Average is Not Normal

A six-foot man can easily drown in a river which is “on the average” five feet deep.

In the US each woman averages 1.64 children during her childbearing years. Does that mean that a “normal” woman has 1.64 kids? Of course not. One kid, maybe two, maybe three, maybe more. A fractional kid, however, would be very abnormal.

Every night our local tv weather people say tomorrow’s high temperature is going to be so many degrees above or below normal. But they don’t really mean normal even though that’s what it says on the graphic; they mean “average”. And average and normal aren’t the same thing. Here in New England ten degrees above or below average is still “normal”. It is highly unlikely that the high on any particular day will be exactly the average; not as unlikely as 1.64 children but not likely either.

In a New York Times article on whether the recent rain and snow will cure California’s drought, Peter Gleick, co-founder of and senior fellow at the Pacific Institute, a research organization specializing in water issues, complains “We don’t seem to get average years anymore.” In fact there is scarcely ever a weather year which is average anywhere. This is especially true in California where drought and deluge have alternated since long before humans have had any effect on climate.

Gleick is credited with inventing the terms “weather whiplash” and “megadrought.” He acknowledges further down in the article that the weather typically changes year over year in California; but he apparently likes to describe weather in apocalyptic terms, perhaps in order to justify “extreme climate action”. The reason I’m ranting about the difference between “normal” and “average” is that I think the distinction is intentionally blurred when talking about weather in order to promote climate hysteria.

According to the New York Times meteorologists are also concerned. From an article with the wonderful headline: Bomb Cyclone? Or Just Windy with a Chance of Hyperbole?:

“The widespread use of colorful terms like ‘bomb cyclone’ and ‘atmospheric river,’ along with the proliferating categories, colors and names of storms and weather patterns, has struck meteorologists as a mixed blessing: good for public safety and climate-change awareness but potentially so amplified that it leaves the public numb to or unsure of the actual risk. The new vocabulary, devised in many cases by the weather-science community, threatens to spin out of control.”

An op-ed in The Times provides a long term perspective:

“I’ve been through a handful of floods, and they needed no hype: 1964, 1969, 1982 to 1983, 1986, 1995, 1997, 2005, 2017. A flood year always breaks the drought years, or so my grandfather the raisin farmer told it. Drought is California. Flood is California. In the wettest years, rain and snowmelt coming down the rivers produce some 200 million acre-feet of water. In the driest years, they produce 30 million. Between the extremes lies an average year, which happens so infrequently that it is a myth we tell ourselves. As long as we keep faith in the average, it is us and not nature in command.”

I’m the first to insist that climate changes; it always has and it will as long as earth has an atmosphere. Nor do I deny that we are capable of accelerating climate change and have already. Hysteria is a terrible way to deal with anything, however – especially things as important as climate and energy policy. Drought is normal for California. Floods are normal for California. An “average” year would be abnormal (although not alarming).  A long-term change in the average may signal an actual change in climate. A day or year which differs from the average signifies nothing – although may still be something we have to deal with.

Average is not normal. End of rant.