Sudden shifts in complex systems such as the climate, financial markets, ecosystems and even the human body can be preceded by surprisingly comparable warning signals. It is crucial to be able to predict such transitions, but this was previously very difficult. In an article in the journal Nature of 3 September, a group of Wageningen University scientists and their colleagues from Utrecht University and from Germany, Spain and the United States showed that systems that are on the verge of a critical transition often emit comparable signals.
At first glance, it appears improbable that a climate shift, an epileptic seizure, the collapse of a fish population or a sudden transition in a financial system have something in common. However, the Wageningen professor Marten Scheffer has no doubts about this. In the article in Nature, Scheffer and his colleagues show that completely different systems – such as the brain, the climate and financial markets – obey certain universal laws when they are at a critical transition point that make it possible to recognise early warning signals.
Transition point
The changes have to do with a phenomenon that is known in mathematics as ‘Critical Slowing Down’. Among other things, this means that fluctuations in the state of a system that is approaching a transition point become slower: in a sense, today seems more like yesterday. Recently, the same Wageningen researchers showed, for example, that such a slowdown in fluctuations consistently occurred before radical climate shifts in the past. Before a critical transition, characteristic changes in spatial patterns can also occur. For example, a specific vegetation pattern can precede desertification, and before an epileptic seizure, the activity in neighbouring neurons in the brain becomes increasingly similar.
Scheffer conducted the research with a community of scientists that included economists, climate experts, ecologists and mathematicians. Although the researchers from various disciplines presented a wide range of examples from practice, Scheffer emphasises that the applications for universal warning signals are still in their infancy. One of the follow-up projects – conducted by Scheffer with the two other winners of the prestigious Spinoza Prize 2009 – will be a joint search for possible warning signals for migraine attacks. Similar to epileptic seizures, these attacks also occur when a critical transition point in the brain is reached.
The research will be financed in part by the Netherlands Organisation for Scientific Research (NWO).
Publication data
Early Warning Signals for Critical Transitions. Nature 3 September 2009.
Marten Scheffer, Jordi Bascompte, William A. Brock, Victor Brovkin, Stephen R. Carpenter, Vasilis Dakos, Hermann Held, Egbert H. van Nes, Max Rietkerk and George Sugihara