er what about when it was an ice age and there was MORE CO2 ?

but then the real deniers are those who hide the data (and the decline) and refuse to allow other people to see their data or workings on the grounds that we only want the data to disprove the hypothisis - well of course we do - that's how science (as against post normal science) works. Put your hypothisis; models; data and working up for inspection so it can be tested to destruction.

Models are not proof of anything. Only models whose predictions come true have any use. How many climate model predictions have come true ? Where is the tropo hotspot that EVERY GCM predicts ? Oops; not there - models falsified; hypothisis needs re-working or binning.

Climate changes

Man has some affect on climate - but probably miniscule and un-measurable.

Sanity check - the AGW hypothisis claims that 1 deg change in temp will destroy life as we know it -- by how much did the temperature change where you live today ?

(A beer 'cos making beer makes masses of CO2)