Carbon Sequestration
Carbon Sequestration
Carbon sequestration is the process of capturing carbon dioxide or transferring carbon already circulating through the atmosphere and biosphere into reservoirs where it can remain for extended periods. Carbon can be stored biologically in plants, forests, soils, wetlands, grasslands, and marine ecosystems, or through engineered and geological systems that place carbon in minerals, construction materials, underground formations, or other durable reservoirs.
Carbon sequestration has become an important component of climate-change mitigation because reducing greenhouse-gas emissions alone may not be sufficient to address all remaining emissions or eventually reduce atmospheric carbon dioxide concentrations. The research literature therefore examines a wide range of approaches, from improved agricultural practices and ecosystem restoration to direct air capture, bioenergy with carbon capture and storage, enhanced weathering, and geological injection.
The different approaches are not interchangeable. They vary greatly in storage duration, cost, technological maturity, land and energy requirements, ecological effects, measurement uncertainty, reversal risk, and potential scale. A central question throughout carbon-sequestration research is therefore not simply how much carbon can be captured, but how securely, sustainably, verifiably, and economically it can be stored.
Soil Carbon Sequestration
Soils constitute one of the world's largest terrestrial carbon reservoirs. Plants remove carbon dioxide from the atmosphere through photosynthesis, and part of that carbon enters soils through roots, root exudates, crop residues, litter, and other organic material. Microorganisms transform this material into different forms of soil organic carbon, some of which can persist much longer than others.
Agricultural management can alter this balance substantially. Cover crops, crop diversification, organic amendments, manure, residue retention, reduced tillage, improved nutrient management, agroforestry, perennial vegetation, and restoration of degraded soils can increase carbon inputs or reduce losses under suitable conditions.
The amount of additional carbon stored, however, depends on climate, soil type, mineralogy, vegetation, water availability, nutrient availability, depth, previous land use, and management history. Carbon gains measured near the soil surface do not necessarily represent equivalent gains throughout the entire soil profile.
Research increasingly distinguishes between rapidly cycling organic matter and more persistent forms of carbon protected inside soil aggregates or associated with minerals. This distinction is important because an increase in total soil carbon does not automatically indicate equally durable climate mitigation.
Soil sequestration also has practical limits. Soils can approach saturation, stored carbon can be lost when management changes, and practices intended to increase soil carbon can sometimes affect methane or nitrous-oxide emissions. Accurate measurement, reporting, and verification are therefore essential when soil-carbon gains are used to generate carbon credits.
Agriculture, Grasslands, and Grazing
Agricultural landscapes offer substantial opportunities to influence carbon cycling because farming determines vegetation cover, soil disturbance, organic-matter inputs, nutrient use, water management, and erosion.
Conservation tillage and no-till systems can increase surface soil carbon in many environments, particularly when combined with residue retention or cover crops. Their effectiveness varies by climate, soil depth, crop rotation, and management system, however, and increases measured in surface layers may not always represent equivalent increases in total-profile carbon.
Grasslands and rangelands contain large belowground carbon stocks associated with extensive root systems. Grazing intensity can either support or undermine these stocks. Some research finds that light or carefully controlled grazing can maintain vegetation productivity and carbon cycling, while intensive grazing can reduce plant biomass, root inputs, and soil organic carbon.
Grazing exclusion can help degraded grasslands recover, but permanent exclusion is not necessarily optimal everywhere. The duration of exclusion, local ecology, rainfall, vegetation composition, and previous degradation all influence outcomes.
These findings show why agricultural carbon sequestration cannot be reduced to a single universal farming practice. Management must be adapted to ecological conditions and evaluated using whole-system greenhouse-gas accounting.
Agroforestry and Landscape Carbon
Agroforestry combines trees or woody vegetation with crops or livestock. Carbon can accumulate simultaneously in tree biomass, roots, litter, and soils, creating multiple carbon reservoirs within a working agricultural landscape.
Research from Africa, Asia, Latin America, and other regions indicates that agroforestry can increase carbon storage while also providing shade, soil protection, biodiversity habitat, diversified farm products, improved nutrient cycling, and greater resilience to drought and climate variability.
Coffee agroforestry, silvopastoral systems, tree-crop systems, and restoration of degraded agricultural lands illustrate the diversity of approaches. Their carbon performance varies according to tree species, density, age, climate, soil, management, and the land use they replace.
Because agroforestry also affects food production and rural livelihoods, its climate value cannot be assessed solely through tonnes of carbon stored. Land tenure, farmer income, biodiversity, local participation, and long-term management are important components of successful projects.
Forest Carbon and Ecosystem Restoration
Forests remove atmospheric carbon dioxide through photosynthesis and store carbon in living trees, dead wood, litter, roots, and soils. Protecting existing forests, allowing natural regeneration, restoring degraded forests, and modifying forest management can therefore influence both present carbon stocks and future carbon uptake.
Young and recovering forests can accumulate carbon rapidly, while older forests often contain very large existing carbon stocks. Protecting an existing carbon-rich forest can consequently provide a different climate benefit from planting new trees on previously nonforested land.
Natural regeneration can sometimes outperform plantations in carbon accumulation, biodiversity, resilience, or cost effectiveness. Outcomes nevertheless differ widely among regions, forest types, climates, species, and management regimes.
Forest carbon is also vulnerable to reversal. Wildfire, drought, pests, logging, land conversion, storms, and climate change can release previously stored carbon or reduce future sequestration. These risks make permanence a major concern in forest-based carbon markets.
Restoration also has ecological limits. Tree planting in drylands or other water-limited ecosystems may produce smaller carbon gains than expected and can create conflicts with water resources or native ecosystems. Carbon objectives therefore need to be aligned with local ecological conditions rather than assuming that more tree planting is always beneficial.
Wetlands, Peatlands, and Blue Carbon
Wetlands can accumulate large quantities of carbon because waterlogged conditions slow decomposition. Peatlands are particularly important because partially decomposed plant material can accumulate over centuries or millennia, producing exceptionally carbon-rich soils.
Drainage, peat extraction, agriculture, fire, and land conversion can turn these ecosystems from long-term carbon stores into major greenhouse-gas sources. Rewetting and ecological restoration can reduce continuing losses and eventually rebuild carbon accumulation.
Restoration outcomes are complex because methane emissions can increase after rewetting. A restored wetland may therefore begin storing carbon before it provides a net cooling benefit when all greenhouse gases are considered.
Coastal ecosystems provide another major form of biological sequestration known as blue carbon. Mangroves, salt marshes, seagrass meadows, tidal wetlands, and potentially some macroalgal systems capture carbon in vegetation and especially in sediments.
Protecting existing blue-carbon ecosystems is particularly important because their destruction can release carbon accumulated over long periods. Restoration can rebuild sequestration capacity, but evidence indicates that losses from continuing ecosystem degradation can exceed gains from restoration.
Methane, nitrous oxide, sediment dynamics, hydrology, disturbance, and shifting ecosystem boundaries can all alter the net climate benefit of blue-carbon systems. Carbon accounting must therefore include more than simple measurements of stored organic carbon.
Biochar and Carbon-Storing Materials
Biochar is produced when biomass is heated under oxygen-limited conditions through processes such as pyrolysis. Some of the carbon originally captured by plants is converted into chemically resistant forms that can persist much longer than untreated biomass.
