It did, Dave, but it wasn't until the 80s and 90s that I was telling my classes about the greenhouse effect. Before that we were talking more about acid rain and the ozone layer, and in the early 70s some scientists were even talking about an impending mini-ice age. The last couple of generations are the ones who (a) could see the warming coming, (b) allowed the fossil fuel industry to control the conversation, along with a bunch of influential deniers elsewhere, (c) completely failed to stop carbon dioxide emissions to rise inexorably, right up to today.