Phytoplankton carbon sequestration in inland waters can not benefit climate warming mitigation

In inland waters, characterized by low salinity and shallower conditions, carbon dynamics are markedly different. In these environments, the organic carbon fixed by phytoplankton tends to decompose more rapidly due to higher microbial activity, releasing CH4, a far more potent greenhouse gas than CO2 . Even if a subset of the CO2 fixed by phytoplankton in inland water environments is buried, this conversion of some of the carbon into CH4 likely contributes to a warming effect. Whether the process by which phytoplankton fix CO2 and subsequently convert it into CH4 leads to a warming effect, as well as the magnitude of such an effect, depends on the efficiency of organic carbon decomposition (x) and the proportion of this organic carbon converted into CH4 (x1).在盐度较低、水体较浅的内陆水域中，碳循环动力学特征存在显著差异。在此类环境中，因微生物活性更高，浮游植物（phytoplankton）固定的有机碳往往分解更快，同时释放出甲烷（CH4）——一种远比二氧化碳（CO2）强效的温室气体。即便在内陆水域环境中，浮游植物固定的二氧化碳（CO2）有一部分被埋藏，上述将部分碳转化为甲烷（CH4）的过程仍可能引发增温效应。浮游植物固定二氧化碳（CO2）并随后将其转化为甲烷（CH4）的过程是否会产生增温效应，以及该效应的强度，均取决于有机碳分解效率(x)与转化为甲烷的有机碳占比(x1)。