Quantitative palaeotemperature reconstruction on MIS1, 5e, 11 interglacial episodes based on pollen assemblages from Lake Biwa sediments

利用日本琵瓦湖沉积物的花粉分析和现代模拟技术（MAT），对化石花粉百分比数据进行定量重建，得到了MIS1、MIS5e、MIS11间冰期的古温度水平。MIS5e和MIS11被视为“地球气候变暖的类似物”，因为它们与目前的气候状态相似。在这里，我揭示了琵浪湖（37N；志贺Pref）与43万年前MIS11间冰期的盐onomisaki海角（33.5N；和歌山Pref）一样温暖。这一温度异常比7000年前的低温期高1-1.5度，比300年前的前工业化时期高2-2.5度。这种变暖的气候远低于预期的全球变暖，但当我们减少大气中二氧化碳的努力取得成功时，情况是相似的。由于在地质记录中没有已知的MIS11灾难性证据，这是一个鼓励我们面对全球变暖问题的结果。

Using pollen analysis and modern analogue techniques (MAT) for Lake Biwa sediment (Japan), I present palaeotemperature levels of MIS1, MIS5e, MIS11 interglacials by quantitative reconstruction from fossil pollen percentage datasets.The MIS5e and MIS11 are seen as "analogues for the warmer Earth climate" because of their resemblance to the present climate state. Here I reveal that Lake Biwa (37N; Shiga Pref) was as warm as the Shionomisaki Cape (33.5N; Wakayama Pref) at the MIS11 interglacials 430,000 years ago. This temperature anomaly is calculated as 1-1.5 degrees warmer than the Hypsithermal episode 7000 years ago, and 2-2.5 degrees warmer than the preindustrial period 300 years ago.This warmer climate was rather lower than the expected global warming, but is similar when our effort to reduce atmospheric CO2 is successful. As there are no catastrophic evident known at MIS11 in geological records, this is a result encouraging us to confront with the global warming problem.