Causes
A single supercontinent, Pangaea, stretched from pole to pole in the Permian Period. This huge landmass created extremely hot, dry conditions across most of the interior. By the Late Permian, global temperatures were thehighest they’d ever been.
The severe conditions meant vast numbers of land and marine species were at risk. And then something happened that tipped them over the edge - one of the biggest volcanic eruptions ever.
Over the course of about 600,000 years huge volumes of viscous basalt lava poured out across Siberia, covering an area roughly 7 times the size of France.
Massive clouds of gases belched out. The sulphur dioxide caused acid rain and global cooling. But this was only short-term. The temperature increased as the eruptions injected carbon dioxide into the atmosphere and yet more escaped from coal deposits exposed in the surrounding area.
As the oceans warmed, frozen methane located in marine sediments may have melted. If so, the release of this potent greenhouse gas could have turned the planet’s temperature up even more.
As well as being devastating for marine and land plants and animals, Late Permian environmental changes created anoxic conditions in the sea. This lack of oxygen caused additional widespread extinctions because it destroyed food chains.