Research on the onset and assessment of the new era of the Earth's environment dominated by human activities

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K12135
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Okayama University
• Principal Investigator: Inoue Mayuri 岡山大学, 環境生命自然科学学域, 教授 (20451891)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: サンゴ骨格 / 海水温 / 塩分 / 温暖化 / 西太平洋 / 火山噴火

Outline of Final Research Achievements

By analyzing the chemical composition of coral skeletal core samples collected from the Philippine and Indonesian archipelagos, detailed reconstructions of variations in marine environments in each region were conducted. By examining oxygen isotope ratios and strontium-calcium ratios, salinity and sea water temperature were reconstructed. Evaluations were also conducted to assess the impact of anthropogenic carbon dioxide using carbon isotope ratios and uranium-calcium ratios. As a result, it was revealed that the Western Pacific region has been significantly affected by anthropogenic warming since 1976, with notable warming observed in the summer. On the other hand, the impact of warming in the Indonesian archipelago is more complex, with varying responses observed depending on the location within the archipelago.

Free Research Field

古気候・古環境学

Academic Significance and Societal Importance of the Research Achievements

この研究からも分かるように、現在では人為的要因による二酸化炭素放出に伴う温暖化が、自然の気候変動を圧倒し支配的になっている様子が伺えた。いかに人為起源による二酸化炭素放出を抑えることが本来の地球環境システムの安定化にとって重要であるかについて、科学的に発信できた点は社会的意義があると考える。また、熱帯から亜熱帯域においては、海水温と塩分の変動が一様ではなく、それぞれの支配要因が異なっており複雑であること、インドネシア多島海の複雑性を再認識するデータを提示できた点は学術的意義があると考える。