Human-Caused Global Warming is not Scientific Fact – but it doesn’t matter
With the Copenhagen Summit underway and the low rumble of discontent over the hacked emails debacle still audible, I feel the need to communicate my feelings on all the claims and counter-claims on the ‘science’ of global warming.
I marched on the ‘Copenhagen Wave’ last weekend, along with tens of thousands of other people from all around the UK. It’s a worthwhile cause, I’m strongly in favour of firm emissions reduction targets, and I believe that human activity is responsible for the climate change going on around us. Note, however, the use of the word ‘believe’ – I don’t know anything – not scientifically, anyway.
‘Scientific facts’ are curious beasts. Science may be said to be incapable of producing hard-and-fast facts. One formulates a hypothesis; one tests it; if the hypothesis is upheld, and is upheld repeatably, then surely we have a scientific fact on our hands? Well, yes and no.
Within the framework of the experiment, we have shown a ‘fact’ – but it’s possible that laboratory conditions or the specific arrangements of a test differ from what we’d assume to be ‘normal’ conditions. Test conditions are capable of presenting spurious, irrelevant or simply untrue ‘facts’. It works the same way as the framing of verbal logic.
So, scientific facts prove only the specific hypothesis which are tested. More importantly, they can only be assumed to do so temporarily. Facts have use-by dates. The first relevant experiment to come along and throw new light on a question or display slightly different results will once again throw doubt onto any ‘scientific fact’, and it is a part of scientific method to assume that proofs are finite in this way. A statement is true until proven false, just as the accused is innocent until proven guilty. The difference is that reasonable doubt runs the other way: if there is reasonable doubt as to the truth of a scientific statement, then it cannot really be called a fact. For this reason, there must be much, much more evidence in support of a claim of scientific fact than there need to be made against it in order to ‘disprove’ it – which is parallel to our legal metaphor, where the onus lies with the prosecution to eradicate reasonable doubt.
The third important point about scientific facts is that, in an important way, they can never get beyond inference. We may observe the correlation between two different things a hundred times in experiments – but all we’ve really seen is the same correlation, a hundred times. So even with the non-existence of contrary evidence, ‘scientific fact’ requires someone to look at the evidence and draw a causal conclusion about it all – to claim “these things are not coincidental: one causes the other”.
These three question-marks can help us to look at the human-caused (‘anthropogenic’) global warming argument objectively:
First of all, anyone who tells you that anthropocentric climate change is proven, certain, a done deal, is either lying to you, or doesn’t know much about science. These will be the sort of people who say ‘climate change deniers’ instead of ‘skeptics’. Even in so far as there is any such thing as a ‘scientific fact’, I cannot in good conscience write that anthropogenic climate change is one – no matter how useful that could be politically.
Why isn’t anthropogenic climate change a scientific fact? First of all, our planet’s atmosphere does not constitute a nice, stable test condition. It has its own ups and downs, is sensitive to the activity of the sun and to its own internal weather patterns, such as el niño. Even today our weather and climate can be altered by unpredictable, freak occurences. Trying to draw a general trend out of this mess, even over fairly long periods, is very hard work. Even worse, climate change scientists will always be frustrated in their efforts to project changes into the future, and a key element of scientific proof is in the success of a model: can we extrapolate our findings into a means to predict what will happen next? In this case, the short-term answer is no.
Instrumental data on warming. The range since useful records began is about 1 degree centigrade in total. From Wikicommons.
Secondly, even with something like an upward trend (which is more or less visible in the data – see the diagram above), there is the problem of cause-attribution. This is made a bigger issue by the fact that the two curves under scrutiny here do not scale particularly well together.
I take as absolutely true that greenhouse gas levels are increasing significantly in the atmosphere, and that these gases are being released because of human activity.
More difficult to prove, but still, in my opinion, true, is the general trend of a warming climate over the last fifty years or so.
But these facts together signify only correlation. I, personally, believe that there is enough evidence to link them causally. This third leap is required for ‘scientific fact’. But the problem is that the rate of the increase in temperature does not match in terms of scale the rate of increase of CO2 in the atmosphere, or adhere to the predictions of scientists. There can be little doubt of an increase in CO2 levels – whereas warming levels can be attributed to other causes, such as solar activity or the (thus far barely understood) planetary rhythm of ice-age to warm-patch.
