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If this is Wednesday…

Then I must be in some sense wacky. Right?

Sadly, this post isn’t about free fiction. It’s about some pushback I got on my last post from a very intelligent friend I first met nearly 40 years ago. Truthfully I hadn’t looked into the climate-change thing too carefully, ’cause it seemed on its face silly–but we’ve exchanged 30+ emails since (though we’ve finally moved on to a new topic: a book club for two! but it’s totally okay for guys to do it!) and I thought I’d share what I learned from the discussion.

Here’s what I said last time

I suggested that if chaotic systems (which are inherently unpredictable even in theory) exist at all, weather is at least one of them. From this I reasoned that predicting global climate (or “temperature” as a proxy for it) is likely to be quite a difficult problem. And very likely impossible. There I rested my case. My friend disagreed, suggesting that temperature might be influenced by both chaotic and non-chaotic factors in such a way that overall trends could be predicted.

So…a valid argument! Therefore I told him I was willing to be convinced via direct proof: simply show me a model of global temperatures that makes accurate predictions over time–and I’ll allow variables (such as solar radiation) to be included. In other words, tell me what factors control temperatures tomorrow, and will continue to do so into the future, and we’ll start measuring what happens.

In fact, I didn’t think success in this was possible. So I offered to make it even easier: show me a model that makes predictions, however inaccurate they may be, that does not lose accuracy over time (assuming course corrections in the form of direct temperature measurements–or logical equivalents–are not input as new data) and I’ll turn cartwheels. ‘Cause that would be really cool.

Apparently no such model exists, or at least not one that worked. Still, maybe that “trends are predictable” argument had something going for it.

Thing is? I saw two problems here:

  1. Stock markets, for instance, have often been traded successfully by trend-following systems. However, reliable systems for predicting trend reversal (or intensification) have yet to be developed. Therefore, if this sort of thing works for global temperatures…well, I’d expect similar advances elsewhere. Shouldn’t we also be arguing that Social Security funds (if there were in fact a separate fund, but never mind…) should be auto-traded by a system such as this, starting right now? Isn’t people’s retirement capital important? Or in medicine: we might be able to do away with a lot of drug and medical-device testing if we can model a human body more accurately. We might be able to accurately predict all drug interactions, in any combination, in a given individual. We might even be able to do very-very-early intervention in the cases of diseases such as cancer. It’s all variations on the same sort of mathematical problem, after all. Cool stuff! I’m in favor! When do we start?
  2. We really need some way to justify the notion that long-term predictions will be more accurate than short-term predictions, unless we also get short-term predictions to be scary-accurate. Like for next Tuesday. ‘Cause typically math works the other way ’round, with accuracy lost over time.

But I could be wrong!

After all, my friend also told me that data clearly showed (1) a correlation between carbon dioxide (CO2) levels and global temperature. And then (2) he pointed out that CO2 levels have been steadily rising, due to human action. I disagreed with neither contention. Scary!

So…I looked into it. My first objection was that my friend was talking about a roughly 130-year timespan, and the “current” (if it’s in fact still going on…more on that in a bit) warming trend actually began a bit over 300 years ago. Not too many factories producing CO2 at the time. Plus, I noted that there are conflicting reports on past temperature…some calculate that the planet is in fact cooler than it was 2000 years ago, and we’ve actually been experiencing a warming spike in an overall cooling trend. But I discarded that second notion on the grounds that I didn’t really know for myself what past temperatures had been. Not my field, after all.

Still, I was left with the strong suspicion that the entire argument for CO2 causing a global temperature increase depended on cherry-picking a particular timespan.

But what if I was still wrong?

Okay, that could happen–after all, I’m just a guy who’s looking at this stuff casually. So…about that correlation between CO2 and temperature? It exists, all right…unfortunately for the “greenhouse” argument, it turns out CO2 is what’s called a “trailing” or a “lagging” indicator. In other words, CO2 increases after the temperature rises.

I went out a bit further on a limb I found convenient and pointed out that after all a long-term atmospheric “greenhouse effect” is essentially the result of a thought experiment. Evidence for it is thin on the ground–okay, that’s a pun, but what I mean is that we’d need accurate and reproducible predictions of its effect to move this greenhouse notion beyond the status of “hypothesis.”

After all: logically, warmed gases would simply rise. In fact they’d tend to cause the volume of a planet’s atmosphere to expand, which would then have a cooling effect. It’s very clear from looking at day/night measurements of our planet’s largest satellite that planetary atmospheres have a generally moderating effect on surface temperatures. Can an atmosphere, without losing mass or volume, suddenly lose all or part of this ability? Maybe! Can an apparently rather small change in its composition have this effect? Maybe! But it’s not as intuitively obvious as talking about a “greenhouse” makes it appear. For some reason this point is seldom raised.

