Look at the evidence Sam, periods of low solar activity, ie sunspots, which are well noted to be cyclic, coincide with a drop in the earths temperature over the same period.
The converse is also true, increase in activity = increase in temperature.
Its been that way for millenia, even before man evolved.
If it walks like a duck and quacks like a duck then theres a fairly good chance that its a duck
The material that has the most effect on climate change is actually water vapour, but they arent doing anything about that because thats another thing, like solar activity, that they cant tax us on or control.