I'm a bit doubtful that it (assuming there is an "it") takes more than 1.5 years? 18 months is 30% of five years. A process that takes X amount of time can't really take Y >> X amount of time to get going.

>we are still lagging on the expected heating due to occur due to increased thermal insulation from CO2 released into the troposhere five years ago

I thought it's being widely reported - this year - that we seem ahead of the warming trend, breaking all sorts of records, etc.

As is mentioned in almost every article about climate change ad nauseum, global temperature increases measured in degrees are small but involve huge amounts of energy, and typically there is said to be a linkage to massive disruptions and suffering.

So saying this temporary source of warming is very small and unnoticeable seems rather equivocal. You can say it, but what is it meant to communicate?

Small and unnoticeable on your thermometer is literally true of the primary trend from CO2, but if you go around belaboring that, you sound like a denier.