新生代气候变冷机制研究进展

深海氧同位素记录揭示新生代以来全球气候呈整体变冷趋势，南北两极先后发育冰盖，地球由温室气候变为冰室气候，但是其变冷机制仍不明确。大气CO2浓度降低和大洋环流模式改变均被认为与新生代气候变冷密切相关，但目前对两者的作用还未达成统一的认识，由此存在各种假说，如BLAG假说、高原隆升-风化假说、构造隆升-碳埋藏假说、火山铁肥效应和岛弧隆升-风化假说及海道开合假说等，用以解释新生代全球变冷。围绕新生代气候变冷机制方面的争论，评述了过去近几十年来相关研究的进展和存在的问题，讨论了不同机制对新生代气候变化的影响，并提出未来需要加强的研究重点：建立准确的新生代大气CO2浓度演变序列、建立更加准确的地球内部排气和青藏高原隆升及海道开合时刻表、建立完善的风化指标体系、加强火山作用及其大洋生物地球化学效应的研究。

The mechanism of Cenozoic cooling: A review of research progress

Deep-sea oxygen isotope records reveal that the earth's climate has experienced times of gradual global coolings and ice sheets expansions at Antarctic and north hemisphere one after another. The mechanism for Cenozoic climate change from greenhouse to icehouse, however, still remain unclear. Various hypotheses related to declining atmospheric CO2 concentration and models for changes in ocean circulation have been proposed to explain the Cenozoic global cooling, such as the BLAG hypothesis, plateau uplift-weathering hypothesis, uplift-organic carbon burial hypothesis, volcanic iron fertilization effect, island arc uplift-weathering hypothesis and passage opening and closing hypothesis. Base on the debates on the mechanism of Cenozoic climate cooling, this study reviewed the progress and defects of related researches in recent decades, and put forward some key points for future study, such as, establishing accurate evolution sequence of Cenozoic atmospheric CO2 concentration, establishing a more accurate timetable of earth’s outgassing, Tibet plateau uplifting and passage opening and closing, establishing a solid weathering index system, reinforcing the study of volcanism and its oceanic biogeochemical effects on carbon cycles.