One word of warning – stick to the instrumental data. Information on the ‘medieval warm period’ is worse than useless, because of course there is no reliable measurement information from that far back. We are limited to the last hundred years or so, and this is both bad news and good news for climate change scientists. It means we must discount the geological probabilities that this planet has been considerably warmer and considerably cooler than it is now at various points in its history, over the course of millions of years.
But these ‘good’ records do show a temperature increase, and it corresponds in terms of timeframe with the start of human industrial activity in earnest. This is enough for me.
Skepticism, it must be noted, is a good thing. It is the scientist’s responsibility to be skeptical, which is why the activities of the UEA scientists is particularly reprehensible. But skeptics must be skeptical always: there is far, far less evidence for ‘alternative’ causes of temperature increase than there is for the greenhouse effect argument, and this is what must be said at the Copenhagen summit.
It is with healthy skepticism that we ought to take action against CO2 emissions. We don’t know anything for certain – but shouldn’t we hedge our bets? I don’t think that scientific rationalism should ever form the basis, by itself, for public policy. But the intuitive response to all this information is to detect a cause, and the response to that intuition is clear.
And wouldn’t it be a noble human objective to cut down on pollution regardless of its relationship with climate-change? Why does no-one ever make that argument?
I don’t think you can say there has been a warming trend over the last 50 years since up to about 1979 it was definitely down. You can say a warming trend since 1850 or indeed 1550.
Also the analogy of doing something to prevent a warming that certainly isn’t happening at the catastrophic level proclaimed, on the chance that it may start as being like “spreading your bets” bears some examination. If you spread your bet across every horse in the race you are going to lose big – for certain. Spending over £400 million a day (cost of Kyoto) on the off chance isn’t that smart. In fact if the “environmentalists” really wanted to spread bets the best option is to do something that will work if we get warming, cooling (as currently) or beneficial even if nothing happens. That would be promoting improved technology – in particular CO2 free nuclear power & space development (orbit being the best place to intercept sunlight).
On both of those the global warming crowd are opposed or, occasionally, merely silent proving that they don’t actually believe this scam either.
You make a solid and brave argument, Simon. Science deals in probabilities, not facts: at a certain point the correlation becomes so vivid that the probability of a link is undeniable: it makes no sense to ignore it. And the probability of a causal link between human industrial emissions and the increasingly extreme climatic trends we are witnessing is as strong as the probability of the causal link between nicotine and cancer, cardiovascular disorders, etc that governments and the tobacco industry spent decades trying to sweep under the carpet.
Of course we should be looking to reduce emissions (and indeed eliminate anthropogenic pollution) for its own sake, because it is a Good Thing. But, given that in the main humans are short-sighted, greedy and (yes, sadly) stupid, we can never expect the necessary degree of miraculous selflessness and clarity of thinking to occur in the absence of a threat of disaster.
NB: I don’t for a moment believe the threat has been manipulated to elicit the desired human response: sadly, the statistical evidence for this particular human-generated f**k-up is undeniable. The threat exists and is growing, and no amount of denial, blustering, vilification, accusations of scam and of conspiracies etc can make it go away. I should love it all to be a lie. But I’ve been reviewing the accumulated evidence with expert colleagues from SGR for years now, and the evidence is compelling.
Jumping to technofix ‘solutions’, such as nuclear energy that merely promise even more dire pollution in the long term is another tactic employed by those who do not wish to take off their blinkers and face the truth.
A sad species, Homo sap. And I mean ‘sap’. It’s way past time our species grew up, stopped behaving like a bunch of greedy kids in a cookie store, and accepted responsibility for its misdemeanours and mistakes.
umm one misplaced comma. sorry
Another excellent article, Kaye, and I don’t doubt that you’re spot on with the scientific information you’ve provided.
I do, however, take issue with your quasi-relativistic definitions of ‘belief’ and ‘fact’, and your comment that “[t]he third important point about scientific facts is that, in an important way, they can never get beyond inference.” This is of course true, in fact it’s not just true ‘in an important way’, it’s true by definition. Science works empirically, and thus is entirely made up on inductions. Thus, as you’ve pointed out, every scientific fact is a potential victim of Hume’s ‘problem of induction’ – but so too are all facts that aren’t purely logically derived (that aren’t apriori true). I fail to see how this is an observation with any more bite than the simple Humean recognition that ‘causality’ can’t ever itself be observed.
