Extinctions
- Past, Current and Future

Past Ordovician extinction,

about 445 million years ago

Species lost: 60-70 percent

Possible causes: Short but intense ice age

Past Devonian extinction

When: about 375-360 million years ago

Species lost: up to 75 percent

Possible cause: oxygen depletion in the ocean

Past Permian extinction

When: about 252 million years ago

Species lost: 95 percent

Possible causes: asteroid, volcanoes

Past Triassic extinction

When: about 200 million years ago

Species lost: 70-80 percent

Possible cause: global warming from volcano CO2

Past Cretaceous extinction

When: about 66 million years ago

Species lost: 75 percent

Possible cause: asteroid strike

Current Anthropocene

When: This sixth mass extinction is happening now.

Known cause: massive worldwide destruction of life’s habitats by humans. This is not human extinction.

Future Human Race Extinction

Speculated seventh mass extinction of all human life. Timelines to extinction may be very short in some cases. Some speculated causes are listed as follows.

Extinctions - Past, Current and Future

Extinctions
- Past, Current and Future