An episode of extreme global warming that left ocean animals unable to breathe caused the biggest mass extinction in the Earth’s history, research has shown.
The extinction event at the end of the Permian period 252 million years ago wiped out 96 per cent of all marine species and 70 per cent of land-dwelling vertebrates.
Scientists have linked what has become known as the Great Dying with a series of massive volcanic eruptions in Siberia that filled the atmosphere with greenhouse gas.
What made the oceans so inhospitable to life has remained unanswered until now.
The study, reported in the journal Science, suggests that as temperatures soared the warmer water could not hold enough oxygen for most marine creatures to survive.
Lessons from the Great Dying have major implications for the fate of today’s warming world, the US scientists said.
If greenhouse gas emissions continue unchecked, ocean warming could reach 20 per cent of the level experienced in the late Permian by 2100.
By 2300, it could reach between 35 per cent and 50 per cent of the Great Dying extreme.