Sequestration Potential Research Articles

Direct CO2 mineralization and evolution behavior of fine CaCO3 from ammonia-induced phosphogypsum mineral carbonation

The mineral carbonation of phosphogypsum (PG) presents considerable potential for simultaneous CO2 sequestration and high-value utilization of PG. Variations in carbon footprints are crucial for enhancing carbonation efficiency and regulating product formation. This study explores the mechanism of direct CO2 mineralization by PG and the evolution of the resulting product. The results demonstrate that 97.14% of the CaSO4·2H2O in PG can be converted to calcite under conditions including a nitrogen–sulfur molar ratio of 3, a liquid–solid ratio of 6, a CO2 flowrate of 0.4 L/min, and a stirring rate of 800 rpm for 60 min. The carbonation rate exhibits significant variation with time, occurring in three distinct stages. Initially, CO2 reacts with ammonia to form (NH4)2CO3, releasing greater heat. This heat inhibits the dissolution of Ca2+ from PG, resulting in a lower carbonation efficiency, as only a limited amount of Ca2+ reacts with CO32– to preferentially form amorphous CaCO3 (ACC). As CO32– formation reaches equilibrium, the endothermic properties of the reaction between CaSO4 and (NH4)2CO3 promote the dissolution of Ca2+ from PG, further accelerating CO2 mineralization and resulting in significant increases in carbonation efficiency and ACC production. The ACC is rapidly transformed into calcite via a “dissolution-reprecipitation” mechanism. However, the carbonation rate of PG decreases as saturation is approached, mainly resulting from the aggregation of fine CaCO3 particles on the PG surface. As a result, the direct CO2 sequestration process by PG follows a carbon footprint sequence of “CO2–(NH4)2CO3–ACC–calcite”. This study provides significant insights into the mechanisms of direct CO2 mineralization and product evolution and offers a basis for optimizing carbonation processes enhancement and regulating product phases.

Seaweed sinking has great potential for climate mitigation in China

With the intensification of the greenhouse effect, the climate-mitigation role of marine carbon sequestration (blue carbon) is gaining more attention. Seaweed aquaculture, as an important nature-based solution that provides various ecosystem services while as a food source, have become the main way of marine biological carbon sequestration. As an emerging carbon dioxide removal strategy, sinking seaweeds to the deep sea for additional CO2 sequestration to contribute to Paris Agreement temperature goal have attracted much attention. Currently, the ecological value assessment of sinking seaweeds is immature, and there is also a conflict between with traditional food values. However, in the long term, the value of carbon sequestration will continuously rise as global emission reduction advance, and rapidly growing seaweed production will be able to fully satisfy food demand in the future. Therefore, sinking surplus seaweeds to convert excess food value into higher ecological value is more compatible with development prospects, and long-term planning for sinking seaweed is particularly important. As the largest seaweed farming country, China accounted for more than half of the world’s production in 2021, possessing a huge potential for carbon sequestration. Incorporating factors such as food requirements, emission reduction demands and population changes, this paper explored the feasibility and planning of sinking seaweeds to serve the achievement of climate goals under five SSP-RCP scenarios in 2020–2050. The results indicate that with the slowdown in population growth and increasing demand for climate mitigation, the ecological value of seaweeds has more development potential than the edible value, and thus the sunken seaweed task should be placed more in the later period (2041–2050 phase) to maximize the ecological benefits of seaweed farming. Sinking seaweed is able to serve the SSP1-2.6 and SSP2-4.5 scenarios relatively well, while the realization of the SSP1-1.9 scenario presents some challenges.

