It might be a good thing to increase CO2. It might be bad. It might be the case that increasing carbon dioxide causes counter balancing effects and therefore increasing CO2 does not increase temperature (I remain skeptical of this but I’m not a climate scientist). But what is beyond dispute is that massively increasing CO2 will cause climatic disruptions while the weather system reaches a new equilibrium.
The reasonable pushback against this is per se isn't a realistic assumption in a system as dynamic as our biosphere.
Note that there are many seemingly obvious things that are false so I could be wrong.
The word "may" is doing a lot of work here. Lots of things may cause massive disruptions to human society. One thing we can say with certainty: the mitigation efforts being proposed to reduce CO2 levels will cause massive disruptions to human society.