When/where does the notion that Ra's is a caring "eco-terrorist" trying to preserve/save the world come into place first? It's not really in any of the older Ra's al Ghul stories, where he's shown as a slaver, a weapons dealer, murderer, kidnapper, and terrorist for profit and vengeance. Wherein he's described as a "Hitler-type," and a bogeyman of organized crime.
But, my readings are all out of order, too, and I know there are gaps. By Tower of Babel, he's at least keeping some rare animals and trying to preserve them. But, even most of his modern stories have absolutely nothing to do with any notion that he needs to reduce the human population to preserve the planet, just that he likes financing and then selling or using horrible biological weapons to keep him in castles, fine threads, and slaves.
The 90s cartoon is the only place I can think of that made the eco bid strongly, and they did that with more than one other character, too. It was a bit of a 90s cartoon theme. Catwoman, preservationist extreme. Poison Ivy, preservationist by death. Joker... okeh, Joker didn't. I think.