by Nina Munteanu
“The stock market, the Arctic, and your brain have more in common than you might think,” wrote Patrick Tucker in the January-February 2010 issue of The Futurist.
Citing a September 2009 paper in Nature by Marten Scheffer and other scientists, Tucker’s article discusses how complex systems from ecosystems and climate to financial markets and human health commonly exhibit early warning behaviors prior to significant and disruptive changes: massive fish die-off in a stressed lake, abrupt shifts in ocean circulation or climate, a stock market crash, or a brain seizure. Tucker is talking about “Tipping Points”; something ecologists have understood and studied for years.
Every system has a critical threshold—a tipping point—where it abruptly shifts from one state to another. College chemistry students understand this concept when they conduct their first titration experiment, where they watch and measure the accumulative effect of adding an acid or a base to a buffered mixture that contains an indicator with no obvious effect until one drop turns the clear fluid to a colour. It can be that sudden. The same occurs in nature, which makes it hard to predict critical transitions. The state of the system often shows little change before the tipping point is reached. Steve Carpenter, one of the paper’s co-authors told Wired Magazine (September, 2009) that “tipping points appear when the feedback loops that normally keep complex systems at equilibrium become stressed. Too many trees are cut down, too many cattle are turned out to graze, too many investors sell low. The system takes longer to recover from variations it normally weathers. Its mathematical representations become jagged rather than smooth.” Carpenter and others suspect that all critical transitions are preceded by the same basic patterns. Manfred Schroeder (author of “Fractals, Chaos, Power Laws: Minutes from an Infinite Paradise” suggested back in 1991 that any system near its critical state of transition shares common properties with all other systems, regardless of the differences between them. “Heart attacks, algal blooms in lakes, epileptic attacks—everyone shows this type of change,” said Carpenter. It is both remarkable and intuitively understandable that this is a universal phenomenon. Fractals, self-organization, complexity and “stable chaos” support this.
In 1982, physicist Kenneth Wilson won a Nobel Prize for his equations that described transitions that don’t happen in a linear, easily predictable way, but are sudden and massive, such as fluids becoming turbulent and metals becoming magnetized. Catastrophic bifurcation, a diverging of ways, propels a system toward a new state once a certain threshold is exceeded. Bifurcations may also mark the transition from a stable equilibrium to a cyclic or chaotic attractor.
Scientists use the term squealing or “variance amplification near critical points” to describe when a system moves back and forth between two states. “Every example of sudden climate change we’ve seen in the historical record was preceded by … squealing,” said Carpenter.
The most promising evidence of useful early warning signs comes from grasslands, coral reefs and lakes. Vegetation-pattern-based early warning signs have been documented in several regions, and transition theory is already being used to guide land use in parts of Australia. Marten Scheffer and other scientists discussed several early warning signals, behaviors that apply to all three systems mentioned.
“Critical Slowing Down” of Part of the System
When part of a system slows down, this might indicate that the system is “seeking to establish a new equilibrium,” says Tucker. Unfortunately, slowing down—or hesitation—can also reduce the ability of that system to adjust to fluctuations and efficiently accommodate them. For example, when a large ship slows down, its ability to steer is undermined. Some suggest that this may have been one of the reasons the Titanic wasn’t able to get out of the iceberg’s way in time. In the financial world, moving investments away from risky bets (like stocks) into safer areas (like U.S. Treasury notes or Canadian bonds) can be construed as slowing-down behavior, says Tucker.
Cheyne-Stokes breathing (or ataxic breathing) characterized by periods of up to 45 seconds of no breathing at all (apnea) and followed by deeper and more frequent respiration as vital organs are deprived of oxygen and waste products build up, is an example of “slowing down” prior to a major shutdown (in this case death).
“Flickering” & “Squealing”
Scheffer et al. describe “flickering” as a “transient excursion” into alternative states. According to these researchers, flickering occurs when part of a system makes such a foray, such as before an epileptic seizure, the end of a glacial period, and in a lake that is about to shift to a turbid state. Flickering is triggered by both internal and external events and built-in feed-back mechanisms of that particular system.
A lake that is evolving toward advanced eutrophication may “flicker” between various “states” due to any number of triggers. A system’s consequential “collapse” may include a diverse set of triggers and vectors from nutrient loading, to algal blooms, oxygen depletion, fish kills and species monopolization. Certain climatic shifts and epileptic seizures may be presaged by flickering (Scheffer et al., 2009). For instance, the brain releases mild bursts of electrical activity minutes prior to an epileptic seizure. The sudden spike just before death in electrical brain activity when blood pressure is greatly reduced (the phenomenon known as “near-death experience”) is another example of flickering.
Too many investors buying “put options” contracts can also suggest “flickering” and imminent collapse. “Put options” let an investor back out of a stock purchase if the price declines significantly in a short time (usually 30 days). The volatility index (VIX), or “fear index”, tracks the number and price of put options. It is generally regarded as the most important indicator of a coming major event and a sudden jump in the price of options contracts is a good symptom of extreme investor fear. Sort of like watching rats congregate on a ship, ready for flight.
The Nature scientists noticed a potential climate change tipping point signal they called “squealing”: a sudden variance between two distinct states in a system. In a forest it may resemble the alteration between barren and fertile phases, before a drought takes its final toll on the woodland, transforming it to a desert (when monsoons won’t bring it back to life). Overfishing may cause increased fluctuations in fish stocks until they pass a threshold, at which point there are too few fish left to bring back the population—even if fishing completely ceases. In financial markets, sudden collapses may be preceded by heightened trading volatility. In climate, squeeling may involve increased variability of the weather—sudden shifts from hot temperatures to colder ones and back again—not unlike what we are currently witnessing. General instability follows and, at some point, the center ceases to hold. Examples of climate change tipping points include loss of the Arctic sea ice, or the release of methane from the melting permafrost of Siberia (Resilience Science; September, 2009).
Several scientists have asserted that our planet has already passed its tipping point for climate change. What exactly this means for life on the planet, is something no one can accurately assess or predict currently. It is too complex and relies on too many interactive variables.
References:
Keim, Brandon. 2009. Scientists seek warning signs for catastrophic tipping points. Wired Magazine, September 2, 2009.
Schroeder, M. 1991. “Fractals, Chaos, Power Laws: Minutes from an Infinite Paradise”. Freeman.
Sheffer, Marten, et.al. 2009. Early-Warning Signals for Critical Transitions. Nature (September) 461: 53-59.
Tucker, Patrick. The Science of Tipping Points. The Futurist (Jan-Feb): 6-7.
Resilience Science (September, 2009). Responses to Early Warning Signals for Critical Transitions paper.
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