When incorporated into soils, biochar can increase carbon stocks while influencing soil structure, water retention, nutrients, microbial communities, and crop productivity. Its performance depends heavily on the original feedstock, production temperature, soil characteristics, climate, and application method.
Biochar can also interact with existing soil organic carbon. These interactions may either increase stabilization or stimulate decomposition, making long-term field studies particularly important.
Researchers are also investigating biochar in concrete and other construction materials. Combining biogenic carbon storage with mineral carbonation could potentially create building materials that function as carbon reservoirs.
The actual climate benefit must be assessed over the entire lifecycle, including biomass sourcing, processing energy, transportation, emissions during production, competing uses for biomass, and the durability of the stored carbon.
Enhanced Weathering and Mineral Carbonation
Mineral carbonation stores carbon dioxide by converting it into stable carbonate minerals. Because these minerals can remain stable for extremely long periods, mineralization represents one of the more durable forms of carbon sequestration.
Enhanced weathering attempts to accelerate naturally occurring reactions between carbon dioxide and reactive minerals. Crushed basalt, silicate rocks, mine tailings, calcium-rich materials, magnesium-rich materials, and industrial residues are among the materials being investigated.
Applications include spreading finely ground rock on agricultural soils, reacting captured carbon dioxide directly with minerals, treating mine wastes, and combining mineral weathering with biochar or ecosystem restoration.
Potential advantages include very long storage duration and the enormous theoretical availability of mineral feedstocks. Major challenges include mining and grinding requirements, transportation, energy use, reaction rates, measurement of actual carbon removal, environmental effects, and the logistics of deploying vast quantities of material.
Geological Carbon Sequestration
Geological sequestration stores compressed carbon dioxide in underground formations such as deep saline aquifers, depleted oil and gas reservoirs, and suitable reactive rock formations.
Injected carbon can be retained through several mechanisms. Structural trapping keeps buoyant carbon dioxide beneath impermeable caprock. Residual trapping immobilizes small quantities within pore spaces. Solubility trapping dissolves carbon dioxide into underground fluids, while mineral trapping eventually incorporates carbon into solid minerals.
These mechanisms operate over different timescales and depend strongly on reservoir geology, pressure, mineral composition, fluid chemistry, permeability, fractures, and injection strategy.
Storage capacity is not determined by pore volume alone. Pressure buildup can constrain injection, and multiple storage projects using the same geological basin may interact. Basin-scale planning and pressure management may therefore be necessary.
Leakage through poorly characterized faults, fractures, abandoned wells, or damaged infrastructure is an important concern. Monitoring systems using seismic techniques, well measurements, geochemical observations, remote sensing, modeling, and other technologies are intended to track plume movement and verify containment.
When suitable formations are properly characterized and managed, geological storage offers the possibility of retaining carbon for very long periods.
Direct Air Capture
Direct air capture removes carbon dioxide directly from ambient air using chemical sorbents, solvents, membranes, electrochemical processes, or other engineered systems. The captured carbon dioxide must then be stored or incorporated into products if the process is to produce durable carbon removal.
DAC has an important theoretical advantage: facilities can potentially operate independently of the original source of emissions. When paired with geological storage or mineralization, it can also provide highly measurable and potentially long-lived carbon removal.
Its major challenge is the low concentration of carbon dioxide in ordinary air. Moving large volumes of air through capture systems and regenerating sorbents requires energy, equipment, infrastructure, and capital.
Costs and removal efficiency depend on sorbent durability, temperature, humidity, energy sources, plant location, contactor design, manufacturing requirements, and the type of permanent storage available.
Large-scale deployment would consequently require extensive clean energy, carbon-transport and storage infrastructure, manufacturing capacity, investment, technological learning, and reliable systems for monitoring and certification.
Bioenergy with Carbon Capture and Storage
Bioenergy with carbon capture and storage, commonly known as BECCS, combines biological carbon uptake with energy production and geological carbon storage.
Plants remove carbon dioxide while growing. Biomass is harvested and converted into electricity, heat, fuels, hydrogen, or other energy products, and a portion of the resulting carbon dioxide is captured and stored underground. If lifecycle emissions are sufficiently low and biomass is sustainably produced, the overall system can result in net atmospheric carbon removal.
BECCS is prominent in many long-term climate scenarios, but its potential scale is constrained by biomass supply. Large biomass requirements can create competition for land, food production, forests, water, biodiversity, and other ecosystem services.
The climate benefit also depends heavily on the counterfactual use of the land and biomass. Harvesting an existing carbon-rich ecosystem to supply bioenergy can produce very different results from using genuine wastes or sustainably produced residues.
Lifecycle accounting, land-use change, transportation, processing, capture efficiency, storage permanence, and alternative uses of biomass are therefore central to assessing whether a BECCS project actually removes carbon from the atmosphere.
Ocean Carbon Dioxide Removal
The ocean already absorbs a large share of anthropogenic carbon dioxide emissions. Researchers are investigating whether this natural uptake can be increased deliberately.
Ocean alkalinity enhancement seeks to increase seawater's capacity to absorb and retain carbon dioxide by adding alkaline materials or generating alkalinity through electrochemical processes. Other proposed approaches involve biomass, minerals, nutrients, or manipulation of biological and chemical processes.
The enormous scale of the ocean gives these approaches potentially large theoretical capacity, but marine carbon removal remains scientifically and institutionally challenging.
Carbon accounting must determine how much additional atmospheric carbon dioxide is actually removed, how long it remains stored, and whether interventions create changes in marine chemistry or ecosystems. Material sourcing, energy use, transport, monitoring, ecological effects, international law, permitting, and transboundary governance all influence feasibility.
Permanence and Reversal Risk
One of the most important distinctions among carbon-sequestration strategies is how long the carbon remains outside the atmosphere.
Carbon stored in vegetation or soils may be vulnerable to fire, drought, harvesting, land conversion, erosion, management changes, or ecological disturbance. Geological formations and stable carbonate minerals can potentially retain carbon much longer.
Temporary storage can still have climate value, but it cannot necessarily be treated as equivalent to storage lasting centuries or millennia. Carbon-accounting systems must therefore consider expected storage duration, probability of reversal, monitoring requirements, and responsibility for replacing carbon that is later released.
Permanence becomes especially important when carbon removals are used to offset continuing fossil-carbon emissions. Fossil fuels transfer carbon from geological reservoirs into the active carbon cycle. Compensating for such emissions with temporary biological storage creates a mismatch between the duration of the original emission and the duration of the offset.
Measurement, Reporting, and Verification
Credible carbon sequestration depends on demonstrating that carbon has actually been removed or prevented from returning to the atmosphere.
Measurement, reporting, and verification systems attempt to establish baselines, quantify carbon changes, estimate uncertainty, identify leakage, assess additionality, and monitor stored carbon through time.
Methods vary by sequestration pathway. Soil projects use field sampling, modeling, digital soil mapping, and remote sensing. Forest projects combine inventories with satellite observations and ecological models. Geological projects use seismic imaging, pressure measurements, geochemistry, well monitoring, and reservoir simulation.
New tools include machine learning, artificial intelligence, physics-informed models, high-resolution remote sensing, automated sensors, and digital mapping systems.
Measurement uncertainty remains a major challenge, particularly where changes are small relative to large existing carbon stocks. Verification standards must therefore account for uncertainty rather than treating estimated sequestration as perfectly known.
