What does a palaeoceanographer deal with?

My field is the geological history of seas and oceans, and climate. To map this, I study sediments which were deposited on the seabed at some point in the past. These sediments contain fossils as well as small sand particles, which can tell us something about how the ocean was structured during a certain period of time. For instance, what lived there, how salty or fresh the water was or how hot or cold it was. By examining multiple layers in the sediment, we can see how these conditions changed over time.

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What kind of research is that? For instance, do you know what you are looking for?

My field of research is very exploratory; it is also not very old. It has been around for about 30, 40 years now. So the way of working was "Well, we have a piece of sediment here, let's see what's in it." Of course, there was also hypothesis-driven research, but the degree of exploratory work was quite high. That is becoming less and less because we know more and more. It’s a bit of a shame, actually, there’s less romance.

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So has the romance in your work completely disappeared now?

One of the past climate changes I have focused on in recent years was discovered in 2003. That's really recent. So fortunately there still remains quite an exploratory character in this research. And also if you look at what we publish, you see that we very often come across unexpected things. We study sediments for a reason, but in about half of the articles the focus is completely different from what we originally thought. Similarly, a lot of the climate changes we have identified in the past were first discovered without anyone expecting climate change to be there.

In 2017, you received an Ammodo Science Award. What did that mean for you and your research?

When I got that scholarship I was super happy, of course. Apparently there are people who like you and have nominated you. And then to think there is a committee that says: we think this madman is good enough for such a prize, that’s just a great honour. But what is special about this prize is that you actually get money for curiosity-driven fundamental research. You can start doing something even before you really have a fully defined, thought-out plan. Basically, you can work on instinct and say: here, I can see something crazy, and we're going to have a look at that. That freedom is something special.

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And what did you start looking at?

One of the things at play is the better integration of my field with mathematical techniques. And especially around trends and the question of causality: what causes what, what responds to a change? We can see that certain things correlate, like temperature and carbon dioxide. But what you actually want to know is to what extent they affect each other. How much of the warming we see is actually due to that carbon dioxide? And conversely, how much of that carbon dioxide increase is actually due to the positive feedback between carbon dioxide and temperature? There have been advances in mathematics that allow us to look at causality more closely, and to determine the probability of causality. But there are all these snags that we need to think about further. There is also a need to improve the way we generate data to make sure they are better suited to these kinds of mathematical techniques. That is a different focus from the one I have now, and also actually more of an instinct. Right now I can't demonstrate whether it works, so I can never write a proposal on this and get it funded. But with this money, it can be done, and I have now appointed someone to work on that. This could never have been done without Ammodo.

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What breakthroughs is your field still waiting for?

That causality is a real thing. If we can get a better grasp of that, that would really be a big step forward. We do see carbon dioxide and temperature varying together, simultaneously, but being able to quantify exactly how much of that warming was caused by carbon dioxide and how much vice versa is really a big question. The other thing we can hopefully say something about is tipping points. We can see these sudden changes in the past. So what caused that? A well-known example of such a possible tipping point is the thawing of the tundra due to warming, which can suddenly release a lot of methane that further amplifies climate change. The question is whether that has an impact and how much.

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And do these breakthroughs have any implications for climate models?

Looking to the future now, we know that doubling carbon dioxide concentrations will eventually lead to warming of between one-and-a-half and four-and-a-half degrees. That answer comes from physics, as far back as 1979. Not changed. We now know much more about the physics of the climate system, but that uncertainty of whether it is one-and-a-half or four-and-a-half has not been reduced. That's not acceptable. So we really want better, we really need better.

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How can that be? Shouldn't that uncertainty be decreasing?

More knowledge does not always lead to more certainty, because you are fundamentally looking at how the climate system works. Which factors influence it ? How do factors interact, and on what time scale? Then you also find out that there are things going on in the climate system that you hadn't actually taken into account. That actually increases the complexity and uncertainty. In fact, it is very often the case that uncertainty increases in such a trajectory. So the fact that this uncertainty, despite the fact that we now understand the climate system so much better, has not actually increased is actually good news. So you can also see it as something very clever. Anyway, what we want is to reduce uncertainty.

Is there a strong urge to apply your research directly to the heated debate on climate? How do you experience your contact as a researcher with society?

It depends. What we learn from the past supports what comes out of physics about climate change. Every stone we turn also shows that carbon dioxide has a big impact on climate. So in that sense, what we are saying is no different. But because I am not dealing with a climate model, and therefore not producing an abstract simulation of the future, I do have a very different perception. When I lecture, it is much easier for me to show what I find interesting. I can actually show that palm pollen grains were once found near the North Pole. Everyone can relate to that and find that interesting. So in that sense, it is much easier for me to connect with people outside the university than an average person making projections for climate change in the future.

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I feel a 'but' coming on...

Where it gets tricky, and this is really something we need to talk about better in the academy, is the question of how far the role of the scientist extends in social discussions. Let me put it this way: scientists generate facts and those facts are challenged ad infinitum in scientific discussion. At some point, some kind of consensus emerges, along the lines of "this is pretty robust." What you want to prevent is for those facts to be questioned again in the public debate. Because, after all, that has already been done by a whole range of experts in the field. So you have to be very careful in the public debate about facts coming from the science. But what is happening on a large scale in the public debate is that conclusions generated from consensus in science are being questioned again. Even by politicians.

Indeed, you don't have to search far to see that. So when Donald Trump says something like "It's SO cold now. This global warming doesn't exist at all." What does that do to you when you read something like that?

By now, of course, I have to laugh a little at that, because I am used to that discussion. It is no different in the Netherlands. Until recently, there were three political parties that also made that statement, namely the VVD, the Forum for Democracy, and the PVV. And these find an audience with a certain part of the electorate. I do understand that it happens, climate change is an uncanny truth and people don't want to go there. You see exactly the same thing in the discussion about vaccinations, which a completely different part of the population opposes. Whereas with climate change it is mainly the less educated who play down the problem and are heard by the parties that oppose the establishment, with vaccinations it is precisely a part of the population that is more educated and quite left-oriented. But the effect is exactly the same.

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So why is that?

Partly because some of the population are fed certain non-scientific information. The internet plays an important role in this. The internet is a huge repository of uncontrolled information, where you can always find what suits your perception. And that is where science really plays a different role than it used to. It used to be that everything that came out of science was largely accepted, at least by the important social players. But that authority of science has completely changed because everyone is now an opinion maker. We now have to relate to the public discussion in a different way because scientific facts, valuable as they are, are increasingly being questioned in the public domain.

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How can we change this?

I think there are two main avenues. The first is surely education. We need to show as best we can what a scientific insight means, what it has been through before it rolls into society at all. We have created our own website (tippingpointahead.co.uk). And that is not so much about 'what have we found now,' but more about 'what question do we ask and how do we try to solve it? And how long does that take?' Maybe then people will get some idea of what it means when a scientist says something.

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The second thing we really need to do something about is the way we communicate with society. And this is already happening more and more. You see that there are really hundreds of scientists in the Netherlands who, despite the workload, make personal contact with people by giving lectures. They go to schools, or seek out teachers' associations to show what is happening. Such a teachers' association plays an incredibly big role I think, and teachers are really looking for this. But it is not only teachers who can be ambassadors, also other people in society who have a lot of contact with all kinds of different people. You can make a huge impact with that, but you have to do it smartly. That too is something in which the university can reinvent itself. Finally, I think the ministry should shoulder more responsibility, because at the end of the day, you do want to make fact-based policy, and that requires democratic support.

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Text: Stephan van Duin

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Published on 6 February 2019.

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Photos: Florian Braakman