The notion that the 1970s scientific consensus was for impending global cooling is incorrect. In actuality, there were significantly more papers in the 1970s predicting warming than cooling.
Scientific studies in the 1970's re global cooling
Most predictions of an impending ice age came from the popular press (eg - Newsweek, NY Times, National Geographic, Time Magazine). As far as peer reviewed scientific papers in the 1970s, very few papers (7 in total) predicted global cooling. Significantly more papers (42 in total) predicted global warming due to CO2. More on 1970s science...
http://www.skepticalscience.com/ice-age-predictions-in-1970s.htm