One could hardly miss the comparison between the recent children’s climate strike and the children’s crusade of 1212, when 30,000 children aimed to cross the Alps, take a ship from Genoa, and sail to Palestine to free the Holy Land. Naturally, many died of hunger, aided by thieves who saw the easy pickings. In Genoa, the survivors were denied shipping and told to return home by Pope Innocent III. The adults of the 13th century opposed the crusade, thereby showing more sense than the adults of today.

Beyond the ludicrous behavior in both the climate strike and the 1212 crusade there is a serious question: Do the climate children or the adults singing their praises care that there is no scientific knowledge backing their claims, nor can there be? Scientific knowledge requires more than a mathematical model (theory); it also requires validation of the model. A host of models predicting increasing global temperatures assisted by human behavior does not provide scientific knowledge. What would provide knowledge is a single model whose predictions have been validated.

Like many complex models being considered today, for instance in medicine, climate models are stochastic, meaning that they have random trajectories starting from a fixed initial condition. This means that predictions are not single outcomes, but are distributions of outcomes. Therefore, for even a single initial condition, one would have to observe many independent climate systems for decades to see if the predicted distribution is in agreement with the test distribution. This is clearly impossible.

As stated by climate scientists Nina Tibaldi and Reno Knutti in their 2007 paper in the Philosophical Transactions of the Royal Society, “Climate projections, decades or longer in the future by definition, cannot be validated directly through observed changes.”

It is not merely that one observation would take decades; a deeper problem is that we only have one Earth and cannot observe multiple independent climate trajectories. It does not matter whether some particular observation agrees or disagrees with some particular prediction, because particular predictions are not relevant. To be validated, a model requires many observed climate trajectories.

The problem is not unique to climate. In the 21st century we confront fundamental issues pertaining to scientific epistemology (the meaning of scientific knowledge) more perplexing than those faced a century ago with quantum theory in physics. Whereas those problems were ultimately seen to fit into classical scientific thinking – in fact, showing the depth of the thinking arising out of the 17th century – it appears that complex systems such as those occurring in climate and biology do not easily fit into our existing understanding of science.

As I discuss in The Evolution of Scientific Knowledge: From Certainty to Uncertainty, we should neither give up nor make erroneous claims to support political agendas; rather, we need to reconsider the ground of scientific knowledge that emerged from the 17th century, has served us well, and continues to serve us well in many areas. The alternative is ad hoc medicine not based on science, a continuing shrill debate on climate by people who have never studied a scientific theory and its validation, and the inability to ground engineering on science across numerous disciplines of great importance to humanity. There is some kind of knowledge in the climate models, but not scientific knowledge.

Our problem consists in understanding what kind of knowledge it is. The situation is not helped by having people, out of ignorance or deceit, claiming that the climate models contain scientific knowledge

Our problem consists in understanding what kind of knowledge it is. The situation is not helped by having people, out of ignorance or deceit, claiming that the climate models contain scientific knowledge. Since predictivity is distributional, individual predictions will almost certainly be wrong, thereby making the entire enterprise look foolish and opening it up to the charge of being falsified by critics, when, in fact, there is neither validation nor falsification. The climate is too important to have it submerged in a cacophony of meaningless assertions and denials.

Children strutting around and carrying ridiculous signs in complete ignorance of the basic problems makes the whole issue of climate change appear risible, but this is what one might expect from an education system that teaches children that macroevolution constitutes scientific knowledge. If it is impossible to validate climate models, think of the absurdity of validating macroevolution.

Let me quote one of the leading theoretical biologists of the last half-century, Stuart Kauffman: “We now know for example, that evolution includes Darwinian pre-adaptations…. Could we pre-state all the possible Darwinian pre-adaptations even for humans, let alone predict them? It would seem unlikely. And if not, the evolution of the biosphere, the economy and civilization are beyond natural law.” That is, they lie outside the range of science.

One must wonder how much time is wasted in the educational day providing children with an anti-scientific bias and calling it “science.” There is a double cost here. First, there is the misrepresentation of science in favor of political dogma. This is a contemporary example of Francis Bacon’s “idol of the theater” (1620) referring to systems that are “stage-plays, representing worlds of their own creation.” A delightful story is made up, bought into by the powers that be, and advertised as scientific knowledge without proof. Second, there is the time wasted that could be spent on mathematics and real science. Indeed, how does US education stand up when its mathematical content is measured against that of Asian nations such as China, India and Iran?

In a gross abdication of responsibility, we are providing an inferior mathematical education to our children, while at the same time teaching them to ignore the requirements for scientific knowledge. Indeed, were they exposed to the thinking of the great minds that developed modern scientific epistemology, from its origination with Galileo Galilei and Isaac Newton in the 17th century to its refinement with Albert Einstein and Erwin Schrödinger in the 20th century, perhaps they would not be shortchanged by having their thinking infected with idols of the mind. However, since they have been shortchanged, we should not be surprised when they act like 13th-century waifs following a religious fanatic. At least the adults of the Middle Ages tried to prevent such lunacy.