Carbon Markets, Additionality, and Economics
Carbon sequestration increasingly interacts with voluntary and regulated carbon markets. Projects may receive credits for removing carbon or increasing carbon stocks relative to an established baseline.
Additionality asks whether the carbon benefit would have occurred without the carbon-finance intervention. If an activity would have happened anyway, issuing credits may not represent additional climate mitigation.
Determining additionality can be difficult because land-management decisions, technology costs, government policies, commodity markets, and expected future behavior all affect baselines. Rules designed to prevent non-additional credits can also unintentionally discourage early adopters or investments that have already begun storing carbon.
Costs differ widely among sequestration approaches. Some land-management practices can provide relatively inexpensive carbon gains alongside agricultural or ecological benefits. Engineered systems such as DAC may provide more durable and measurable removal but currently involve much higher capital and energy requirements.
Economic comparisons therefore need to incorporate not only the immediate cost per tonne of carbon dioxide but also storage duration, reversal risk, monitoring, replacement obligations, ecological effects, and uncertainty.
Environmental and Social Trade-Offs
Carbon removal is not automatically environmentally beneficial simply because it reduces atmospheric carbon dioxide.
Large-scale afforestation can alter water availability or replace native grasslands. Biomass production can compete with food, habitat, or existing forests. Mining minerals for enhanced weathering can create energy demand and ecological disturbance. Ocean interventions may alter marine chemistry. Geological storage requires infrastructure and management of underground risks.
Conversely, some sequestration projects can generate substantial co-benefits. Soil restoration can improve fertility and water retention. Wetland restoration can support biodiversity and flood management. Agroforestry can strengthen rural livelihoods. Forest conservation can protect habitat and watersheds.
Distribution also matters. Communities may bear land, infrastructure, environmental, or economic costs while benefits accrue elsewhere. Land tenure, Indigenous and local rights, public participation, community consent, equitable distribution of revenues, and transparent decision-making are therefore important components of carbon-removal governance.
Carbon Sequestration and Emissions Reduction
Carbon sequestration is increasingly viewed as necessary for balancing residual emissions from sectors that are extremely difficult to eliminate completely and potentially for reducing atmospheric carbon dioxide after emissions approach net zero.
It should not, however, be treated as a substitute for reducing greenhouse-gas emissions at their source. Carbon-removal capacity is limited by land, energy, materials, ecological constraints, economics, social acceptance, and storage availability.
Heavy dependence on uncertain future removal could allow continued fossil-fuel emissions today while transferring the technological, financial, and environmental burden of removal to future generations.
A robust climate strategy therefore combines rapid emissions reductions with the careful development of carbon-removal systems capable of addressing genuinely residual emissions and, where necessary, producing sustained net-negative emissions.
Conclusion
Carbon sequestration is not a single technology or land-management practice but a broad family of biological, geological, chemical, and engineered processes for transferring carbon away from the atmosphere and into longer-lived reservoirs.
Soils, grasslands, agroforestry, forests, peatlands, wetlands, mangroves, and seagrasses can increase biological carbon storage while frequently providing ecological and social benefits. Biochar can convert biomass into more persistent carbon. Enhanced weathering and mineral carbonation can transform carbon dioxide into stable minerals. Geological storage can isolate captured carbon deep underground. Direct air capture and BECCS can actively remove atmospheric carbon when paired with sufficiently durable storage.
Each pathway also has constraints. Biological reservoirs can saturate or reverse. Engineered approaches can require substantial energy, infrastructure, minerals, biomass, or investment. Ecological interventions can create land, water, biodiversity, and social trade-offs. Carbon markets introduce difficult questions involving additionality, baselines, measurement, permanence, and responsibility for future reversals.
The central challenge is therefore not merely maximizing the number of tonnes labeled as sequestered. Effective carbon sequestration requires demonstrating real atmospheric carbon removal, storing it for an appropriate duration, minimizing lifecycle emissions and environmental harm, measuring outcomes credibly, protecting communities and ecosystems, and ensuring that carbon removal complements rather than replaces rapid reductions in greenhouse-gas emissions.
Carbon Sequestration: Foundations, Assessments, and Policy Resources
Reviews genome-engineering strategies to improve photosynthesis and channel more atmospheric carbon into durable plant biomass and soils while considering biological and deployment constraints.
Argues that meaningful carbon sequestration should persist for climate-relevant periods of thousands of years and examines implications for carbon-removal standards and intergenerational responsibility.
Surveys advances in carbon-capture materials, catalytic utilization, microbial conversion, storage, efficiency improvements, and economic feasibility.
Reviews major carbon-capture technologies, geological storage methods, prominent CCS projects, costs, sectoral applications, and obstacles to large-scale deployment.
Synthesizes experimental methods and geological controls affecting CO2-storage efficiency, reservoir behavior, trapping mechanisms, and future technology development.
Carbon Dioxide Removal | U.S. Department of Energy | DOE | 2025
Provides an overview of federal research on direct air capture, soils, biomass carbon removal, enhanced mineralization, marine carbon removal, and forest-based approaches.
What is carbon sequestration? | U.S. Geological Survey | USGS | 2024
Provides an accessible overview of carbon sequestration and explains the biological and geological pathways through which carbon can be removed from the atmosphere and stored.
Contrasts geological storage beneath the Earth's surface with biological carbon storage in vegetation, soils, wood, wetlands, and aquatic ecosystems.
Coastal Blue Carbon | Janine Harris and NOAA Coastal Blue Carbon Working Group | NOAA | 2023
Summarizes the carbon-storage value, durability, costs, monitoring issues, and restoration potential of mangroves, salt marshes, and seagrass ecosystems.
Provides a global spatial assessment of grassland soil-carbon stocks and discusses sequestration potential under improved livestock and grassland management.
Assesses soil-carbon management, forests, grasslands, peatlands, biochar, ecosystem restoration, costs, permanence, saturation, monitoring, and mitigation potential across land systems.
Carbon sequestration | Food and Agriculture Organization | FAO AGROVOC | 2021
Defines carbon sequestration and summarizes the importance of long-term soil-carbon storage for agricultural climate mitigation.
Introduces guidance on African soil-carbon stocks, land-use impacts, measurement, data interpretation, and practices for conserving and rebuilding soil carbon.
Explains deep geological CO2 storage, suitable underground formations, trapping mechanisms, and the potential for long-term isolation of captured carbon.
Reviews losses of soil carbon from land-use change and agricultural practices capable of rebuilding soil organic carbon while improving productivity and ecosystem services.
Explains carbon pools and fluxes in drylands and examines how soil management can rebuild organic carbon lost through cultivation and land degradation.
Carbon sequestration in dryland soils | Food and Agriculture Organization | FAO | 2004
Provides a comprehensive assessment of carbon sequestration opportunities, policies, economics, and land-management practices in dry and degraded regions.
Explains how soil organic carbon forms, why it is central to soil health, and how sustainable soil management can increase net carbon storage.
Summarizes global soil-carbon stocks, threats from degradation, monitoring programs, sequestration opportunities, and FAO's RECSOIL initiative.
Soil Carbon Sequestration | Food and Agriculture Organization | FAO Soils Portal | Current resource
Surveys agricultural soil-carbon strategies including restoration, conservation practices, grazing management, agroforestry, afforestation, and organic-soil rewetting.
Soil Carbon Sequestration and Agricultural Management
Reviews how cover crops supply organic matter, reduce erosion, alter microbial activity, improve soil structure, and potentially increase long-term carbon storage.
