Scaled biotic disruption during early Eocene global warming events

[摘要] Late Paleocene and early Eocene hyperthermals are transient warming eventsassociated with massive perturbations of the global carbon cycle, and areconsidered partial analogues for current anthropogenic climate change.Because the magnitude of carbon release varied between the events, they arenatural experiments ideal for exploring the relationship between carboncycle perturbations, climate change and biotic response. Here we quantifymarine biotic variability through three million years of the early Eocenethat include five hyperthermals, utilizing a method that allows us tointegrate the records of different plankton groups through scenarios rangingfrom background to major extinction events. Our long time-series calcareousnannoplankton record indicates a scaling of biotic disruption to climatechange associated with the amount of carbon released during the varioushyperthermals. Critically, only the three largest hyperthermals, thePaleocene–Eocene Thermal Maximum (PETM), Eocene Thermal Maximum 2 (ETM2) andthe I1 event, show above-background variance, suggesting that the magnitudeof carbon input and associated climate change needs to surpass a thresholdvalue to cause significant biotic disruption.

[学科分类] 地球化学与岩石