Climate change – either it is certain OR it is science

Is there a place for absolute certainty in science communication?

Keith S. Taber

I just got around to listening to the podcast of the 10th October episode of Science in Action. This was an episode entitled 'Youngest rock samples from the moon' which led with a story about rock samples collected on the moon and brought to earth by a Chinese mission (Chang'e-5). However, what caused me to, metaphorically at least, prick up my ears was a reference to "absolute certainty".

Now the tag line for Science in Action is "The BBC brings you all the week's science news". I think that phrase reveals something important about science journalism – it may be about science, but it is journalism, not science.

That is not meant as some kind of insult. But science in the media is not intended as science communication between scientists (they have journals and conferences and so forth), but science communicated to the public – which means it has to be represented in a form suitable for a general, non-specialist audience.

Read about science in public discourse and the media

Scientific and journalistic language games

For, surely, "all the week's science news" cannot be covered in one half-hour broadcast/podcast. ¹

My point is that "The BBC brings you all the week's science news" is not intended to be understood and treated as a scientific claim, but as something rathere different. As Wittgenstein (1953/2009) famously pointed out, language has to be understood in specific contexts, and there are different 'language games'. So, in the genre of the scientific report there are particular standards and norms that apply to the claims made. Occasionally these norms are deliberately broken – perhaps a claim is made that is supported by fabricated evidence, or for which there is no supporting evidence – but this would be judged as malpractice, academic misconduct or at least incompetence. It is not within the rules of that game

However, the BBC's claim is part of a different 'language game' – no one is going to be accused of professional misconduct because, objectively, Science in Action does not brings a listener all the week's science news. The statement is not intended to be understood as an objective knowledge claim, but more a kind of motto or slogan; it is not to be considered 'false' because it not objectively correct. Rather, it is to be understood in a fuzzy, vague, impressionistic way.

To ask whether "The BBC brings you all the week's science news" through Science in Action is a true or false claim would be a kind of category error. The same kind of category error that occurs if we ask whether or not a scientist believes in the ideal gas law, the periodic table or models of climate change.

Who invented gravity?

This then raises the question of how we understand what professional academic scientists say on a science news programme that is part of the broadcast media in conversation with professional journalists. Are they, as scientists, engaged in 'science speak', or are they as guests on a news show engaged in 'media speak'?

What provoked this thought with was comments by Dr Fredi Otto who appeared on the programme "to discuss the 2021 Nobel Prizes for Science". In particular, I was struck by two specific comments. The second was:

"…you can't believe in climate change or not, that would just be, you believe in gravity, or not…"

Dr Friederike Otto speaking on Science in Action

Which I took to mean that gravity is so much part of our everyday experience that it is taken-for-granted, and it would be bizarre to have a debate on whether it exists. There are phenomena we all experience all the time that we explain in terms of gravity, and although there may be scope for debate about gravity's nature or its mode of action or even its universality, there is little sense in denying gravity. ²

Newton's notion of gravity predominated for a couple of centuries, but when Einstein proposed a completely different understanding, this did not in any sense undermine the common ('life-world' ²) experience labelled as gravity – what happens when we trip over, or drop something, or the tiring experience of climbing too many steps. And, of course, the common misconception that Newton somehow 'discovered' gravity is completely ahistorical as people had been dropping things and tripping over and noticing that fruit falls from trees for a very long time before Newton posited that the moon was in freefall around the earth in a way analogous to a falling apple!

Believing in gravity

Even if, in scientific terms, believing in a Newtonian conceptualisation of gravity as a force acting at a distance would be to believe something that was no longer considered the best scientific account (in a sense the 'force' of gravity becomes a kind of epiphenomenon in a relativistic account of gravity); in everyday day terms, believing in the phenomenon of gravity (as a way of describing a common pattern in experience of being in the world) is just plain common sense.

Dr Otto seemed to be suggesting that just as gravity is a phenomenon that we all take for granted (regardless of how it is operationalised or explained scientifically), so should climate change be. That might be something of a stretch as the phenomena we associate with gravity (e.g., dense objects falling when dropped, ending up on the floor when we fall) are more uniform than those associated with climate change – which is of course why one tends to come across more climate change deniers than gravity deniers. To the best of my knowledge, not even Donald Trump has claimed there is no gravity.

