Kent Pitman

Kent Pitman
New England, USA
Philosopher, Technologist, Writer
I've been using the net in various roles—technical, social, and political—for the last 30 years. I'm disappointed that most forums don't pay for good writing and I'm ever in search of forums that do. (I've not seen any Tippem money, that's for sure.) And I worry some that our posting here for free could one day put paid writers in Closed Salon out of work. See my personal home page for more about me.


OCTOBER 31, 2012 9:35AM

Climate Change vs. The Weatherman Problem

Rate: 14 Flag

People are bad at discussing probabilities—and it could kill us all.

A weatherman may predict that there is an 80% probability of rain, but then when it doesn't rain we'll often say “he was wrong.” It's rare to hear anyone say “this must be the one in five cases where he said there would be no rain” even though that is the very meaning of an 80% chance of rain.

People also shorten “the weatherman says there's an 80% chance of rain” to just “the weatherman is predicting rain,” losing the part about an “80% chance” as if it were a mere detail or, even worse, as if it were a phrase that contributed no useful information at all.

In speaking of an 80% chance, the forecaster is saying “given these particular weather conditions, four times out of five there will be rain and one time out of five there will not be rain.” Or, put another way, an 80% chance of rain is the same as a 20% chance (one chance in five) that it won't rain. So if there are 250 occasions where there is such a chance of rain, and if 200 of those 250 (4 out of 5) have rain while 50 of those 250 (1 out of 5) don't have rain, then he was 100% right—that is, he was completely correct, not 80% correct, in his claim that there was an 80% likelihood of rain.

Unfortunately, when it doesn't rain, the weatherman just takes heat. I call that The Weatherman Problem, and it must be maddening to someone who is struggling to do the right thing.

Not only is it bad for their sense of personal happiness and self-image, but it could be actively bad for their career. If people are wanting to shoot the messenger in the case of bad news, why not bias things in a way that makes them want to do it less? Better to hide behind “Who could have known for sure?” than “I should have known better.”

So the tendency, I'm suggesting, is to bias downward. In our society, failing to know something is often more defensible than claiming to know something with too much certainty. The latter appears to be the sin of arrogance and if we even smell the possibility of that, we punish it unreasonably harshly.

Effects like this are enough to make one not to want to make predictions. Not just predictions about weather, predictions about anything. Why sign up for that kind of grief? One wants to be sure, but one cannot be 100% sure. Maybe one is 80%, 90%, 95% sure. Maybe it's hard to turn into a specific number. When is the right time to make a prediction with any confidence? Better to hold back until one really knows.

The Weatherman Effect happens in any domain, not just weather. I'm just giving it this name to remind us of how familiar it should be. But it happens anywhere that requires science augmented by guesswork. Medicine, for example. Or legal liability. Or Climate science.

It's hard to say for any given individual with lung cancer precisely what the cause is. Yet if 100% certainty were the requirement, we might not have warnings on the side of cigarette packs where they belong. In spite of this lack of complete proof, we've come to believe as a society that smoking is bad for us—that it's better to reason about this as a truth than as a “questionable claim.”

Of course, there are always skeptics, and in the modern world many of them are paid by people and organizations with special interests, such as the cigarette industry or the fossil fuel industry.

Skeptics eat legitimate ethical concern for breakfast, finding ways to run on it the rest of the day. They are focused on telling us that the things that Climate scientists tell us are not true, and often their flimsy rationale is that nothing about nature can ever be known to 100% certainty. Well, duh. But seriously—do they expect this should shut down all discussion on all things we're not certain of? That's just crazy talk. Or cynically manipulative talk. Either way, it's not good for society.

We know many things well enough. 100% certainty is too high a bar. For most things it's enough to know probably true.

We hear a lot from Climate skeptics about how they think there's too much speculation being done about Climate. They want it dialed back. But what if they're wrong? What if there's really too little speculation because the people who mostly know the truth are afraid to speak—afraid of having their reputations ruined by people who misunderstand or manipulate this problem I'm calling The Weatherman Problem.

The skeptics would have us believe that we don't need to know what's going on about Climate. But I'm suggesting it's just the opposite. I'm suggesting not just that we need to know, but that we already might know and that people are being incentivized not to say. There's no reward for being almost right, only a huge penalty for being wrong. There's no incentive to speculate even a little, so no incentive to talk about what's “probably true.”

What if, as a consequence of this fear, the Climate problem is worse than people talk about because we've not been overhyping the problem but actually underhyping it?

What if respectable scientists don't want to risk their reputation falling victim to The Weatherman Problem so they delay telling us things they only probably know? By holding back, critical information about effects that will only probably happen are not mentioned at all.

If that happens a lot, it could spell disaster.

In the skewed conversational space we've created for Climate, there is only what's certain and “what's not discussed,” which is not the same as ”what's not happening.” But it's easy to confuse the two.

But if we're going to be honest about risk, we have to be willing to be wrong by having prepared for things that maybe won't happen or maybe won't happen yet. That's far less dangerous than failing to prepare for things that do.

We would never prepare for terrorism or disease by looking only to what we are certain of and never raising a finger against the things that probably will happen or even just might happen. Yet somehow we don't do the same with Climate.

We need to change the way we talk about probabilities, or it could kill us. Can I say that with a certainty? No. But I can say it with enough probability what we ought not be dismissing it.

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To put it another way the potential for Climate Change is just one of many things that could happen as a result of pollution and it is perhaps the least conclusive although I think it should be clear by now that there is something to it even if all the details aren't precise.

