Climate change, the universe and everything

This post has its origins in a Facebook exchange, which had got rather long even before I editted it to add more, so I decided that it had better become a blogpost. It might not be the most lyrical post I’ve ever done, it lacks wimsey  or political edge, but it’s given me an entertaining evening pondering the place of scepticism in  science (which is what I do when I’m not ranting about politics, knitting or post industrial Scotland) and in society more widely.

The post was provoked by a comment on a link I posted on how much credence should be given to climate denial. The comment was

“scepticism is the order of the day. Ambiguity, doubt and ‘knowledgeable ignorance’ or ‘unbelief’ is the foundation of autonomous, free enquiry (σκέψις, skepsis) into the nature of the universe and the human relation to it. We’re in Hume and Feyerabend territory here. Science – today’s certainties – is no more exempt from freethinking than religion – yesterday’s certainties – was. According to Chomsky, this is why schools don’t teach or nurture critical thinking: their social function is to produce compliance and orthodoxy.”


Now, before this descends into the name calling which all too often goes with the climate change/climate denial debate, I’ll point out that I don’t think that the poster was particularly disputing the idea that climate is changing –  it was more of a call for people to wake up and start questioning everything. Which is a good thing.  Picking apart who is elling us what; what we really know and what we’ve just accepted is very empowering. We need critical thinking, but is that what climate “sceptics” are doing?

But in the context of climate change can questioning everything be dangerous? Does it give licence to those who for various reasons want to carry on with business as usual while the overwhelming majority of climate scientists believe that we are facing a serious problem? The answer lies in how well we ask the questions; our assessment of the answers and how we act on them. Questioning and sceptical assessment is not something  which is generally encouraged.  Look at the “big picture” on any issue you like but don’t let it get so big that you question the status quo!

So returning to science should we question everything? Well, yes, but some things are more open to doubt than others. So at the scale of the universe that we operate at gravity makes things fall to the floor; plants need light and water to grow; ice melts when it’s heated etc. These are well known phenomena and the theories behind why they are as they are have stood up to challenge. We tell stories to explain what we see (but we may not see everything e.g we miss effects at the very large, very small or very distant levels). Sometimes they’re wrong (the earth is not sitting on a turtle), sometimes they’re reasonable given the state of knowledge at the time but later proved wrong, which shows the value of sceptism e.g the phlogiston theory or the idea of four humours governing mood and personality etc. When theories relate to observations which we can make ourselves we should test them ourselves.

When the observations are made by someone else then we have to view everything through a “reliability filter”. This is where the scientific peer review process is useful and also where conspiracy theories abound. This is where science can start to get subjective (and it inevitably does because it’s carried out by people). Do we believe the observer? Are they seeing what they think they see? Are they lying? Has the instrument screwed up? Are the investigators shoe-horning their observations into an established theory when they fit something else better? Are we giving credence too easily to a “big name”? Being aware of the subjectivity and asking the questions is something which  science educators tend not to encourage. In science and even more in wider society we don’t like mould-breakers and iconoclasts.

So yes, there is scope for questioning even the most established theories, but those questions must lead to testable hypotheses otherwise they’re just speculation. Speculation can be fun (there are some good sci fi plots in it as well as the basis of various myths, and some plain weirdness) or it can be harmless and possibly constructive e.g mulling over whether there might be parallel universes (which can produce some elegant theories from philosophers and mathematicians, but nothing which can be proved in the physical world very easily at the moment), and lots of conspiracy theories, but a limited amount of activity which is likely to shed any new light on anything.  But ill informed or badly executed scepticism can be at best a distraction and at worst dangerous. In other cases scepticism can make room for alternative view points given our current state of knowledge.

I don’t know how dowsing works, but have been somewhat gobsmacked to find that I can detect buried pipes and cables with a couple of metal rods – this shouldn’t happen, but it does. I don’t know how, but it does. I can see no basis by which homeopathy can work but some people are convinced: is this just a result of subjectivity or misplaced cause and effect? Or is there something happening which we don’t understand? (At the moment I think subjectivity, placebo effects and the persuasion of snake oil salesmen probably explain homeopathy, but I could be proved wrong in time). In both of these examples the consequences of the alternative theories are not terribly serious.

Whether speculation is a problem or not depends on the consequences and on the motivations of those who indulge in it. With climate change the consequences are extremely serious, and the motivation of the “sceptics” sometimes extremely murky. The basis of climate change theory is well established and fairly easily testable. The idea that some gases such as carbon dioxide absorb heat has been established for over a century and Arrhenius published a theory on how this might affect global temperatures in 1896.


As far as I’m aware none of the climate “sceptics” have questioned this theory or produced any observations to disprove it. Therefore the point stands that increasing levels of CO2 and other gases are almost certain to lead to heat trapped in the earth’s atmosphere and so in increase in average global temperatures.

What the climate “sceptics” tend to question is the measurements and the effects of increasing greenhouse gases. Humans can’t directly detect increasing greenhouse gases or small temperature increases over long periods, so we do have to be aware of possible bias in the measurement and reporting. In the case of greenhouse gas concentrations I am not aware of any evidence that they are falling on decadal timescales (they do fluctuated seasonally which is expected as leaves fall from trees and regrow). So while I can question the answer to the question, the evidence that we have is that there is nothing wrong with the measurements which have been made in different places and in different ways over a reasonable period.


We can question why this increase is happening, but we know that humans are acting in ways which are likely to emit greenhouse gases, and do little that removes them. Other factors are involved, but so far nothing has been suggested which could plausibly cause the change in atmospheric and oceananic CO2 concentrations we have seen. We need to wake up and do something about this. Urgently!

Finally climate “sceptics” and many scientists can question what the effect of these changes in greenhouse gas concentration will be on the world’s weather. This is where is gets really complicated and there is lots of scope of debate and many genuine unknowns because the interaction between land, atmosphere, oceans, biosphere, the sun, and clouds etc is complicated. It takes a lot of measurement and computing power to get at this. Perhaps even Deep Thought. The answer may be 42 – but probably not as climate change is only part of the question! And as Hitchhikers Guide to the Galaxy points out the answer is only the lead-in to the next question!

HINT next question might be what is motivating the climate “sceptics”?