The Straight-line Theory of Progress
Perhaps the simplest theory about the future is what can be called the straight-line theory of progress. This is the theory that technological and scientific advances are producing a fairly steady rate of progress for mankind. The theory can be represented by the following line graph.
The numbers on the left of the graph represent some level of progress such as knowledge, power, or standards of living. This straight-line theory of progress has been held by many millions of people throughout the past 150 years or earlier (although belief in it took a hit during the dark years of World War I and World War II). The basic idea is that progress in medicine, electronics, education, and other areas is proceeding at a nice, steady clip, leading to a gradually improving human lot.
The Theory of Accelerating Progress
Fairly recently there has come into prominence a theory of the future that is even more optimistic than the straight-line theory of progress. This is the theory of Accelerating Progress. A prominent advocate of such a theory is Ray Kurzweil, who has said that there is a Law of Accelerating Returns, which causes technological growth to occur at an exponential rate. The Theory of Accelerating Progress can be illustrated by the following line graph. Again, the numbers on the left of the graph represent some level of progress such as knowledge, power, or standards of living.
The Theory of Overshoot and Collapse
Despite the optimism of the Theory of Accelerating Progress, there are many reasons for being pessimistic about the future. One of the main concerns of ecological observers is that man's activities are causing a host of ecological problems such as global warming, deforestation, soil depletion, clean water depletion, and ocean acidification. Many are worried that man may be on track for an ecological phenomenon called overshoot and collapse.
Overshoot and collapse is what is observed when a population of living organisms increases in number, until it greatly exceeds what is known as the carrying capacity of the environment – the maximum population that can be supported for an indefinite period. At some point after this, the population can then plummet. An example occurred on St Matthew's Island in Alaska, where 29 reindeer were introduced in 1944, to an island that could support perhaps 1000 reindeer indefinitely. The reindeer population increased to about 6000 by 1963, which was a tremendous overshoot beyond the carrying capacity. At that point there was a dramatic “die-off.” Almost all the reindeer died, and there were only about 42 left by the next summer.
The Overshoot and Collapse theory is that something like this may happen to the human population. It has been estimated that the carrying capacity of our planet is only about 2 billion people, meaning that is the highest population the Earth could support for an indefinite time period such as thousands of years. We have now greatly exceeded that carrying capacity. The result may be global warming, deforestation, a sharp decline in fresh water, a very dangerous depletion in soil fertility, famine, and various other ecological curses that one day cause man's population to plummet.
Here is a graph illustrating the Overshoot and Collapse theory. The numbers are rather arbitrary, but the shape of the curve illustrates the basic idea. The numbers on the left of the graph represent some level of progress such as knowledge, power, population, or standards of living.
The Theory of Collapse and Rebirth
Historians know that the collapse of civilizations is very common. But they also know that when one civilization collapses, it is very common for some new civilization to arise from its ashes. When one civilization collapses, it may leave behind seeds of thought and learning and science that are replanted by some later civilization. One of the great examples is the civilization of Renaissance Italy, which came into being to a large extent from the learning and literature left behind by the ancient Greeks and Romans.
So even if we gloomily imagine some future collapse of human living standards or population, or both, we are entitled to suppose that after that occurs some successor civilization may carry human progress to even higher levels than they were at before the collapse. We can develop such an assumption into a theory of Collapse and Rebirth. This is the theory that our civilization will undergo a collapse, but will later be succeeded by another civilization that scales even greater heights. Here is a graphical depiction of such a theory.
This theory is a kind of marriage of pessimism and optimism. We can flesh out this theory by imagining that after our civilization has paid for its follies, some successor civilization will learn the lessons taught by our mistakes, and will forge forward in a sustainable fashion, avoiding our mistakes.