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Climate Hustle

Uncertainty is Exxon's friend, but it's not ours

Posted on 1 December 2015 by Guest Author

Stephan Lewandowsky is a cognitive scientist at the University of Bristol who studies uncertainty in climate-human interactions.

Richard Pancost is a Biogeochemist who studies ancient climates and is the Director of the Cabot Institute at the University of Bristol.

Timothy Ballard is a cognitive scientist at the University of Queensland.

Beginning in the late 1970s, Exxon scientists started telling their top executives about the risk from climate change. By the 1980s, Exxon scientists shared the consensus view that the global climate was sensitive to greenhouse gases such as carbon dioxide.

However, when the issue of cuts to carbon emissions became prominent in the early 1990s, Exxon assumed a different position in public and embarked on a campaign against the increasingly clear fact that the Earth is warming from greenhouse gas emissions. This campaign was centered on scientific uncertainty: time and again, Exxon executives expressed their doubts about the science, turning their backs on their own scientists’ research.

This was no accident: Appeals to uncertainty to preclude or delay political action are so pervasive in political and lobbying circles that they have attracted scholarly attention under the name “Scientific Certainty Argumentation Methods”, or “SCAMs” for short. SCAMs are politically effective because they equate uncertainty with the possibility that a problem may be less serious than anticipated, while ignoring the often greater likelihood that the problem may be more deleterious.

In the case of climate change, analyses of the role of scientific uncertainty in the climate system have repeatedly revealed that greater uncertainty about the climate’s sensitivity to carbon emissions means that there is greater, not lesser, risk.

Potential climate surprises are more likely to be calamitous than benign, because the probability of adverse climate events, such as flooding resulting from sea level rise, increases with increasing uncertainty, all other factors being equal. A sea wall that might cost $1,000,000 if we knew the extent of sea level rise with great precision may cost $2,000,000 if the same expected sea level rise is known with lesser precision.

Given that the extent of uncertainty translates into the magnitude of the risk and hence into the price tag of adaptation measures, uncertainty—ironically—is a source of actionable knowledge rather than an indicator of ignorance.

Uncertainty can be a source of knowledge in a number of ways.

First, in many cases uncertainty is a mathematical expression of the knowledge we do have. Concerning climate change, our knowledge is extensive and firm: We know that doubling the concentration of carbon dioxide in the atmosphere compared to pre-industrial levels will cause warming of somewhere between 1.5°C and 4.5°C. That range is determined by our recognized knowledge of the climate system.

A troubling aspect of this range is that it has a “fat upper tail”, implying that deleterious surprises are more likely than benign surprises. Related to this fact is that if the range of estimates increases, even if it is by a lowering of the lower bound, that seemingly good news may in fact be bad news: When the IPCC lowered its lower estimate of the range of warming from 2°C to 1.5°C, intuitively this appeared to signal that things may not be so bad after all. In actual fact, mathematics developed by Mark Freeman and colleagues show otherwise, and the decreased lower boundary (from 2°C to 1.5°C) combined with an unchanged upper boundary (4.5°C) has actually increased the expected risk.

Even deep systemic uncertainties, often described as “unknown unknowns”, can—ironically—be a source of knowledge. Wendy Parker and James Risbey have recently shown that although unknown unknowns, by definition, cannot be anticipated in the particular, the likelihood that one or the other surprise may arise can be anticipated. We cannot specify what the unknown unknowns are but it doesn’t follow that it is impossible to recognize the risk that such features exist in climatic-ecological-social systems.

The potential for future surprises is particularly large in systems in which surprises have arisen in the past: The climate system has revealed its potential instability through Dansgaard–Oeschger events during the Last Glacial period or the rapid carbon release and warming of the Paleocene-Eocene Thermal Maximum. Moreover, the risk of surprises is known to increase if complex systems are driven outside the conditions in which they have been operating in the past. Within the past year, CO2 concentrations have exceeded 400ppm probably for the first time in 3 Million years.

We therefore know that we are driving a complex system that is prone to sudden surprises outside the conditions in which it has been operating for millennia. We therefore know that we are increasing the chance of encountering unknown unknowns, and this knowledge arising out of deep uncertainty entails an impetus for climate mitigation.

Another way in which uncertainty about the future can be a source of knowledge is indirectly, through its adverse psychological consequences. Those consequences have been largely overlooked to date. For example, perceived uncertainty increases people’s response to aversive stimuli if they occur: we respond more emotionally to adverse outcomes when they are uncertain. Uncertainty also comes with a price tag concerning our ability to think: under conditions of uncertainty, people have been shown to be biased against creativity and prefer mundane functionality instead. The uncertainty that inevitably arises in times of crises may therefore stimulate a bias against the very creativity that would be needed to solving the crisis.

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Comments 1 to 14:

  1. I find it dismaying that Exxon executives, like tobacco execs, will only be in formal trouble for misleading Congress or giving other kinds of false sworn testimony; the climate consequences of their decisions will probably not even be in the running as something they will be held responsible for.

    More broadly I wonder if there is a clear incentive for executives to avoid being well informed because if they remain ignorant they can argue they didn't know and avoid liability arising from their decisions.

