One of the aspects of the climate change debate that I find most baffling is how seemingly intelligent people can waste so much of their time arguing over whether or not the acronym ‘CAGW’ was invented by the sceptics, or indeed arguing which side first used the term ‘catastrophe’ in the context of climate change, or uses it most. The accusation seems to be that sceptics have set up a straw man by first asserting that the alarm lying behind initiatives such as Net Zero is based upon a wish to avert catastrophe, and then suggesting that the science fails to provide sufficient evidence of such an outcome. The argument is that ‘catastrophe’ is not a scientific term and so has never entered into the scientific debate. Consequently, CAGW and all talk of ‘catastrophe’ is just the sceptics’ way of keeping an argument going long after the actual science has been settled. Those who think this debate matters so much seem to expend a lot of effort seeking to establish historical precedence and engaging in seemingly endless arguments regarding the meaning of words. I profess to being somewhat unmoved.
Climate change itself is deemed a big deal. It has to be, otherwise why are people advocating profoundly transformative changes to the way we live our lives? Why are people on the streets, protesting under the banner of ‘Extinction Rebellion’? And why are scientists signing petitions expressing support for them and threatening to go on strike if more isn’t done by the politicians? If all of this isn’t in order to avert something that can reasonably be referred to as a catastrophe, then I don’t understand what it is for. That is why I am quite comfortable with the idea that the great debate must be with regard to anthropogenic global warming that is potentially catastrophic, and I certainly see no reason why I should not abbreviate this concept using the acronym CAGW. It doesn’t matter a jot who coined this acronym or whether ‘catastrophe’ is a sufficiently well-defined term. The point is that ‘catastrophe’ is part of the patois on both sides of the debate and, as such, it is serving a useful purpose.
That certainly seemed to be the position held by IPCC Lead Author, Prof Robert Muir-Wood when he wrote his book on ‘How we can stop manufacturing natural disasters’. It’s a book full of examples illustrating the perils of such disasters and how mankind has, or has not, adapted to the risks posed. And what did he call that book? He called it “The Cure for Catastrophe”.1
Now, I’m sure that the good professor is as aware as the next person that ‘catastrophe’ is a subjective term. But that didn’t stop him adopting it for the title of his book, and then repeating it on just about every page. He even coined the term ‘Catastrophysics’ in order to use it as the heading for his chapter 3. For Muir-Wood there is no doubt; ‘catastrophe’ is a very useful word for his purposes.2
In fact, if sceptics truly are the group that must take responsibility for the promotion of the term ‘catastrophe’ then this could actually be very much to their credit. If the word ‘disastrous’ had been chosen (hence DAGW), a similar sentiment might have been conveyed; however, that would not have quite captured the essence of the situation. As Muir-Wood explains when discussing the great Lisbon earthquake of 1755:
“Across Northern Europe the earthquake inspired a shift from a philosophical ‘best of all worlds’ optimism, ruled over by a beneficent God, to a new, darker world order of rational scepticism. The contrasting old and new worlds are captured in the original meanings of the terms ‘disaster’ and ‘catastrophe’. ‘Disaster’ derives from the Greek for an ill-fated, or ‘bad’ star—in Italian, the dis-astro. ‘Disaster’ captures the essence of astrology. A conjunction of planets, or the passage of a comet, triggers a calamity on earth. ‘Catastrophe’ describes the final resolution of the story in a Greek drama. In a tragedy by Aeschylus or Euripides, within the ‘catastrophe’, one or more of the main characters will die. The catastrophe is the inevitable consequence. The catastrophe is the moral.”
This is indeed a useful distinction to be made and Muir-Wood does so throughout his book by emphasising the human factors that court calamity. It is in that sense that we ‘manufacture natural disasters’. The calamities that are posited for AGW are certainly catastrophic in the sense that they are anthropogenic and deemed inevitable if nothing is done about it. In this sense, ‘catastrophic’ has a meaning that is relevant to the debate, whichever side you are on. However, there is another aspect to the word that bestows upon it great utility – it defies a singly quantified definition.
