The Nowcast Fallacy

This is an opinion piece. That is, it is my opinion. Some of you may feel that I am wrong. If so, you are welcome to disagree. Please feel free to express your own views in the next issue of this magazine.

In 1962, Rachel Carson published a very important book called “Silent Spring”. Some people claim that it was the beginning of the modern conservation movement, and it certainly presented a great deal of vital information, leading to constructive change. However, it also included a major prediction that turned out to be wrong.

Rachel Carson was talking of the ecological impact of pesticide use. The pesticides back then included DDT, Malathion, Chloroquin, Sodium pentachlorophenate, 2,4,5 T and many others of equal ill. They tended to be both environmentally persistent and broad spectrum, killing many non-target species. The title of the book was the prediction. “Silent Spring”. Rachel Carson predicted that, unless pesticide use was curtailed, bird song would disappear as birds died out. If anything, since then, pesticide use has increased.

Yet every spring, I sit on my deck, coffee in hand, listening to the wonderful song of tuis as they feast on flax flower nectar. This experience is repeated, for many different song bird species, by people all around the world. Her prediction failed. Why?

In 1968, Dr. Paul Ehrlich published his book, titled “The Population Bomb”. He looked at population growth, and its impact on food availability. His prediction was that, before the end of the 1970's, population growth (especially in India and Pakistan) would be so great that it would overtake food production, and a billion people would die in the subsequent famine. It never happened. Why?

In 1972, the Club of Rome published their findings from computer models, in a missive called “Limits to Growth”. Their focus was resource scarcity. They were convinced that the world would run out of vital resources within a few decades, and they had the figures to prove it. One example of their predictions is that the world would run out of oil by the year 2000. Obviously, they were wrong. Why?

There were many books published with assorted predictions of doom and gloom. All have in common the simple fact that they were wrong. Why?

Today, we see a new wave of predictions of doom and gloom. Many are centred on global climate change. My belief is that they will also fail. Why do I think that?

Enter the Nowcast Fallacy. This is my own idea, based on personal reading and observation. It is not a widely accepted view, hallowed by decades of discussion within the halls of dusty academia. So again, feel free to disagree.

The problem, I feel, is that modern predictions, as opposed to the old fashioned ‘reading the tea leaves' variety, tend to look at one important trend. There is a failure to recognise that these changes are dependent on other factors. Rachel Carson looked only at trends in pesticide use. Paul Ehrlich looked only at population growth and subsequent lack of food. The Club of Rome looked only at proven resource availability and trends to increased resource use. They all failed to see one more vital factor. They assumed that only their subject trends would change. They assumed that other vital trends would remain as they are now. Hence Nowcast.

So, what factors do they ignore?

The main one, which has the biggest impact, is human progress. If a prediction is made of things that are decades in the future, it is vital to take into account that technology will also become more advanced.

A second one is the growth in human wealth. Even an impoverished nation like Somalia has an economic growth of about 3.5% per year. If you want to see what the Somalian people will be doing in 50 years, remember that they will be wealthier.

A third factor often overlooked is the steady reduction in human fertility. Fifty years ago, globally it was 5.5 (meaning that every woman on average had 5.5 children). Today it is 2.4 and falling. Any prediction of things decades ahead that depends on population growth needs to bear this in mind. I recommend Professor Hans Rosling's book “Factfulness” to get your data in this field. Among other things, he shows that as wealth grows, fertility drops. As nations achieve relative wealth, their rate of population growth falls.

Rachel Carson's prediction of a silent spring failed to take into account that pesticide technology would improve, and the chemicals would become biodegradable and less toxic to non-target species. To be fair, her influence did also help drive the research in that direction.

Paul Ehrlich's disastrous prediction of a billion dead from hunger failed to take into account developments in agriculture, meaning that more food could be grown per hectare. The Club of Rome failed to realise that the technology for obtaining resources would grow substantially. For example, fracking alone has substantially increased the availability of oil and gas. (There is another technology around the corner that should increase it again - the use of microwaves to liquify currently unavailable resource.)

So, do we need to watch out for present day would-be scientific prophets making the same error? Most definitely! Several issues of this magazine back, I wrote of some of the horrible predictions of climate scientists who stepped outside their specialty. They claim that, as the world warms, so will tropical diseases increase. This is a classic Nowcast Fallacy, since it ignores new technologies for preventing this happening.

For example, in my latest (18 February, page 18) issue of New Scientist magazine, it is reported that a genetic technique for killing diamondback moths in the USA has been tested and proven. It will now be used on disease carrying mosquitoes. A mutated genetically modified male mosquito is released in large numbers. They mate only once and the mutation kills all female offspring. The lethal mutation is passed to the surviving male offspring, and then on to the next generation. Since only the females carry disease, killing them selectively seems rather nice. Clearly deadlier than the male!

Another Nowcast Fallacy prediction is that the warming world will cause massive crop failures, and thus mega-deaths from hunger. This is mostly because of the limited temperature range of present-day wheat. But this is the mistake Paul Ehrlich made, ignoring progress in agricultural science. My guess is that there must be about a million agricultural scientists, technicians and geneticists in the world, and they will be working on new and better crops. Will they succeed? Here is a clue. The most vitally important crop is rice, since about half the world's population depends on rice as a staple. Now use google under the key words “C4 rice”.

There is immense scope for increased, not reduced, food production. My personal prediction, if I may be so bold, is that even with an increase in global population to 12 billion by 2100, the number of people going hungry will get less, not more.

So, my fellow skeptics, polish up your bullsheet detector. When you read so-called scientific predictions of the future, check and see if they have taken into account all relevant factors, not just the one trend they are obsessed with.