They Just Don’t Know

H/T James Delingpole for an article in the Mail predicting the Thames will freeze over:

Forget global warming – it’s Cycle 25 we need to worry about (and if NASA scientists are right the Thames will be freezing over again)

…leading climate scientists yesterday told The Mail on Sunday that, after emitting unusually high levels of energy throughout the 20th Century, the sun is now heading towards a ‘grand minimum’ in its output, threatening cold summers, bitter winters and a shortening of the season available for growing food.

Solar output goes through 11-year cycles, with high numbers of sunspots seen at their peak.

I don’t think it’s quite right to say that the sun is emitting lower levels of energy. The power output of the sun remains more or less constant, and amounts to about 1360 watts per square metre at the radius of the Earth (the very figure I was using a few days ago to estimate the temperature of an airless planet). It’s this solar constancy that has had climate scientists looking around for something else to explain the variation in the terrestrial climate – such as the concentration of carbon dioxide in the atmosphere. What does vary in 11-year cycles is solar magnetic activity and the solar wind from the sun.

Henrik Svensmark (who gets a mention in the Sunday Mail article) has theorised that the strong solar wind that accompanies high numbers of sunspots deflects cosmic rays from outside the solar system away from the Earth. Since he reckons these cosmic rays seed cloud condensation nuclei in the atmosphere, fewer cosmic rays mean less cloud, and less solar radiation reflected back into space by clouds, and so higher terrestrial temperatures. The recent CLOUD experiment at CERN in Switzerland seems to have confirmed that cosmic rays actually do form condensation nuclei.

But there are other cycles at work. It seems that oceans like the Pacific warm up and cool down in a cyclic manner over periods of decades or more (and so its called the Pacific Decadal Oscillation or PDO), and this also has effects on the terrestrial climate.

Other, longer term cycles – most of which entail changes in the orbit of the Earth around the sun – are believed to control longer term warming and cooling of the Earth,  and to cause long ice ages or brief interglacial periods like the one we’re currently enjoying.

But all of it is supposition. Nobody really knows what causes the 11-year solar cycle, or what effect it might have on the Earth’s climate. Nobody really knows why Pacific water temperatures rise and fall. Nobody really knows what causes ice ages either. And nobody really knows what effects (if any) carbon dioxide in the atmosphere may have on global climate. But there are any number of rival theories. The current carbon dioxide-driven AGW theory which has been dominant for the past 20 years or so, and now appears to be in headlong retreat (because the Earth hasn’t warmed over the past 15 years, as the AGW theory predicts), appears only to have become the “consensus” view simply by stifling all opposing theories (as the Climategate scandal attests).

It’s the same with cancer. Nobody really knows what causes it. But there are lots of theories around. Radioactive fallout is one possible culprit. Human Papilloma Virus is another. Vehicle exhaust fumes yet another. And of course there’s smoking, which has been the unquestionable consensus culprit for the past 50 years, largely (much like in climate science) by stifling all opposing theories.

It’s rather surprising, really, that it’s in those areas of human inquiry where nobody really has a clue what causes what, that scientists seem to become zealots favouring one theory over another, pouring scorn on anyone who dares to dissent. It seems that, the less certain we are about what’s going on, the more we feel we must pretend to be certain. Or perhaps, in the absence of real knowledge, there regularly arises a blind faith in one doctrine or other.

It’s true of more or less everything else as well. Nobody really understands how economies work, and why they lapse into slumps at one point in time, or are galvanised into booms in another. But, as ever, there are plenty of theories, and the rival theorists very often aren’t on speaking terms with each other.

One thing that you never will see, however, is any one of these scientists and epidemiologists and economists standing up and saying, “We just don’t know.” Even when it has become obvious to everyone else that they haven’t a clue what they’re talking about, and are just making stuff up.

…

A heads-up for Telegraph readers. On visiting the Telegraph website today to read the Delingpole article, I was asked if I would like to fill in a brief reader’s survey. Unusually for me, I accepted the offer, and was soon tapping in responses. After a while it became clear that they were looking for people to leave money to charity in their wills, and midway through asked why they might do so. Only towards the end did they reveal that they had just one charity in mind – Cancer Research UK (CRUK) -. Would I consider giving them any money? Angrily I hit all the No-Never-Absolutely-Not buttons. After all there’s no way a smoker like me would ever give any money at all to those bastards. I’d rather burn it. And I waited to be asked why I wouldn’t. But the question was never asked. In retrospect, if I’d been forewarned, when being asked to explain why I might give money to charity, I would have explained at some length that I thought some charities – e.g. RNLI – were truly worthy causes, and others like CRUK and ASH were utterly vicious, and caused enormous harm, and should be closed down, and their employees should be flogged to within an inch of their lives. So be warned of what’s coming if you start answering that particular survey.

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