2011/03/14 08:30 Marten Scheffer, "Resilience Revisited", Resilience 2011, Arizona State University

Resilience 2011 --  Resilience, Innovation and Sustainability:  Navigating the Complexities of Global Change -- Second International Science and Policy Conference -- March 11-16, 2011

This digest was created in real-time during the meeting, based on the speaker's presentation(s) and comments from the audience. The content should not be viewed as an official transcript of the meeting, but only as an interpretation by a single individual. Lapses, grammatical errors, and typing mistakes may not have been corrected. Questions about content should be directed to the originator. The digest has been made available for purposes of scholarship, by David Ing.

Lunchtime speaker will be Jared Blumenfeld, from the EPA

Panels on water, energy, and social services

  • Synthesis between policy and practice

Mock court, panel 3 now in main room; flip with Navajo

  • Two perspectives:  diversity and learning

Introduction by Frances Westley

Marten Scheffer, Netherlands

  • Book, Critical transitions, is becoming a classic

[Marten Scheffer]

What is resilience?

  • Many interpretations, could be a strength
  • Will go through different interpretations
  • Different understandings as Buzz Holling went through change

Resilience means embracing change and transformation over time

  • However, Estee Lauder Resilience Lift Extreme means trying to preserve the same
  • There are ways of measuring this

Best people to talk to are engineers

  • The speed at which a system will return to its original state, when you challenge it
  • A resilence system bounces back quickly, otherwise will take time
  • Can measure it

Is this useful for describing complex systems and ecosystems?

  • Just bouncing back to the original state in nature, there are many examples of systems that wobble around, and then jump to a different regime
  • Organism, used to have 1000s per square metre, then had a regime shift, a change in the system not bouncing back to the original state

Regime change happens in financial markets

  • Shifts happen in states
  • The climate changes, we live in the holocene, as compared to longer history of jumping up and down, then 10,000 year constancy
  • Had a jump of 9 degrees

Life on earth: millions of years of little change, but 6 major changes with extinctions within a short time

Wonder why it happens

Similar things happen to big systems:  impact of meteor

  • When have a big change, want to know who did it

Salvador Dali a fan of Rene Thom, a mathematician, catastrophe line

Holling in 1972 made an observation:  for ecosystems, that might be relevant

  • Not just returning to equilibrium
  • If have catastrophe line as a function of conditions, then the system state will change
  • There could be multiple stable states
  • If the landscape gradually changes, the state will only change gradually, but then the basic of attraction is very small, and will only need a small perturbation to change to another stable state
  • Chair tipping:  Don't see change over time, but the system becomes fragile, so if a mosquito lands on it, and then it tips

Prediction of changes in systems is hard, because don't see the underlying fragility coming up

  • Scheffer, Carpenter, Walker, Foley and Folke, 2001, Nature

Sahara Desert was a lush region with lakes and pushes, can find hippos that show were different

  • How did change happen?
  • Can reconstruct through time series on ocean sediments off the coast of Africa
  • Desert dust Caluassen et al 1999 Geophysical Research Letters 26, 2037-2040
  • Trend line, with a huge drop

Challenge: how to predict critical transitions?

  • Extrapolation doesn't work

Can do stratistics, e.g. Adler 2001 Nature 414 480-481 to see the probability of a collapse of countries in failure

  • Doesn't work

Experimentation is good

  • Can do this with lakes, can study flips between turbids and clear
  • Can find many times, put phosphorus in one, take the fish out of another lake
  • Limitations on replicated experiments, can't do them on all systems

Alternative is to understand the past behaviour of the system

  • Go back, look at ice core data, looking at heating and cooling
  • Limitations, off the scale, don't have an analogous situation for what has happened in the past

If know how the system works, can create a model

  • Large global circulation models
  • To predict what will happen, it's tricky
  • People who create the models don't really believe them, too complex
  • Understand more and more, but can't predict critical transitions

Can we predict critical transitions, even if we don't understand the system?

  • No, there's always the mosquito landing on the chair

Ecological resilence?

  • Size of basins of attraction, find an indicator for shrinking of the basin of the attractor
  • Could try to look at the maximum perturbation that the system could take, to estimate the size of the basin, but this would destroy the system
  • Want to measure without destroying the system
  • Like a crystal vase that want to know how strong it is, without destroying it

Tipping points are fundmental properties

  • When there is a bifurcation point, they are universal
  • The details of behaviour across those points are the same across all system

Leads to the idea of general indicators of resilience

  • Drafted 2009 Nature Early-warning signals for critical transitions
  • As you move a system towards a tipping point, don't see the change, but the stability landscape changes, and can probe what happens
  • If systems is far away from tipping point, then slope matters
  • Critical eigenvalue
  • Critical slowing down, known in physics
  • Van Nees & Scheffer "Slow recovery from perturbations", American Naturalist 2007

Engineering resilience is an indicator for Holling resilience

  • Don't have to perturb the system beyond the tipping point
  • Will do some experiments on brains to see if can do something on migraines

