State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China.
Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA.
Sci Adv. 2023 Feb 15;9(7):eabq4082. doi: 10.1126/sciadv.abq4082.
Massive carbon dioxide (CO) emissions are widely assumed to be the driver of the end-Permian mass extinction (EPME). However, the rate of and total CO released, and whether the source changes with time, remain poorly understood, leaving a key question surrounding the trigger for the EPME unanswered. Here, we assimilate reconstructions of atmospheric co and carbonate δC in an Earth system model to unravel the history of carbon emissions and sources across the EPME. We infer a transition from a CO source with a thermogenic carbon isotopic signature associated with a slower emission rate to a heavier, more mantle-dominated volcanic source with an increased rate of emissions. This implies that the CO degassing style changed as the Siberian Traps emplacement evolved, which is consistent with geochemical proxy records. Carbon cycle feedbacks from terrestrial ecosystem disturbances may have further amplified the warming and the severity of marine extinctions.
大量二氧化碳（CO）排放被广泛认为是导致二叠纪末大灭绝（EPME）的原因。然而，CO 的释放速度和总量，以及来源是否随时间变化，仍然知之甚少，这使得 EPME 触发因素这一关键问题仍未得到解答。在这里，我们将大气 co 和碳酸盐 δC 的重建纳入地球系统模型中，以揭示 EPME 期间碳排放和来源的历史。我们推断，从与较慢排放速率相关的具有热成因碳同位素特征的 CO 源转变为具有更高排放速率的更重、更受地幔控制的火山源。这意味着随着西伯利亚陷阱的就位，CO 的脱气方式发生了变化，这与地球化学示踪剂记录一致。陆地生态系统干扰的碳循环反馈可能进一步放大了变暖效应和海洋灭绝的严重程度。