There is also the poisoning of the water, carbon poisoning that shifts the climate to the benefit of trees that eat that over mammals that require oxygen, deforestation etc. If we spent more time discussing all the other aspects that this would be obvious and it would become even clearer that the skeptics are drawing conclusion first then doing the research to fit them.
A failure to comprehend probability troubles politics just as it does physics and statistics. The Rabid Right may be in denial about climate change, but the Lofty Left is in denial that each and every third-party vote increases the probability of making things even worse even faster. By increasing the chance climate change deniers win election, the Lofty Left violates another little understood law -- The Law of Unintended Consequences.
Oh, Kent. You're thinking about this all wrong. As a close relative of mine often reminds me, Climate Change isn't about data. It's all a hoax for climate scientists to get more research money. Refute *that one*, smart guy! I knew you couldn't!! :-)
Zachery is right on. I saw a presentation at MIT a few years ago on micropollution. Industrial processes often generate dust that is too fine to see or control. That dust settles into the soil, eventually reaches the water table, and ends up pervading the local ecosystem. Over time, these microscopic pollutants build up, and none of us really knows what happens at that point.

Babies, for example, are now born with measurable amounts of PCBs in their body, courtesy of the mother's absorption of them from the environment. (

This kind of pollution is like tossing talcum powder into a mechanical clock. It will kill the mechanics and is virtually impossible to remove without completely dismantling the system. Contrast that with simply poking a stick into the clock, which is easily seen and removed.

We're living in interesting times.
Stever I'm sure that if people made a list of all the things that are being ignored by the corporate media, on this topic or any other, then that list would grow at a steady pace until it reaches epidemic proportions. There are many more where that came from. Just thinking about the one that was highlighted by Erin Brokovich and another one in Massachusetts that was portrayed by Travolta in "A Civil Action" (I think) the one a few months or was it years ago about students with tics in upstate New York and many many more and we have a much bigger problem.

Tom referring to me as the "Lofty Left" won't change the fact that Barack Obama didn't make that list or even keep the promises about the issues he did address in 2008.

He represents his contributors and we get his propaganda.
Zachery, I heartily recommend James Hanson's Storms of My Grandchildren, which among other thing talks about the complex interaction of pollution and Climate. Some of it is non-intuitive (and in a scary way) but it's all stuff we should have a more open discussion about. There are ways in which cleaning up the air in particular can hasten climate problems, and yet in which not cleaning up the air, while delaying immediate problems makes long-term problems worse. A terrible choice that won't get any easier by delaying.

Tom, good to see you. And you bring good points with you as usual.

Stever, thanks for visiting, too. Yes, scarily interesting times.

Lefty, it's appealing to a more primitive reasoning system that predates logic and goes on a “Where there's smoke there's fire” theory.
I wonder what Al Gore is thinking right now! But what's more important - what are Republicans thinking? R
"So if there are 250 occasions where there is such a chance of rain, and if 200 of those 250 (4 out of 5) have rain while 50 of those 250 (1 out of 5) don't have rain, then he was 100% right—that is, he was completely correct, not 80% correct, in his claim that there was an 80% likelihood of rain."

Indeed, since we're dealing with a probabilistic system (rather than deterministic) (or random events), if we were to repeat the "experiment" 100 times using the same input conditions, the phenomenon is expected to happen 80% of the time. If the outcome is known with certainty, then there is no need to estimate probabilities.
Marilyn, I'm going to steer clear of trying to read people's minds and so I'll just hope we can get the rank and file of all parties to see the importance of treating this issue properly.

Kanuk, yeah, the problem is of course you really can't repeat the experiment even once. But even so, I hope that “detail” didn't detract from my point.
Good points Kent but I don't think the Weatherman Effect is silencing the scientists. There's plenty of research and discussion in the scientific journals and at conferences but it flares up as a mainstream media topic only sporadically.

I like to use the climate change percentages in other ways. The figures are approximate as I couldn't find the table I was looking for in a three minute google. But, even if we take fairly moderate action to limit increases in carbon emissions, there's around a 10% chance of a 6 degree Centigrade (about 11 degrees Fahrenheit) within a couple of generations. That would be catastrophic with deaths easily into the hundreds of millions.

Now, I pay for property insurance for the 1 in 10,000 or so chance of a major fire, flood etc. You'd think the same principle ought to apply to global warming but for a big chunk of the population, willful ignorance trumps that.
Abrawang, I think you're on the right track mentioning insurance. The fossil fuel reps may be able to indulge the luxury of pretending there's no Climate Change, but the actuaries get no such freedom. Insurance companies are not blindly writing policies as if there's no Climate Change, they're deciding not to offer all kinds of coverages they used to because they can see the handwriting on the wall.
Several major insurers, including Farm Bureau, are not renewing any home policies because they oversold (meaning underpremiumed) before a recent surge of ill-weather phenomena -- tornados, Sandy and an increase in damaging electrical thunderstorms -- and are now strapped with hefty claims. Whether they're blaming global warming or an angry god, they're reacting, which is a leading indicator of where we're all headed.
I inadvertently left out " Southeastern Virginia." The area might be more extensive, but I know for certain it affects this immediate region..
CM, yeah, that'll have cacade effects starting with their competitors wondering if they will take on a big pool of high-risk customers or similarly pull out...
Good point about the insurance industry and their assessment of (future) risk. If their actuaries believe that the risk is increasing, this means the companies believe the climate is changing (in one form or another).

I'm surprised that The Demon/Firestorm hasn't showed up yet.
I call anyone brave enough to allow us to hear the truth about what is probably next heroes of the finest order. I count Carl Sagan among these.
Very fine article. Wish I'd written it.

The answer to anything compelling from the climate sciences is to shout "USA" in unison. Ignorance has gone tribal. (r)