https://www.washingtonpost.com/news/wonk/wp/2014/02/11/there-have-been-five-mass-extinctions-in-earths-history-now-were-facing-a-sixth/?utm_term=.3adc32e9d283
According to climate science deniers, the above chart would mean that extinction events happen all the time and are natural. So, go back to watching Family Guy.
The causes are different. but yes, until now, the events all happened due to non-man made events.
In the worst, the end-Permian,
The worst mass extinction of all time came about 250 million years ago [the Permian-Triassic extinction event]. There's a pretty good consensus there that this was caused by a huge volcanic event that went on for a long time and released a lot of carbon-dioxide into the atmosphere. That is pretty ominous considering that we are releasing a lot of CO2 into the atmosphere and people increasingly are drawing parallels between the two events.
One thing we do know from studies of past events is that the big die offs go quickly with quick changes in, you guessed it, climate change. The case for us at the cusp of the next great die-off is plausible.
Is anybody plugging ten more years to live into their retirement calculator to see if they have enough to live on until the end and so can retire?