> I also find it odd that it wasn't until the 1990s that global warming became a 'thing.' "A 'thing'" usually implies widespread general discussion. "Scientist

> I also find it odd that it wasn't until the 1990s that global warming became a 'thing.' "A 'thing'" usually implies widespread general discussion. "Scientists" is only a subset of people. Scientists could well have noticed the trend long before it became a "thing" in the general public. Here's Asimov in 1989 talking about the discussion of the greenhouse effect, as the "most interesting scientific event of 1988." http://climate.nasa.gov/blog?m_y=01-2011 http://climate.nasa.gov/blog?m_y=01-2011 . In addition, Asimov says "I had been talking about the greenhouse effect for 20 years at least. And there are other people who talked about it before I did. I mean I didn’t invent it." This lecture takes place before the sudden collapse of Communism. And here's Asimov in 1977 talking about the greenhouse effect in a CBC interview - http://www.cbc.ca/archives/categories/environment/climate-change/turning-up-the-heat-four-decades-of-climate-change/why-is-it-called-the-greenhouse-effect.html http://www.cbc.ca/archives/categories/environment/climate-ch... . It mentions discussion about some scientists who were worried about the effect of SST (supersonic transport) on the greenhouse effect. Therefore, no, it isn't the case that scientists had only noticed the data in the 1990s, nor that it wasn't a "thing" until the 1990s, nor that it postdates the collapse of communism.