While many people pay lip service to objectivity and provide evidence in support of their assertions, true objectivity is very rare. Science is supposedly a body of knowledge assembled dispassionately by researchers looking at all available evidence in a totally unbiased way. This, at least, is the utopian vision encapsulated by Karl Popper, who argued that any scientific hypothesis should only be regarded as valid until falsified (for which even a single verifiable piece of evidence is sufficient).
All very straightforward, but such a purist view of science ignores the facts that scientists are human and evidence is often open to interpretation. Despite the attraction of Popper’s views, the philosopher who surely more clearly covers the reality of scientific progress is Thomas Kuhn, who argued that knowledge advances via a series of paradigm shifts. In simple terms, one version of received wisdom is replaced by another only when a sufficient body of evidence has accumulated for a change in the consensus view to occur.
The unfortunate downside of this reality is that dissent is often not tolerated by the scientific establishment until new evidence or a different interpretation of existing evidence becomes simply too compelling to ignore. Influential scientists build their reputations by breaking new ground when they are young but, by and large, plough the same furrow for the rest of their careers while entrenching themselves as experts in their field (with apologies to anyone who thinks that is an extended metaphor too far…).
A new paradigm may take decades to become established, needing the expert arbiters of the old one to retire before the next generation acquire the status of defenders of the new truth. Having spent one’s life researching and promoting one view of reality, it goes against human nature to give in gracefully and – in effect – admit that your career was spent going down a blind alley.
With this in mind, it becomes more and more difficult to defend science as the path to true knowledge but, even as practised by researchers with all the normal human frailties, the scientific method remains the best guide we have. The alternative is to promote personal theories based on no evidence at all or, at best, supported by the flimsiest of correlation or circumstantial evidence (beware the weasel words ‘linked to’, for example).
The problem with some hypotheses is that they are difficult to falsify, largely because solid evidence is hard to come by. A classic case is climate change. Trying to be objective (while recognising the difficulty of this), the current paradigm is that average global temperature is rising at an unprecedented rate because the increasing level of greenhouse gases (primarily carbon dioxide) in the atmosphere (mainly driven by human use of fossil fuels and agriculture) is causing a positive feedback process. Unless drastic action is taken, the argument goes, this will cause temperatures to increase to a level that will have dire consequences for our species and others.
In fact, very few people would argue with the fact that, all things being equal, the steady increase in atmospheric CO2 will tend to increase average temperatures. The crux of the controversy on the issue is the extent of this rise and the knock-on effect on weather extremes, sea level etc. Put like that, it sounds a bit like the modern equivalent of the apocryphal theological argument about how many angels could dance on the head of a pin, but with rather more serious real world consequences.
The dispute has become bitter indeed, with defenders of the current paradigm tarring anyone who questions the received wisdom with the brush of ‘denialism’. Their influence is such that, in the case of the BBC, anyone critical of the paradigm is effectively banned. Of course, as the defender of free speech and balanced argument, the Beeb would beg to differ with this interpretation: they argue that what has become known as the Catastrophic Anthropogenic Global Warming hypothesis (CAGW) is, in effect, now unassailable truth.
To be fair to this venerable institution, they share this view with most of what can be called the Establishment, which these days is overwhelming Left-leaning and liberal. For whatever reason, there are very few people in this part of the political map who question the paradigm or, indeed, will tolerate others who do the questioning. For many who may have their doubts, the power of groupthink is often enough to steer them back towards the straight and narrow. After all, who wants to be ostracised from the group?
In August Al Gore (oh so nearly 43rd President of the United States) gave an interview on BBC Radio 4 to promote his new film, An Inconvenient Sequel. In this, he is apparently guilty of claiming that record temperatures, flooding and rising sea levels were proof of the argument he made in An Inconvenient Truth that climate change would bring an increase in extreme weather events. For this, he was taken to task by Lord Lawson, erstwhile Chancellor of the Exchequer under Margaret Thatcher and now chairman of the Global Warming Policy Foundation.
This air time for a known sceptic of the extent and impact of warming predicted by proponents of the CAGW hypothesis was a welcome sign of tolerance of alternative positions, albeit a rather rare one. However, the BBC chose to follow this up with a report on its website about Anger over ‘untrue’ climate claims. Lord Lawson was hauled over the coals in particular for questioning Mr Gore’s claim that "climate-related extreme weather events have grown far more numerous and far more destructive".
Two high-profile scientists who broadcast on the Beeb made strong criticisms. Professor Brian Cox said it was "irresponsible and highly misleading to give the impression that there is a meaningful debate about the science", while Jim al-Khalili said via Twitter "For @BBCr4today to bring on Lord Lawson 'in the name of balance' on climate change is both ignorant and irresponsible. Shame on you. There should be NO debate anymore about climate change. We (the world minus Trump/Lawson et al) have moved on."
I have to say that I find this very worrying. We should expect false arguments to be exposed by debate and questioning rather than simply suppressed in a way akin to the ‘no platforming’ of people in other fields whose views may be controversial. Unfortunately, in the case of climate change, there is a danger that the Scientific Establishment might be seen to be censoring critics because their own arguments are not as watertight as they say.
This should only encourage dissenters to make their voices heard. At the end of the day, free debate, backed up by credible arguments, is the only way to advance our understanding, and those brave enough to put their heads above the parapet should be praised rather than condemned and ignored. Without a good understanding of the problem, we cannot develop an optimal solution.