Accumulation of soil microbial necromass carbon and its contribution to soil organic carbon after vegetation restoration in the Tibetan Plateau

Vegetation restoration has been proved as an effective strategy to increase soil organic carbon (SOC) sequestration in degraded ecosystems. However, due to different vegetation restoration practices and climate zones, changes of SOC content, dynamics, sources and their controlling mechanisms after vegetation restoration remain inadequately addressed. Taking the advantage of four-year vegetation restoration, we explored the effects of vegetation restoration on SOC through its fractions, soil aggregates, soil enzymes and microbial necromass contribution to SOC in a desertification region in the Tibetan Plateau (TP). Results showed that vegetation restoration increased SOC contents by 68% for 0 – 10cm, 29% for 10 – 30cm and 11% for 30 – 50cm compared to site without vegetation restoration. Vegetation restoration increased soil macroaggregates (> 0.25mm) and decreased soil microaggregates (0.53 – 0.25mm), but increased their associated SOC contents. Meanwhile, vegetation restoration enhanced microbial necromass and its contribution to SOC. Structural equation model revealed that increasing microbial necromass carbon, changing soil aggregates and their associated SOC were the main mechanisms of increasing SOC content after vegetation restoration. Our result further indicated a large potential of SOC sequestration through vegetation restoration in the TP. These findings have important implications for natural based solution for carbon neutrality for China.

Triple impact: Biochar, no-tillage, and cover crops for soil carbon enhancement and climate resilience in soybean farming

With the dissemination of conservation agriculture, no-tillage (NT) and cover crops have widely been adopted globally. However, their effects on greenhouse gas (GHG) emissions are controversial. Biochar is posited to mitigate climate change by increasing carbon (C) sequestration and decreasing GHG emission in soil. To investigate the comprehensive effect of NT, cover crops, and biochar on soil organic carbon (SOC) sequestration and net global warming potential (GWP), a split-split-plot experiment was conducted. The experiment involved various combinations of two tillage methods (NT; Moldboard plowing, MP), two cover crop treatments (Fallow, FA; Rye, RY), and two biochar treatments (with biochar application, WB; no biochar application, NB). NT and RY demonstrated a trend of increasing N2O emission, while WB tended to reduce the N2O emission in NT plots. NT–RY–WB increased the SOC stock (0–30 cm) by 23.2% in 2020 and 30.2% in 2021 compared with MP–FA–NB, indicating that this combination promoted C sequestration. Due to the heightened SOC stock, the net carbon dioxide (CO2) retention effectively compensated the GWP arising from non-CO2 emissions. Consequently, the triple combination of NT, RY and WB positively contributed to a decreased net GWP in the soybean field (−1231 kg CO2 equivalent ha−1 year−1 in 2020 and −2767 kg CO2 equivalent ha−1 year−1 in 2021). These findings highlight the considerable potential of the combined NT–RY–WB for SOC sequestration and net GWP decrease, positioning it as an environmentally beneficial agricultural system for mitigating climate change in Asia’s long-term food production.

Timber and carbon sequestration potential of Chinese forests under different forest management scenarios

Developing forestry action plans with the goal of carbon neutrality is a critical task to identify carbon sink potential and balance the pathways of China's forests. Current research that predicts forest biomass carbon stock and sink potential has shortcomings, such as an incomplete assessment of China's forest carbon sink range, assumptions based on unchanged forest area in the base year and insufficient consideration of natural and human disturbance factors. This study utilised the national forest inventory (NFI) data to construct a model of forest growth and consumption using a machine learning algorithm (i.e. random forest), identified suitable areas for future forest expansion by integrating multi-source data, and set up three future forest management scenarios: business as usual (BAU), enhanced policy scenario (EPS) and maximum potential scenario (MPS). In addition, changes in the area, volume stock and biomass carbon stock in China's forests between 2020 and 2060 were predicted under three forestry activities (i.e. existing forest, afforested/reforested (AR) forest and forest conversion) and three climate scenarios (i.e. SSP126, SSP370 and SSP585) based on the 9th NFI (2014–2018). According to China's relevant planning goals and suitable forest space, the area of AR forests is predicted to be 55.55 × 106 hm2 by 2060, and the forest coverage rate is predicted to increase from 23% in 2018 to 28% by 2060. Biomass carbon sequestration (BCS) between 2020 and 2060 in AR forests is predicted to be 36.00 TgC per year. By 2060, the average BCS is predicted to be approximately 140.00–287.56 TgC per year in China's forests, which is mainly owing to arbor forest management. Under the BAU and EPS scenarios, BCS in China's forests is expected to decline from 2020 to 2060. However, under the MPS, BCS in China's forests is projected to increase and be maintained at 322 TgC per year or above by 2060, with wood production reaching 4.71 × 108 m3 per year. China's forests are predicted to experience an increase in biomass carbon stock in the future and play a role as a carbon sink. By taking measures to achieve the maximum growth potential of all forest types, China's forests will achieve a win‒win situation between carbon sinks and timber production.