Then I pointed out that water vapor (of which we have lots more around here than we have CO2) is also considered to be a greenhouse gas. I can buy that, I guess, if such an effect exists on a long-term basis…but even climate scientists seem to agree that increased water vapor in the atmosphere would be a natural result–whether or not it’s also a cause–of higher temperatures. Since we have so much water lying around, that suggests this: higher temperatures mean more clouds. Which reflect sunlight…which would be true regardless of the height or temperature of the clouds, and if models that suggest higher-plus-warmer clouds are correct? That doesn’t help their argument for overall surface-level warming, because it just reduces the scope for a greenhouse effect below those same clouds. In short…it’s not at all clear that more clouds mean more warming. Data to date in fact suggest otherwise, and this notion (too) depends on the accuracy of unproven/untested models.

But what if I’m still wrong?

My friend said that (1) at least one claim has been made that most warming actually follows CO2 increases, and that (2) we should presume that models produced by experts are correct until proven otherwise, unless we want to become experts ourselves–and of course the actual experts are well aware of the existence of water vapor!

Okay! Fair enough! Only…

  1. I make no claim about a causal effect or lack thereof between CO2 and global temperatures. I merely point out that for all we know either might cause the other. In fact the notion that “rising global temperatures cause an increase in CO2, and as a separate matter so does human action” is a better fit to observed data (see Occam’s Razor here) than we get by pointing the arrow of causation in the direction my friend desires. And for that matter, correlation doesn’t have to mean causation at all: both temperatures and CO2 might rise due to outside factors that affect both. And in any of these three scenarios, one would expect most of the rise in temperature to follow the increase of CO2, so that’s not a very productive line of argument to begin with.
  2. Oh wow. See, with the scientific method, one is supposed to presume that a hypothesis is incorrect until proven otherwise. First you get an idea. Then you test that idea and get results that seem to validate it. Then you can start looking at reproducibility and also consider other hypotheses that might lead to the same experimental results. We’re stuck at a pretty early point in the process at the moment. More on this later too.

But what if I’m even wronger by now?

Look. I’m wrong bunches of times every day. Really. I wish I were exaggerating here. But I’m not. The possibility is always worth considering, in any context.

So it’s time to consider results of the IPCC’s predictions thus far. And…well, if you were to get a ruler and draw a line from the beginning of the (possibly cherry-picked) timespan they say they’re working with, through the date of the release of their predictions, and up to the present day? Unfortunately, you with your ruler would have achieved more accurate results than their models have.

It gets worse. CO2 has increased recently, possibly as a direct result of human action (I’m not arguing this either way–it’s a side issue at best), but actual global average temperature has not increased between 1998 and the present. This is what’s caused “the pause” and it has various folks all a-twitter.

This appears to mean that warming has clearly happened over a given timespan, but we don’t yet know quite why. Or (obviously) what to do about it either. Or whether it’s a curse or a blessing if it does continue into the future…but that, though interesting, is beyond the scope of this post.

But what if I should still assume I’m wrong?

Here my friend acknowledged that the results of the models’ predictions to date didn’t by any means demonstrate that their underlying premises were correct (which would be the “the science is settled” position you hear so often).

But he then pointed out the dangers of assuming the IPCC is full of hot air (sorry! couldn’t resist!) if in fact they’re not. What if in fact we need to take action right now to avert catastrophe? What if my stubbornness and insistence on the scientific method dooms the planet?

Well, that’s certainly possible–or it would be if all my teeming minions (last known count: zero) followed my example. But…I could just as easily imagine a doomsday scenario with different premises that calls for diametrically opposed emergency action.

This sort of thing is a lot like Pascal’s Wager (the notion that one should behave as God is said to command us to behave, on the off chance God exists, ’cause it costs less when you’re wrong than does the opposite assumption). It’s valid only if you already suppose the particular God you have in mind is in fact the one you’ll be dealing with–rather than any of an infinite range of possible god-like beings who might have different preferences. In other words, it’s not wrong per se…but it only seems convincing to those who already buy the conclusion you’re selling.

I’ll go a step further. The whole argument (models based on historical data vs. the accuracy of their predictions) seems to me to be analogous to the results of population studies vs. double-blind clinical trials. The population studies often suggest various “superfoods” or possibly valuable dietary supplements…but the clinical trials damn near always show these notions to be either inconclusive/unproven/iffy or flat wrong. So, the population studies–to my mind–are excellent hypothesis-generating machines. As is the study of historical temperature/climate data. But the science is what happens after you form a hypothesis. If, in fact, it happens at all.

But okay. I’m still wrong.

Could be true! See, I’m not even trying to be “right.” I’m merely pointing out that it’s not yet time to believe in any particular climate-related model. Or doomsday scenario either.

Still…I haven’t even gotten to the worst part of my argument against buying what the IPCC et al are selling. Suppose we take the last hundred-or-so years, and try to come up with a useful predictive model for global average temperature. Just from looking at the graph…will you have more confidence in your model if it suggests an increase or a decrease in temperature?

