Global cooling in the 1970's is a myth
and it's used to prove that "we shouldn't believe global warming predictions now, because in the 1970's they were predicting an ice age and/or cooling" surfaces. But its not an argument used by respectable and knowledgeable skeptics, because it crumbles under analysis.
William M. Connolley at RealClimate writes about how this myth arised:
Where does the myth come from? Naturally enough, there is a kernel of truth behind it all. Firstly, there was a trend of cooling from the 40's to the 70's (although that needs to be qualified, as hemispheric or global temperature datasets were only just beginning to be assembled then). But people were well aware that extrapolating such a short trend was a mistake (Mason, 1976). Secondly, it was becoming clear that ice ages followed a regular pattern and that interglacials (such as we are now in) were much shorter that the full glacial periods in between. Somehow this seems to have morphed (perhaps more in the popular mind than elsewhere) into the idea that the next ice age was predicatable and imminent. Thirdly, there were concerns about the relative magnitudes of aerosol forcing (cooling) and CO2 forcing (warming), although this latter strand seems to have been short lived.
Further reading: The global cooling myth.
I think the article about global cooling myth was informative, I came accros there because of my earlier writing about Crighton.
I've been trying to find scientific articles on the subject:
BBC Nature & Science.
An analysis of various papers that mention the subject is at "Was an imminent Ice Age predicted in the '70's?".
Here is a link to probably the most comprehensive list of global dimming research papers on the Internet......at least the best list I could find; for anyone that would be interested further in global dimming.