What I remember of that Cosmos episode, “Heaven and Hell,” was that Sagan criticized the fact that other scientists tried to suppress Velikovsky’s works. If memory serves, Sagan said, “The suppression of uncomfortable ideas might be popular in religion or politics. But it is not the path to knowledge, and has no place in the endeavor of science.”
Which strikes me as a bit hypocritical coming from a guy who was on the same side as the man-made global warming folks, who are engaging in the same suppression.
Sagan WROTE the primary attack on Velikovsky and admitted he had not bothered to read the works before doing so. . . He was a hypocrite. On the other hand, Albert Einstein wrote the forward to Velikovsky’s book.
Sagan didn’t invent the bogus greenhouse for Venus (and Mars, and Earth), he merely made it more bogus. :’)