Human caused global warming may indeed not be a scientific fact, but that’s because, though extremely weighty, the evidence is not yet strong enough to gain it such an illustrious status. It is (assuming you trust the scientific consensus) a scientific fact that the vast majority of evidence is in favour of global warming being human caused. Evolution on the other hand IS a scientific fact, and it is so despite being a theory made up of myriad proven independent hypotheses, and being purely empirically discovered (it’s not a logical necessity that evolution be true). I don’t understand why you count those two factors as issues for scientific facts.
These aren’t major points (I’m sure I’ve not said anything that you’re not fully aware of) – I just think you’re putting far too much of a burden on the definition of ‘fact’, which, if we’re going to squabble over having empirical sources, would only qualify logical truths such as ’1+1=2′ and ‘a=a’ under the title. It wouldn’t just be a problem for scientific facts, but historical, cultural, and everyday ‘facts’ too.
Likewise, I question your statement: “I believe that human activity is responsible for the climate change going on around us. Note, however, the use of the word ‘believe’ – I don’t know anything – not scientifically, anyway.” Does it make sense to say one believes something but doesn’t know it? Of course it does in an ‘analysis of knowledge’ sense, where knowledge is externalised (so one could never know whether they knew X or merely believed it), but I’m not sure the distinction makes sense in the way you’ve used it. It was my understanding (from university, but as you know, only a bachelors) that to ‘believe X’ was to ‘treat X as true’ – and thus, to assume one possesses knowledge of X. I can’t get my head round the idea of saying that one believes X but doesn’t know X, as if to say ‘I believe X, but I don’t think it’s true that X’. Do you believe evolution? Or that you live in England? Surely – if we’re being ultra, logical-certainty requiring, strict about knowledge like that, even extremely evidentially supported beliefs like that couldn’t count as knowledge. Again, I think you’re putting far too strong a definition on ‘knowledge’ (and perhaps too weak a definition on ‘belief’).
That may all be nonsense, I’m writing having read your post yesterday, and not reread it today (sorry).
Several grammatical (and probably intellectual) errors. Also sorry.
Thanks for the responses!
Neil – I’m certainly less satisfied by my ‘hedge the bets’ argument than any other part of what I wrote here. That said, if we account for risk – the plausible costs of even a mild warming scenario – then I think the case for determined action as a precaution is reinforced. But I take your point.
Mum – Your comparison of this debate to the connection between smoking and ill health is intriguing, because in this case it is governments that are trying to pursuade us that there IS a problem.
Shiro – An excellent intervention. I think that your key points – 1. that I may over-burden my definition of ‘scientific fact’ and 2. that I may be rendering a false distinction between belief and knowledge – may have basis in the same issue of mine. I tried to write this in a sort of broad, non-terminological way – and perhaps I didn’t spend enough time defining my terms. The distinction I was trying to render was between the self-evident or indisputable ‘fact’ and the more commonplace, intuitive ‘belief’ on the basis of incomplete evidence or just limited data.
The reason this distinction is important is that science and scientific findings are popularly accorded a status parallel to that first kind of indisputable knowledge when, as you say, such evidence is rarely of any more value than a ‘historical fact’ or an item of ‘common knowledge’: all of them are dependent upon inference and inductive reasoning. This little bit of writing is my attempt to fight the debate ‘from science’ – where everyone seems to believe that the person who can claim the most ‘scientific fact’ is going to win the argument. It’s a nonsense in what is an ultimately unknowable set of outcomes – the real argument is predicated upon relative assessment of risks and the presence (or non-presence) of a certain environmentally ethical mentality. I dispute that Anthropogenic climate change lives up to even the (very low) benchmark of qualification as ‘scientific fact’ that I set out, and I think I made clear why I feel that is the case as well – and why it doesn’t matter a jot.
So the distinction between belief and knowledge here is the implied one of relative ‘certainty’, and not really a technical one.
Based on my own hyper-skeptical benchmarks, do I believe evolution to be a scientific fact? Yes; I think the body of evidence for evolution amounts to a case that is self-evidently true to any that would approach it rationally.
All I’m really saying here is that not everyone who is skeptical of anthropogenic climate change is irrational, and a lot of people who believe in it… are.
It’s a little off topic and a little late, but I’ve been thinking about it all day.
This question is going to sound like it’s got some kind of hidden meaning or implicit criticism, but I mean it entirely at face value: What was your goal when going on the climate change march? What do you expect it to achieve?
Blimey. What does anyone ever hope for when they join a protest or a sit-in or a march? Why do people sometimes stop being citizens and start being activists? I’d be the first to question the actual, real-terms utility of this kind of thing, you know that.