Relationship Between Evolutionary Diversity and Aboveground Biomass During 150 Years of Natural Vegetation Regeneration in Temperate China.

While the link between plant species diversity and biomass has been well-studied, the impact of evolutionary diversity on community biomass across long timescales or ongoing change remains a subject of debate. We elucidated the association between evolutionary diversity and community aboveground biomass (AGB) using an ideal experimental system with over 150-year history of natural vegetation regeneration. Higher phylogenetic diversity facilitated the sampling effect under the influence of environmental filtering, and caused an increase in AGB. Phylogenetic structure varied from aggregation to dispersion during the later period of vegetation recovery (70-150 years), which was correlated with increases in niche complementarity and increasing AGB. Woody plant evolutionary diversity was used as a key to predict the relationship between vegetation recovery and AGB, with a total explanatory power of ~84.7%. Mixed forests composed of evergreen conifers and deciduous broadleaf forests had higher carbon sequestration potential than that of pure forests, which is advantageous for increasing top-stage AGB. This research expands our knowledge of the causes and effects of biodiversity and ecosystem function dynamics over time and space, which is important for accurately predicting future climate change effects.

Enhanced carbon use efficiency and warming resistance of soil microorganisms under organic amendment

The frequency and intensity of extreme weather events, including rapid temperature fluctuations, are increasing because of climate change. Long-term fertilization practices have been observed to alter microbial physiology and community structure, thereby affecting soil carbon sequestration. However, the effects of warming on the carbon sequestration potential of soil microbes adapted to long-term fertilization remain poorly understood. In this study, we utilized 18O isotope labeling to assess microbial carbon use efficiency (CUE) and employed stable isotope probing (SIP) with 18O-H2O to identify growing taxa in response to temperature changes (5–35 °C). Organic amendment with manure or straw residue significantly increased microbial CUE by 86–181 % compared to unfertilized soils. The microorganisms inhabiting organic amended soils displayed greater resistance of microbial CUE to high temperatures (25–35 °C) compared to those inhabiting soils fertilized only with minerals. Microbial growth patterns determined by the classification of taxa into incorporators or non-incorporators based on 18O incorporation into DNA exhibited limited phylogenetic conservation in response to temperature changes. Microbial clusters were identified by grouping taxa with similar growth patterns across different temperatures. Organic amendments enriched microbial clusters associated with increased CUE, whereas clusters in unfertilized or mineral-only fertilized soils were linked to decreased CUE. Specifically, shifts in the composition of growing bacteria were correlated with enhanced microbial CUE, whereas modifications in the composition of growing fungi were associated with diminished CUE. Notably, the responses of microbial CUE to temperature fluctuations were primarily driven by changes in the bacterial composition. Overall, our findings demonstrate that organic amendments enhance soil microbial CUE and promote the enrichment of specific microbial clusters that are better equipped to cope with temperature changes. This study establishes a theoretical foundation for manipulating soil microbes to enhance carbon sequestration under global climate scenarios.

