Ok, not a catchy title.  But basically, this is about a blast from the past.

250 million years ago, something happened that killed 96% of all living species on earth.  A world of great coral reefs, sabre toothed lizards, forests and trilobites disappeared, making room for the dinosaurs.

And what happened is a lesson for us now.

The current thinking is that runaway global warming caused the catastrophe.  Massive volcanic activity in Siberia over thousands of years, extending over an area the size of western Europe released greenhouse gases into the atmosphere.  Ocean currents changed, depriving the reefs of their richly oxygenated water and resulting in a black, anaerobic muddy seabed.  As the continents began to merge into Pangaea, the reefs began to disappear and the centre of the landmass began to experience unprecedented extremes of temperature.

The killing blow may have been the release of methane compounds from the ocean in response to the gradually rising temperatures accelerating global warming even more.

The earth warmed up about 6 degrees.  It took at least 20 million years to recover the loss of biodiversity.

From In Our Time.