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  2. I find it hard to get too wound up about what a bunch of suits who are not scientists did or did not express on a scientific topic.  Morally, they made a bad choice, but since they are legally obligated to persue the interests of company shareholders rather than their own, or even a moral cause, it's a bit of a mess.       We (in the USA) no longer acknowledge that there exists any higher law than immediate convenience, and so a CEO of a public company who declares they are going to take a hit for the next 20 quarters because of X moral reason is likely to be fired, and could be personally sued for any lost company income. 

    Considering that they're required to express the interests of the shareholders, I don't understad why anyone would even ask them about climate change, much less give their answers any weight.   Exxon did not have climate science locked away from the public, the science of interest was and is available to the public for anyone who cared to read it.  

    In short, the execs made a bad choice, but it is absurd to blame them for the failure of others to use their own minds.  


    What is popularly believed to be true changes from time to time, usually due to fashion, sometimes due to passion, and within natural science and on rare occasions due to an advance of knowledge.  If we get in the habit of putting people in the dock for expressing incorrect thoughts, the people in the concrete cells will be the creative ones, the scientists and those insist on pointing out that the emperor has a hairy ugly beer gut.  

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  3. As a Civil Engineer, who also happens to have an MBA, I have always been very concerned about the 'uncertainty' related to the ability of built things to survive severe events (it has been my life's work).

    The most severe expected events are the design basis for so many things. Uncertainty of global climate change affects every existing and planned to be built structure (and rain run-off affected system) that Exxon (and every other pursuer of profit) relies on to hope to 'make money'.

    The climate change uncertainties include:

    • how fast the winds will blow?
    • how intense can a localized gust be?
    • how rapidly can a localized rain event accumulate?
    • how much total rain can fall in an event (in a day or a multi-day event)?
    • how much snow might accumulate including wind blown drifts?
    • how wet and heavy will accumulated snow be?
    • how much ice may form due to freezing rain?
    • how much ice will form on a waterway - enough for a winter bridge?
    • how rapidly will ice breakup on a waterway and potentially dam it, damning anyone upstream and threatening everyone downstream when the unplanned dam breaks?
    • what is the highest temperature condition a structure will be exposed to?
    • Will permafrost be able to be kept as permafrost?
    • What is the highest water wave likely to hit a sea-side feature?
    • And so much more ...

    Increased uncertaintiy of the design requirements results in increased risk of failure of existing items to perform their required function. And it results in increased risk of failure of newly designed items unless extra expense is made upfront in the hopes that some degree of 'hoped to be over-design' will be enough over-design.

    The truth has always been that gambling risk-takers pursuing maximum personal gain willingly gamble on getting away with cheaper, riskier and more damaging pursuits betting that they will 'not personally suffer the consequences (even if they know that other people would be likely to suffer immediate consequences but be unlikely to be able to penalize the trouble-making gambler). And those gamblers love it when the consequences are likely to be in the future rather than be immediate consequences because future people are even less likely to be able to penalize such a deliberate gambling trouble-maker. An engineer's responsibility is to protect the public from such pursuers, not to maximize profit for them.

    The truth is there will always be some people who are determined to demand more freedom to do things they actually understand are less acceptable. And those people will always try and try again to get away with less acceptable pursuits of personal benefit by claiming their freedoms cannot be restricted except by absolutely certain proof, not just proof beyond a reasonable doubt, of the unacceptability of what they want to get away with.

    National design and construction standards are also under arttack as international competition leads pursuers of profit to challenge why a national standard 'has to be met when they can find a lower standard somewhere else'. That pursuit combined with the denial of climate change is a double-down bet made by many wealthy gamblers who illigitimately won through their competetive advantage that was obtained by deliberately caring about others and the future as little as they can get away with.

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  4. One Planet Only Forever @3

    Not sure why you head your list of uncertainties to be considered as "The climate change uncertainties include:".  Surely these uncertainties have always applied to the climate rather than to climate change.  Are you saying these uncertainties are only now being considered? 

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  5. ryland@4

    The climate affected design values for any region are based on the past history of gathered observations and the associated related understanding of the weather effects at a location.

    Rapid Climate Change and the uncertainty of how any specific location's weather extremes will be affected reduces the certainty of appropriate design values because the observation history is a less certain basis for determining appropriate design values.

    So my reference to Climate Change is to the current term being applied to the more rapid climate changes now better understood to be caused by human impacts. Climate has always changed ... rather slowly.

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  6. ryland@4

    Thinking a little more about your question the following may be the answer you were asking about.

    The typical design basis for structures and water run-off is not the range or variation of weather conditions for a location, it is the statistical expected extreme of a design condition such as the maximum large-field wind speed expected to occur once in a 50 year period. My use of the term large-field is meant to differentiate the wind speed experienced concurrently by all of a large structure vs. the faster wind speed and resulting larger local forces a structure.

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  7. @1 the point you raise is, I suspect, even more poignantly significant, if not terribly ironic, than you first thought.

    Ignorance of the law is no excuse: but of the moral law apparently not so! 