But the first comment that gave me pause for thought was:

"…we now can attribute, with absolute certainty, the increase in global mean temperature to the increase in greenhouse gases because our burning of fossil fuels…"

Dr Friederike Otto speaking on Science in Action

Absolute certainty?

That did not seem to me like a scientific statement – more like the kind of commitment associated with belief in a religious doctrine. Science produces conjectural, theoretical knowledge, but not absolute knowledge?

Surely, absolute certainty is limited to deductive logic, where proofs are possible (as in mathematics, where conclusions can be shown to inevitably follow from statements taken as axioms – as long as one accepts the axioms, then the conclusions must follow). Science deals with evidence, but not proof, and is always open to being revisited in the light of new evidence or new ways of thinking about things.

Read about the nature of scientific knowledge

Science is not about belief

For example, at one time many scientists would have said that the presence of an ether ³ was beyond question (as for example waves of light travelled from the sun to earth, and waves motion requires a medium). Its scientific characterisation -e.g., the precise nature of the ether, its motion relative to the earth – were open to investigation, but its existence seemed pretty secure.

It seemed inconceivable to many that the ether might not exist. We might say it was beyond reasonable doubt. ⁴ But now the ether has gone the way of caloric and phlogiston and N-rays and cold fusion and the four humours… It may have once been beyond reasonable doubt to some (given the state of the evidence and the available theoretical perspectives), but it can never have been 'absolutely certain'.

To suggest something is certain may open us to look foolish later: as when Wittgenstein himself suggested that we could be certain that "our whole system of physics forbids us to believe" that people could go to the moon.

Science is the best!

Science is the most reliable and trustworthy approach to understanding the natural world, but a large part of that strength comes from it never completely closing a case for good – from never suggesting to have provided absolute certainty. Science can be self-correcting because no scientific idea is 'beyond question'. That is not to say that we abandon, say, conversation of energy at the suggestion of the first eccentric thinker with designs for a perpetual motion machine – but in principle even the principle of conservation of energy should not be considered as absolutely certain. That would be religious faith, not scientific judgement.

So, we should not believe. It should not be considered absolutely certain that "the increase in global mean temperature [is due to] the increase in greenhouse gases because [of] our burning of fossil fuels", as that suggests we should believe it as a doctrine or dogma, rather than believe that the case is strong enough to make acting accordingly sensible. That is, if science is always provisional, technically open to review, then we can never wait for absolute certainty before we act, especially when something seems beyond reasonable doubt.

You should not believe scientific ideas

The point is that certainty and belief are not really the right concepts in science, and we should avoid them in teaching science:

"In brief, the argument to be made is that science education should aim for understanding of scientific ideas, but not for belief in those ideas. To be clear, the argument is not just that science education should not intend to bring about belief in scientific ideas, but rather that good science teaching discourages belief in the scientific ideas being taught."

Taber, 2017: 82

To be clear – to say that we do not want learners to believe in scientific ideas is NOT to say we want them to disbelieve them! Rather, belief/disbelief should be orthogonal to the focus on understanding ideas and their evidence base.

I suggested above that to ask whether "The BBC brings you all the week's science news" through Science in Action is a true or false claim would be a kind of category error. I would suggest it is a category error in the same sense as asking whether or not people should believe in the ideal gas law, the periodic table, or models of climate change.

"If science is not about belief, then having learners come out of science lessons believing in evolution, or for that matter believing that magnetic field lines are more concentrated near the poles of a magnet, or believing that energy is always conserved, or believing that acidic solutions contain solvated hydrogen ions,^[5] misses the point. Science education should help students understand scientific ideas, and appreciate why these ideas are found useful, and something of their status (for example when they have a limited range of application). Once students can understand the scientific ideas then they become available as possible ways of thinking about the world, and perhaps as notions under current consideration as useful (but not final) accounts of how the world is."

Taber, 2017: 90

But how do scientists cross the borders from science to science communication?

Of course many scientists who have studied the topic are very convinced that climate change is occurring and that anthropogenic inputs into the atmosphere are a major or the major cause. In an everyday sense, they believe this (and as they have persuaded me, so do I). But in a strictly logical sense they cannot be absolutely certain. And they can never be absolutely certain. And therefore we need to act now, and not wait for certainty.