Blue Carbon Assessment in the Salt Marshes of the Venice Lagoon: Dimensions, Variability and Influence of Storm‐Surge Regulation

AbstractSalt marshes are intertidal coastal ecosystems shaped by complex feedbacks between hydrodynamic, morphological, and biological processes. These crucial yet endangered environments provide a diverse range of ecosystem services but are globally subjected to high anthropogenic pressures, while being severely exposed to climate change impacts. The importance of salt marshes as “blue carbon” sinks, deriving from their primary production coupled with rapid surface accretion, has been increasingly recognized within the framework of climate mitigation strategies. However, large uncertainties remain in salt marsh carbon stock and sequestration estimation. In order to provide further knowledge in salt marsh carbon assessment and investigate marsh carbon pool response to management actions, we analyzed organic matter content in salt marsh soils of the Venice Lagoon (Italy) from 60 sediment cores to the depth of 1 m and estimated organic carbon stock and accumulation rates in different areas. Organic carbon stocks and accumulation rates were highly variable in different marshes, being affected by organic and inorganic inputs and preservation conditions. Our estimates suggest that the studied marshes store 17,108 ± 5,757 tons of carbon per square kilometer in top 1‐m of soil and can accumulate 85 ± 25 tons of carbon per square kilometer per year. However, flood regulation may reduce the annual marsh CO2 sequestration potential by more than 30%. Our results contribute valuable information for regional carbon assessments, reinforcing the need for integrated coastal management policies to preserve the ecosystem services of coastal environments, and underscore the importance of considering local variability and methodological variations.

Environmental benefits of ozonated water for sustainable grapevine disease control: A life cycle and carbon sequestration analysis

The oxidative capacity of ozone makes it a highly effective biocide, widely used in the food and processing industry, as well as in drinking water plants. In a context of tighter restrictions on the use of synthetic plant protection products at the regulatory level, wineries are looking for alternative methods to control diseases, making the application of ozonated water an option to consider. To determine the environmental sustainability of this alternative vineyard disease control treatment, an environmental impact assessment was conducted using the Life Cycle Assessment (LCA) methodology. The assessment was carried out in a vineyard located in the D.O. Rías Baixas of Galicia, located in northwestern Spain. The analysis was conducted on the basis of two functional units: i) 1 kg of grapes and ii) 1 ha of land managed and using a cradle-to-gate boundary system. Ten impact categories were assessed using the ReCiPe method, except for the water scarcity indicator, which was quantified using AWARE.The environmental sustainability of the vineyard was further analyzed by measuring its carbon sequestration potential to obtain a more complete environmental profile. The RothC-26.3 model was chosen to estimate absolute carbon sequestration and annual sequestration rate from 2020 to 2040. Since the ozone-only scenarios lost all harvest, no environmental assessment was performed for such scenarios. For the remaining scenarios, the findings suggest that those using a combination of ozonated water and fungicides have the worst environmental performance due to notable reductions in grape yield and more frequent disease control interventions, particularly in certain scenarios. When evaluating environmental performance per hectare of land managed, the scenario using ozonated water with a limited number of disease control interventions exhibited the most favorable environmental profile, primarily due to reduced use of fungicides and disease control passes. In addition, the main contributors to the vineyard environmental profile identified were diesel fuel combustion during field operations, fertilizer use and production, and irrigation. In addition, the research indicates that the vineyard sequesters carbon annually, but this alone is insufficient to offset its greenhouse gas emissions. However, it is estimated that through the application of more appropriate soil management practices, the vineyard could achieve carbon neutrality and potentially increase soil carbon stocks over time.

