So, are we currently in the middle of a mass extinction? If we really are, this time the cause is not a meteorite impact or volcanic eruptions. It is the work of a single species: Homo sapiens. Habitat destruction and climate change from rising carbon dioxide levels has driven extinction rates to levels reminiscent of the mass extinctions of the ancient past.
The similarities between today and the past are uncanny. The majority of past extinctions are associated with carbon dioxide from volcanoes causing rapid global warming, which led to a number of environmental cascade effects. The cause may be different, but the results will be the same.