Try to conceive the scale of these four things:
* The entire Earth plus its atmosphere;
* The oceans, seas, and larger lakes of the Earth;
* Volcanoes - land and undersea;
* Mankind - who could all sit down for a picnic in the State of Delaware(the second smallest state in the US!), with room to spare.
Human activity, short of a massive nuclear holocaust, is puny in comparison to volcanoes, which are very small in comparison to the Earth's oceans, etc., which are a fraction of the entire Earth with atmosphere! Mankind and its doings are all but insignificant.
If something very small compared to the oceans are having a "measurable" effect on climate and weather, how many other factors are there that affect climate about which we do not know?!
How in Hades can mankind, with its 3 centuries or so of weather observation (as opposed to inferences from things like tree rings and under-ocean debris fields from melting ice bergs, which are equivocal), be making projections of climate, which is a phenomenon spanning millennia (and has never been static!)? And why aren't these Warmista Climate Diviners residents of padded condos?!