Applying the tipping point theory and complex system approach to issues in the nature – health arena; a novel approach combining ecology, mathematics and psychology

While biodiversity declines worldwide and the gap between people and nature widens, our 21th century lifestyle is impacting on physical and mental health and wellbeing. Although there are many distinct problems, I argue that all are interconnected, bound together in a web of complex relations; we appears to be caught in a negative socio-ecological spiral. The theory of critical transitions (tipping points) offers a new way of looking at such interconnected complex systems with nonlinear dose response relations and (positive and negative) feedback loops. Even without a full mathematical model, the theory and tools offer valuable insights in how to develop early warning signals, and clues about how to shift the balance from an undesirable state of the system to a more desirable one. Tipping points are described both in nature and in human systems; it is new to focus on the nature – human interface. For illustration, I use two examples. The first one is the system overconsumption / obesity. Obesity has reached epidemic proportions globally, with at least 2.8 million people dying each year as a result of being overweight or obese. The hypothesis under investigation is that overconsumption of food, leading to both environmental problems and health problems, is being maintained by feedback loops in the subconscious mind. I show the preliminary results of an ongoing experiment. The second example focuses on the impact of nearby nature on quality of life of the ageing population. Loneliness, social isolation, depression, forgetfulness and onset of dementia all occur in urbanized neighbourhoods with an elderly population. The hypothesis under investigation is that the symptoms and issues are all connected in a network, and greening the neighborhood can cause a cascade of positive effects in this web. At least three mechanisms may play a role. (1) Stress reduction is one of the proven mechanisms in the investigation of nature and health; (2) Green environment stimulates exercise, and exercise stimulates the operation of the brains (in particular, memory), in addition to other bodily functions. Exercise also enhances a healthy body weight; moreover, fresh air and exposure to daylight are important for good sleep. (3) Green environment promotes social cohesion. Social cohesion promotes health and wellbeing. Particularly participation in the planning process is beneficial.