Consensus doesn't make science (that's more empirical research, testing and experimentation) but consensus does assess its worth,via peer review.

I'll skirt over your unilateral flat out rejection of reading anything published in the Guardian (despite yr expectation of others to read features stuffed with unattributed miscellanies).

“When paleoclimates are known to the nth degree.....” No: the implications of the instrumental temperature record alone are worrying enough. I’d go further, the temperature rises in the last 20 years are worrying enough for it to be foolish not to be rapidly decarbonizing.

“When climate models work flawlessly” No: models will always be models and there will always be some discrepancy between modelling and practice. We don’t have time.

“When all cyclical variations both of the earth and sun are fully understood”. Is there significant scientific evidence that the numerous worrying phenomena of species extinction, global surface temperature increase, Arctic ice cover retreat, coral bleaching and extreme weather events are caused purely by cyclical variations of the earth and sun? If so, please link to it, I’m very interested to read it.