this IBD article is so bogus. there was much less data available in 1971. climate models were more primitive. and, maybe most important, the computer power to do large scale climate simulations - to validate those models and to test new theories - has evolved radically since then. (all those "high performance computing" inititiaves by the government, massive supercomputer development with climate modelling as one of the five main challenge projects, etc.)
skepticism is always good. but sowing doubt just to make folks feel more comfy with the status quo is hard to justify. (this particular article argues on the edge of ad hominem.)