Treebeard, I appreciate your insight. I fully agree that human consciousness and social organization are not deterministic and cannot be accurately modeled, something that Atheists get wrong, and unfortunately, an approach that modern science and economics emulate too much (though they need not since there is nothing inherently reductionist about the scientific method). However, some things in the universe indeed are reductionist, and cannot be wished away simply by taking a different view of reality.
While it is folly to apply material reductionism in order to derive theories to predict how complex, non-deterministic systems behave, it is equal folly to presume that everything operates this way and to assume that genuinely deterministic systems aren't, and to rely on hope and faith, and a positive attitude in the hopes that maybe, just maybe, if we all just change the way we think and act, that things won't turn out that way. That is one of my biggest complaints about contemporary philosophy / thought / academia -- an unwillingness to understand when reductionism is valid or not, and a willy nilly application of reductionism when it's not warranted, which then alienates a lot of people from using reductionism where it is warranted!
Unfortunately, on the scale of resources that are needed to sustain civilizations and to prevent St Matthews Island-esque collapses, those processes are thermodynamic and therefore deterministic. They are fully predictable and that is what we are facing. While you may dismiss an overpopulated deer population as being too simplistic a model to apply to our own future, it is not. You point out that the "solutions" we are applying to agriculture (more mechanism, oil use, and further soil degradation) are from the same mentality that got us into this mess. I would agree; however, those previous naturally fertile soils would never sustain 7 billion people, the math just doesn't support it. That is the problem. Your argument would be sound if the global population was 100 million. If you disagree, the onus is on you to explain how changing our consciousness and perception of reality, and presumably our social systems as well, is going to somehow magically and radically increase per-hectare agricultural yields beyond anything seen before in the history of the world in any natural system.
I am glad that the 50,000 elephant cull example was brought up. This is a perfect example of how animal populations can be decimated. However, they can never be increased (sustainably) beyond the carrying capacity of the land. And as an aside, I have heard some criticisms of Allan Savory's claims. While I'm sure there is some truth to what he is saying, some of his claims just verge on bizarre.
And the thing about you being a doomer back in the 70's only to never see it materialize ... well the only reason disaster was averted then was because the US dollar reigned global, backed by the military, to become the sole reserve currency. This enabled the US to use the rest of the world's resources after it ran out. If not, it would have indeed collapsed in the 1970's. In 2015, there is nowhere else to run.
I don't envision fossil fuels running out, to a point that there won't be enough to feed the world, for at least several decades, maybe a century or more. But as I alluded to in my comment above, the end of growth will lead to economic and social chaos which will have a similar effect as starvation -- in fact, one could view this economic collapse as being simply the first signs of a die-off in an overly complex system. We are not going to be able to reach the 10% enlightenment necessary to make social-wide changes to avert this reality; we needed that 20 years ago.
Now, as to how we individually and culturally can react to the reality of the collapse that's coming, sure, I fully agree that we need a revolution in consciousness. It will help people in their chances of surviving, and maybe be useful in helping our descendants bring back a future civilization (of much less population) that does not destroy itself and the world, again. But it isn't going to prevent the collapse that is before us.