It's the lag effect, stupid.
The last time there was this much Co2 in the atmosphere, because most of the population lives near the coast, the place you are sitting and reading this will be underwater and on a timeline not of centuries, but decades.
We just have not seen the actual effects of the thresholds we have crossed yet. It's an inevitable runaway train. The surface of Venus, our virual twin, is about 867°F, because of runaway greenhouse heating due to a buildup of Co2. Just in case anyone forgets just how powerful of a greenhouse gas Co2 is.
Some of you are obviously too young to understand that.