Sprecher
Beschreibung
The greatest diversity losses in Earth’s history occurred at the end of the Paleozoic Era, during the end-Permian extinction event (EPE). For life on land, plants are unparalleled archivists of the EPE, preserving evidence of ecosystem dynamics, biodiversity and biogeography changes, climatic instability, and carbon cycle (dys)function.
The EPE is characterized by the largest climate-state change of any mass extinction event, transitioning from coolhouse to hothouse, driven by massive and rapid greenhouse gas emissions. However, it is not yet clear how much influence other stressors (e.g., UV-B, phytotoxic metals) may have played in the downfall of terrestrial ecosystems.
This presentation will propose a simple hypothesis: greenhouse gas-driven climatic changes played the central role in the EPE. If this hypothesis is correct, and since most mass extinction events share a similar underlying cause, they can be placed on a spectrum of severity with the EPE as the worst-case scenario. While the timing and severity of each hyperthermal event are unique, the EPE could offer a standardized yardstick against which other events can be compared.
As the tempo and magnitude of these changes are being revealed, the relevance of the EPE to our presently warming world is becoming more relevant. Deep-time records offer our only observational window into ecosystem responses of greenhouse gas-driven climate changes over the longest-possible timescales. While the EPE represents climatic change beyond all IPCC future climate scenarios, it may presage longer-term forecasts, if our species doesn’t take drastic preventative action.