Evaluates diversified farming systems over the long term, linking farm productivity with soil-carbon storage, microbial functions, and soil health.
Examines how returning organic materials to high-altitude farmland affects soil organic carbon accumulation, nutrient cycling, and wheat productivity.
Evaluates biomass carbon and CO2 sequestration associated with large-scale tree planting and landscape restoration under Ethiopia's Green Legacy Initiative.
Presents a digital soil-mapping framework for carbon MRV that combines field observations with spatial modeling to quantify soil-carbon change and uncertainty.
Connects land-use transitions with changes in carbon sequestration and the long-term economic value of ecosystem carbon services.
Field-tests biochar and fertilizer combinations and evaluates their effects on soil carbon balance, crop production, and greenhouse-gas emissions.
Examines how carbon-market additionality rules can discourage investment in agricultural carbon sequestration and considers alternative approaches to rewarding accumulated carbon.
Maps stabilized soil organic carbon globally and examines where long-lived mineral-associated carbon pools could provide the greatest opportunities and constraints for climate mitigation.
Compares organic fertilizer, biochar, rice straw, and mineral fertilizer treatments and examines how they affect soil structure, aggregates, and long-term carbon stabilization in saline-alkali paddy soils.
Compares plantations and agroforestry systems on reclaimed sodic soils and estimates biomass carbon, sequestration rates, and potential carbon-credit value.
Uses the CAST model to estimate soil-carbon gains from manure, mulching, agroforestry, regenerative olive farming, and other carbon-farming practices in Greece, Italy, and Spain.
Uses experience from Western Kenya to examine whether soil-carbon credit programs can support land restoration, farmer livelihoods, food security, and credible carbon accounting.
Meta-analyzes dryland farming studies to assess how no-till, mulching, irrigation, and nitrogen management affect soil carbon, greenhouse gases, and crop productivity.
Investigates interactions among straw return, nitrogen fertilization, iron minerals, soil aggregates, and organic-carbon stabilization in saline paddy soils.
Meta-analyzes more than 1,500 observations to assess how cover crops affect soil carbon, methane, nitrous oxide, rice yields, and prospects for lower-emission rice production.
Shows how biochar feedstock and chemical modification affect soil microbes, organic-carbon storage, carbon stability, and crop yield in arid agricultural soils.
Compares natural vegetation, extensive pasture, integrated crop-livestock-forest systems, and no-till agriculture and quantifies changes in soil-carbon stocks to one meter depth.
Compares agricultural management practices to determine their effects on soil carbon accumulation and crop productivity.
Examines microbial priming in agroforestry landscapes and finds differences between forested hedgerows and adjacent cropland that affect soil-carbon persistence.
Reviews accelerated soil carbonation using calcium-, magnesium-, and industrial by-product materials as a pathway for durable mineral carbon storage.
Models integrated management strategies involving biochar, irrigation, and fertilizer optimization for simultaneously increasing crop yields and soil organic carbon.
Examines how regenerative farming affects soil aggregates and the physical protection of organic carbon against microbial decomposition.
Reviews soil-carbon formation and stabilization, cover crops, biochar, microbial processes, measurement challenges, and approaches for increasing long-term soil carbon.
Finds that biofertilizer can increase vegetation and soil-carbon sequestration while reducing greenhouse-gas emissions relative to conventional chemical fertilizer.
Uses the long-running Broadbalk experiment and a wider synthesis to examine how nitrogen and phosphorus fertilization alter plant inputs, microbial processing, and soil-carbon accumulation.
Combines measurements with RothC modeling to explore how land management and climate change could alter future soil-carbon storage in an eastern Kenyan dryland.
Shows how fixed-depth sampling may underestimate sequestration when improved management deepens carbon-rich topsoil and alters soil bulk density and structure.
Synthesizes hundreds of studies to compare biomass and soil-carbon stocks across agroforestry systems, climate zones, and soil types.
Models conversion of agricultural residues to biochar and evaluates greenhouse-gas reductions, costs, sequestration potential, and carbon-credit economics.
Examines how biochar, manure, crop residues, litter, and other amendments influence soil organic carbon, aggregation, microbial communities, and carbon stabilization.
Finds that diversified tropical cropping can increase soil-carbon stocks and macroaggregate-associated carbon relative to simpler crop rotations.
Compares cropland and agroforestry soils and finds important differences in soil organic carbon, nutrients, tree density, and ecological resilience.
Reviews nutrient management, water management, biochar, conservation agriculture, varieties, and other approaches for increasing carbon retention in flooded rice systems.
Uses nearly four decades of experimental data to show how combinations of fertilizers, manure, and green manure influence soil carbon and methane and nitrous-oxide emissions.
Measures soil-carbon outcomes associated with perennial forage species and management practices across contrasting agroecological zones in Kenya.
Uses thousands of observations to evaluate cover-crop effects on soil carbon, yields, and nitrous oxide and identifies conditions where benefits are greatest.
Models the economic and climate potential of increasing carbon storage on agricultural land and examines possible new revenue streams for farmers.
Examines Finnish farms attempting carbon farming and identifies plant productivity, soil structure, nutrient deficiencies, microbial activity, and waterlogging as important limitations.
Examines how cover crops alter distinct carbon pools rather than simply total soil carbon, helping distinguish rapidly cycling carbon from more persistent storage.
Uses more than 13,000 field trials to quantify relationships between soil organic carbon and maize, wheat, and rice productivity.
Finds that cover crops increase several soil-carbon pools, while mineral-associated organic carbon responds more slowly than microbial and particulate fractions.
Synthesizes land-management effects on soil organic carbon worldwide and identifies practices and environmental conditions associated with gains and losses.
Demonstrates the major role of microbial carbon-use efficiency in determining how much plant-derived carbon ultimately becomes persistent soil carbon.
Synthesizes 61 studies and finds that cover crops generally increase soil organic carbon in maize-based rotations, with outcomes strongly influenced by soil, climate, biomass production, and management.
Conservation Tillage, Grasslands, Rangelands, and Grazing
Combines 24 earlier meta-analyses to compare no-till and reduced-tillage effects on soil carbon across climates, crops, soil types, and management conditions.
Meta-analyzes more than 4,000 observations to determine how long livestock exclusion should continue to maximize soil-carbon recovery in degraded Chinese grasslands.
Finds that fencing increases topsoil carbon but that the rate of accumulation varies with depth and duration, suggesting that indefinite exclusion is not always optimal.
Shows that grazing exclusion generally increases global grassland soil carbon but that vegetation and soil responses can diverge substantially at regional scales.
Models seasonal grazing and concludes that grazing reduces long-term grassland carbon storage, with summer grazing producing particularly strong effects.
Finds that conservation tillage can increase surface carbon stocks while producing more complex effects on carbon stability and deeper soil fractions.
Links long-term conservation tillage and straw retention with calcium-organic associations, microbial processes, aggregate stability, and increased soil-carbon storage.
Evaluates 17 years of tillage and residue treatments and their effects on carbon sequestration, carbon stability, and agricultural greenhouse-gas emissions.
Meta-analyzes conservation tillage across Northeast China and finds context-dependent effects on both crop production and soil organic carbon.
Quantifies soil-carbon sequestration potential and formation efficiency across China's temperate grasslands and examines environmental controls on belowground carbon.
Shows that soil mineralogy strongly influences how no-till and straw return alter soil aggregation and long-term organic-carbon storage.
