Globally resolved surface temperatures since the Last Glacial Maximum
Globally resolved surface temperatures since the Last Glacial Maximum
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DOI：
10.1038/s41586-021-03984-4
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发表时间：
2021-11-11
期刊：
影响因子：
64.8
通讯作者：
Poulsen, Christopher J.
中科院分区：
文献类型：
--
作者：
Osman, Matthew B.;Tierney, Jessica E.;Poulsen, Christopher J.
过去24，000年的气候变化为地球系统对外部强迫的反应提供了关键见解。气候模式模拟（1，2）和代用数据（3-8）独立地允许对这一关键时期进行研究;然而，它们有时会得出不同的结论。在这里，我们利用这两种类型的信息，使用古气候数据同化（9，10），以产生第一个代理约束，全场再分析的表面温度变化跨越末次冰期最大，目前在200年的分辨率。我们证明，在过去的24000年的温度变化与两个主要的气候机制：冰盖和温室气体的辐射强迫;和海洋翻转环流和季节性日照变化的叠加。与之前基于代理的重建（6，7）相比，我们的结果表明，自全新世早期（约9000年前）以来，全球平均气温略有但稳定地变暖了0.5摄氏度。与最近的温度变化相比，我们的再分析表明，相对于过去2.4万年的变化，现代变暖的速度和幅度都是不寻常的。古气候数据集与气候模型相结合，重建了自末次盛冰期以来的全球表面温度，显示了持续变暖，直到全新世中期。
Climate changes across the past 24,000 years provide key insights into Earth system responses to external forcing. Climate model simulations(1,2) and proxy data(3-8) have independently allowed for study of this crucial interval; however, they have at times yielded disparate conclusions. Here, we leverage both types of information using paleoclimate data assimilation(9,10) to produce the first proxy-constrained, full-field reanalysis of surface temperature change spanning the Last Glacial Maximum to present at 200-year resolution. We demonstrate that temperature variability across the past 24 thousand years was linked to two primary climatic mechanisms: radiative forcing from ice sheets and greenhouse gases; and a superposition of changes in the ocean overturning circulation and seasonal insolation. In contrast with previous proxy-based reconstructions(6,7) our results show that global mean temperature has slightly but steadily warmed, by 0.5 degrees C, since the early Holocene (around 9 thousand years ago). When compared with recent temperature changes(11), our reanalysis indicates that both the rate and magnitude of modern warming are unusual relative to the changes of the past 24 thousand years.Paleoclimate datasets are integrated with a climate model to reconstruct global surface temperature since the Last Glacial Maximum, showing sustained warming until the mid-Holocene.