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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]

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]

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]

• 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]