Reviews how roots, root exudates, grazing, cultivation, warming, and rainfall changes regulate grassland carbon storage and nutrient cycling.
Finds that light grazing can increase net carbon uptake and water-use efficiency while heavier grazing progressively weakens grassland carbon fluxes.
Uses long-term alpine-grassland data to examine how grazing changes plant root strategies and ultimately influences soil organic carbon distribution.
Finds that controlled grazing and more diverse vegetation cover can increase particulate and mineral-associated organic carbon in semi-arid Kenyan rangelands.
Examines how different grazing intensities alter plant carbon, soil nutrients, enzyme activity, and soil-carbon fractions at multiple depths.
Compares major grassland-management practices globally and shows that their carbon effects depend strongly on climate, management intensity, and ecological context.
Compares grazing and mowing and finds contrasting effects on carbon dioxide emissions, methane uptake, vegetation biomass, and belowground nutrient cycling.
Synthesizes hundreds of observations and finds that reduced tillage, mulch tillage, and no-till can increase surface soil carbon in sandy dryland soils, although long-term gains remain uncertain.
Finds that grazing intensity reduces the carbon-sink strength of dry temperate grasslands, largely through losses of soil organic carbon.
Uses a 46-year field experiment to examine where within the soil profile no-tillage and crop rotations increase carbon and nitrogen stocks.
Synthesizes 902 comparisons to assess how straw return, reduced tillage, and no-till influence carbon storage and nitrous-oxide emissions.
Uses three decades of full-profile soil measurements and finds that prairie and rotational pasture maintained carbon while several annual cropping systems lost it.
Evaluates restoration strategies for degraded Tibetan grasslands and their capacity to rebuild vegetation, ecosystem function, and carbon storage.
Shows why finite grassland carbon accumulation cannot indefinitely compensate for continuing methane and nitrous-oxide emissions from livestock.
Agroforestry and Landscape Carbon Sequestration
Examines how vegetation structure and species diversity influence carbon allocation between biomass and soil in coffee–enset agroforestry systems.
Reviews the potential for wider agroforestry adoption to increase carbon sequestration, soil fertility, agricultural resilience, and farmer income in South Asia.
Reviews evidence from African agroforestry systems showing opportunities to increase carbon storage, biodiversity, agricultural resilience, and rural livelihoods simultaneously.
Synthesizes how shade structure, tree diversity, management, and local conditions influence carbon storage, coffee production, climate resilience, and livelihoods.
Compares agroforestry, silvopastoral, conventional farming, and natural ecosystems to evaluate soil emissions, soil quality, and carbon-storage performance.
Reviews carbon storage across agroforestry systems together with permanence, additionality, measurement, land tenure, and carbon-market policy considerations.
Finds that rubber-based agroforestry can increase soil organic and mineral-associated carbon alongside changes in soil properties and microbial-community structure.
Links woody-species richness, stand structure, and aboveground carbon storage in Ethiopian agroforestry landscapes.
Quantifies carbon storage within a Congo Basin agroforestry system and examines how tree composition can support climate mitigation in smallholder landscapes.
Evaluates tree-based farming in terms of crop productivity, carbon sequestration, microbial ecology, soil quality, and economic performance.
Forest Carbon, Reforestation, Natural Regeneration, and Disturbance
Examines carbon and economic consequences of converting Amazonian forest to coffee production and estimates resulting losses in sequestration value.
Examines whether continuous-cover forestry can maintain greater carbon in trees, understory vegetation, and soils than more intensive harvesting systems.
Reviews how drought, wildfire, land-use change, pests, and community management influence Ethiopian forest carbon stocks and ecosystem services.
Reviews afforestation, restoration, conservation, and forest-management options for increasing carbon storage while improving forest resilience to climate change.
Investigates social and behavioral factors determining whether communities participate in forest-carbon projects, highlighting the human dimension of sequestration programs.
Uses Congo Basin data to examine how appropriately managed tropical production forests can retain substantial carbon density and sequestration capacity.
Reviews interactions among forest productivity, climate change, disturbances, forest management, carbon uptake, and ecosystem feedbacks.
Examines plantation age and carbon uptake on China's Loess Plateau and finds evidence that sequestration rates are reaching or passing their peak in some restored forests.
Estimates the scale and cost of forest-based carbon mitigation across more than 200 countries and develops national supply curves for restoration and improved management.
Investigates tropical-forest nutrient limitation and finds that greater nitrogen availability can accelerate woody carbon accumulation under certain ecological conditions.
Uses biomass mapping to identify a continent-scale shift in African woody vegetation from net carbon sink toward net source, driven particularly by tropical forest loss.
Demonstrates remote-sensing methods for tracking changes in forest carbon storage using Sentinel and Landsat imagery.
Examines Australian forest-carbon projects and argues that some national datasets underestimate vegetation recovery visible in project-scale evidence.
Reassesses global restoration potential across forests, shrublands, grasslands, and wetlands and argues that realistic carbon-removal potential is smaller than some previous estimates.
Uses long-term observations to show limitations to relying on tree plantations for carbon sequestration in water-limited dryland environments.
Examines how wildfire alters tree-carbon stocks and future sequestration across forests of the western United States.
Models how federal forest investment could affect U.S. carbon sequestration and assesses which management actions provide lower-cost climate mitigation.
Compares managed and unmanaged European temperate forests and finds larger soil-carbon stocks in many unmanaged stands, especially in surface mineral soils.
Models forest-management interventions in Norway and identifies pre-commercial thinning and active reforestation as particularly important long-term CO2-removal strategies.
Finds that ecosystem restoration generally rebuilds soil organic carbon but often fails to return stocks fully to those of undisturbed reference ecosystems.
Finds that newly established forests account for a large proportion of net sequestration gains resulting from global land-cover transitions.
Finds especially high carbon-removal rates in many 20- to 40-year-old secondary forests and highlights protection of existing regrowth as a climate strategy.
Compares young planted and naturally regenerating forests across China and finds higher current aboveground carbon accumulation in natural regeneration.
Explores how wildfire, climate stress, land-use change, and other disturbances threaten the permanence of forest carbon relied upon in climate mitigation pathways.
Maps more than 200 million hectares with potential for tropical natural regeneration and estimates the resulting multi-decadal aboveground carbon-removal opportunity.
Provides global spatial data for evaluating forest recovery after wildfire and the associated restoration of vegetation carbon stocks.
Compares natural regeneration and plantation forestry and shows that the least-cost carbon strategy varies geographically rather than favoring one approach everywhere.
The enduring world forest carbon sink | Various authors | Nature | 2024
Uses decades of forest inventories to show that global forests remain a major carbon sink even as sink strength shifts substantially among biomes.
Uses national forest inventories and modeling to estimate how management timing, forest age, harvest decisions, and wood products could increase China's forest carbon sink.
Models how selecting climate-adapted tree provenances and species could help preserve forest carbon uptake as European climates warm.
Quantifies carbon accumulation in recovering tropical forests across the Amazon, Central Africa, and Borneo and documents major regional differences in recovery rates.
Estimates how much additional carbon could potentially be stored in existing forests and low-human-pressure landscapes while recognizing land-use and ecological constraints.
Siberian carbon sink reduced by forest disturbances | Lingxiao Fan et al. | Nature Geoscience | 2023
Shows how fire and other disturbances substantially diminish the carbon-sink strength of Siberian forests.
