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Global Warming, Skepticism, and Analysis Paralysis

Last decade I was skeptical that there was any significant current change occurring in global temperatures. Today I accept that average global temperature has increased about one degree Fahrenheit in the last hundred years but am skeptical both that this has statistical significance sufficient for predicting the next hundred years and that we know that the coincident dramatic increase in atmospheric carbon dioxide during this same hundred years is the cause of the temperature increase.

How can I persist in being so pigheaded? You may ask (some people have). Having been wrong before, wouldn’t it be better to keep quiet now?

Reader Adrian Cockburn comments:

“The global warming denialists are a small vocal minority who have been repeatedly shown to be cranks or have vested interests. There are also an increasing number of groups who are overstating the problem and confusing short term weather with long term climate change. For a skeptical and scientifically sound viewpoint I recommend tracking the Stoat blog http://scienceblogs.com/stoat/ Governments need to be upgrading levees and sea defenses in areas at risk, we should expect more disasters due to larger fluctuations in weather patterns, and we should be reducing CO2 levels.”

I have no vested interest in denying global warming although am, perhaps, a crank. But I thoroughly agree with Adrian that “skeptical” and “scientifically sound” go together and that short term weather should not be confused with long term climate. Skepticism isn’t denial; it’s the right way to approach both observations and hypotheses. It was right – not wrong – to be skeptical of last decade’s observations even though the more moderate of them proved to be correct and it is right to be skeptical of current accepted wisdom even if it’s subscribed to by exPresidential candidates and legions of scientists endorsed by the UN. But skepticism is not denial! It would be just as unskeptical and unscientific to say categorically that anthropogenic carbon dioxide emissions have NOT affected the pace of global warming as it is to assert that they are, beyond reasonable doubt, the main cause of the recent acceleration.

Reader Mike Kowalchik writes:

“I agree that there is a tremendous amount of hubris in believing that we are in control of our climate / environment. I also have a personal theory (I'm sure shared by many others) that human beings are *awful* at understanding complex systems with lots of interacting variables. We're terrible at understanding real cause and effect as you point out…

“This does however bring up a problem with the argument you're making. Like you say, there is a possibility that we *are* causing global warming. There is no way to use the scientific method to prove or disprove this hypothesis however. It's not a system we can reduce, or isolate variables effectively. There is also only one climate, so experimentation is impractical as well. This is one of the reasons "the science isn't conclusive" argument put forth by many people really bothers me, it will never be conclusive.

“If we have no control over climate, then so be it, but if we *do* isn't it worth it to try to control the variables we can? I have my doubts whether we truly understand what's going on, but if we control only a few of the inputs to the system, I think it behooves us to try and reduce and/or manage those inputs.”

Couldn’t agree more with Mike. Life isn’t business school. You can’t wait until all the facts are in to act. Not acting is an act in itself. He’s also right that we don’t have any laboratory – except history – in which to do climate experiments and we can’t control the historic variables.

Since it is often necessary to act before we certain, it is especially necessary to remain skeptical even AFTER we act. It is a huge mistake to convince ourselves that we’re certain of something just because we have a need to act. When we act in advance of certainty – which we usually do in real life – then we MUST remain open to the possibility that the actions we’re taking will be proven wrong. We must discover our mistakes as soon after we make them as possible and correct them without hesitation.

If we convince ourselves that all global warming is CERTAINLY a result of manmade CO2 and that we know how to affect the climate by reducing it, then we open ourselves to huge dangers including the following:

  1. we spend huge resources reducing CO2; the effort has no significant effect; global warming accelerates;  we wasted critical money and time which we should have been spending relocating people from coastal areas.
  2. we reduce CO2 just as some other cycle reverses and we find ourselves having to deal with intense global cooling which would have been mitigated by the current CO2 levels (after all, the onset of another ice age is about due).
  3. we take radical steps like adding reflective ash to the atmosphere or recycling deep ocean water (some – not me – would include building new nukes in this category) and end up with drastic and unforeseen consequences.

Instead, we need to proceed skeptically. This does mean working rapidly towards reducing the use of fossil fuels per capita of “developed world” life style – especially since many more people are becoming rich enough to enjoy that lifestyle. We’d have to do that for economic reasons anyway.

We do need to study – but not begin to implement – some of the more drastic countermeasures against warming in case it continues and leads to rising water levels (itself not a certainty).

We need to spend relief money on moving people out of constantly flooded areas rather than rebuilding in situ.

We also need to continue to try to DISPROVE both the hypothesis that anthropogenic CO2 is causing global warming and the hypothesis the global warming inevitably leads to higher ocean levels. Why? Not because we know they’re wrong or even because we want them to wrong but because we ARE acting on these hypotheses and need to find out as quickly as we can if we’re doing the wrong things. We need to be skeptical.

