Let’s say that, like Al Gore, you believe in catastrophic global warming or catastrophic climate change. Now you observe the recent increase in devastating hurricanes, one right after the other, as well as the many wild fires and high winds that have ravaged large sections of Northern California — events that Al Gore and others have said would result from catastrophic climate change, necessitating a radical reduction in our use of fossil fuels.
Question: Having observed these terrible events, can you say with confidence that your belief in catastrophic climate change has been confirmed? In other words, can you say that these catastrophic events confirm the truth of your theory?
The answer is no, because that would be to commit a logical fallacy. You cannot infer from “Global Warming implies an increase in devastating storms" to “An increase in devastating storms implies Global Warming,” which is the fallacy of "Affirming the Consequent." "If I set a tree on fire, then it will burn" does not imply that "if a tree is burning, then I will have set it on fire.”
It is this kind of fallacy that underlies confirmation bias.
(Edited by William Dwyer on 10/19, 11:30pm)