Mechanism of the late Miocene global cooling driven by decline of CO2

2016 Fiscal Year Final Research Report

• Project/Area Number: 26287129
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: Hokkaido University
• Principal Investigator: Seki Osamu 北海道大学, 低温科学研究所, 准教授 (30374648)
• Co-Investigator(Kenkyū-buntansha): 阿部 彩子 東京大学, 大気海洋研究所, 准教授 (30272537) ; 堀川 恵司 富山大学, 大学院理工学研究部(理学), 准教授 (40467858) ; 小野寺 丈尚太郎 国立研究開発法人海洋研究開発機構, 海洋生態系動態変動研究グループ, 主任研究員 (50467859) ; 岡崎 裕典 九州大学, 理学研究院, 准教授 (80426288)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 後期新生代 / 後期中新世 / 古気候 / 古海洋 / 古気候モデル / 全球寒冷化 / 二酸化炭素

Outline of Final Research Achievements

The Earth has undergone a dramatic climate transition from hothouse to icehouse conditions occurred during the past 10 million years. It is important to understand cause of the long-term glaciation for better understanding of long-term stability of ice sheet yet the causes of the climate transition is still uncertain. In this study we reconstructed pale oceanographic changes and pCO2 from marine sediment cores collected from different parts of the ocean. We found that a dramatic global cooling (late Miocene global cooling) and marked decline of CO2 concentration occurred several million years before the intensification of Northern Hemisphere Glaciation (NHG). This suggests that CO2 played a substantial role in the long-tern climate evolution overt the past 10 million years.

Free Research Field

古気候学