School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, United Kingdom.
School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, United Kingdom.
Proc Natl Acad Sci U S A. 2022 Jul 19;119(29):e2204369119. doi: 10.1073/pnas.2204369119. Epub 2022 Jul 11.
The biological carbon pump (BCP) stores ∼1,700 Pg C from the atmosphere in the ocean interior, but the magnitude and direction of future changes in carbon sequestration by the BCP are uncertain. We quantify global trends in export production, sinking organic carbon fluxes, and sequestered carbon in the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) future projections, finding a consistent 19 to 48 Pg C increase in carbon sequestration over the 21st century for the SSP3-7.0 scenario, equivalent to 5 to 17% of the total increase of carbon in the ocean by 2100. This is in contrast to a global decrease in export production of -0.15 to -1.44 Pg C y. However, there is significant uncertainty in the modeled future fluxes of organic carbon to the deep ocean associated with a range of different processes resolved across models. We demonstrate that organic carbon fluxes at 1,000 m are a good predictor of long-term carbon sequestration and suggest this is an important metric of the BCP that should be prioritized in future model studies.
生物碳泵（BCP）将大气中约 1700 PgC 储存于海洋内部，但未来 BCP 碳封存的规模和方向尚不确定。我们在最新的耦合模式比较计划第六阶段（CMIP6）未来预测中量化了海洋外输生产力、沉降有机碳通量和碳封存的全球趋势，发现 SSP3-7.0 情景下，21 世纪碳封存增加了 19 到 48PgC，相当于 2100 年海洋碳总增加量的 5%到 17%。这与海洋外输生产力的全球减少-0.15 到-1.44PgCy 形成对比。然而，与不同模型解析的一系列不同过程相关的有机碳向深海的模型未来通量存在很大的不确定性。我们证明，1000 米处的有机碳通量是长期碳封存的良好预测指标，并建议这是 BCP 的一个重要指标，应在未来的模型研究中优先考虑。
