professor stephan lewandowsky (uwa) on denial, page-15

Yes we model pit designs but we have drill core assay results which allow us to determine grade and overburden for each block of material we mine.

More science than art, but some art required.

AGW is a very soft science at the moment, I agree there is no other Earth to model on, hence the use of computer models.

All quite legitimate and most industries do similar modelling all the time.