Because of the alkaline nature and high calcium content of cements in general, they serve as a CO₂-absorbing agent through carbonation processes, resembling silicate weathering in nature. This carbon uptake capacity of cements could abate some of the CO₂ emitted during their production. Given the scale of cement production worldwide (4.10 Gt in 2019), a life-cycle assessment is necessary to determine the actual net carbon impacts of this industry. We adopted a comprehensive analytical model to estimate the amount of CO₂ that had been absorbed from 1930 to 2019 in four types of cement materials, including concrete, mortar, construction waste, and cement kiln dust (CKD). In addition, the process CO₂ emission during the same period based on the same datasets was also estimated. The results show that 21.02 Gt CO₂ (95 % confidence interval, CI: 18.01–24.41 Gt CO₂) had been absorbed in the cements produced from 1930 to 2019, with the 2019 annual figure mounting up to 0.89 Gt CO₂ yr⁻¹ (95 % CI: 0.76–1.06 Gt CO₂). The cumulative uptake is equivalent to approximately 55 % of the process emission based on our estimation. In particular, China's dominant position in cement production or consumption in recent decades also gives rise to its uptake being the greatest, with a cumulative sink of 6.21 Gt CO₂ (95 % CI: 4.59–8.32 Gt CO₂) since 1930. Among the four types of cement materials, mortar is estimated to be the greatest contributor (approximately 59 %) to the total uptake. Potentially, our cement emission and uptake estimation system can be updated annually and modified when necessary for future low-carbon transitions in the cement industry. All the data described in this study, including the Monte Carlo uncertainty analysis results, are accessible at https://doi.org/10.5281/zenodo.4459729 (Wang et al., 2021).

The main contributor to the greenhouse gas (GHG) footprint of the cement industry is the decomposition of alkaline carbonates during clinker production. However, systematic accounts for the reverse of this process – namely carbonation of calcium oxide and other alkaline oxides and/or hydroxides within cement materials during cements' life cycles – have only recently been undertaken. Here, adopting a comprehensive analytical model, we provide the most updated estimates of CO₂ uptake by cement carbonation. The accumulated amount of global CO₂ uptake by cements produced from 1930 to 2021 is estimated to be 22.9 Gt CO₂ (95 % confidence interval, CI: 19.6–26.6 Gt CO₂). This amount includes the CO₂ uptake by concrete, mortar, construction waste and kiln dust, accounting for 30.1 %, 58.5 %, 4.0 % and 7.1 % respectively. The cumulative carbon uptake by cement materials from 1930 to 2021 offsets 55.1 % of the emissions from cement production (41.6 Gt CO₂, 95 % CI: 38.7–47.2 Gt CO₂) over the same period, with the greater part coming from mortar (58.5 % of the total uptake). China has the highest cement carbon uptake, with cumulative carbonation of 7.06 Gt CO₂ (95 % CI: 5.22–9.44 Gt CO₂) since 1930. In addition, the carbon uptake amounts of the USA, EU, India and the rest of the world took 5.0 %, 23.2 %, 5.6 % and 34.8 % separately. As a result of rapidly increased production in recent years, over three-quarters of the cement carbon uptake has occurred since 1990. Additionally, our results show little impact by the COVID-19 pandemic on cement production and use, with carbon uptake reaching about 0.92 Gt CO₂ (95 % CI: 0.78–1.10 Gt CO₂) in 2020 and 0.96 Gt CO₂ (95 % CI: 0.81–1.15 Gt CO₂) in 2021. Our uniformly formatted and most updated cement uptake inventories provide coherent data-based support for including cement carbon uptake into future carbon budgets from the local to global scale. The latest version contains the uptake data till 2021, showing the global uptake's increasing pattern and offering more usable and relevant data for evaluating cement's carbon uptake capacity. All the data described in this study are accessible at https://doi.org/10.5281/zenodo.7516373 (Bing et al., 2023).

