicals. CC can be achieved by three main approaches, i.e., post-combustion, pre-combustion, and oxyfuel combustion. Post-combustion and chemical-looping are the common CC approaches utilized in process industries, with the first being widely applied due to its ease of incorporation, and the latter is commonly used in the cement industry. CC with the capacity in the range of 0.4–2 Mt-CO 2 /yr is planned for cement plants relative to current capacities of 75 kt-CO 2 /yr. Similarly, CC capacity up to 0.8 Mt-CO 2 /yr has been integrated into iron and steel plants, in which captured CO 2 is utilized for enhanced oil recovery (EOR) applications. In the oil and gas industry, CC has been widely utilized, in the context of gas purification, being an essential gas processing unit, with CC capacities up to 1.4 Mt-CO 2 /yr, and plans to reach 4 Mt-CO 2 /yr. CC cost is the main challenge for the widespread implementation of CC in process industries with a wide range of reported costs of USD9.8-250/t-CO 2 depending on the process industry and the CC technology used. [Display omitted] • Process industries emit about 18.5% of the global carbon emissions. • Cement, iron & steel, and oil refining are the major CO 2 emitting processes. • Carbon capture (CC) is a major mitigation action of climate change. • The current process industry's CC capacity of 7 Mt-CO 2 /y has to increase to the Gt-CO 2 /y scale. • CC cost and integrability to existence processes present the main challenges. [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]

• A review on the encapsulation of carbon dioxide using gas hydrates was performed. • The effect of additives in CH 4 and CO 2 hydrate formation were studied. • Gas hydrate formation mechanisms on porous media with CH 4 /CO 2 were studied. • The use of gas hydrates as a mechanism for energy storage is explored. • Effect of porous media in energy storage, as well as methane release, were studied. Adverse effects of excess greenhouse gases in the atmosphere emanating from fossil fuels have prompted intense research on clean energy sources as replacements and carbon capture. Research on natural gas hydrate has intensified in the past century due to the occurrence of natural gas hydrate in numerous places around the world on the sea beds and in permafrost regions. Due to its energy value and ability to form a clathrate hydrate with water, the methane molecule has proven to be useful as both a viable energy store and a means of carbon dioxide sequestration in natural gas hydrates. Methane can be produced from natural gas hydrates while controlling carbon dioxide emission, by replacing methane molecules with carbon dioxide from its crystalline structure. This review focuses on the encapsulation of carbon dioxide by a replacement reaction of methane from natural gas hydrates, with methane-carbon dioxide replacement models presented and discussed. Experimental variables affecting the CH 4 -CO 2 replacement process along with reported theoretical findings were reviewed. These are discussed along with the challenges and limitations in the replacement process. In addition, the fundamentals of hydrate formation mechanisms on porous media are detailed. Finally, an extensive discussion and comparison of the experimental studies of hydrate formation involving various porous media materials such as activated carbon, glass beads, solid and hollow silica in the presence of chemical additives and nanoparticles, with carbon dioxide and methane gas molecules are presented. Climate change mitigation strategies in minimising CO 2 emissions while harnessing energy by replacing methane with CO 2 from the hydrate structure. [ABSTRACT FROM AUTHOR]

[Display omitted] • Agriculture/climate relationship is one of the most important contemporary problems. • Agriculture is a significant source of GHG emissions and carbon sequestration. • Agriculture must minimize greenhouse gas emissions without reducing yields. • Integrating trees with agricultural landscapes is strategy in climate change mitigation. Agronomy has significant impacts on climate stability due to the emission of large amounts of greenhouse gases and C sequestration in soil and plants and can influence on reducing the negative impact of agronomy on climate does not need to result in a reduction in yield. Nevertheless, satisfying both goals require the implementation of new methods. The present assessment was based on over 190 scientific publications. Forecasts from the beginning of the 21st century showed that the increase in temperature and CO 2 concentration would improve the productivity of crops by extending the growing season and allow for the cultivation of new species. However, this beneficial effect may be limited by the increasing intensity of the extreme weather phenomena such as: rainstorm, droughts, early frosts, storms etc. Here, we review more recent studies which indicate, however, that this beneficial effect of climate change will not be permanent and, consequently, will significantly reduce crop yields. Climate change is forcing the agronomy sector to implement adaptive methods for minimizing possible crop losses consisting, inter alia, (i) using crop species/varieties that are less sensitive; (ii) optimizing water management; (III) improving pest, disease and weed control efficiency. The pressure on the agriculture sector to increase food production due to the increase in the human population and the present hunger in specific regions run counter to the need to reduce the adverse climate impacts of agriculture. The current state of knowledge indicates that despite the implementation of new technologies, agricultural measures will not be able to significantly reduce climate change. Indeed, these approaches will not replace the need to reduce greenhouse gas emissions in other sectors. However, without the participation of agronomy in reducing GHG emissions by increasing carbon sequestration, the goals of the 2015 UN Climate Change Conference in Paris will not be achieved. [ABSTRACT FROM AUTHOR]

Highlights: [•] Intensification GHGs can be compensated/outweighed by increased C sequestration. [•] Intensification could increasing climate change mitigation success of agroforestry. [•] This could help reduce pressure for further forest conversion to agriculture. [Copyright &y& Elsevier]

