By Anthony Watts
Watts Up With That?
From the UNIVERSITÉ DE GENÈVE
The cold exterminated all of them
Through age determinations that are using the radioactive decay of uranium, scientists have discovered that one of the greatest mass extinctions was due to an ice age and not to a warming of Earth temperature
Permian-Triassic boundary in shallow marine sediments, characterized by a significant sedimentation gap between the black shales of Permian and dolomites of Triassic age. This gap documents a globally recognized regression phase, probably linked to a period of a cold climate and glaciation. CREDIT © H. Bucher, Zürich
The Earth has known several mass extinctions over the course of its history. One of the most important happened at the Permian-Triassic boundary 250 million years ago. Over 95% of marine species disappeared and, up until now, scientists have linked this extinction to a significant rise in Earth temperatures. But researchers from the University of Geneva (UNIGE), Switzerland, working alongside the University of Zurich, discovered that this extinction took place during a short ice age which preceded the global climate warming. It’s the first time that the various stages of a mass extinction have been accurately understood and that scientists have been able to assess the major role played by volcanic explosions in these climate processes. This research, which can be read in Scientific Reports, completely calls into question the scientific theories regarding these phenomena, founded on the increase of CO2 in the atmosphere, and paves the way for a new vision of the Earth’s climate history.
Teams of researchers…