There has to be an end to this torment of speculation. As a rule of thumb we can say we are about halfway through the unknowable sequence of what it is to be human. Because, humans became fully human, genetically, between about one hundred thousand years ago and fifty thousand years ago, and if we choose to make the present out to be the halfway point on that time-line that would give us some hundred thousand years of future to ponder over and speculate about. Perhaps we will have a long, and pleasant future by using our superior intelligence to find ways to harmonize our needs, and live in peace with all other humans.
In the previous blogs the goal of maximizing the total number of years of human vigor has been searched, and the only way for truly long term – thousand year – longevity is by applying a fair way of maintaining population at some human specified level. That population has to be well within the carrying capacity of the planet, and that is dependent upon the total solar input energy, and other probably other unknowns of capacity. That permanent population capacity is estimated to be as low as ten million humans. With that small number of people there could be maintained a high tech civilization that could be healthy, happy, wise and wealthy for a very, very long time. It is the time times the numbers of humans that is the measure of total human vigor.
A more likely scenario, however, is one where some population of humans tries to gain, and maintain dominance over others, and for isolated human groups to maximize their breeding potential. That inevitably leads to a population explosion, and increasingly deadly conflicts, and because the knowledge for making truly devastating weapons is now available, and proliferated it will be impossible, in this unregulated population scenario, to prevent mass homicide at various turning points in the future.
It is likely that this policy will bring on a cycle of recurrent Doomsdays, and at each of these recurrent Doomsdays there will be a horrible population collapse, and a long period, a thousand years or so, of recovery. But with each recovery there will be fewer species of plants, and animals, and probably growing climate challenges, with abrupt weather swings, because there are ever fewer living things with which dampen the various runaway solar energy input processes. Each time humanity goes through one of these Doomsday cycles things will get worse. And, because humans have more options than other animals these other creatures will die off in their variability over time, and there will be left fewer, and fewer species of smaller, and smaller sized creatures of both plants, and animals, but these hardy few will be in great abundance. On the other hand these new varieties of species will be very difficult for humans to wrest a living from. Humans will manipulate the plants genetically to do their bidding, but with vast numbers of wild things with almost identical genomic makeup with other options in their best interest these wild plants, and animals will come to dominate the domesticated ones.
These wild weeds will, as if intentionally, breed themselves to be hostile to humans. Making themselves increasingly unpleasant in every way that the natural processes of selection can permit them to modify themselves. And then, as much as these wild things are capable of, to interbreed with the human manipulated crops to make those crops useless to the humans. This is just natural selection as nature usually runs the process it just takes longer with the slower breeding species. With fast cycling things like viruses it goes on much more rapidly, and in the last hundred years we have witnessed many human created antibiotics be overcome by these tiny living organisms in only a few decades. When we extrapolate these processes over hundreds and thousands of years, not only do the antibiotics become totally adapted to by the rapidly cycling tiny things, but also the bigger, slower changing, things which humans want to defeat modify themselves. The surviving plants, and animals will slowly convert all other living things into hostile beings. On the opposite side of this the human caused dilemma of helping genetically unhealthy humans survive make the human species increasingly susceptible to disease, and genetically induced failure.
People could make our future into a paradise, but it requires doing things which at the present time, and perhaps forevermore are totally unacceptable. Thus we choose to make our planet into a self created living hell. As bad as that sounds it is quite pleasant living at this time at least in the short run. With a lot of luck we might get in another fifty years of huge population viable humanity before the Doomsday events finally shut us down. In any case were are presently on a collision course with Doomsday.