The big environmental movement started in the 70's. I remember as a very young kind in the 90's that it was drilled into our innocent minds at school. People have been worrying about resources and the environment for a very long time before that, as well.
I remember in the late 80s/early 90s it seemed like all the environmental stuff was about the ozone hole and acid rain. By the late 90s it seemed to be all about preserving the rainforest to the exclusion of almost anything else—incidentally, did we... win that one? Or hopelessly lose it so everyone gave up? It seems like the chatter there has dropped to almost nothing, though for a while it was the environmental issue.
Global warming per se didn't get center stage until later. I don't remember hearing much about it back in the days of soda-by-the-pitcher and Made in America signs on racks at Wal-Mart (gave up on that one pretty fast, haha).
I think Asimov might have disagreed. In 1989 he said:
> I thought the most interesting scientific event of 1988 was the way everyone started speaking about the greenhouse effect just because there was a hot summer and a drought, when I had been talking about the greenhouse effect for twenty years, at least. - http://www.ubcome.com/AsimovSaveCivilization.html
He also talks about the rainforest in '89:
> I said therefore, when Brazil begins to cut down the rainforest of the Amazon, not only is it destroying a habitat for vast numbers of plant and animal life which could be of great use to us, there are perhaps pharmacological products we know nothing about that are produced by these forms of life that if we knew about could advance the art of pharmacology and the practice of medicine, enormously. And we'll never find out, we're going to drive them to extinction. We're going to destroy the ground, because the soil of a rainforest isn't very good, and when you chop it down it doesn't make for good farming, what it makes is for good deserts. And finally, we're going to cut down on absorbing the carbon dioxide and on producing oxygen, so that we are actually tampering with the climate of the Earth and with the very atmosphere that we breathe, so that under those circumstances it is useless for Brazil to say that she can do what she wants with her own, that the rainforest belongs to her and if she wants to cut them down, she can. The rainforest doesn't belong to her, it belongs to humanity, she is merely the custodian of the rainforests.
It's been a building problem with a clear trajectory for a long time, but typically people are only getting the message long after there's something meaningful they could have done.