Critical slowing down, Kramer & Ross in physics, but is too easy for us

Can we measure critical slowing down?  Can't perturb world or climate systems

  • However, all systems are perturbed continously
  • Always a stochastic regime shaking the system
  • Mathematics:  can show critical slowing down will result in an increased autocorrelation in time, i.e. yesterday looks more like today
  • Simulations:  close to tipping point, shows a different pattern with increased variance (which is generic) but also increased autocorrelation

Tested in models:  Lenton, Myerscough, Philosophical Transactions 2009

Carpenter Ecology Letters 2006, Rising variance, a leading indicator

Vasilis Dakos: Measured climatic transitions, PNAS 2008

  • end of Greenhouse Earth, Younger Dryas, Glaciation I, Glaciation III
  • Could see increased autocorrelation
  • Probably all related to earth systems reaching a tipping point

Nature, Drake and Griffen

  • See species driven to extinction, in the lab

Climate system?

  • Climate system is slow, now being pushed fast
  • Can't see in oceanic
  • Maybe can see with monsoons

Epileptic seizure:  length of time series needed

Also need data resolution

Spatial pattern may warn earlier

  • In equations, can switch space for time
  • In vegetation, before the system crashes, see larger patterns forming
  • Time signal early warning indicator, with spatial signals better
  • Desert vegetation, financial markets:  Dakos 2010, Theoretical Ecology

In science, easier with smaller things, or a lake

  • We want to understand the large, complex system

How can we understand the large things happening in systems?

  • Could we have seen the Middle East revolutions happening
  • Creating space for novelty, so new things emerge?  Are these important?  Part of systems resilience
  • We are in holocene
  • If we want to prevent climate change, we'll have to adapt, change in society required to prevent flipping out of the basic of attraction
  • Society trapped in current behaviour, hard to get out, happens at all scale
  • Don't want resilience in a poverty trap, want to push out of that
  • Hugely complex system, want to see change as part of resilience

Do we understand the system?

  • No theory is complete
  • We tend to accuse science as fragmented
  • Would like to find ways to unite, we need theories
  • Theories narrow the mind, and we don't see things in another way

Want Holism 2.0, a holy grail

  • People have always been holistic
  • Trying to understand with systems of beliefs
  • Now we have science, don't need vague visions
  • Science keeps us to partial views of the work
  • Not only connecting branches of science, but also not being stuck in particular worldviews

How to deal, not with the vague feel, but using the strength of the science

  • Not being trapped in any particular theory


What does it mean when a basin is deep and wide?

  • Almost all systems will have that connection
  • Things are rounded in nature, not square graphs
  • Most basins wil be rounded, then it's inevitable that they will become more shallow as we approach the bifurcation
  • Accepted models of nature, hard to not have that property

Fly landing on the chair.  What happens if it doesn't land, but there's a small wind on the chair?

  • Wind could help to reduce resilience
  • What is the perturbation, and the conditions changing over time?
  • Perturbation could be an elephant, e.g. killing 1000 elephants and see what happens
  • Continuum, could be a small hiccup

Indigenous people as holism 1.0.  What's the approach to holism 2.0?

  • Trapped in partial understandings of the world
  • Not only particular branches of science, but inevitable consequence of having a theory
  • Theory is good, then fall in love with it
  • Chamberlin:  Love makes blinds
  • Try to not be blinded by theory
  • When there are different interpretations of resilience, don't be sorry, don't be blinded

Thoughts on tradeoffs between resilience and fragility? Robustness?  Tipping the chair looks disasterous, but then afterwards, could be a better stable state

  • Original focus by Holling on the adaptive cycle
  • Can try to make the system resilience, building higher and higher dikes, but then when it fails, it's disastrous
  • Prevent small forest fires, but then the big one will be disasterous
  • Companies:  if want to be resilient, can make themselves strong, and want to be strong, and don't want hold hands so have small failures here
  • In science, trapped in theories:  theories are most comfortable, but most dangerous
  • Challenge: how to move with new information to be adaptive
  • Relies on thinkers who don't rely on theories, but it's difficult to get into journals with new ideas

Activists crucial in links between policy and science. e.g. James Hampson, talking about points on irreversible climate change.  Reflection on predictions on key scientists in climate?  Should we take away a sense of urgency?

  • Was at climate conference leading to policy conference
  • Gathering most of the important climate scientists, and policy makers
  • Sense that climate scientists were too laid back, no one wants to be accused of being an alarmist
  • Politicians upset about this
  • Living in a complex world, where merchants of doubt can have a large influence on the dynamics
  • From Frances Westley:  fear isn't driving people anywhere, novel expectations may be good for change
  • Sense of urgency is important
  • See lots of change, know about tipping points, but don't know where they are
  • Challenge for science is to be relevant, should be dispassionate
  • Buzz Holling visiting in Holland, many activists attending who thought should change:  Holling driven by curiosity
  • Still building on insights, but not curiosity about anything, curiosity about what's important