The nature of Holocene temperature changes is controversial because of the apparent discrepancy between global temperature reconstructions and climate modelling results. Here we present evidence indicating that the discrepancy can be attributed to the combination of seasonal biases in the proxy temperature records and insufficient understanding of the mechanisms within climate models. We obtained independently dated records of mean annual air temperature (MAAT) based on glycerol dialkyl glycerol tetraethers (GDGTs) from Bangong Co in the western Qinghai-Tibetan Plateau (QTP) and two loess-palaeosol sections in the northeastern QTP. One of the most prominent features in the composite MAAT record is the relatively cool Middle Holocene, ~2 °C cooler than the Early and Late Holocene. The MAAT variations are consistent with orbitally forced modelling results that show increasing regional temperatures since the Middle Holocene, but they contrast with global temperature reconstructions that mainly reflect summer temperature variations. Our findings suggest that changes in boreal summer insolation that led to variations in precipitation patterns and vegetation dynamics were the key factor modulating MAAT during the Holocene. Overall, our study sheds light on possible approaches to solving the Holocene temperature conundrum by considering internal feedbacks within the climate system.

中文翻译：

---

内反馈迫使青藏高原中全新世冷却

由于全球温度重建与气候模拟结果之间存在明显差异，全新世温度变化的性质存在争议。在这里，我们提供的证据表明，这种差异可归因于代理温度记录中的季节性偏差以及对气候模型中机制的理解不足。我们基于青藏高原西部班公公司和青藏高原东北部两个黄土-古土壤剖面的甘油二烷基甘油四醚（GDGT）获得了独立的年平均气温（MAAT）记录。复合 MAAT 记录中最突出的特征之一是相对凉爽的中全新世，比全新世早期和晚期凉爽约 2 °C。MAAT 变化与轨道强迫建模结果一致，显示自中全新世以来区域温度升高，但它们与主要反映夏季温度变化的全球温度重建形成对比。我们的研究结果表明，导致降水模式和植被动态变化的北方夏季日照变化是全新世期间调节 MAAT 的关键因素。总的来说，我们的研究通过考虑气候系统内的内部反馈，揭示了解决全新世温度难题的可能方法。我们的研究结果表明，导致降水模式和植被动态变化的北方夏季日照变化是全新世期间调节 MAAT 的关键因素。总的来说，我们的研究通过考虑气候系统内的内部反馈，揭示了解决全新世温度难题的可能方法。我们的研究结果表明，导致降水模式和植被动态变化的北方夏季日照变化是全新世期间调节 MAAT 的关键因素。总的来说，我们的研究通过考虑气候系统内的内部反馈，揭示了解决全新世温度难题的可能方法。