Finds that young and middle-aged boreal and temperate forests contributed disproportionately to recent increases in global live-biomass carbon.
Reviews evidence that the global terrestrial carbon sink has strengthened and examines the relative roles of CO2 fertilization, climate, nitrogen, and land management.
Biochar, Pyrolysis, and Carbon-Storing Materials
Compares biochar and hydrochar production, persistence, greenhouse-gas effects, and life-cycle performance as soil-based carbon-removal technologies.
Examines how feedstock characteristics and pyrolysis conditions determine carbon retention and reviews biochar applications in soils, construction materials, and steelmaking.
Combines a global meta-analysis with a multi-year tropical field experiment using sewage-sludge biochar to assess carbon retention under real-world conditions.
Studies how biochar aging, soil moisture, pH, and organic-mineral associations jointly influence carbon stability and cadmium immobilization.
Finds that biochar's carbon-storage effects differ strongly among types of saline and alkaline soils and identifies different stabilization mechanisms.
Explores seawater batteries as multifunctional systems capable of energy storage and desalination while potentially converting carbon dioxide into stable carbonate minerals.
Maps how efficiently biochar carbon enters particulate and mineral-associated soil-carbon pools across Chinese croplands.
Examines biochar as a combined carbon-storage and soil-remediation technology capable of retaining carbon while immobilizing environmental contaminants.
Reviews how biochar feedstock, pyrolysis, dosage, and particle structure affect carbon storage, carbonation, thermal performance, and mechanical properties of building materials.
Finds that six years of biochar application changed aggregate structure, carbon chemistry, hydrophobicity, and soil-carbon preservation.
Compares pyrolysis pathways for converting invasive plants into biochar and evaluates sequestration costs, energy efficiency, and life-cycle emissions.
Maps technical, economic, regulatory, social, and supply-chain barriers to widespread adoption of carbon-sequestering construction materials.
Reviews positive and negative priming, aromatic carbon stability, mineral interactions, and microbial pathways influencing the net climate benefit of biochar.
Questions whether soil CO2 flux alone is a reliable measure of biochar sequestration and compares it with changes in soil and microbial carbon pools.
Shows how mineral modification of biochar affects carbon retention, soil aggregates, dissolved organic carbon, microbes, and carbon stability.
Studies how biochar pore structure influences carbon dioxide uptake, carbonation, strength development, and carbon storage in cement composites.
Reviews how biochar influences carbon persistence, soil chemistry, aggregation, and microbial ecology and the mechanisms that protect organic carbon from decomposition.
Reviews biochar production, soil interactions, sequestration potential, durability, environmental consequences, and major research gaps.
Examines rice-straw biochar as a recycled-concrete additive and measures carbon uptake, durability, microstructure, and compressive strength.
Reviews biochar stability, microbial effects, methane uptake, soil greenhouse gases, and chemical characteristics governing carbon persistence.
Reviews methods for mineralizing CO2 within concrete and construction wastes, including reaction mechanisms, process optimization, lifecycle storage, and engineering applications.
Tests biochar-containing core-shell aggregates as a means to store biogenic carbon in concrete while limiting losses in material strength.
Reviews biochar's potential to increase soil carbon, improve fertility and water retention, and strengthen agricultural resilience to drought and climate change.
Explores machine learning and literature-mining approaches for identifying feedstocks and production conditions associated with durable biochar carbon storage.
Tests combined biochar and bentonite amendments in sandy soils and reports improvements in soil properties, carbon retention, and greenhouse-gas mitigation potential.
Reports an additional sequestration mechanism in which biochar-amended soil can directly sorb atmospheric CO2 beyond the carbon already stored within biochar.
Reviews stable biochar carbon, soil aggregation, microbial activity, soil remediation, greenhouse gases, and agricultural applications.
Studies compost-biochar combinations in urban green-space soils and links carbon accumulation with plant inputs, microbial metabolism, and soil enzymes.
Wetlands and Peatlands
Uses GIS, remote sensing, and machine learning to quantify how restoration has changed carbon storage in degraded wetlands surrounding China's Chaohu Lake.
Shows how warming may weaken the climate-cooling balance of temperate wetlands by changing the relationship between carbon dioxide uptake and methane emissions.
Examines microbial carbon-fixation pathways across natural, reclaimed, and restored wetlands and identifies hydrology and nitrogen as major controls.
Measures carbon fluxes during early restoration of former peat extraction and grazed peatland sites and demonstrates that initial trajectories differ strongly by degradation history.
Reconstructs decades of sediment deposition and shows that wetland rewetting can rapidly increase organic-carbon burial before the ecosystem fully stabilizes.
Provides a dataset of soil-carbon accumulation rates for California tidal wetlands that can improve blue-carbon inventories and restoration assessments.
Shows that plant traits and community composition can strongly influence carbon accumulation in natural wetlands, with large slow-growing hydrophytes associated with greater storage.
Combines remote sensing and machine learning to map soil organic-carbon density and quantify changes following lake-wetland restoration.
Models carbon dioxide, methane, vegetation, peat formation, and albedo responses following restoration of forestry-drained peatlands.
Examines aquatic sediments as active components of the carbon cycle whose storage performance depends on redox conditions, mineralogy, hydrology, and management.
Examines emissions generated by restoration work itself and asks how quickly later carbon benefits repay the carbon cost of machinery, materials, and implementation.
Synthesizes peatland restoration studies and evaluates changes in hydrology, carbon dioxide, methane, sequestration, and ecological recovery.
Reviews forest-to-bog restoration and finds that greenhouse-gas, hydrological, chemical, and biodiversity recovery can require years to decades.
Summarizes research showing that rapid Sphagnum recovery can rebuild peat-forming vegetation and produce substantial carbon accumulation after peatland restoration.
Examines how submerged vegetation and surrounding landscape characteristics influence carbon and nitrogen storage within shallow brackish sediments.
Examines baselines, permanence, methane, additionality, measurement uncertainty, and other issues involved in issuing carbon credits for peatland rewetting.
Uses a long-term controlled restoration experiment to examine recovery across several types of forestry-drained boreal peatlands.
Reports a large Indonesian rewetting experiment showing reduced peat subsidence and substantial spontaneous recovery of native peat-swamp forest species.
Slow wetland sink recovery | Samuel Royle | Nature Climate Change | 2024-04-10
Highlights evidence that restored wetlands may become carbon sinks relatively quickly but can require much longer to deliver a net climatic cooling benefit once methane is included.
Shows that greenhouse-gas emissions after peatland rewetting change through time and argues against treating restored peatlands with a single static emission factor.
Synthesizes wetland, peatland, grassland, and other restoration studies and finds important trade-offs among carbon dioxide uptake, methane, and nitrous oxide.
Shows that restoration can rapidly improve peatland hydrology while carbon fluxes and other ecosystem functions may take substantially longer to recover.
Models interactions among peatland degradation, fire, restoration, and climate change and finds that worsening fires could substantially erode the northern peatland carbon sink.
Finds that post-extraction fen rewetting can restore vegetation and growing-season carbon uptake, although methane emissions remain an important climate consideration.
Reviews whether restored peatlands regain enough hydrological, ecological, and carbon-storage function to remain resilient to drought, flooding, and wildfire.
Compares five years of carbon balances between rewetted and drained peat and evaluates when restoration begins delivering climate benefits.
