Ecologist Marten Scheffer: The spirit must be free

We arrange to meet at ecologist Marten Scheffer’s detached 1930s home, ­beside the River Waal not far from Tiel. The conservatory, with its dining ­table, has a view of the river dike 30 metres away, a massive grass embankment that towers over the house. The house and garden match their owner perfectly: relaxed, informal, natural. A box containing strap-on Frisian skates still stands in the middle of the lounge; children’s drawings and craft work decorate the walls. An occasional table is disappear­ing under all sorts of things – papers, notebooks, textbooks and sheet music (French Sonatas Volume 1, for violin & ­piano). Lying in the red sitting area is a guitar that’s just asking to be picked up. Scheffer lives here with his wife, 14-year-old son and 12-year-old daughter. He got to know his wife while work­ing as a postdoc in the United States. ‘She does research on terrestrial ecology and I do aquatic ecology. Now and then we do something together. A few months ago we co-authored an article in Science.’ Such projects do not mean that science is discussed at the dining table, says Scheffer. ‘No, projects like this always involve more researchers, so we simply set up a work meeting.’ The Science publication develops the theme with which Scheffer made his name internationally: alternative stable states of complex systems, and the transitions between them. This subject emerged when he got involved in research into cloudy and clear lakes in the late 1980s. The article in Science describes the resilience of rainforests and savannas. ‘We used satellite images to map them ­afresh all over the world.’ Scheffer also examined whether extreme El Niño rains can be used to restore vegetation in areas that have lost their trees. ‘Sometimes an extreme event can force a transition to another state. But sometimes an ecosystem is stuck in a situation and then, for example, extreme rainfall due to El Niño can give a de­forested area a helping hand, enabling it to get out of the trap of a treeless situation.’

Notebook

The telephone interrupts the conversation a couple of times. Nonetheless, he says, ‘In terms of office hours, I am seldom at work. I do many other things as well. On the other hand, you can say that I am working all the time because I am always doing something to do with my work.’ Scheffer picks up a notebook of small sketches and writ­ing. ‘If I am walking somewhere or sitting in the train and I have an idea, I jot it down at once. Some ideas get elaborated. I work few explicit office hours; a substantial part of my work is thinking and I can do that just as well cycling to Wageningen. I use those 20 kilometres quite deliberately as time to think; they count as productive hours too.’ The separation between work, workplace and private life is unclear, admits Scheffer. ‘But if you are lucky, the subject grabs you. That can also be a pitfall, because you can’t distance yourself from it. For much of my career, I have worked four days a week. The rest of the time I’ve spent mainly making music – while I’m doing that, think­ing about anything else is simply out of the question – and doing all the other things I enjoy. Such as gardening and pruning trees, cooking tasty food, and making a couple of hundred litres of juice every autumn from the apples in the orchard. And I can really enjoy my children: chatting endlessly and making music together. With their lack of inhibition and their curiosity, children are a very good ­antidote for narrow-mindedness. Thanks to them I get to learn about all sorts of new music styles, for in­stance.’ Music and science are a recurring theme in Scheffer’s family history. When he was growing up here in this same house with two musical parents, many musicians used to visit. Other ancestors were active in the field of science. He walks over to the wall units and proudly hands over a hefty tome on nutrition in the Dutch East Indies published in 1904 by his great-great-grandfather Dr C.L. van der Burg. One of his grandfathers on his mother’s side knew the pio­neer of Dutch nature conservation Jac P. Thijsse, and taught Scheffer the names of plants and birds. It was virtually taken for granted that he would go to both university (Biology) and a college of music. ‘I couldn’t decide and so I started them both. But at some point it become too much, so I left the college of music.’ But he has never stopped performing. These days he connects music and science on the stage. In a show entitled Concerted Science, he talks about scientific insights and tries to make the audience appreciate that new routes for scientific research can be discovered through intuition and association.

