中文摘要：

全球变化科学最重要的问题之一是如何平衡大气CO2收支至今仍存在每年10亿吨级的陆地碳汇不知去向，即所谓的“遗失碳汇”问题．这些不明碳汇的位置、量级、变化和形成机制目前仍不确定，并存在巨大争议．尽管全球变化和岩石化学风化的正相关关系已体现在大气CO2的地球化学模型中，但这一反馈被认为只在地质长时间尺度起作用，因此，针对人类活动对碳收支影响的讨论时常不考虑风化碳汇的贡献，本文基于岩石风化研究的最新进展，并综合水生生态系统碳泵效应研究的成果，发现陆地水-碳酸盐-CO2-水生光合生物相互作用产生的碳汇不仅很重要（每年近5亿吨碳），而且在气候变暖和土地利用变化的影响下呈现显著的增加趋势，因此，必须包括在现今全球碳收支的评价中．

英文摘要：

One of the most important questions in the science of global change is how to balance the atmospheric CO2 budget. There is a large terrestrial missing carbon sink amounting to about one billion tonnes of carbon per annum. The locations, magnitudes, variations, and mechanisms responsible for this terrestrial missing carbon sink are uncertain and the focus of much continuing debate. Although the positive feedback between global change and silicate chemical weathering is used in geochemical models of atmospheric CO2, this feedback is believed to operate over a long timescale and is therefore generally left out of the current discussion of human impact upon the carbon budget. Here, we show, by synthesizing recent findings in rock weathering research and studies into biological carbon pump effects in surface aquatic ecosystems, that the carbon sink produced by carbonate weathering based on the H2O- carbonate-CO2-aquatic phototroph interaction on land not only totals half a billion tonnes per annum, but also displays a significant increasing trend under the influence of global warming and land use change; thus, it needs to be included in the global carbon budget.