I really like this analogy between McLuhan (as technological environmentalist) and Rachel Carson, the environmentalist:
"McLuhan would have considered himself a media ecologist in this sense: he was trying to create an awareness about the hidden effects of electronic technologies, in much the same fashion that Rachel Carson, in Silent Spring, exposed the unintended consequences of pesticides (Morrison 5-6, 23n3). James Morrison argues that if we see McLuhan in his true light as a "technological environmentalist," it will expose the blindness of his misperceiving critics who see him as a booster of technology; "in truth, he was no more so than Rachel Carson was a promoter of DDT" (Morrison 6). From this ecological framework, we can see that people today do not merely live in a world of the physical. The world is symbolic. We live in a reality filtered by various media; call it what you will: Plato's cave wall, the world outside and the pictures in our heads, mediated reality, second-hand world, the media environment, the media torrent. As argued above, when a new technology or new symbol system enters a culture, the entire system will change. The examination of this phenomenon is the work of the media ecologist/medium theorist." Marc Leverette, "Towards an Ecology of Understanding."