> There won't be an extinction event.
This also ignores the fact that we are currently in the 6th largest extinction event in the history of life on this planet [1]. Elizabeth Kolbert's The Sixth Extinction is a great book on this (and the history of our understanding of species extinction as well).
So aside for being naive about the science, your comment reads a bit like claiming you don't think it will rain today while in the midst of being soaked in a massive rain storm.
Eocenic period had high CO2 levels, but it didn't lead to ocean anoxidation. In fact, at the end of the period, the eocene-oligocene exctinction event happened in connection with reduced CO2 and global cooling of the climate. [0]
[0] https://en.wikipedia.org/wiki/Eocene–Oligocene_extinction_ev...