Are tipping points suitable concepts for developing environmental policies?

Large data analysis reveals pitfalls of focusing on abrupt ecosystem chances

UNIVERSITY OF OLDENBURG

IMAGE
IMAGE: THE STUDY BY HILLEBRAND AND CO-AUTHORS WARNS THAT THE REACTION OF NATURAL ECOSYSTEMS (HERE: A FLOODPLAIN FOREST IN LOWER SAXONY, GERMANY) TO MINOR ENVIRONMENTAL CHANGE SHOULD NOT BE UNDERESTIMATED. view more 
CREDIT: UNIVERSITY OF OLDENBURG

Many policies tackling the consequences of global environmental change rely on the concept of tipping points: If an impact, such as biodiversity loss, becomes too large, an ecosystem might flip into a different often less desirable state. This suggests that environmental pressures should remain below a certain threshold to keep the ecosystem in a safe operating space. An international team of scientists led by the biodiversity expert Prof. Dr. Helmut Hillebrand of the University of Oldenburg, Germany, is now questioning whether this concept is suited for developing environmental policies.

Using detailed statistical analyses of published results from more than 4,600 field experiments, the scientists found little evidence for thresholds. When focussing on tipping points, scientists and policy makers may thus risk overlooking the negative impact of gradual changes on ecosystems – with potentially disastrous consequences. The analysis has been published in the Journal Nature Ecology and Evolution.

Over the past years, many ecological case studies have been published that indicate the tipping behaviour of ecosystems. For example, coral reefs may switch into an algae-dominated stage if eutrophication is large enough to reduce the proportion of corals. This is why policy makers increasingly rely on thresholds to draft strategies for sustainably safeguarding ecosystems. “However, if such thresholds are to become the standard tool to assess global change, we should be able to show at which levels such thresholds might be”, says Hillebrand, director at the Helmholtz-Institute for Functional Marine Biodiversity at the University of Oldenburg.

The biodiversity expert and his co-workers therefore wanted to find out whether threshold levels can be identified from available environmental data at all or, even better, whether they can be predicted for different drivers of environmental change. “In order to develop environmental policies we need a general guideline”, Hillebrand points out. “But the problem is, that thresholds might be hard to detect in natural ecosystems when the anthropogenic change hasn’t been large enough yet. And we can’t determine thresholds for each process in each ecosystem.”

To get a better overview of how ecosystems respond to change, the scientists turned to experimental data derived from already published synthesis efforts – so-called meta-analyses. “This is a statistical method ecologists apply to summarise the general outcome of many field experiments”, explains Hillebrand, who is an expert in such synthesis efforts. In particular, the analyses look at the consequences of present-day but also future pressures, such as increased CO2 or nutrient levels. They also asses the functional responses of the ecosystems, such as changes in the cycling of elements or the production of biomass.

In total the authors used information from 36 meta-analyses, which cover 4601 unique field experiments on natural or close-to-natural ecological communities. This is the largest effort ever synthesising scientific literature on global change, according to the authors. Each experiment was characterised by a certain amount of pressure that resulted in a specific response of the ecological communities to this change.

Based on this the authors calculated the so-called effect size, that is how strongly a system responds. The researchers then devised statistical tools that allowed them to test whether the magnitude of response related to the strength of pressure. If this was the case, they investigated whether there was a certain amount of pressure where extraordinarily strong responses started to occur. “This change in the response would then indicate the presence of thresholds”, explains co-author Dr. Jan Freund, modelling expert at the Institute for Chemistry and Biology of the Marine Environment at the University of Oldenburg.

“The results of this analysis were stunning”, Hillebrand says. Whereas the vast majority of the 36 meta-analyses found that the strength of pressure affected the response magnitude, only very few (3 out of 36) showed statistical evidence for threshold transgression. However, the fact that thresholds did not emerge could still mean two things, Hillebrand points out: “The thresholds are either truly absent or they exist but they remain undetectable by our statistical approach”.

To elucidate this question, Julian Merder – a PhD student joining the project – simulated different forms of responses to global change, either with or without the presence of a threshold. When there was little statistical noise in the simulated data sets, the scientists were able to distinguish between cases with and without thresholds. “However, as soon as we introduced only moderate statistical noise, the thresholds become undetectable”, Merder points out. The statistical noise mimicked situations in the actual data, for examples different magnitudes of pressure needed for threshold transgression or different response magnitudes around the threshold.

