I'm going to use common sense followed by some evidence to back my claims.
It is known that about 1 million people migrate to US cities per day. We also know that the world's resources are finite. And, through biology, we know that when there is a population problem the planet induces properties to curb that population problem. This can be found all over the world, and we are a part of the Earth's processes.
So why have we been able to have 7 billion people on this planet?
Innovation. Innovation is mankind's way of battling mother earth. However when you watch this video (
The Surprising Math of Cities and Corporations) Geoffrey West not only makes statements about businesses, but makes statements about these required innovations. These innovations not only bring profit, but has allowed our population to get so high. The catch is, the rate at which these innovations have taken place has steadily increased, because they have to, because population is growing at a faster rate. Eventually, humanity will not be able to catch up. Either we will not be able to conceptualize the new innovation (which would happen eventually) or we would not be able to implement the idea fast enough. Or both. That is the three possibilities.
But think of it this way. Our infinite growth paradigm is not physically possible. It isn't. We can push the boundaries with this, and I will show you how humanity can push it more, but eventually there will be conditions that most of humanity will not be able to adapt/innovate through,
assuming we keep the infinite growth paradigm. I'm sorry, but it is eventually going to collapse. We cannot grow infinitely, there is only so much Earth. That is the common sense I was talking about.
But how we could push it more, is essentially have computers do the thinking and execution for us. (Robotics are going to have to be accepted, regardless of the consequences in order for this to work.)
Stephen Wolfram is essentially creating a computer system that has two major parts. First, a calculator on steroids, and second, a database of all known knowledge that humanity has. The result? A computer computing the theory of everything. But what I am getting at, is with the advancements in virtualization technology and physical computer hardware, we could create a super computer that would innovate for humanity. And, if the rate of innovation gets so quick, we could program robots to execute the innovation. All of this is possible, assuming there are available resources.
But I am going to close with one more idea, and it is The Gaia Hypothesis. There is a lot to this theory (an overall theory on how the world works) but one central claim is that the animate and inanimate of the planet have a symbiotic relationship. This means, that the planet is a super-organism. The animate cannot live without the inanimate and the inanimate cannot live without the animate. And if this symbiotic relationship gets out of balance, natural conditions are created on earth to preserve whichever is low, so that ultimately both can continue, so that Gaia (Earth) still exists. Gaia is an organism, and will induce conditions to preserve Gaia, life, and the inanimate.
Therefore, I believe eventually Gaia will enact conditions, whether it is heating, a plague, rising oceans, different atmospheric concentrations, what have you, in order to preserve the inanimate. Simply because, the inanimate is a requirement for life and therefore Gaia to exist.
If we innovate over Gaia and consume all resources, we would have essentially killed Gaia. And to some people, this is okay. They don't value the planet simply because humanity is separated from nature. (Decartes) So it is up to us. Do we keep things the same? Or do we change? I can tell you, with how humans think and with how our system works right now, it is all about keeping things the same as long as possible to accrue the most wealth. It could be the very downfall of our sustainability.