The Steward and the Predator
I have no idea when it first was understood that environment changing activities of the East African Plains Ape could produce major collateral damage, but the Ancient Greeks knew and discussed the matter. Recognizing the need for conservation is not quite the same as accomplishing it, though. Small scale societies far less sophisticated than the Ancient Greeks faced the problem, solved it and thrived, or failed, collapsed and disintegrated.
Thus it is strange to me that there are those in our modern society who fail to grasp this elementary principle - or claim to fail to grasp it. Of course there is always tension in a society over the control of resources - the age-old battle between the poacher and gamekeeper, between man the predator and man the steward.
Some of the blame belongs to three pernicious religious (or quasi-religious) ideas, of which I will mention three: the notion of the "End of Days," Marxism, and Capitalism in their religious forms.
The notion of the "End of Days" implies that it is pointless to prepare for a future that will never come, so that it makes sense to max out those credit cards and prepare for the rapture. Marxism and Capitalism (in its most extreme form) both seem to believe that economics can trump physics and biology - that "history" or "the market" will solve any problems worth solving.
The number of devotees of any of these notions is probably too small to be significant in itself, but skillfully wielded as weapons by would be predators, they can help paralyze the will to cooperate to solve environmental problems.
Another fundamental problem is the inherent conflict between long-term and short-term benefit. Should I have that chocolate fudge sunday right now for the short-term benefit or forego it in favor of the hope for a healthier and thinner longer-term future. Humans were designed to plan for the future, but not for too long a future.
Finally, there is the problem of uncertainty. How do we plan for the future if the cost and hope of averting an adverse future eventuality, and the the probable cost of the feared future are all uncertain?