This brings up at least two issues:

  1. I talked before about curve-fitting. Basically, the problem here is that historical correlation is a great way to create a hypothesis. But it’s a bit…disingenuous?…to also claim that historical data is sufficient evidence to “prove” the hypothesis you created using that same data. You really need to make predictions, and measure the results.
  2. Unfortunately that’s not the last step in the process. You also have to consider alternative hypotheses. In other words, since nearly anyone, using that same data and some other set of assumptions/premises, would likely also end up predicting an increase in temperature…well, even if the data we’ve gathered since 1998 had fit the IPCC’s predictions at all closely? It still wouldn’t be a strong argument that their underlying premises (which are widely labeled both “science” and “settled”) were in any way correct.

In that sense, the “pause” since 1998 is a terrible lost opportunity for the IPCC. If they’d gone against the intuitive “temperatures will rise” prediction, they’d have gained all sorts of credibility. As things stand…well, they essentially have nothing at all. Seriously: the Emperor has no clothes. And I’ll go back to averting my eyes post-haste!

So, with all respect to my good friend and any others who disagree, I’ll stand by my “scam” claim for now. Our emails were actually wider-ranging than this post, but everywhere I looked I saw more of the same. This thing just doesn’t hold together. Yet. Maybe someday.

On the bright side for the opposing argument? For all I know there exists some subset of climate-scientist types who absolutely got it right, for 1998 and every year since–but, since their position was understandably unpopular, their contribution simply didn’t get to become the IPCC’s officially-selected model. It could be true! Unfortunately, for most people and probably all organizations, stuck in a “our side vs. their side” paradigm, these things are always politically influenced. In one sense or another.

But I’ll still bet against a conclusively demonstrated predictive model for global temperatures…for now. And I’ll still hope I’m wrong, ’cause it’d suggest all sorts of excellent advances in other fields are also forthcoming. Some of which might save my life. Or yours.

Taking the IPCC’s predictions at face value, today, logically requires utterly abandoning the scientific method itself. I’m not quite ready for that.

And here’s some snark!

Hey! What if we just assume I’m totally wrong on all counts (because I’d have to be, to justify any action whatsoever at this point)? What then?

Well, most “solutions” I’ve seen proposed seem to hinge on some sort of government action. Who’s to say they’d be more effective than the USA’s Tripartite War on drugs/poverty/terrorism, in which as far as I can tell the “warriors'” standard metric of success is the identification/creation of ever-more enemy combatants over time? Heh.

Lest you conclude that I think human foolishness is confined to governments, I’ll note here that I once took a job, ostensibly to develop software, as a contractor for a large company–but it turned out that actually producing software was strongly discouraged. The person who’d hired me was building herself an empire instead: as long as projects forever increased in scope without being completed, she could keep hiring new people. And software that’s never “shipped” is also conceptually perfect! No user complaints at all! No support needed!

That story gets even funnier, ’cause the organization (run for profit! and therefore efficient!) decided to deal with all the contractors being hired by…trying to encourage us to convert to full-time employee status.


They offered such inducements as 40% cuts in pay and the ability to park in parking lots nearer the building–previously all lots had been open on a first-come-first-served basis, but suddenly contractors had to park a quarter-mile or so from the main building. At least.

May I point out that contractors bill by the hour? I simply started charging them from the time I shut off my car’s engine–and until I’d started it again at the end of the day. And demanded–and got–a raise in pay. And volunteered to walk the 5 miles between their office and my home, charging by the hour of course, if that would make them even happier.

I am, as you all know, nothing if not agreeable. {8′>

Then I left for another group within the same company, and that story’s even goofier–a night in jail! another raise! a quick move to another state!–but I’ll save it for another time.

Have fun out there!

Published inRandom Rants


  1. Sally Jardon

    David, we have been trying to predict the climate for as long as I can remember and let’s say I’ve been around for longer than I admit. Most to the time, no all the time, the prognostication has been wrong. For fun go to YouTube and search for ‘the coming ice age’ .

    All the best, Sally

    • David

      Well…it would be a neat trick to pull off! I remember the “ice age” thing too–and of course there are people who still say it’s coming Real Soon Now. And then there are the people who reject what the IPCC says and simultaneously counter with their own preferred predictions–whether they’re objecting to the notion that mean temperature will rise or that it’ll be harmful if/when it does varies. Either way, they’re just telling us what it is that they want to believe. ‘Cause, you know, models are hypotheses and are only useful insofar as they give measurably correct predictions. This applies to everybody’s pet notions.

      Until we can start predicting them, trends are things we recognize in the past. The future remains unknown. I guess a lot of folks don’t feel happy with that. Which is…well, I’m going to say it’s just fine. Human cussedness is a beautiful and powerful force. We’d be a much poorer species without it.


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