Sequestration, basically. All of those fossil fuels we burn today have at one point not returned into the atmosphere. An increase in CO2 also leads to an increase in vegetation. Ocean acidification is a concern that I can't dismiss, but that's true of many concerns and I can't cater to them all.

> Those CO2 peaks mark descents into Ice Ages and cataclysmic events during millions of years.

I was referring to the interglacial cycles, these are not cataclysmic per se.

https://www2.atmos.umd.edu/~zeng/papers/Zeng03_glacialC.pdf

As for the descent into an ice age, according to the interglacial cycle, we were right on schedule for that. Perhaps our ancestors will thank us for averting it?