Mayot Nicolas, Buitenhuis Erik T, Wright Rebecca M, Hauck Judith, Bakker Dorothee C E, Le Quéré Corinne
School of Environmental Sciences, University of East Anglia, Norwich, UK.
Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
Nat Commun. 2024 Sep 28;15(1):8429. doi: 10.1038/s41467-024-52641-7.
The ocean will ultimately store most of the CO emitted to the atmosphere by human activities. Despite its importance, estimates of the 2000-2022 trend in the ocean CO sink differ by a factor of two between observation-based products and process-based models. Here we address this discrepancy using a hybrid approach that preserves the consistency of known processes but constrains the outcome using observations. We show that the hybrid approach reproduces the stagnation of the ocean CO sink in the 1990s and its reinvigoration in the 2000s suggested by observation-based products and matches their amplitude. It suggests that process-based models underestimate the amplitude of the decadal variability in the ocean CO sink, but that observation-based products on average overestimate the decadal trend in the 2010s. The hybrid approach constrains the 2000-2022 trend in the ocean CO sink to 0.42 ± 0.06 Pg C yr decade, and by inference the total land CO sink to 0.28 ± 0.13 Pg C yr decade.
海洋最终将储存人类活动排放到大气中的大部分二氧化碳。尽管其重要性不言而喻，但基于观测的产品和基于过程的模型对2000年至2022年海洋碳汇趋势的估计相差两倍。在此，我们采用一种混合方法来解决这一差异，该方法保留了已知过程的一致性，但利用观测结果来约束结果。我们表明，混合方法再现了基于观测的产品所表明的20世纪90年代海洋碳汇的停滞及其在21世纪头十年的恢复，并与它们的幅度相匹配。这表明基于过程的模型低估了海洋碳汇年代际变化的幅度，但基于观测的产品平均高估了2010年代的年代际趋势。混合方法将2000年至2022年海洋碳汇的趋势限制在0.42±0.06Pg C yr decade，并据此推断陆地总碳汇为0.28±0.13Pg C yr decade。