Mangroves, Seagrasses, and Blue Carbon
Quantifies sediment organic carbon in Mauritius's seagrass and mangrove ecosystems to improve national blue-carbon inventories and restoration assessments.
Compares seagrass sediment carbon stocks across marine protected, locally managed, and unmanaged sites within Kenya's Lamu Archipelago.
Finds that carbon losses caused by salt-marsh degradation and conversion currently exceed gains achieved through restoration, emphasizing the importance of protecting existing marshes.
Uses natural CO2 vents in Italy to investigate how long-term acidification affects organic-carbon burial in Posidonia oceanica meadows.
Reviews tidal freshwater and forested wetlands as additional blue-carbon ecosystems alongside mangroves, salt marshes, and seagrass.
Reconstructs changes in seagrass sediment carbon and finds increasing sequestration and storage capacity at study sites in northern Morocco.
Quantifies previously underappreciated methane emissions through mangrove stems and shows that these emissions reduce—but do not eliminate—the climatic benefit of mangrove carbon burial.
Provides global estimates of carbon stored in living seagrass biomass and captured through net primary production, complementing sediment-based blue-carbon inventories.
Reviews mangrove carbon sources, sediment burial, root systems, microbial processes, carbon transport, and methods for estimating mangrove sequestration.
Estimates carbon stocks and sequestration associated with Portuguese kelp forests and evaluates macroalgae as a potentially overlooked component of blue carbon.
Synthesizes paired observations showing that soil-carbon losses following disturbance vary substantially by ecosystem, disturbance type, and soil depth.
Uses field inventories and decades of satellite observations to compare biomass recovery in natural, rehabilitated, and regenerated mangrove stands.
Shows that shifting meadow boundaries can prevent some seagrass systems from accumulating the deep, persistent sediment carbon expected from more stable meadows.
Evaluates biodiversity, forest structure, and carbon accumulation a decade after mangrove restoration.
Estimates large mitigation opportunities from protecting and restoring Southeast Asian peat-swamp forests and mangroves, including rewetting drained peat.
Builds a large global seagrass database and provides revised estimates of soil carbon stocks and potential emissions caused by seagrass degradation.
Models future carbon accumulation in the Bahama Banks under continuing seagrass loss versus large-scale restoration scenarios.
Shows that methane oxidation substantially reduces the methane penalty associated with mangrove blue-carbon sequestration, particularly in saline systems.
Combines long-term carbon burial with methane and nitrous-oxide flux measurements to refine estimates of seagrass climate benefits.
Ocean Carbon Dioxide Removal and Alkalinity Enhancement
Integrates engineering, ecological, permitting, carbon-accounting, and economic analysis for a proposed Baltic Sea alkalinity-enhancement pathway.
Demonstrates that circulation, mixing, and regional ocean conditions strongly influence how efficiently added alkalinity produces verified atmospheric carbon removal.
Examines how acid generated by electrochemical alkalinity enhancement could be neutralized or turned into useful products rather than becoming a waste stream.
Investigates calcium- and magnesium-rich mining wastes as lower-energy alkaline feedstocks for increasing ocean carbon uptake.
Argues that large scientific uncertainties, ecological and social risks, and inadequate governance must be addressed before marine CDR can responsibly scale.
Uses an Earth-system model extending to 2500 to assess the long-term atmospheric carbon and ocean-acidification effects of sustained alkalinity enhancement.
Reports autonomous high-frequency alkalinity measurements during a field trial and illustrates technologies needed for marine carbon-removal MRV.
Examines where marine-carbon-removal scientists agree and disagree about measurement, verification, baselines, uncertainty, and international MRV standards.
Evaluates whether hydrated carbonate minerals can deliver net carbon removal after accounting for electricity, material production, transport, and other lifecycle impacts.
Ocean Carbon Dioxide Removal and Storage | Various authors | Chemical Reviews | 2026-01-06
Reviews natural ocean carbon storage and engineered approaches including alkalinity enhancement, macroalgae pathways, direct ocean capture, and associated MRV challenges.
Enhanced Weathering, Mineralization, and Mine Tailings
Reviews carbonation reactions in mafic and ultramafic rocks and connects mineral CO2 storage with broader geological carbon and hydrogen cycles.
Reviews laboratory approaches for converting captured CO2 into stable calcium-carbonate minerals and evaluates reaction controls and opportunities for scaling.
Surveys mine-tailings and crushed-rock weathering experiments and assesses mining infrastructure as a potential platform for large-scale mineral carbon removal.
Reports a five-year field experiment in which glacial rock flour weathering contributed to inorganic carbon removal while also affecting soil organic-carbon dynamics.
Finds that basalt amendment increased carbon accrual in crop systems through processes extending beyond simple inorganic weathering chemistry.
Demonstrates a direct-air-capture pathway in which captured CO2 can be reacted with waste brine and converted into solid carbonate minerals.
Compares calcium- and magnesium-rich feedstocks for mineral carbonation, including reaction pathways, efficiencies, products, durability, and industrial applications.
Tests combined dunite and biochar amendments and finds interactions affecting mineral weathering, soil properties, and both inorganic and organic carbon storage.
Demonstrates electrochemical pH control for precipitating stable calcium carbonate from mine-tailings water while simultaneously valorizing mining waste.
Reviews mineral carbonation using natural rocks and industrial wastes and evaluates mechanisms, feedstocks, waste utilization, durability, and scale-up constraints.
Reports a reforestation field experiment combining crushed silicate rock with microbiome manipulation and examines consequences for tree growth and carbon accumulation.
Demonstrates enhanced carbonation of ultramafic mine tailings while retaining sufficient mechanical strength for use as underground backfill.
Reviews mechanical, chemical, thermal, and hybrid methods for accelerating permanent carbonate formation in calcium- and magnesium-rich mine wastes.
Laboratory experiments with Brazilian flood basalts demonstrate rapid carbonate precipitation and highlight South American basalt provinces as possible permanent CO2-storage resources.
Geological Carbon Sequestration
Synthesizes structural, residual, solubility, and mineral trapping and examines how processes operating at different scales determine long-term storage security.
Uses deep reinforcement learning to optimize injection locations and schedules while accounting for storage volume, pressure, geomechanical effects, and leakage risk.
Reviews how underground microbes can change injected carbon dioxide through biomethanation, biomineralization, and other reactions affecting storage performance.
Uses probabilistic economic modeling to analyze investment risk, carbon-price thresholds, and financial viability for Denmark's offshore Project Greensand storage project.
Reviews India's geological storage potential, storage formations, trapping mechanisms, infrastructure, monitoring, policy, risks, and deployment challenges.
Reviews structural, residual, solubility, mineral, and hydrate trapping together with suitable formations, leakage risks, and monitoring methods.
Reviews open-source models, datasets, and data-science tools for evaluating offshore geological carbon-storage systems.
Compares nuclear magnetic resonance with seismic and conventional monitoring methods and advocates hybrid systems for tracking trapping, plume movement, and leakage.
Separates the physical mechanisms controlling CO2 and brine leakage and assesses the implications for safe storage in saline aquifers and other geological formations.
Explains how subsurface pressure constraints can limit CO2 storage before available pore volume is exhausted and advocates coordinated basin-scale pressure management.
Models injection into a depleted offshore gas reservoir and evaluates storage capacity, heterogeneity, trapping mechanisms, and offshore CCS potential.
