Alternative titles included “WWTKD” and “Am I precipitating a crisis?”
The March edition of Nature featured an interesting perspective by Tiffany Shaw and Bjorn Stevens entitled “The other climate crisis”. Shaw and Stevens suggest that climate modelling is reaching a breaking point, and we are due a revolution in the field. I won’t dwell on their arguments further, but you should read the article. What really caught my interest is that Shaw and Stevens drew on a book entitled “The Structure of Scientific Revolutions” by the late historian of science Thomas Kuhn. The book has obsessed me for some time.
If we were in a film, I would now reduce the colour saturation and cut to a flashback scene. I am sitting at the mouth of a horseshoe-shaped table separating me from nine senior scientists. It looks like an Alamy stock photo of a job interview, except it actually is a job interview. Things are going well. I am relaxed until the scientist directly across from me clears his throat and bowls around the wicket:
““Tell me why your work is not incremental””
There is a pause. I have never been asked this question before. Worse, I have not considered this question before. Much worse than that, I have not considered its premise before. Cogs whir. A mediocre answer appears before me. Then it appears before him.
“Tell me why your work is not incremental” is a big box with three containers inside. The first is made of dull steel, it’s nearly full and rattles when you shake it. It contains the definition of “incremental”, and near the bottom you can find what it means to not be incremental. I’ll open that in the next section. The second container does not reveal its contents when shaken. It is cylindrical and contains a pressurised gas nearing condensation. This gas implies that incremental work should be avoided, particularly by those seeking success and scientific fortune. I’ll open that in the last section. The third is the smallest by far. It is square and roughly hewn from a wood that I recognize but can’t name. It contains the reason that my work is not incremental.
The Weaknesses of Nullius In Verba
Towards the end of my PhD I went through a phase of hyperscepticism. When somebody told me the time, I checked my watch. “Nullius In Verba” is the motto of the Royal Society, and is best translated as “Don’t take anybody’s word for it”. Prove everything for yourself, rather than taking anything on trust. This approach gets tiresome. It was tiresome for me, and it was tiresome for others. Thomas Kuhn saw Nullius In Verba for what it is, and also saw that scientists don’t operate in a state of full scepticism most of the time because of its tiresome nature. Contrary to the work of his predecessor Karl Popper, he identified the absence of perma-scepticism as a good thing. Rather than constantly questioning everything all the time, it’s much easier to have a paradigm of rules and laws that we follow and assume to be true. From that foundation we can probe outside the paradigm more effectively. The paradigm is a labor-saving device that does not aim to describe reality, but rather make frontier discovery more possible. He referred to working in alignment with the paradigm as “Normal Science”. We would do ourselves a disservice if we considered coriolis deflection or relativity every time we aimed a cricket ball. We understand the ball as if we are on a flat pitch that is not moving, and in this paradigm we can effectively study the fluid-dynamical air resistance to a sphere, or the biomechanics of the human arm.
But as we probe further and further outside a paradigm, discrepancies build up. Rather than throwing a cricket ball, we’re firing a missile. Isn’t it weird how we keep having to aim to the left of the target? Kuhn refers to this kind of aiming issue as an anomaly. When anomalies become too abundant to ignore, scientists begin to doubt their own paradigm (the flat Earth). Kuhn terms this a Crisis, and this is what’s referenced by Shaw and Stevens in their title. Sometimes crises go away as anomalies are resolved. Medhaug et al. give a very interesting account of how this happened with the “global warming hiatus”. Another way to resolve a crisis is a paradigm shift. We realise we are on a spinning sphere. This is nicely illustrated by Dorothy opening the door of her house to find she’s in Oz (cue that colour saturation back up by the way). Her discovery totally realigned the questions she could ask, and the direction of her main inquiries. Her paradigm had changed.
I am precipitating a crisis
I think it’s worth saying that incremental science (Kuhnian “Normal Science”) can absolutely improve and save lives. Numerical weather prediction is a triumph of incrementalism and it has radically improved human wellbeing and flourishing. Peter Bauer makes this case extremely well in Episode 77 of Mike White’s Forecast podcast. But more importantly, Normal Science is necessary to precipitate a Kuhnian crisis, which is in turn necessary to shift a paradigm. If we don’t have normal, incremental science, then we cannot produce anomalies, the crisis does not occur, the paradigm never shifts. Put another way, one cannot manifest an undue paradigm shift in their field. We need to do the work. I am doing the work!
So the answer I wish I’d been able to give to that interviewer: I am producing Kuhnian anomalies and precipitating a crisis. I am challenging a paradigm. It is an often stated assumption (although there is some degree of preference falsification here) that Ku-band radar waves penetrate snow on sea ice. This has been a very useful paradigm, and has allowed us to meaningfully advance the state of sea ice science. For instance, it’s obviously clear that when you initiate a forecast with a sea ice thickness product made in this paradigm, the forecast improves. The paradigm produces sea ice thickness estimates that closely map the evolution of sea ice thickness over a year.
However, anomalies to the paradigm are growing. I won’t list them all, but our work involving salt movement through snow, in-situ and airborne radars, and CryoSat data itself has produced many anomalies to the “full penetration” paradigm. There’s some review of these anomalies on Pages 12 & 17 of a book chapter I helped write (Mallett et al., 2024), and also in Nab et al. (2024). It is possible that these anomalies will be resolved in a Medhaug-esque effort, perhaps involving beam geometries. And it is also possible that they will lead to a paradigm shift.
In The Sun Also Rises, Mike is asked how he went bankrupt. “Two ways,” he replies. “Gradually and then suddenly.”