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The term carbon (C) sequestration has not just become a buzzword but is something of a siren's call to scientific communicators and media outlets. Carbon sequestration is the removal of C from the atmosphere and the storage, for example, in soil. It has the potential to partially compensate for anthropogenic greenhouse gas emissions and is, therefore, an important piece in the global climate change mitigation puzzle. However, the term C sequestration is often used misleadingly and, while likely unintentional, can lead to the perpetuation of biased conclusions and exaggerated expectations about its contribution to climate change mitigation efforts. Soils have considerable potential to take up C but many are also in a state of continuous loss. In such soils, measures to build up soil C may only lead to a reduction in C losses (C loss mitigation) rather than result in real C sequestration and negative emissions. In an examination of 100 recent peer‐reviewed papers on topics surrounding soil C, only 4% were found to have used the term C sequestration correctly. Furthermore, 13% of the papers equated C sequestration with C stocks. The review, further, revealed that measures leading to C sequestration will not always result in climate change mitigation when non‐CO2 greenhouse gases and leakage are taken into consideration. This paper highlights potential pitfalls when using the term C sequestration incorrectly and calls for accurate usage of this term going forward. Revised and new terms are suggested to distinguish clearly between C sequestration in soils, SOC loss mitigation, negative emissions, climate change mitigation, SOC storage, and SOC accrual to avoid miscommunication among scientists and stakeholder groups in future. [ABSTRACT FROM AUTHOR]

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