In my previous blog, I mentioned that predicting the future is not sensible; the future generally refuses to behave exactly as you think it should. That, however, does not mean that general trends are not real, even if they are not immediately followed. One example comes from the American biologist Paul Ehrlich, who in 1968 wrote The Population Bomb. His argument was that with finite planetary area, there cannot be continual growth because sooner or alter all the available resources, such as area for farming, get used up. Worse, if the growth is unconstrained, it follows the exponential form, i.e. the rate of growth is proportional to the size, and like compound interest, as it approaches a constraint, the last part of the growth is far more significant and far more difficult to reverse than the early parts.
In accord with the difficulties of predicting the future, Ehrlich’s predictions have been shown to be wrong in that the food supply per unit area has increased greatly and we have far more food available than he predicted. However, Ehrlich appears to be unrepentant, and in my opinion, rightly so. Everything has not happened as he predicted, but the basic argument is correct: the size of the planet has not increased, and the amount of resources has not increased. We may have found more than he expected, but that does not alter the fact that they are limited. From the mathematical point of view, Ehrlich’s original equation was missing some terms, but there is no evidence the missing terms would alter the overall consequence.
There are three types of effects that will greatly affect our future. The first is population. Quite simply, the more people, the less use they can each make of the finite resources. The second is the second order effects of the population. For example, I was a teenager in a farming area. Thanks to irrigation, the area is now far more productive, and is an example of where Ehrlich’s predictions failed. Food production is the product of area and productivity, and while area is constant, productivity has increased. However, it cannot increase indefinitely, and so far it has done so at the price of a poorer river quality and excessive nitrates in the aquifers. Similarly, the 9 Gt of carbon being burnt each year is almost certainly going to lead to very significant sea-level rises, which will wipe out vast amounts of prime agricultural land, while the increased acidity in the oceans will most likely lead to the extinction of marine animals such as shellfish that require the deposition of aragonite to form their shells. The third is that we are chewing through the fossil resources. Oil is the obvious one, but when I hear enthusiasts point out that wind power will solve the energy shortage, most of those enthusiasts have never considered the problem of supplying the neodymium for the magnets. Many solar cells also use elements that are difficult to obtain, however it is also possible to make solar cells based solely on silicon, so if we have sufficient energy to make them, silicon is effectively unlimited. Nevertheless, solar energy has inevitable problems, one of which is power density. I have seen one proposal to power the UK though solar energy in the Sahara. The required area is very large but it is available, although there may be competition for the area. But then the problem comes, what happens in a sand storm? A brown-out until the cells are cleaned/replaced?
As I said in the previous blog, the future refuses to cooperate. There are things we can do to avoid the very bad outcomes, but to do so we have to start now. We have to decide what might work, then we have to make it work. Will we? In my futuristic ebooks, I suggest that we do not. Now, of course it is desirable to have struggling situations in fiction, but I still think this will happen. Of course, equally in the fiction I can propose answers to the then current problems. Those answers work much better in advance!