How big is big? I used that word earlier when saying that climate change is deemed a big deal. But what size of deal are we talking about? And does the fact that ‘big’ may imply different sizes depending upon context and one’s perspective mean that I should not use the word? It is vague and subjective – like ‘catastrophic’ – but is that any reason to veto its use? In fact, the English language is full of such vague words; they are called degree adjectives, and without them English would be impoverished indeed.
There are some who view vagueness in language as a linguistic anachronism – a legacy of our primitive past, when sophistication and precision provided little evolutionary advantage. I disagree. Our love of vague terms is not a failure to divest ourselves of a bad habit. On the contrary, the vagueness lying at the heart of our language provides utility that enables us to operate effectively and efficiently in an uncertain world. ‘Catastrophe’ is not a degree adjective but, as a noun, it has a quality that enables its use in a variety of contexts. Calamity is involved but one should not be demanding a particular scale of calamity before the term ‘catastrophe’ can be applied; it will always be context-specific and value-laden. This remains the case even when one takes into account definitions of the precautionary principle that talk of irreversible changes and ‘serious’ environmental damage.
Given its qualities, it is no wonder that ‘catastrophe’ features prominently in the rhetoric of advocates.3 So when sceptics refer to ‘CAGW’ they are using the term ‘catastrophe’ to encourage others to question whether the concern that is energising the advocates justifies what they advocate, and whether their conception of the calamity can be justified by reference to the science. ‘Catastrophe’ is a useful epithet for that purpose.
Of course there are other equally vague and subjective words at everyone’s disposal, and even scientists are not averse to using them. Take this quote, for example, from Muir-Wood’s book:
“I was there, in Exeter, when the German climate scientist Hans Joachim Schellnhuber’s proposal of a ‘guard-rail’ rise in global temperature of 2 degrees Celsius [3.6 degrees Fahrenheit] was declared to be the definition of ‘dangerous’ climate change.”
Danger is another of those things that can come in degrees (no pun intended) and so, like the word ‘safe’ when used in safety engineering, it is more useful when qualified. In the same way that safety engineers talk of ‘sufficiently safe’ or ‘acceptably safe’, rather than just ‘safe’, one should talk about ‘too dangerous’ or ‘unacceptably dangerous’ in the context of global warming. The ‘guard-rail’ of 2 degrees Celsius is an arbitrary threshold set to delineate the acceptable from the unacceptable. We can argue about its scientific foundation (and worry that any arbitrary threshold is vulnerable to the sorites paradox) but, at the end of the day, a vague and value-laden word is being used here.
Systems safety engineers dislike vagueness because it reflects uncertainty. Nevertheless, as long as they continued using adjectives such as ‘safe’, ‘reliable’ and ‘predictable’ in their safety arguments, they had to accept that linguistic vagueness was playing a central role. And rather than suffering unnecessary embarrassment, they recognised the importance of this and worked with it. Safety cases are written for an audience that was brought up on natural language and the one thing that linguists can say for sure is that natural language is riddled with vagueness. But the engineers are still perfectly capable of constructing a reasoned argument and acting upon it, enabled rather than challenged by the subtleties and mysteries of linguistic vagueness. The same applies to the terminology used in the climate change debate. It is useful to spend time investigating the science behind a cause and effect, but it is a colossal waste of time trying to glean a straw man from the sceptics’ use of a term that has so much ubiquity and utility.
 First published, 2016, Oneworld Publications, ISBN 978-1-78607-005-0.
 Muir-Wood is also the head of a firm (RMS) that specialises in ‘catastrophe modelling’. Not such an unscientific term after all.
 For example, Nicola Sturgeon has warned that failure to meet targets agreed at the COP26 summit in Glasgow would be “catastrophic” for the planet.