A multi-objective optimization framework for regional land-use allocation: Fully utilizing terrestrial vegetation to mitigate carbon emissions

Human-induced changes in land use and land cover (LULC) considerably impact the global carbon cycle. Rational LULC optimization with full utilization of terrestrial vegetation facilitates reconciling carbon reduction and socio-economic development. To this end, this study develops a multi-objective framework for low-carbon LULC spatial optimization that incorporates carbon suitability, historical suitability, and socio-economic needs. The framework is applied to Hubei Province, China. The key findings include: (1) Considering spatial variations in vegetation carbon sinks could lead to remarkable carbon reductions of 2.75 × 106 t C by 2030 and 7.68 × 106 t C by 2060. It would also lower carbon emissions per unit of gross domestic product (GDP) and enhance carbon sequestration per unit of vegetation by 2030, signifying enhanced carbon reduction efficiency. (2) Integrating carbon sequestration potential and historical suitability can considerably minimize emissions while sustaining socio-economic growth. Our method, compared with strategies based solely on historical development laws, can reduce carbon emissions by approximately 1.3–1.6 × 106 t C·a−1. (3) We also propose targeted low-carbon development suggestions for different LULCs. This study provides optimal spatial LULC allocations and strategic advice for regional LULC planning aimed at low-carbon development, demonstrating the feasibility of reconciling the tension between carbon reduction and socio-economic growth at the regional scale.

Conservation value and carbon sequestration potential of urban green spaces in a growing city: Case of the city of Bouaflé

Faced with the effects of climate change, green spaces are very determining in the provision of ecosystem services, particularly in carbon sequestration. This is why, from a perspective of sustainable management of these high-value spaces, this study was carried out. Surface and itinerant survey methods were combined to collect floristic data. At the end of the inventories, 99 species distributed between 33 families and 75 genera including 24 species with special status were recorded in eight (08) types of development. The total biomass of all the species inventoried at Bouaflé is 4385.78 t, corresponding to a carbon rate of 2192.91 t for a CO2 equivalent of 8047.99 t. The economic value of the rate of CO2 sequestered by all types of development varies from 24143.97 Euros, or 15814274 FCFA according to the CDM carbon price to 112671.86 Euros, or 73800068 FCFA according to the REDD+ carbon price. Social and educational establishments recorded the highest biomass (1841.88 t) while the lowest biomass (5.53 t) was estimated in sports equipment. The average biomass estimated in all types of development is of the order of 232.02±185.64 t/ha, which corresponds to a carbon rate of 116.01±92.82 t/ha and an equivalent CO2 of 425.76±340.65 t/ha. Considering each type of development, the average value of biomass varies between 24.83 t/ha in sports facilities and 468.79 t/ha in cemeteries.

Carbon Absorption Potential in Sargassum sp. and Padina sp. in The Waters of East Melano Bay, Lemukutan Island, Bengkayang District, West Kalimantan Province

Increasing human activities have caused negative impacts on the environment, such as rising earth's surface temperature and extreme climate change. This impact is caused by increased greenhouse gas emissions such as carbon dioxide and methane. Marine vegetation such as seaweed Sargassum sp. and Padina sp. It can also help absorb carbon and reduce carbon emissions through the process of photosynthesis. Seaweed that has the potential to reduce carbon emissions is Sargassum sp. and Padina sp. which is located in the waters of East Melano Bay, Bengkayang Regency. This study aims to determine the density of seaweed species Sargassum sp. and Padina sp. in East Melano Bay, as well as analyzing the carbon sequestration potential of seaweed. The method used is to use the descriptive method of exploration. The descriptive method of exploration aims to describe the state of a phenomenon. This study uses the quadrant transect method in sampling in the field, while the determination of carbon content uses the analysis of biomass, ash content, moisture content and volatile substances. The results of the analysis that have been carried out show the density value of Sargassum sp. has the highest value of 102.4 Ind/m2 and Padina sp. 76.05 Ind/m2. Carbon sequestration by seaweed Sargassum sp. is 105,637 tons of C/ha and Padina sp. amounting to 78,032 tons of C/ha. Based on the description in this study, it can be concluded that the highest carbon absorption is in Sargassum sp.