Personal notes: I’m greatly influenced at the moment by philosopher/trader/skeptical empiricist Nassim Nicholas Taleb whose Fooled by Randomness I’ve just read and whose Black Swan I’m now enjoying greatly.

We’ve “acted” personally by installing solar hot water, getting the permit for and preparing to install photovoltaic generating capacity, and beginning the installation of a geothermal heat pump. So skeptics CAN act, although our actions are motivated as much by the desire to reduce dependence on imported fuel as to reduce emissions. 


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Tom Evslin


I'm sorry to get your name wrong. I do appreciate your comments. Posted today on the Arctic melt and what that might mean. Couldn't agree more that we will more likely lurch thru change with Black Swans than creep thru it incrementally. Change is a fractal...


Thanks for the helpful links. Haven't worked thru the math but it does make sense that, whatever the overall temperature effect of atmospheric CO2, it's highly unlikely to be linear.


I agree that the IPCC consensus is not much to go on (nor are all contributors to the IPCC more than amateurs when it comes to the relevant disciplines).

Thanks for the link to forcastingpriciples.com. looks like there's good fodder there for future posts.

I learn a lot from all your feedback.

Richard Sprague

What, exactly, are we supposed to do with this information? Personally I think it's a waste of time for us amateurs to speculate on whether the IPCC is right or wrong. I care much more about the resulting policy implications, and so far I haven't heard any suggestions that don't make (better) sense for reasons that have nothing to do with global warming. As you say, solar hot water and other actions are worth doing simply because they reduce dependence on unstable foreign oil supplies. Who cares what the IPCC says -- you should still do it.
Incidentally, you should look at the work of Scott Armstrong (U-Penn and author at http://www.forecastingprinciples.com ). He analyzed thousands of "expert" long-range forecasts to understand which ones turn out well and which don't. Conclusion: the IPCC projections are almost certainly wrong, partly due to the Black Swan effect and partly because of overall methodology.

Mike M.

Your game is weak Cockcroft, starting with your embarrassing use of the phrase "hardcore denialist." Your link to Monckton doesn't work. You don't address Lubos' points on climate sensitivity. And your boy James Hansen is a complete tool..


Note that the previous posts recommending Monkton and Lubos are promoting hard core denialists who have had a lot of what they claim debunked repeatedly (see this on Lubos http://scienceblogs.com/stoat/2007/09/return_of_the_dead_global_cool.php and this on Monckton http://scienceblogs.com/stoat/2007/09/just_in_case_you_feel_inclined.php) at the Stoat blog for example). Note the tactic of tagging them with "real smart guy" and "Harvard Physicist" to try and give them more credibility. Lubos is a string theory expert, not a climatologist. A detailed rebuttal of many denialist arguments can be found at http://illconsidered.blogspot.com/2006/02/how-to-talk-to-global-warming-sceptic.html

Mike M.

A real smart guy slices and dices...

Mike M.

A real smart guy slices and dices...

Mike M.

And here's a Harvard physicist explaining the actual climate sensitivity to co2...

Mike M.

Why, here's a little test for the AGW hypothesis...

Adrian Cockcroft

Thanks for the quote, although my surname is Cockcroft, not Cockburn...

I did not mean to imply that you were a denialist, I think your position is skeptical and you aren't endorsing any of the denialist or crank theories. I do think that the IPCC is remarkable in itself, its incredibly hard to get thousands of scientists and government organizations on a worldwide basis to agree on something. They agree that it is very probable that global warming is happening and that it is very probably caused by people, and they strengthened this position in the most recent report. The denialists claim that the IPCC is a conspiracy but the only thing that this large and diverse set of people have in common is the scientific method. I'm a Physics graduate, I understand how the scientific method works, and its clear that you do to, but one of the big problems with explaining this to the "general public" is that too many of them are scientifically and statistically illiterate.

I'm also a big fan of Taleb's books and one aspect of the Black Swan is relevant here. We tend to average things out too much, and miss the unpredictable large events that are outliers. My personal worry is that the climate models we are using are only able to model the average events, and that we could have an unexpected large outlier such as rapid large scale melting of Greenland or Arctic ice, that would be a Black Swan event. The record extent of Arctic ice cap reduction this year is not in itself enough data to move the climate average. It was described in The Inconvenient Truth, but I don't think it was expected or predicted to happen this soon. Its an outlier, and we don't yet know whether the ice will come back next year or whether we will have an even worse outlier. William is taking bets on this at the Stoat blog...

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