Abstract: Pricing greenhouse gas emissions is a burgeoning and possibly lucrative financial means for climate change mitigation. Emissions pricing is being used to fund emissions-abatement technologies and to modify land management to improve carbon sequestration and retention. Here we discuss the principal land-management options under existing and realistic future emissions-price legislation in Australia, and examine them with respect to their anticipated direct and indirect effects on biodiversity. The main ways in which emissions price-driven changes to land management can affect biodiversity are through policies and practices for (1) environmental plantings for carbon sequestration, (2) native regrowth, (3) fire management, (4) forestry, (5) agricultural practices (including cropping and grazing), and (6) feral animal control. While most land-management options available to reduce net greenhouse gas emissions offer clear advantages to increase the viability of native biodiversity, we describe several caveats regarding potentially negative outcomes, and outline components that need to be considered if biodiversity is also to benefit from the new carbon economy. Carbon plantings will only have real biodiversity value if they comprise appropriate native tree species and provide suitable habitats and resources for valued fauna. Such plantings also risk severely altering local hydrology and reducing water availability. Management of regrowth post-agricultural abandonment requires setting appropriate baselines and allowing for thinning in certain circumstances, and improvements to forestry rotation lengths would likely increase carbon-retention capacity and biodiversity value. Prescribed burning to reduce the frequency of high-intensity wildfires in northern Australia is being used as a tool to increase carbon retention. Fire management in southern Australia is not readily amenable for maximising carbon storage potential, but will become increasingly important for biodiversity conservation as the climate warms. Carbon price-based modifications to agriculture that would benefit biodiversity include reductions in tillage frequency and livestock densities, reductions in fertiliser use, and retention and regeneration of native shrubs; however, anticipated shifts to exotic perennial grass species such as buffel grass and kikuyu could have net negative implications for native biodiversity. Finally, it is unlikely that major reductions in greenhouse gas emissions arising from feral animal control are possible, even though reduced densities of feral herbivores will benefit Australian biodiversity greatly. [Copyright &y& Elsevier]

Abstract: Soil C sequestration in cropland could play an important role in mitigating the rapidly increasing CO2 emissions in China. Many efforts had been dedicated to estimating the potential for C sequestration in croplands. Potential increases in SOC in China''s croplands had been recently evaluated using inventory-up-scaling simulation and crop-soil C process-based modeling. In this study, data of SOC change at monitoring sites from croplands across mainland China were collected from publications available from 1985 to 2006 to perform a statistical analysis. The data set comprises 1081 observations (404 from rice paddies, RPs and 677 from dry croplands, DCs). Frequency analysis indicates that over 70% of observations show an increase in SOC, which is higher among RPs than DCs. To quantify SOC dynamics, a Relative Annual Change Index in gkg−1 year−1 (RAC, gkg−1 year−1) is defined and calculated using the initial and final SOC values for the duration of monitored observations. RAC values ranged from −0.806 to 0.963gkg−1 year−1 for DCs and from −0.597 to 0.959gkg−1 year−1 for RPs, respectively. From this data, the average is estimated to be 0.056±0.200gkg−1 year−1 for DCs, and 0.110±0.244gkg−1 year−1 for RPs, with an overall estimate for China''s croplands, with RPs and DCs combined, of 0.076±0.219gkg−1 year−1. A mean increase in topsoil C (0–20cm) stock of China''s croplands was estimated to be 25.5TgCyear−1 (8TgCyear−1 in RPs and 17.5TgCyear−1 in DCs) between 1985 and 2006, with a total topsoil C stock increase of 0.64 Pg C over the whole period. The annual stock increase may offset ∼20%, on average, of the total CO2 emissions of China for 1994. This study suggests an important role of China''s croplands, especially rice paddies, for C sequestration to mitigate climate change. [Copyright &y& Elsevier]

The mitigation of climate change, abatement of greenhouse gas emissions and thus, fundamentally, the separation of CO 2 from various gas streams are some of the most pressing and multifaceted issues that we face as a society. De-carbonising our entire civilisation will come at a great cost and requires vast amounts of knowledge, initiative and innovation; yet, no matter how much time or money is spent, some sectors simply cannot be de-carbonised without the deployment of carbon capture and storage technologies. The technical challenges associated with the removal of CO 2 are not universal – there exists no single solution. Capturing the CO 2 on solid sorbents has been gaining traction in recent years given its cost-effectiveness as a result of its ease of application, relatively small energy requirements and applicability in a wide range of processes. Even with the myriad materials such as zeolites, carbons, metal organic frameworks, mesoporous silicas and polymers, the challenge to identify a sorbent with optimal capacity, kinetics, selectivity, stability and ultimately, viability, still persists. By tailoring these solid materials through comprehensive campaigns of surface modification, the pitfalls of each can be mollified and the strengths enhanced. This highly specific tailoring must be well informed so as to understand the mechanisms by which the CO 2 is adsorbed, the surface chemistry that has influence on this process, and what methods exist to facilitate the improvement of this. This review endeavours to identify the surface functional groups that interact with the CO 2 molecules during adsorption and the methods by which these functional groups can be introduced. It also provides a comprehensive review of the recent attempts and advancements made within the scientific community in the experimental applications of such methods to enhance CO 2 capture via adsorption processes. The primary search engine employed in this critical review was Scopus. Of the 421 references cited that embody the literature focussed on surface modification for enhancing the selective adsorption of CO 2 , 370 are original research papers, 43 are review articles and 7 are conference proceedings. Image 1 • Critical review of surface modification methods employed to enhance CO 2 adsorption. • Assessment of CO 2 adsorption mechanisms in the context of surface functional groups. • Evaluation of the methods used to introduce functional groups on adsorbent surfaces. • Critical discussion of the reagents used in surface modification of adsorbents. [ABSTRACT FROM AUTHOR]

There has been a careless use of terminology like “climate change mitigation” and “mitigate global warming” in scientific papers on no-tillage management in agriculture. This is because it has yet to be shown unequivocally that no-tillage can lead to carbon (C) sequestration let alone climate change mitigation. I briefly summarize evidence that shows that the claims of climate change mitigation through no-tillage agriculture are highly overstated. [ABSTRACT FROM AUTHOR]