Effect of biochar application on physiochemical properties and nitrate degradation rate in a Siliciclastic Riverine Sandy soil

This study investigated the efficacy of biochar as a soil amendment for enhancing soil physicochemical properties and solute transport dynamics, with implications for agricultural sustainability and environmental stewardship. Batch laboratory experiments and column studies were conducted to assess the effects of biochar application on soil parameters and solute transport under saturated conditions. The saturation soil extraction approach was employed in batch leaching tests, while column experiments replicated subsurface conditions. Transport modeling using CXTFIT 2.1 elucidated solute dispersion dynamics in biochar-amended soils. Batch experiments revealed significant alterations in soil pH, electrical conductivity, and nutrient release following biochar addition. Biochar exhibited adsorption capacity for fluoride ions and released dissolved organic carbon, highlighting its potential for soil carbon sequestration and microbial activity. Column studies demonstrated enhanced solute dispersion and increased microbial activity in biochar-amended soils, as evidenced by changes in breakthrough curves and degradation rates of nitrate. Indeed, nitrate first-order degradation coefficients were 9.08E-06 for the column with only sandy soil, 3.09E-05 and 1.47E-04 for the columns with minimum and maximum doses of biochar respectively. Biochar application significantly influenced soil physicochemical properties and solute transport dynamics, with potential implications for nutrient management and contaminant attenuation in agricultural systems. Despite limitations in laboratory-scale experiments, this research provides valuable insights into biochar-soil interactions. It underscores the need for further investigation under field conditions to validate findings and optimize biochar management practices for sustainable soil and environmental management.

Evaluation of carbon sink and photovoltaic system carbon reduction along roadside space

As China's photovoltaic (PV) sector experiences rapid growth, the availability of land resources has become a pivotal policy focus, driving the need for comprehensive research and strategic planning for roadside PV initiatives. Utilizing a fuzzy multi-criteria decision-making approach, combined with GIS spatial analysis and a modular design framework, our study quantitatively compared the carbon reduction capabilities of PV systems against the carbon sequestration potential of various vegetative arrangements along the roadside space. The roadside space analysis modular considers a range of factors including topography, meteorology, and construction costs. We examined the spatial distribution of suitability for PV installation and vegetation establishment along the provincial expressway network in China. The results revealed that Inner Mongolia stood out as the frontrunner in carbon reduction potential within high-suitability zones for PV construction, achieving an impressive 4.845 million tons of carbon reduction—nearly four times greater than that of Shaanxi Province. In contrast, the carbon sequestration attributed to vegetation greening in areas less suited for PV development revealed a higher propensity in the southeastern provinces. Guangdong led the charge with an impressive annual carbon sequestration of 2.89 million tons. This was closely followed by Yunnan, Sichuan, Hebei, Guizhou, and Henan, each achieving carbon sequestration amounts exceeding 2 million tons. These results offer valuable quantitative support and practical recommendations for achieving low-carbon objectives in the construction of China's expressways.

Electrogenic performance and carbon sequestration potential of biophotovoltaics.

Biophotovoltaics (BPV) is a clean and sustainable solar energy generation technology that operates by utilizing photosynthetic autotrophic microorganisms to capture light energy and generate electricity. However, a major challenge faced by BPV systems is the relatively low electron transfer efficiency from the photosystem to the extracellular electrode, which limits its electrical output. Additionally, the transfer mechanisms of photosynthetic microorganism metabolites in the entire system are still not fully clear. In response to this, this article briefly introduces the basic BPV principles, reviews its development history, and summarizes measures to optimize its electrogenic efficiency. Furthermore, recent studies have found that constructing photosynthetic-electrogenic microbial consortia can achieve high power density and stability in BPV systems. Therefore, the article discusses the potential application of constructing photosynthetic-electrogenic microbial aggregates in BPV systems. Since photosynthetic-electrogenic microbial communities can also exist in natural ecosystems, their potential contribution to the carbon cycle is worth further attention.

