古新世-始新世极热事件(LPTM或PETM)是地球历史中最强烈的全球升温事件之一,又因其温室气体的排放与当前工业废气排放水平相当,因而在全球变化与地球系统科学研究中具有重要的研究意义。Gaia理论强调生物通过负反馈作用调节全球系统,使之趋于稳定。在前人研究资料的基础上,对比分析了分布于全球不同地区大洋钻孔与陆地剖面P/E界线附近的δ^13C变化,综合了P/E极热事件对全球碳循环的影响以及事件的成因。认为P/E极热事件之后,地球系统在生物作用下逐渐恢复平衡。如果将生物与地球作为整体来看,那么这个整体是一个具有自我平衡能力的系统。地球历史中,其他与碳循环扰动有关的地质事件,应该也可以用Gaia理论的思路,从生物调节环境的角度分析碳循环的变化以及地球系统的平衡机制。
The abrupt warming that took place in the Late Paleocene-Epoch (55 Ma) is one of the most pronounced, transient climatic events in the geological record. It is known as the Late Paleocene Thermal Maximum (LPTM) or the Paleocene/Eocene Thermal Maximum (PETM). This paper discusses the effects of the PETM, the variation of δ^13C and the perturbation of the carbon cycle on the basis of the available literature. The factors causing PETM are discussed in detail. It is likely that this warming was related to greenhouse-gas emission released from sea-floor gas-hydrate accumulations. On a millennial timescale, the rate of greenhouse gas emission at the P/E boundary is approximately comparable to current industrial levels, and thus provides a unique insight into our uncertain greenhouse future. All of the data quoted by this paper come from the ODP and DSDP holes as well as the continental sections distributed around the world. Based on the Gala theory, which regards life and the Earth as a living entity with the capacity of self-regulation, we have analyzed the negative feedback mechanism for the Earth system. We suggest that higher productivity is the feedback mechanism required to bring the Earth system back normal. We believe that other events related to perturbation of carbon cycle may be studied from this thinking as well.