Oh c'mon. We mandated the use of sulphur scrubbers on power stations, and catalytic converters on vehicles.

Which is not the same as "just fading away".

Edit: 1985 Helsinki Protocol (UK and USA conspicuously absent), and superceded by the 1988 NOx Protocol that includes UK and USA: https://en.wikipedia.org/wiki/Nitrogen_Oxide_Protocol

see lliamander's citations on this thread

No one (I hope), disputes there were published papers and news reports of those papers on cooling, but it was not the consensus. It wasn't frequent. Those citations above point to a handful of reports.

At the same time there were also reports of heating, which were more frequent. Though there weren't exactly loads of those yet either.

Now, there were certainly one or two that blew it up, e.g. the remaindered paperback I picked up for 50p or something round about 1980. I'm pretty sure BBC's Horizon never touched it, though they did do the odd "out there" programme each series. They did one myth-busting von Däniken's silliness sometime in the early or mid 70s.