Catastrophists claim that carbon dioxide alone determines the Earth's climate, and that we will all be safe if we only stop using fossil fuels and get to "net zero" carbon emissions by some arbitrary future date.

Mike Rowe recently opined that one thing bad people have in common is certainty.

The assumption of the climate change catastrophists is not just that horrific global warming is a possibility, but rather that it is a certainty — a 100-percent certainty.

You never hear them address the topic of probability.  If you are certain about something, you don't need to worry yourself with bothersome details such as probability.

They do often give us dates certain.  Those dates come and go, and nothing happens, but the catastrophists never show the slightest regret.  They just blithely make up new dates and never learn from their errors.  They should have lost every bit of their credibility decades ago, but true believers remain true.

Veering into the realm of probability would get them uncomfortably close to the issue of uncertainty.  Uncertainty might cause their confederates to get all squishy.  Besides, the topic of probability is above the climate alarmists' pay grade.  It would make their brains hurt.  It's better just not to go there and hope no one notices.

Any future event has a probability between zero and one.  Your local weather forecaster might say, "There is an 80 percent chance of rain tomorrow."  In other words, the probability of rain tomorrow is 0.8.

A valuable tool for decision-making is something called "expected value."  Put simply, that's the supposed cost or supposed benefit of some future event multiplied by the probability of the event happening.  Expected value tells us how much we should worry about or hope for something in the future. 

If a future event is too complex for us to calculate its probability, that actually makes the event's outcome less certain, not more certain.  For example, given the supposed cost of catastrophic global warming, unless we can also at least estimate the probability of that event happening, we know next to nothing about its expected cost.  We don't know whether to dread the event or ignore it.

A famous quote by the 19th-century scientist Lord Kelvin is, "I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind."

Ron Ross, Ph.D. is a former economics professor and author of The Unbeatable Market.  He resides in Arcata, California and can be reached at rossecon@aol.com.  His website is rossecon.com.

Image: Robert A. Rohde.