Carbon sequestration potential of tree planting in China

China’s large-scale tree planting programs are critical for achieving its carbon neutrality by 2060, but determining where and how to plant trees for maximum carbon sequestration has not been rigorously assessed. Here, we developed a comprehensive machine learning framework that integrates diverse environmental variables to quantify tree growth suitability and its relationship with tree numbers. Then, their correlations with biomass carbon stocks were robustly established. Carbon sink potentials were mapped in distinct tree-planting scenarios. Under one of them aligned with China’s ecosystem management policy, 44.7 billion trees could be planted, increasing forest stock by 9.6 ± 0.8 billion m³ and sequestering 5.9 ± 0.5 PgC equivalent to double China’s 2020 industrial CO2 emissions. We found that tree densification within existing forests is an economically viable and effective strategy and so it should be a priority in future large-scale planting programs.

3775-year-old wood burial supports "wood vaulting" as a durable carbon removal method.

Six-times more carbon dioxide (CO2) is removed each year by terrestrial photosynthesis than fossil fuel emissions. However, the carbon is mostly returned to the atmosphere by decomposition. We found a 3775-year-old ancient wood log buried 2 meters belowground that was preserved far beyond its expected lifetime. The wood had near-perfect preservation, with carbon loss less than 5% compared to a modern sample. The lack of decay is likely due to the low permeability of the compact clay soil at the burial site. Our observation suggests a hybrid nature-engineering approach for carbon removal by burying woody biomass in similar anoxic environments. We estimate a global sequestration potential of up to 10 gigatonnes CO2 per year with existing technology at a low cost of $30 to $100 per tonne after optimization.

Effects of Organic Fertilizer Application on Cultivated Land Productivity and Carbon Pool

The promotion and application of organic fertilizers in agriculture not only enhance the soil organic carbon pool but also offer viable solutions for addressing climate change. This paper, grounded in a comprehensive review of existing literature, analyzes the effects of organic fertilizers on cultivated land productivity and soil carbon pools. It summarizes the mechanisms through which organic fertilizers improve agricultural productivity and evaluates their carbon sequestration potential within the soil carbon pool. Finally, the environmental impact of organic fertilizer application process was discussed. In the future, through scientific application methods, organic fertilizer will play a more positive role in achieving food security, protecting soil health, and promoting carbon sink capacity.

Improved modelling of carbon sequestration potential on agricultural land.

Improved modelling of carbon sequestration potential on agricultural land.

Dynamic environmental payback of concrete due to carbonation over centuries

This research introduces a dynamic life cycle assessment (LCA) based carbonation impact calculator designed to enhance the environmental evaluation of cement-based construction products. The research emphasizes the limitations of static LCAs which fail to capture the time-dependent nature of carbon sequestration by carbonation.We provide an easy-to-use spreadsheet-based LCA carbonation model. The model is available in the supplementary information, and includes a suite of changeable parameters for exploring the effect of alternative environmental conditions and concrete block composition on carbonation. The tool enables use of both a static and dynamic LCA method to calculate the production emissions and carbonation sequestration of a concrete block over a 1000-year time horizon.Carbonation can partially mitigate initial production emissions and adjust radiative forcing over long periods. Using a static attributional LCA approach, carbonation sequesters 6 % of the CO2 generated from its production emissions. We describe the ratio of carbonation to production emissions as the partial “carbonation payback”, and with dynamic LCA show the variation of this ratio over time. Considering time by applying the dynamic LCA approach, we find this partial “carbonation payback” is split between uptake during the 60-year service life (0.13 kg CO2) and the 940-year end of life period (0.12 kg CO2) in our baseline case. Further scenario analyses illustrate the significant variability in carbonation payback, driven by environmental factors, cement composition, and the use of supplementary cementitious materials.The results highlight the critical role of modelling choices in estimating the carbonation payback. The carbonation calculator developed in this study offers a sophisticated yet user-friendly tool, providing both researchers and practitioners with the ability to dynamically model the sequestration potential of concrete, thereby promoting more sustainable construction practices.