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  8. @4, uncertainties change. The problem is no one can put their finger on any solid numbers with enough certainty to warrant investor panic.

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  9. @One Planet Only Forever

    Another way to explain your point would be to consider dam construction.  In my area, state law requires dams to be able to withstand a 100 year flood.  That would be something like what Hurrican Camille did to Virginia back in the 1960s.  However, if climate change makes the 100 year flood more like whatis now a 1000 year flood, then everything we build is rather underdesigned.  Even in this case, there well always be someone who thinks a 50 year flood is plenty.

    It is not that there is uncertainty in climate, weather changes one year to the next, but that climate change itself quantitatively changes the uncertainty in weather parameters that must be assumed in the design process.  It may well be that today's robust design in 50 years is woefully inadequate.

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  10. In most legislations, ignorance is no defence.

    I wonder if there is a case in US or world courts for suing Exxon for their share of the climate damage done since 1980, when they became aware of the consequence of their actions. I say this with some reluctance as I'm well aware that the primary beneficiary of any action would be lawyers hired by both sides of the argument.

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  11. knaugle@9

    The example you presented can be repeated for every climate related weather behaviour that affects a built item. But it is important to understand that there is even more involved in a dam design than how much total volume will end up being held behind the dam.

    In addition to the basic design rule of a once in 100 year rain event volume being the 'regular upper limit on water levels', every dam is also evaluated for its ability to hold back more than a one in 1000 year event without being 'overtopped'. Associated with the evaluation of the overtopping is the rate of safe by-pass through the feature designed to safely allow flow to by-pass the dam to avoid catastrophic over-topping.

    The 2013 flooding of Calgary was the result of a very intense rain event in the mountains upsteam of Calgary early in the spring. The result was an impossible to respond to rate of water trying to pass through the Calgary waterways. The many dams upstream of Calgary were not able to mitigate the event. Scientific evaluations have been performed to try to determine what run-off events could occur and what features may best mitigate those potential events, and rapid climate change adds significant uncertainty to those evaluations.

    There have also been cases in Calgary of very recent wind events resulting in parts of buildings, including window panels, being blown off of already completed buildings that have been standing for many decades.

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  12. A clarification of my comment@11.

    The event that flooded Calgary ion 2013 included large amounts of rain falling at higher elevations in the mountains that would have been a snow acumulation at that time of year if it was just a bit cooler. Also, the ground at higher elevations was still frozen which is not uncommon in the late spring but may have been due to a lower than normal thickness of snow insulating the ground from freezing during the winter (thicker snow will reduce the depth of freezing in the ground it covers) ... Lots of added uncertainty with rapid rates of climate change, including the interactions between different factors.

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  13. It may be better to say that what the Exxon executive did was attempt to 'raise doubts' about the changes required by the developing understanding of the climate change impacts caused by human burning of fossil fuels.

    There is a significant difference between 'identifying uncertainty' and 'raising doubt'.

    Identifying valid uncertainty needs something to be shown to deserve to be considered an uncertainty requiring clarification of understanding. It requires a decent degree of understanding to be the basis for identifying the ucertainty.

    Raising doubt simply requires a willingness of an audience to accept a claim, and such claims do not even require an understanding of the actual facts of the matter, just an understanding of how to influence the beliefs of people (the science of marketing).

    The people who actually better understand an issue yet deliberately try to raise unjustified doubts about it deserve to be considered to be criminals (people who wilfully did something that they could understand was unacceptable) or perhaps be given the benefit of the doubt and be considered to be lower level criminals who did something unacceptable but did not have the ability to understand its unacceptability (A person in a position of leadership should not be able to claim they belong in this second category unless they give up their position and any wealth they got that they obviously did not deserve to get ... and agree to develop the change of mind that is required for them to qualify to be in such powerful positions of responsibility for the welfare of others before they take on another leadership role).

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  14. Adding to my previous comment, there is another difference between a person who legitimately identifies an uncertainty and a person who tries to raise unjustified doubts.

    A person legitimately raising an uncertainty will accept an explanation that clarifies that the claimed uncertainty is not valid or justified (including when new reseach focused on addressing the uncertainty is developed, such as the better understanding that the mention of a warming haitus was regarding the rate of warming when measured up to 1998 vs. a slower rate after 1998, and that even that is no longer valid because of more recent research and the most recent very warm years).

    A person trying to raise doubt will continue to make an unjustified claim after they have been provided with an expalantaion of why the claim is not justified. Doubt raisers will continue to try to abuse the false claim for as long as their research indicates it is having the desired result (in public opinion and actions of leadership that is swayed by 'popularity' rather than 'understanding and the responsibility to develop a lasting better future for all'). Also, doubt raisers will not make mention of any new research related to a false claim they are trying to 'milk' benefit from.

    The deliberate raisers of unjustifiable doubt are clearly 'unhelpful to the advancement of humanity to a lasting better future for all'. They clearly need to be identified and be generally understood to be the trouble-makers that they are. Hopefully legal procedings will not be required to effectively block the success of such people because it is known that illigitimate wealth and power can and do distort the legal process, keeping it from effectively limiting the pursuits of wealthy powerful people.


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