Hyperthermal-driven mass extinctions: killing models during the Permian-Triassic mass extinction.

Area of Science:

• Paleoclimatology
• Paleontology
• Volcanology

Background:

• Mass extinctions are often linked to rapid geological heating events.
• Large igneous province volcanism, such as the Siberian Traps, is a suspected driver of these hyperthermals.
• These events raised global temperatures significantly, impacting ecosystems.

Purpose of the Study:

• To review proposed mechanisms by which massive volcanic eruptions caused past mass extinctions.
• To assess the impact of extreme temperatures and environmental changes on marine and terrestrial life.
• To provide evidence for the killing effects of past hyperthermals.

Main Methods:

• Review of existing literature on mass extinctions and volcanism.
• Analysis of proposed environmental killers (anoxia-euxinia, heating, drought, acid rain).
• Examination of physiological experimental data on organismal tolerance to temperature changes.

Main Results:

• Marine life (benthos, plankton) perished due to anoxia-euxinia and lethal heating, shrinking the habitable ocean depth.
• Terrestrial life faced reduced habitable land area from extreme heat and drought, with acid rain damaging flora and soils.
• Most plants and animals cannot tolerate temperatures of 35-40°C, though some show limited adaptation to smaller increases.

Conclusions:

• Geologically rapid hyperthermals driven by volcanism are significant extinction drivers.
• Extreme heat, drought, anoxia-euxinia, and acid rain were key factors in past mass extinctions.
• Evidence from modern organisms and environmental change rates supports the devastating impact of past hyperthermals.