A substantial amount of CO₂ is released into the atmosphere from the process of the high-temperature decomposition of limestone to produce lime. However, during the lifecycle of lime production, the alkaline components of lime will continuously absorb CO₂ from the atmosphere during use and waste disposal. Here, we adopt an analytical model describing the carbonation process to obtain regional and global estimates of carbon uptake from 1930 to 2020 using lime lifecycle use-based material data. The results reveal that the global uptake of CO₂ by lime increased from 9.16 Mt C yr⁻¹ (95 % confidence interval, CI: 1.84–18.76 Mt C) in 1930 to 34.84 Mt C yr⁻¹ (95 % CI: 23.50–49.81 Mt C) in 2020. Cumulatively, approximately 1444.70 Mt C (95 % CI: 1016.24–1961.05 Mt C) was sequestered by lime produced between 1930 and 2020, corresponding to 38.83 % of the process emissions during the same period, mainly contributed from the utilization stage (76.21 % of the total uptake). We also fitted the missing lime output data of China from 1930 to 2001, thus compensating for the lack of China's lime production (cumulative 7023.30 Mt) and underestimation of its carbon uptake (467.85 Mt C) in the international data. Since 1930, lime-based materials in China have accounted for the largest proportion (about 63.95 %) of the global total. Our results provide data to support including lime carbon uptake into global carbon budgets and scientific proof for further research of the potential of lime-containing materials in carbon capture and storage. The data utilized in the present study can be accessed at https://doi.org/10.5281/zenodo.7896106 (Ma et al., 2023).

The hydration products of cement materials can absorb atmospheric CO₂, and this carbonation process provides an important decarbonization pathway for the cement industry. Global carbon sequestration by cement materials has been reported, but carbon uptake in different countries remains unquantified. Here, we quantify the national cement carbon uptake from 1928 to 2023 based on 58 517 activity data from 163 cement-producing countries and regions worldwide and 6186 carbonation parameters from detailed data records of 42 countries, and we project the trend in carbon uptake by countries in 2024. The global CO₂ uptake by cement materials has increased from 7.74 Mt yr⁻¹ (95 % confidence interval, CI: 5.84–9.85 Mt CO₂ yr⁻¹) in 1928 to 0.84 Gt yr⁻¹ (95 % CI: 0.71–1.00 Gt yr⁻¹) in 2023, and it was projected to rise to 0.86 Gt yr⁻¹ (95 % CI: 0.73–1.02 CO₂ yr⁻¹) in 2024. The accumulated CO₂ uptake from 1928 to 2023 is 21.26 Gt CO₂ (95 % CI: 17.93–25.17 Gt CO₂), which offsets about 46 % of the cement process emissions (46.06 Gt CO₂) in the past 96 years. Simultaneously, the dominance in cement carbon uptake has shifted from the USA, Japan, and some European countries to emerging economies such as China and India, which account for 38.0 % and 9.1 % of total CO₂ uptake, respectively, in the last decade (2014–2023). By analysing the long time series of carbon emissions and uptake of the 42 countries with detailed data, we find that they contributed 82.1 % of global cement CO₂ uptake from 1928 to 2023, including 21 countries for which cement emissions have peaked and 21 countries for which they have not yet peaked. The annual carbon offset level (the ratio of uptake to process emissions in a given year) shows a remarkable decrease due to the temporal lag in cement carbon uptake. This is significant for countries with higher cement imports; for example, the cement industries in Australia and Japan have achieved net-zero emissions when considering the cement carbonation sink. This study provides an accurate bottom-up quantification of cement carbonation sinks at national and global levels. All of the data described in this study are accessible at https://doi.org/10.5281/zenodo.14583866 (Wu et al., 2024).

The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model is a concise approach to evaluate the status of habitat quality for supporting ecosystem management and decision making. Assigning parameters accurately in the InVEST model is the premise for effectively simulating habitat quality. The purpose of this study is to propose an available method for assigning the important parameters in the Habitat Quality module of InVEST. Herein, the methods of principal component analysis (PCA) and grey relational analysis (GRA) were utilized to assign the weights of threat factors and the sensitivity of each habitat type to each threat factor, respectively. Through a case study of the habitat quality of Fuzhou City, we find that using PCA and GRA methods to assign parameters is feasible. Generally, the habitat quality of Fuzhou City in 2015 and 2018 was above the fair suitable level, and the proportion of fair suitable and good suitable habitats was about 83%. The areas with higher habitat quality were mainly concentrated in forest, wetland and grassland ecosystems. The spots with lower habitat quality were scattered all over the main urban areas of districts and counties, and their periphery. GDP per capita and population density were the main factors that affect the habitat quality of Fuzhou City. Narrowing the economic imbalance gap is an important way to reduce population shift and relieve the pressure of the urban environment in economically developed areas. This study is expected to provide an effective method for assigning parameters in the InVEST Habitat Quality Module and support regional ecosystem conservation.