Is it reasonable to deny climate change based on the evidence?

Ben Hale writes that climate change deniers may not be ideologically driven and instead have “competing ontological and epistemological claims, as well as competing views about what counts as good or reliable science.”  Wow! That’s what I get for reading philosophy blogs.  If I understand correctly, Ben’s asking whether one can look at the evidence and still reasonably deny anthropogenic climate change (ACC).  Environmentalists inspect the data and find it “compelling and overwhelming.”  ACC deniers think otherwise.

We should remember that determining humans’  effect on carbon dioxide concentrations is really fu**ing hard! We have to disentangle natural variations from volcano eruptions from fossil fuels.  We have to account for the land-use and absorption by oceans and rain forests.   We also have to try predict the effect of technological change and economic growth.  Answering these questions requires several thousand scientists in fields as diverse as climatology, ecology, and economics.  The very structure of the IPCC proves that climate science is neither obvious nor straightforward.  Given how complicated it is, it doesn’t seem that unreasonable that some people look at climate science and disagree with the consensus.  These people may ultimately be wrong, that doesn’t make them unreasonable.  It is possible to be both wrong and reasonable at the same time.

Consider these two comments by RickA on a different Hale post.  Here’s  a short excerpt:

Science has not yet answered these questions to my satisfaction:

1. What is the plan to validate the climate models so we know they are scientifically and statistically valid? Right now we have to rely on just trust, not science.
2. Why is the warming trend going to double, triple, quadruple, etc. – when it has been 1.3 degrees C since 1978?
3. If there is a 60 years ENSO or other ocean current cycle – how do we know that we aren’t panicking over just ½ (the warming phase) of the entire cycle. In other words, might the trend actually drop with another 25 or 30 years of data, rather than increase?
4. Given all the other influences we have discovered that bear on the current warming – carbon black causing dirty ice, methane leaking out from under the permafrost, low solar activity, etc. how do we know that cutting carbon emissions will actually achieve any slowing of warming? Or might not the effort be a waste of money?

It’s pretty obvious to me that Rick tried to understand the issue.  He clearly spent a lot of time looking at the data and simply does not agree with the mainstream conclusion.   I find it hard to criticize his stance because he’s doing what scientists themselves do all the time: disagree about data-interpretation.  If AAAS had its way, even 5th graders would understand that “sometimes scientists have different explanations for the same set of observations.”  Since we often tell people to think and act like scientists, it’s somewhat inconsistent to criticize them for doing just that.  We cannot insist the public examine evidence before reaching conclusions and then complain when they reach conclusions we don’t like.  If we really want people to act like scientists we’ll have to accept that their occasional disagreement.

Now I’m sure that there are flaws in Rick’s analysis or facts.  I’m also sure someone more qualified than me can identify them.  But that’s part of the problem.  The science is so complicated that even educated citizens who’ve researched the issue don’t really understand it.  A little more reading probably would not help and we shouldn’t give the impression that it would.

I think that climate change connects with some deeper problems in all of science communication.  Many scientific issues are really too complicated for the public regardless of their education or science literacy.  The important message about climate change isn’t that the evidence is obvious and straightforward.  It’s the exact opposite.  Instead of telling people the evidence is clear-cut, we should be telling it is really complicated and they’d probably screw up if they tried to understand it.

I believe in ACC not because I’ve done an exhaustive literature review but because the relevant experts tell me so.  I trust that they’ve done a good job and I trust they’ve tested their conclusions.  On some level I think we all have to do this.  Of course we don’t blindly accept their policy preferences and we must guard against technocracy.  But insisting that an untrained public examine climate science data trivializes the complexity of the research and imbues them with a false confidence.

In the end, I don’t think it’s too unreasonable to study the evidence and deny climate change.  But I do think it’s a little unreasonable to study the evidence too closely in the first place.


  1. Praj:

    Thank you for being so polite.

    It is a pleasure to engage with somebody who doesn’t automatically assume that a person on the other side of the issue is evil or an idiot.

    I would like to avoid the term denier however.

    It should be reserved for people who do not believe that the Earth has warmed since 1900 – which does not describe me.

    I actually agree that the Earth has warmed since 1900 and even agree that it will warm an additional 1.3 degrees C by 2100 – assuming the current temperature trend continues.

    So I do not think I am a denialist.

    I merely question the additional feedback driven warming.

    Unlike you, I do not agree with “experts” simply because they are experts.

    The appeal to authority is a commonly used argument technique – but just moves the argument to a higher plane – namely argument among the experts.

    The problem is that in advocating change – the experts are now trying to convince the public to spend trillions of dollars changing our energy production over to a carbon free form – and some of their arguments devolve to “trust me – I am an expert”.

    Because of the amount of money and potential harm to others (caused by more expensive energy, food, fuel, taxes, etc.) I would like to wait for 25 to 30 years to gather better, more accurate, widespread data.

    The world has now begun the process of rebuilding the temperature data from source records – with an open process so every adjustment to the data can be viewed, understood and critized.

    This is a good thing – and will give us a lot more confidence in the data, which has been tweaked in a number of ways which are questionable.

    With better data going back to 1900 and better data gathered in the future – we will be in a much better postiion in 25 or 30 years to answer the question of how much warming we will experience by 2100.

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