The human population explosion certainly presents huge problems to the human race (and life on the planet in general). Like almost any aspect of human life, it presents good and bad aspects, and, while it has been increasingly easy thus far to see the negative consequences, the longer view of centuries and millennia begs the question, is this actually a good thing?
Sooner or later, any successful species, if successful enough, seems to propagate beyond the level of sustainability and approach natural constraints. It may evolve to cope with and surmount, or avoid the risks and catastrophic consequences of hitting its limits, but that can only be temporary, as new limits will become apparent sooner or later. A Petri dish of bacteria presents the species with a pretty hard limit as far as expansion, food supplies, and avoidance of pollution from waste, for example. But if the Petri dish is breached or broken, the next set of limits may be the walls of the laboratory room in which the Petri dish was kept. It may be a long time before the bacterial colony expands far enough to reach those physical limits, but, unchecked and with sufficient resources (another set of limits) eventually it will reach them.
Similarly, humankind expanded at some point in the distant past to regional limits, but developed transportation systems (better legs and posture, shoes, boats) to expand its range, eventually to the global scale we have now. At some point in the distant future, if the human race is sufficiently wise and adaptable, humans may populate habitable planets across our galaxy, but then run into the limitations of intergalactic space.
As adaptable and capable of learning and evolving as we are, the imposition or encountering of the next set of limits is always the spur to learning, development, and evolution. It separates those who adapt from those who can not. In that vein, the limits of the Earth, as far as ability to feed and sustain the rapidly increasing numbers of humans, is as much a challenge as it is a threat. Like the bacteria that may have reached the edge of the Petri dish and even moved through the seal to the outside, we have placed a very few humans in orbit, both in free orbit and, occasionally, on our nearest natural satellite, the moon. So far we have not figured out how to establish sustainable settlements off of the Earth, and it appears we are still a long way from doing so, so our challenge will be first to control our numbers and more sensibly manage what the Earth provides us.
Needless to say, survival through the next century appears to present almost insurmountable challenges, but few species have succumbed entirely to such challenges in the past, and most have managed to send at least a small group of representatives onward into the future, possibly with significant adaptations from their prior state. The challenges of the future almost always look dire when we first begin to see them, but, like a range of mountains, they are surmounted eventually, in steps, slips back, occasional leaps ahead, and with significant learning and adaptation. The coming test of the human species looks great and terrible to us now, but we have the capacity as a learning and evolving species to survive and proceed on to even bigger challenges we can’t conceive of yet. This challenge was inevitable, and I hope our continued success will prove to have been inevitable, too.
Let the learning, adaptation, and evolution go on. Let us look forward positively, driven by hope as well as fear (whatever it takes), as the survival imperative implicit in all life forms will drive us to overcome the greatest challenge to our species yet. We must work hard and prove we are the most creative and intelligent species on the planet, or the next round may go to another species as it has to others in the past. Your thoughts?