We have plenty of examples where we've tried to improve things (e.g. for invasive species) and actually made it worse.
On the other hand, we know exactly what is screwing the climate.
Geoengineering feels like saying "smoking is killing me, but I won't stop smoking: I'll try to ingest medicine that I believe should help, but may just kill me faster".
https://www.space.com/terraforming-in-alien-universe , dynamically overriding all the shit our alien earth system is throwing at us, on demand, even retroactively.