Robust assessments of global carbon uptake are important for understanding Earth's carbon cycle and its response to human impacts. Here, based on the most recent oxygen budget, we presented an alternative estimate of ocean and land carbon sinks over the past few decades and future projections under climate change. For the period from 1990 to 2015, the ocean and land carbon sinks were ∼2.16 ± 0.73 and 1.37 ± 0.91 GtC/yr, respectively, which are in good agreement with the results from the Global Carbon Project (GCP). Our estimated temporal evolution of oceanic carbon uptake, however, presents a stronger decadal variation than the quasi-monotonous increase estimated by the GCP. Future projections of carbon sinks show significant discrepancies under different scenarios. At the end of this century, the ocean and land sinks will be 2.96 and 0.75 GtC/yr, respectively, under RCP4.5 (representative concentration pathways), while these values will be much larger under RCP8.5 at ∼5.70 and 3.69 GtC/yr, highlighting the vital role of the human-induced influence on the carbon cycle.

中文翻译：

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基于最新氧收支估算海洋和陆地碳汇

对全球碳吸收的可靠评估对于了解地球的碳循环及其对人类影响的反应非常重要。在这里，基于最近的氧气收支，我们提出了过去几十年海洋和陆地碳汇的替代估计以及气候变化下的未来预测。1990 年至 2015 年期间，海洋和陆地碳汇分别为~2.16±0.73 和 1.37±0.91 GtC/yr，这与全球碳项目（GCP）的结果非常吻合。然而，我们估计的海洋碳吸收的时间演变呈现出比 GCP 估计的准单调增加更强的年代际变化。未来碳汇预测在不同情景下存在显着差异。到本世纪末，海陆汇分别为2.96和0。