Up in smoke! Terrestrial carbon cycle feedbacks during warm climates

沉积岩中保存的有机碳（化石OC）是一个主要的碳库，在大气CO2和O2的长期演变中起着至关重要的作用，从而影响全球气候。在隆升、折返和侵蚀过程中，化石有机碳的氧化有可能通过正气候反馈成为大气中CO2的重要来源。然而，化石有机碳氧化在未来温暖气候中的重要性仍然是我们理解的一个主要空白。测试地球在比现在更温暖的气候状态下的行为的一种方法是检查地质记录。古新世/始新世热峰（PETM）是近代地质史上最迅速的变暖事件，是未来气候变化的模拟。这一时期的诱人证据表明，化石OC氧化可能起到正反馈的作用。然而，这一点还有待全球证实。该项目的目的是使用多代理方法来测试温暖的气候是否与化石OC的侵蚀，动员和氧化有关，并确定这种机制是否可能作为大气CO2的主要来源。

Organic carbon preserved within sedimentary rocks (fossil OC) is a major carbon reservoir and plays a crucial role in the long-term evolution of atmospheric CO2 and O2, and thus global climate. The oxidation of fossil OC during uplift, exhumation and erosion has the potential to become an important source of CO2 to the atmosphere through positive climate feedbacks. However, the importance of fossil OC oxidation in future warm climates remains a major gap in our understanding.One way to test the behaviour of the Earth in warmer-than-present climate states is to examine the geological record. The Paleocene/Eocene Thermal Maximum (PETM) is the most rapid warming event in recent geologic history and is an analog for future climate change. Tantalizing evidence from this interval suggests that fossil OC oxidation may act as a positive feedback. However, this has yet to be globally confirmed. The aim of this project is to use a multi-proxy approach to test whether warm climates are associated with enhanced erosion, mobilization and oxidation of fossil OC and to determine whether this mechanism might act as a large source of atmospheric CO2.