Threshold and pattern dynamics may allow everything from earthquakes, drougths and even epidemics to be predicted
Credit: AFP
By using a computer to simulate the whole fault system, it is possible to see thousands of years of geological activity, Rundle explains. His program simulates the tectonic plates in a fault moving away from each other at a constant rate. After a century or so a threshold is reached where the stresses on the fault are so great that the rocks slip - and a quake occurs. This temporarily lowers the stress on the fault, and the process starts again.
The team still cannot predict the precise time of an upcoming earthquake, "but we can now say that it is likely to happen in one of a small number of areas within a certain time window," says Rundle.
Research into thresholds has many possible uses, he adds. "For example: why do countries go to war? Take the United States where, in 1941, it wasn't really until Pearl Harbour that some sort of a social threshold was reached when people en masse decided: ‘We're not going to stand for this. We are going to war'."
A similar pattern occurred with the World Wide Web, which didn't achieve widespread use until a certain level of connectivity was reached. "It looks more and more like this was a sudden process, a threshold. You had to reach some critical level in connections between the computers of the world before the usefulness of the Web became apparent to most people," says Rundle.
Michael Raupach, an atmospheric scientist with Australia's research agency, the CSIRO, is analysing past abrupt climate changes - from ice ages to salinity - to try and identify the external forces that might cause our present climate patterns and ecosystems to collapse. "With salinity, for a long time while the saline groundwater is rising, you see nothing," he says. "But when the salty water reaches the surface or root zone of plants and trees – the threshold – you see sudden death across a wide area. This is due to a relatively subtle shift in the level of the groundwater."
Another example is the drought which has lately afflicted eastern Australia. The subtle difference from past dry periods was the interaction between drought and warming. While this drought was similar to past events in lack of rainfall, a new feature this time was heat: it was by far the hottest drought on record, because of global warming. This combination pushed many parts of the landscape, including deep-rooted trees, beyond the threshold of no return.
By identifying the external forces that drive such events, it may be possible to predict critical changes and either prevent them or else manage the consequences, says Raupach. His research uses well-understood systems - like fires and stockmarkets - and analyses them to understand the drivers. It has revealed hallmarks common to other complex systems, an indication that there may be universal factors that can be used to analyse all systems.
Raupach's research asks four questions: Are there thresholds? How will things be different if we cross the threshold? What drives the threshold? Can we manage the system to lower the possibility of bad outcomes?
"One of the fundamental questions is: 'Can we identify what the crucial interactions are so we can get some idea of how likely this is?'," he explains. "We might be able to figure out how close we are to the threshold and determine the probability of tipping our climate into a different state."
His research opens the way to better manage human actions that do the greatest damage to the environment and natural ecosystems. "This will mean we are not completely powerless in influencing the trajectory of man-made climate change," says Raupach.
According to Ian Prosser of the CSIRO, drought intensifies the impact of flooding on Australia's water and land-based ecosystems. Heavy floods cause severe erosion of the land and degrade water quality, which in turn can cause havoc in both freshwater and marine environments.
Futuroception
It's always interesting to discuss whether everything is happening due to a terribly complicated game of cause and effect or whether the future is fundamentally unpredictable. I think this might be an unanswerable question. However, in the book 'Futuroception' Peter Lemans tries to give an answer and introduces futuroception as a common human sense. I would like to discuss his conclusions with other people, who have read the book.
Wayne
prediction
evrything is so interesting and sometimes you wonder if peopole are making it up and they just want ot make a little money. Now like everything else, science has taken over prediction. it kind of takes away the spooky-ness and the wonder. horoscopes are so old now.