Reading 5.2: Time lags and surprises
Time lags, or delays, are common in many systems. If you imagine a complex web of interrelated factors, significant time may have passed before changes in one factor get back through all the various components to have an effect on it. A good example is setting an optimal water temperature when you are having a shower. The initial outflow of water is cold, so you turn the tap to a much hotter setting hoping that the water will turn warm soon. Then suddenly you get a surge of hot water and you quickly turn the taps to a cooler setting. This hot-cold-hot-cold cycle is repeated several times until you finally get the temperature you want (and then somebody else turns the hot tap on in the kitchen so you have to start all over again!). The reason for all this messing about with taps is the delay in the response time between you turning the taps and the resulting change in water temperature coming out of the shower.
More generally, system delays can result in major surprises for people who initiate change in a situation and expect instant change. When the effect does not materialise, they continue with their action, only realising too late that their continuing action has now resulted in a response that oversteps their initial intentions of change. Learning the length of time lag between control action and effect is a major part of the skill in activities such as steering a yacht or setting appropriate stock levels in a supermarket. In relation to the environment, the emissions of greenhouse gases into the atmosphere since the industrial revolution, and the current level of relatively benign effects on world climates, may prove to be a clear example of a time lag within the climate system, and even if human carbon emissions were to drop radically right now, the climate system as a whole would go on warming for some time to come. In fact, some experts believe that it is already too late to stop climate change whatever we do, and that we should start thinking about adaptation rather than mitigation. The emissions that we have already released may have already initiated a delayed reaction with potentially catastrophic consequences.
Time lags are important, because there may come a time when so many parts of a system have been knocked out that the system can no longer function in its current form, and this point might not be detected in time to change anything if lags are not taken into account. Such a crossing of a threshold from stability to chaos is often called a ‘tipping point’. Tipping points are usually initiated when dominant negative feedback processes, which maintain stability, are overwhelmed by positive feedback processes, which propel change. The development of deadly cancer is a perfect example of a tipping point. The human body has a range of mechanisms to control cellular growth. For example, hormonal regulation stops excessive production of cells when they achieve the desired proportions for a healthy body. Cancerous cells no longer respond to the hormonal signal to stop growing. Instead, they multiply exponentially, and if not destroyed in time, take over essential organs often resulting in death.
Unfortunately, it is the nature of systems that once change is initiated, it is not generally possible to predict the form and function of the new system, if indeed it survives the change! Many well intended interventions have resulted in disastrous consequences, such as the introduction of new supposedly useful species to a country. Australia has a catalogue of horrific consequences when species such as the prickly pear cactus, the fox, the cane toad and countless others were introduced to resolve specific problems but ended up devastating native ecosystems.
A number of commentators, such as Thomas Homer-Dixon (Homer-Dixon, 2006), Stephen Lincoln (Lincoln, 2006), and Colin Mason (Mason, 2006) state that several drivers will combine within the next twenty years or so to form a disastrous tipping point for humanity. In this case, we may actually need to push our own social systems towards tipping points to change them into more sustainable forms.
In most books on systems thinking aimed at managers this activity is called ‘identifying leverage’. In other words, the task is to figure out points of intervention within the system you want to change, either to remove a stabilising negative feedback cycle or to reinforce a transforming positive feedback cycle.
All these authors propose points of leverage at a range of organisational scales, from the individual to global institutions, in order to transform our social systems. But one can never overestimate the resistance to changing mental models. People find comfort in the familiar, while they fear the unknown. They even stop others from changing by isolating and ridiculing those that take the first step. Changing the destructive social systems will take courage and perseverance.