But a part of me relished a moment of civil not-quite-disobedience. It’s the exercise of freedoms that works for me – and of course the miniscule contribution to what adds up to a nice illustration for the next day’s newspaper articles on a topic that matters.
The activist question is a (fascinating) debate in itself, but I have to admit I was more concerned with the actual march itself, knowing – as you say – that you’re bound to have considered it in ‘actual, real-terms utility’.
We can both agree that activism is something to ‘relish:’ it’s undoubtedly fun to get on a bus to Manchester or wherever with a bunch of people you often haven’t met before, and shout at things. I suspect that part of the emotional effect is simply the feeling of validation that comes with discovering – in emotional terms, regardless of whether you knew it already in theory – that there are lots of people who agree with you, and will stand with you against the (often nebulous) forces against which one’s principles have come to oppose.
But if all it achieves is a ‘nice illustration [in a] newspaper article,’ what is it actually achieving in any ‘tactical’ sense? Is self-validation and the resulting increase in general morale the (inward looking, introverted) goal? Or is there a culture-moving agenda? Some marches are definitely aimed at building morale: I’d argue that the continuing marches of the Orange Order and the Countryside Alliance fit that model – look at us, we’re still here (just)! Nyaaagh! Etc etc.
Some demonstrations are intended to cause fear in the opposition through simple ‘demonstration’ of superior numbers or organisation. I’d argue that that statement probably applies to a number of movements who would be greatly (and genuinely) offended at the idea that that was their goal: they’d suggest that their aim was to display the strength of popular feeling arrayed against whichever idea they oppose (we’re living in a very reactive age…). The anti-war movement, I suspect, worked on that model in 2003, and it’s a model with a history of success (Eastern European ‘colour’ revolutions, etc).
The environmental movement never struck me as exactly following that pattern. I might be wrong, but reading the literature and following their activist pattern the green strategy is to advance on two different fronts – one, direct action in the form of militant attacks on polluting industry and the creation of ‘climate camp’ style temporary autonomous zones. I suspect that this isn’t particularly the model you support…
The second are the marches, the Copenhagen Wave (check out the googleterms…) etc, which might be closer to the ‘demonstration of popular will’ model but seem to differ in a few respects. This wider, more moderate platform seemed – and you’re closer to ground zero on this than me, hence why I asked – to be focused on ‘building awareness’ (whatever that is!) of the issue, spreading consciousness of the problems and potentials emerging.
I’m really rather curious about your opinion on the ‘tactical’ utility of the green marches and your view of where the ‘point of victory’ lies. Is there some kind of Schwerpunkt in the polluting system, whereby if there is suddenly enough ‘awareness’ the entire stinking evidence will fall down? Is it simple “we’re watching, and we aren’t going to vote for you if you muck up” tactics (you weren’t anyway…). What is the end goal, in your view?
Simon, I agree with your entire article, and it is written beautifully.
I just stumbled over this – Christopher Hitchens on supremely smug form, but basically summarising the ‘let’s do something about it anyway’ argument: http://www.youtube.com/watch?v=BDj6WechLhw&feature=related
Richard, I think that the question of the actual utility of marches and protests is one to be addressed by the political scientists. My own view is that such events tend to be demonstrations of a popular force of opinion on a given issue – a spontaneous and totally unbinding plebiscite, if you like. The fact that marches and so on are usually organised by and constituted of minority groups or interests rather undermines that idea, however.
In terms of tactics, then – marches may raise awareness, or at least spread information, and, if the broader polity takes an interest, they might just put some pressure on the establishment (assuming they get big enough).
Perhaps some activists think that they’re setting up the catalyst for revolutionary, bottom-up change, but I think that in social terms the effect is just the opposite: protests let off steam and prevent more serious and widespread public reaction.
“We are limited to the last hundred years or so, and this is both bad news and good news for climate change scientists”
That shows your bias. A lack of information (even if we assumed proxies like tree rings were less reliable than human measurements which are certainly subject to the urbanisation effect) is never good news for any real scientist. You mean it is good news for those pushing alarmism.
In fact the proxies are pretty good & there are several differnt ones so we can be sure that the medieval warming was warmer than now & the climate optimum (9,000-5,000 BC significantly warmer.
And incidentaly the theory is not just that there is global warming, which history shows would be a good thing, but that there is catastrophic anthroprogenic global warming (CAGW) for which there is absolutely no evidence & which is the only thing that wopuld justify the Luddites War on Fire.
ahh!
i agree with you.
and i was also at the wave!!
hi fellow wave-er!