I’ve had that theory but for longer. We measure globular warming back to the 1800s a lot. All of Europe burned every last scrap of wood, peat and coal to power the industrial revolution. The sky was dim. Then comes the little ice age. Then a crap scientist, lets measure from there!
Yeah, that is pretty much what they do. Don't forget the old "hockey stick" graph that seemed to show that temperatures were all normal and steady before that. Turned out later it was a fraud.
And after 25 years or so, we are still in the position where just about every "solution" for climate change does little or nothing for climate change.