How do you know whether a claim is true or false?  One of the first things to consider is whether or not the claim can ever be proven true, or proven false — and if so, how?  The ability to disprove an assertion is crucial to scientific reasoning, but it is equally important to day to day discourse, if it is to mean anything. 

The question of whether an assertion can be proven false, is informed by the concept of “falsifiability.”  The idea of falsifiability was made famous by Karl Popper, a Viennese-born (1902) philosopher who moved to England in 1946, for the last half of his life and work (d. 1994). 

Falsifiability is the ability of a theory—a working framework for explaining and predicting natural phenomena—to be disproved by an experiment or observation.[1] The ability to evaluate theories against observations is essential to the scientific method, and as such, the falsifiability of theories is key to this and is the prime test for whether a proposition or theory can be described as scientific. __  RationalWiki

Cycle of Reasoning

https://explorable.com/falsifiability%5B/caption%5D

For Popper, a theory is scientific only if it is refutable by a conceivable event.  Every genuine test of a scientific theory, then, is logically an attempt to refute or to falsify it, and one genuine counter-instance falsifies the whole theory.  In a critical sense, Popper’s theory of demarcation is based upon his perception of the logical asymmetry which holds between verification and falsification: it is logically impossible to conclusively verify a universal proposition by reference to experience (as Hume saw clearly), but a single counter-instance conclusively falsifies the corresponding universal law.  In a word, an exception, far from ‘proving’ a rule, conclusively refutes it.  Every genuine scientific theory then, in Popper’s view, is prohibitive, in the sense that it forbids, by implication, particular events or occurrences.  As such it can be tested and falsified, but never logically verified.  Thus Popper stresses that it should not be inferred from the fact that a theory has withstood the most rigorous testing, for however long a period of time, that it has been verified; rather we should recognise that such a theory has received a high measure of corroboration.  and may be provisionally retained as the best available theory until it is finally falsified (if indeed it is ever falsified), and/or is superseded by a better theory. _  Stanford Encyclopedia on Karl Popper

Pseudo-scientists — such as those who currently profit from the milieu of climate apocalypse — refuse to be held to the strict discipline of falsifiability and scientific reasoning.  This makes the entire enterprise of climate apocalypse — from the scientific to the political — meaningless, except as a gauge of the people who espouse radical economic and political transformation based upon unfalsifiable pseudoscience. 

Political propaganda — such as we see from Russian state media, Chinese state media, or British state media such as the BBC — is another example of essentially worthless unfalsifiable assertion.  Since state propaganda is not held to the discipline of being disprovable, it is only a tool of power — meant to influence gullible and undisciplined minds. 

Most discussion on the internet does not come close to the level of falsifiability.  Strict scientific falsifiability requires a good deal of mathematics and esoteric knowledge.  Common speech and writing requires only reliable documentation — and the understanding that sometimes one must take his best shot, until more and better evidence comes in.  The poorer the evidence, the more important it is to collect better evidence before making a significant commitment to the idea — depending upon the time allowed by the situation. 

If someone is approaching from a dark alley, holding a metallic object that glistens dimly from a streetlight, time may dictate a quick decision as to fight or flight. 

No matter how much schooling a person has had, if he is not comfortably acquainted with the idea of falsifiability — and the levels of falsifiability in daily life — he cannot be said to be educated.  Education often has nothing to do with schools or schooling, and the sooner a child learns that lesson, the brighter his prospects will be for an informed and liberated life.