Reviews mineral trapping within saline aquifers, including reservoir mineralogy, brine chemistry, reaction kinetics, catalysts, monitoring, and economic challenges.
Develops reduced-order models for faster forecasting and optimization of underground CO2 migration and injection strategies.
Reviews systems that circulate carbon dioxide through geothermal reservoirs while simultaneously producing energy and storing some CO2 underground.
Reviews developments in reservoir simulation, reduced-order models, uncertainty analysis, data assimilation, permitting, and risk assessment.
Reviews carbon capture, transport, saline-aquifer storage, depleted reservoirs, basalts, monitoring, economics, and North American CCS deployment.
Integrates structural, residual, solubility, and mineral trapping into a modeling framework for evaluating and optimizing saline-aquifer CO2 storage.
Combines laboratory experiments and geochemical modeling to study mineral reactions, brine chemistry, and long-term trapping in saline formations.
Reviews geological, well-design, pressure-management, planning, injectivity, and containment challenges associated with large-scale saline-aquifer storage.
Applies physics-informed neural networks to simulate CO2 migration and trapping in geologically layered saline formations.
Uses numerical simulations to examine how reservoir properties, salinity, caprock characteristics, and operating conditions influence different forms of CO2 trapping.
Reviews carbonate-reservoir storage potential, petrophysical complexity, trapping mechanisms, numerical modeling, and lessons from existing underground storage research.
Investigates dissolved-water CO2 injection as a strategy for limiting near-well salt precipitation and maintaining injectivity during underground carbon storage.
Models how reservoir mineral composition influences dissolution, precipitation, reactive transport, and long-term carbon trapping.
Models how fracture networks and injector positioning influence CO2 migration, containment, trapping, and storage efficiency within carbonate saline aquifers.
Uses material recovered from a field-scale basalt mineralization project to characterize the carbonate phases that form during permanent subsurface CO2 storage.
Reviews structural, stratigraphic, reservoir, plume-migration, and numerical-modeling requirements for evaluating geological carbon-storage sites in Atlantic Canada.
Reviews exploration and suitability assessment for deep saline aquifers, depleted hydrocarbon reservoirs, unmineable coal seams, and basalt formations.
Reviews how salt precipitation near injection wells can reduce permeability and examines strategies for maintaining injectivity during geological sequestration.
Direct Air Capture and Engineered Atmospheric Removal
Reviews solid adsorbents, liquid absorbents, electrochemical systems, process engineering, costs, and technological barriers to large-scale DAC.
Models pathways for scaling direct air capture and finds that strong near-term deployment, learning, infrastructure, and investment are essential to approach gigaton-scale removal by 2050.
Examines DAC carbon-credit integrity and argues that permanence and quantification can be comparatively strong while project delivery and economics remain difficult.
Discusses industrial requirements for DAC including sorbent durability, weather tolerance, energy use, air flow, pressure drop, maintenance, and scalability.
Reviews new DAC contactor geometries and process-intensification methods designed to lower pressure drop, energy demand, and mass-transfer limitations.
Compares conventional industrial carbon capture with DAC and reviews current technical limitations, energy demand, cost, and sorbent requirements.
Compares more than 150 DAC scenarios involving different sorbents, energy supplies, manufacturing routes, costs, and life-cycle greenhouse-gas footprints.
Compares alkaline washing, temperature-vacuum adsorption, electro-swing capture, and accelerated-weathering capture for their potential to scale industrially.
Describes a Kenya pilot combining solar-powered direct air capture with subsurface carbon mineralization in the Great Rift Valley.
Reviews DAC thermodynamics, adsorption kinetics, sorbent classes, regeneration processes, system designs, and economic performance.
Demonstrates an atmospheric capture system designed to combine CO2 removal with water adsorption and lower-energy regeneration.
Shows that temperature, humidity, and geographic location can substantially change DAC energy requirements, operating costs, and net removal efficiency.
Compares DAC and direct ocean capture in terms of mechanisms, scale-up, energy requirements, lifecycle impacts, infrastructure, and environmental constraints.
Compares liquid scrubbing, solid sorbents, electrochemical capture, cryogenic methods, and membranes using technical, environmental, and cost criteria.
Explores distributed DAC mounted on vehicles, ships, aircraft, and other mobile platforms rather than relying exclusively on large stationary plants.
Surveys more than 50 DAC companies and compares sorbents, electrochemical approaches, business models, CO2 utilization, and storage partnerships.
Presents perspectives from researchers and companies developing electrochemical systems that remove carbon directly from air or seawater.
Assesses technology readiness, planned facilities, materials requirements, investment needs, and barriers to scaling DAC from pilots to climate-relevant capacity.
Reviews integration of atmospheric capture with chemical conversion as a strategy for reducing equipment and energy requirements.
BECCS and Biomass-Based Carbon Removal
Reviews biomass cultivation, conversion, capture technologies, transport, storage, lifecycle performance, economics, and existing BECCS projects worldwide.
Treats BECCS as an integrated chain and shows how feedstock properties, impurities, capture, transport, geological uncertainty, and monitoring interact.
Examines how bioenergy, capture, utilization, permanent storage, market incentives, and regulation interact in emerging BECCUS systems.
Examines China's biomass resources, CCUS infrastructure, project sequencing, technology choices, and potential pathway toward larger-scale BECCS deployment.
Reviews combustion, gasification, pyrolysis, and other thermochemical pathways coupled with carbon capture and permanent storage.
Reviews biomass combustion, CO2 capture, pollution control, economics, technology readiness, and global BECCS demonstration projects.
Reviews lifecycle assessments of BECCS and highlights how system boundaries, land-use assumptions, biomass sources, and energy inputs determine whether systems are genuinely carbon negative.
Finds wide variation in estimated BECCS lifecycle emissions and emphasizes that captured biogenic CO2 does not automatically equal net atmospheric removal.
Reviews technological, economic, policy, social-acceptance, regulatory, and environmental barriers to BECCUS deployment.
Surveys BECCS and BECCU technologies while examining costs, land and water requirements, food-security concerns, and barriers to commercialization.
Permanence, Verification, Economics, and Carbon-Removal Governance
Warns that poorly designed carbon-removal policy can prolong fossil-fuel use and argues that removals must supplement rather than substitute for rapid emissions reductions.
Argues that community participation, distribution of benefits and harms, and planning institutions should be built into carbon-removal deployment before projects reach large scale.
Argues that sustainable carbon-removal capacity is limited and should be prioritized for genuinely hard-to-abate emissions and temperature-overshoot management.
Develops a framework for understanding governments, companies, researchers, communities, and other stakeholders whose interests and influence shape carbon-removal deployment.
Compares 16 carbon-removal approaches using technical potential, environmental and social considerations, governance, and expected storage durability.
Examines political risks of relying on future CCS-based removals without simultaneously building the institutions, financing, infrastructure, and regulations needed to deliver them.
Compares national climate pledges with modeled future carbon-removal requirements and finds a substantial gap unless emissions decline much faster.
Examines biochar recovered after 15 years in agricultural soil and finds persistent inert carbon fractions relevant to claims of durable biochar carbon removal.
The cost of permanent carbon dioxide removal | Various authors | Joule | 2023
Develops a framework for comparing carbon-removal options after accounting for storage duration, reversal risks, monitoring costs, and replacement of temporary storage.
Argues that credible carbon-removal markets require strong certification rules addressing additionality, quantification, durability, reversal risk, and transparent verification.
