Permian Extinction
Around 252 million years ago, immense Siberian volcanism helped drive rapid warming and ocean oxygen loss. Warmer water held less oxygen while animals needed more, creating a deadly squeeze during Earth’s largest mass extinction.
Around 252 million years ago, immense Siberian volcanism helped drive rapid warming and ocean oxygen loss. Warmer water held less oxygen while animals needed more, creating a deadly squeeze during Earth’s largest mass extinction.

Annual surface temperature from CESM (T): a model estimate, not a direct observation of the past.
0 Ma: pre-industrial climate/CO₂; modern sea-level and O₂ references.
Glacial-interglacial cycles with 120m+ sea level swings. Homo sapiens spread from Africa across the globe, and most megafauna went extinct.
Annual model means · 0 Ma: pre-industrial
Present