I do not know if Dr Otto would refer to 'absolute certainty' in a scientific context such as a research paper of a conference presentation. But a radio programme for a general audience – all ages, all levels of technical background, all degrees of sophistication in appreciating the nature of science – is not a professional scientific context, so perhaps a different language game applies. Perhaps scientists have to translate their message into a different kind of discourse to get their ideas across to the wider public?

The double bind

My reaction to Dr Otto's comments derived from a concern with public understanding of the nature of science. Too often learners think scientific models and theories are meant to be realistic absolute descriptions of nature. Too often they think science readily refutes false ideas and proves the true ones. Scientists talking in public about belief and absolute certainty can reinforce these misconceptions.

On the other hand, there is probably nothing more important that science can achieve today than persuade people to act to limit climate change before we might bring about shifts that are (for humanity if not for the planet) devastating. If most people think that science is about producing absolute certain knowledge, then any suggestion that there is uncertainty over whether human activity is causing climate change is likely to offer the deniers grist, and encourage a dangerous 'well let's wait till we know for sure' posture. Even when it is too late and the damage has been done, if there are any scientists left alive, they still will not know absolutely certainly what caused the changes.

So, perhaps climate scientists are in a double bind – they can represent the nature of science authentically, and have their scientific claims misunderstood; or they can do what they can to get across the critical significance of their science, but in doing so reinforce misconceptions of the nature of scientific knowledge.

Coda

I started drafting this yesterday: Thursday. By coincidence, this morning, I heard an excellent example of how a heavyweight broadcast journalist tried to downplay a scientific claim because it was couched as not being absolutely certain!

Works cited:

• Wittgenstein, L. (1953/2009). Philosophical Investigations (G. E. M. Anscombe, P. M. S. Hacker, & J. Schulte, Trans. P. M. S. Hacker & J. Schulte Eds. Revised fourth ed.). Chichester, West Sussex: Wiley-Blackwell.
• Schutz, A., & Luckmann, T. (1973). The Structures of the Life-World (R. M. Zaner & H. T. Engelhardt, Trans.). Evanston, Illinois: Northwest University Press.
• Taber, K. S. (2013). Classroom-based Research and Evidence-based Practice: An introduction (2nd ed.). London: Sage.
• Taber, K. S. (2017). Knowledge, beliefs and pedagogy: how the nature of science should inform the aims of science education (and not just when teaching evolution). Cultural Studies of Science Education, 12(1), 81-91.
• Taber, K. S. (2019). The Nature of the Chemical Concept: Constructing chemical knowledge in teaching and learning. Cambridge: Royal Society of Chemistry.

Notes

¹ An alternative almost tautological interpretation might be that the BBC decides what is 'science news', and it is what is included in Science in Action, might fit some critics complaints that the BBC can be a very arrogant and self-important organisation – if only because there are stories not covered in Science in Action that do get covered in the BBC's other programmes such as BBC Inside Science.

² This might be seen as equivalent to saying that the life-world claim that gravity (as is commonly understood and experienced) exists is taken-for-granted Schutz & Luckmann, 1973). A scientific claim would be different as gravity would need to be operationally defined in terms that were considered objective, rather that just assuming that everyone in the same language community shares a meaning for 'gravity'.

³ The 'luminiferous' aether or ether. The ether was the name given to the fifth element in the classical system where sublunary matter was composed of four elements (earth, water, air, fire) and the perfect heavens from a fifth.

⁴ Arguably the difference between forming an opinion on which to base everyday action (everyday as in whether to wear a rain coat, or to have marmalade on breakfast toast, not as in whether to close down the global fossil fuel industry), and proposing formal research conclusions can be compared to the difference between civil legal proceedings (decided on the balance of probabilities – what seems most likely given the available evidence) and criminal proceedings – where a conviction is supposed to depend upon guilt being judged beyond reasonable doubt given the available evidence (Taber, 2013).

Read about writing-up research

⁵ Whether acids do contain hydrated hydrogen ions may seem something that can reasonably be determined, at least beyond reasonable doubt, by empirical investigation. But actually not, as what counts as an acid has changed over time as chemists have redefined the concept according to what seemed most useful. (Taber, 2019, Chapter 6: Conceptualising acids: Reimagining a class of substances).