Thinking fast

In exactly the same way, Scheffer himself seeks con­nections and patterns that transcend his discipline. His approach showed that the mathematical models that can describe the change from a clear to a cloudy lake can also be useful when describing abrupt changes in financial markets. Or disruptions to the interaction between neurons at the first onset of brain diseases. Since the first publications on this subject, increasing success has been achieved in describing these changes in systems – critical transitions – and even in detecting the signals that pre­cede them. Mental leaps, that’s how he describes those first inspirations. All sorts of cognitive research has shown that people can think in two ways, says Scheffer: ‘thinking slow and thinking fast’ as Daniel Kahneman calls it. The first way is purposeful and rational reasoning, often done ­sitting at a desk. The ‘fast’ thinking is unconscious, intuitive and associative. ‘Often, it is during thinking of this ­type that the bigger connections happen. All major break­throughs in science involve these intuitive clicks. But all the systems we use to structure our work are about think­ing slow: sitting, having meetings, timekeeping. We have no way at all of facilitating and institutionalizing spontaneous and associative thinking.’ So how can you stimulate people to make leaps in their thinking more often? ‘By ensuring that they take a broad­er view of things and get more input from other fields and methods. Reading and talking on a wide range of topics. And having the time to process that. That’s not something you do at a desk, it happens much more easily if you go and eat or walk with people. If you want to stimulate that, you have to do some social engineering: ensure that people get together. And if you don’t want to use coercion, then you need to make sure, for example, that there’s really tasty food. If you look at famous institutes, at one the secret will be a really good expresso-maker, at another it will be a weekly get-together for drinks on a roof terrace, or a canteen with long tables. That may sound mundane but in our normal office life, all that social interaction is seen as wasted time.’

Lighting a fire

Behind his house, Scheffer has put his ideas about social engineering into practice. We walk there, past the treehouse next to the front door, past chickens scratching about for food and the stationwagon parked casually on the grass. Scheffer calls the self-built accommodation a shed with a wood-burning stove, but it is actually a fine house with French doors opening onto the orchard. This is where he receives scientists. There is a table, a kitchen­ette and numerous whiteboards on the walls. The landing provides enough space to play music. ‘I hold small workshops here. Such informal gatherings work well. A few years ago a workshop that consisted mainly of walking led to an extensively cited Nature article about generic early warning signals.’ Visiting researchers spend the night at a small local hotel; they cycle to Scheffer’s home. ‘We talk in the shed and now and then we walk to the river. We light a fire. At things I organize, half the time is spent eating, walking or taking the occasional swim in the nearby gravel pit lake. These gatherings are unconventional but enormously productive. I think that we suffer greatly from the zeitgeist of control, which makes us want to manage both the scientific output and the process that gives rise to it. That is a mis­taken notion of how you can arrive at new insights.’ New breakthroughs do not present themselves for the picking, like ripe apples on the tree of knowledge. Besides thinking and having ideas, Scheffer spends much time and energy on reading up on new disciplines and seeking clarification from researchers. ‘It takes a while before you have enough knowledge to get beyond a naïve understand­ing and get a grasp of the really interesting questions . But after all these years, I am getting better and better at know­ing what works in this interdisciplinary approach, both in the social sphere and in terms of the scientific directions in which you can search. So the dynamics of the practice of science are showing me the way. But the outcome is ­always uncertain. Sometimes it comes to nothing, and at other times you do hit on something. It is a calculated risk, but I enjoy being occupied in an adventurous way. If you don’t keep on the move, you won’t find any new paths.’ Marten Scheffer (Amsterdam, 1958) 1985 Ecology degree, Utrecht University 1990 Dissertation entitled ‘Simple models as useful tools for ecologists’, Utrecht University 1985-1987 Researcher, National Institute for Research in Forestry and Landscape Structure at ‘De Dorschkamp’ estate 1987-1997 Senior researcher, Institute for Inland Water Management and Wastewater Treatment (RIZA) 1998- present Professor of Aquatic Ecology and Water Quality Manager at Wageningen UR Kees Slingerland, director, Environmental Sciences Group: ‘Officially, I am Marten Scheffer’s manager but as with all chair holders there is no boss-subordinate relationship. None whatsoever in Martin’s case: he is entirely self-directing and knows exactly what he is going to do. In every respect, Marten is authentic, completely himself. A really amiable fellow and someone who practises science at top level, who can explain things very well and who makes fine music to boot. Marten goes for content and is not driven by commerce. But he does valorize his ecological research very well by making connections with all kinds of other fields of science.’ Vasilis Dakos, former doctoral student, now postdoc under Jordi Bascompte in Spain: ‘Marten develops his scientific work everywhere: at the university, at home, riding his bike. If I have to describe his manner of working in two words, freedom and creativity come to mind. He stimulates you to think out of the box, to be open to other influences and to seek collaboration. Now I am trying to do that myself: to work creatively and build bridges. As a person he is very generous, friendly and positive. Over the past six years, his house has become my second home.’