I think you need to learn more about Earth's history. Not to dispute the fact that it has increased, but it's totally false to say this is unseen in Earth's history.
Dynamical systems are often sensitive to the value of a parameter, its rate of change and/or its rate of rate of change.
Eg. You can warm milk to a certain temperature (the parameter) on a stove on gentle heat and it will be fine. If you warm it to the same temperature on high heat (i.e. increased rate of parameter), it will burn. That's because the convection process in this system has limited maximum speed.
If you look at when previously the Earth's atmosphere had high CO2, it took hundreds of thousands to many millions of years get there. We did it in a 100 years, so at least a thousand times faster.
I'm not denying that the rate is significant in this specific conversation, but maybe that wasn't the best example?
From a cursory look, any such events look like they were part of mass extinctions. I'm curious what exact data you are looking at so I may better understand your statement.
Again, if you have any evidence or citations to the contrary, "put up or shut up".