NOAA/WDS Paleoclimatology - Western Pacific Geochemistry, Stable Isotope, and Atmospheric CO2 Data over the last 20 Million Years

The carbon dioxide (CO2) content of the atmosphere has varied cyclically between ~180 and ~280 parts per million by volume over the past 800,000 years, closely coupled with temperature and sea level. For earlier periods in Earth's history, the partial pressure of CO2 (pCO2) is much less certain, and the relation between pCO2 and climate remains poorly constrained. We use boron/calcium ratios in foraminifera to estimate pCO2 during major climate transitions of the past 20 million years. During the Middle Miocene, when temperatures were ~3 to 6C warmer and sea level was 25 to 40 meters higher than at present, pCO2 appears to have been similar to modern levels. Decreases in pCO2 were apparently synchronous with major episodes of glacial expansion during the Middle Miocene (~14 to 10 million years ago) and Late Pliocene (~3.3 to 2.4 million years ago).

本存档古气候学（Paleoclimatology）研究数据集可从美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）下属的国家环境信息中心（National Centers for Environmental Information, NCEI）获取，该数据集隶属于古气候学世界数据服务（World Data Service for Paleoclimatology, WDS）体系。其关联的NCEI研究类型为古海洋学（Paleoceanography）。数据集涵盖西太平洋区域的古海洋学参数，时间覆盖范围为距今（before present, BP）20000000年至0年的日历纪年。如需了解参数与研究区位的详细信息，请查阅元数据（metadata）。使用本数据集时，请引用该研究。