According to lead author Hillebrand, this result has major implications: “If scientists cannot measure how close a certain ecosystem is to a threshold inducing a tipping point, how useful can then a regulation or policy be relying on such a threshold?”, he asks. Co-author Dr. Ian Donohue, ecologist at Trinity College Dublin (Ireland) adds: “I think we need to abandon the idea of safe operating spaces. It gives the completely erroneous impressions that small pressures do not affect ecosystems at all”. Rather, the statistical analysis of the data would demonstrate that responses to even the smallest change can be large.

“If we wait to see clear tipping points in response to any of the major human-induced environmental changes such as warming or biodiversity change, we risk overlooking the small gradual changes which sum up to a shifting baseline over time, that is a shift in the perception of what a healthy ecosystem looks like”, Hillebrand adds. In his view, scientists and policy makers should therefore rather focus on the size and lifetime of random fluctuations and their possible consequences to be able to act according to the precautionary principle.

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From EurekAlert!

48 thoughts on “Are tipping points suitable concepts for developing environmental policies?

    • This is a web page with the title of ‘Tipping Points’ – but it does not specify any.

      Instead, it gives a list of ’10 years to prevent disaster’ type scenarios, such as the Greenlands Ice-cap melting. These are not tipping points – they are hypothetical impacts. None of which, incidentally are at all likely……

    • The most dangerous tipping point has already been reached. The corruption of climate science by the IPCC/UNFCCC has tipped all science from conforming to the scientific method to conforming to a political narrative.

    • A tipping point was reached 12000 years ago, when the ice sheets started melting. They still are, at a reduced rate.

      • No, the ice sheets started melting around 20,000 years ago. By 12,000 years ago they were almost all gone.

  1. Anyone who has studied chaos theory for more than 5 minutes will tell you that the best you can do is to estimate a statistical probability model of tipping points. These are not mechanical constructs, where you can calculate where and when the tree will fall as you saw through it. Moreover, you cannot avoid them when they are baked into your environment. See Per Bak’s experiments with piles of sand.

    • Good point.

      Tipping points, versus incrementalism, or uniformitarianism, or whatever concept we would use in contrast, are really how nature works, in many ways.

      I add a heat source to a piece of paper. It heats up. Until it catches fire.

      I apply cold to liquid water. It gets colder. Until it transitions into ice.
      The game kerplunk.

      I add straws to the baskets on my camel’s back. Until its back breaks.

      I fire a pellet gun round at 350 FPS. 700 FPS. 950 FPS. No sonic boom to bother the neighbors.

      The dose makes the poison.

      The Progs are merely taking this reality of tipping points and building their Communist politics around this.

      This does not nullify tipping points in nature.

    • Mount St. Helens was a dramatic tipping point! I hope I don’t live to see the next tipping point in the Yellowstone formation!

  2. Hmmm….
    ““If we wait to see clear tipping points in response to any of the major human-induced environmental changes such as warming or biodiversity change, we risk overlooking the small gradual changes which sum up to a shifting baseline over time, that is a shift in the perception of what a healthy ecosystem looks like”, ”

    Isn’t that evolution?

  3. “an ecosystem might flip into a different often less desirable state. ‘

    Who decides what is desirable?

  4. The paper is arguing that since we cannot determine if a change will be good, we must assume change is bad. Even the smallest change. And since a whole lot of small changes add up to a big change, we must prevent even the smallest change.

    If one accepts this argument, then no human induced changes can be allowed. For example, a road through a forest cannot be allowed. Regardless of any benefits that might be realized.

    This is what is missing from the analysis. The emphasis on cost without considering benefit. in such a world, one would never step outside of the house, because of the risk.

    • “If one accepts this argument, then no human induced changes can be allowed.”

      That does seem to be the operating state for most modern environmentalists. Allow nothing, anywhere, at any time.

      On the other hand, getting rid of the works of man, even if those works have been in place for hundreds of years, is not considered a change.

    • ferdberple said : “The paper is arguing that since we cannot determine if a change will be good, we must assume change is bad. Even the smallest change. And since a whole lot of small changes add up to a big change, we must prevent even the smallest change.”

      This was my take-away too, I suppose it’s a logical conclusion to their myopic view of nature and it’s often remarkable and proven ability to adapt and evolve, and nowadays humans bend over backwards to help them with that adaptation.

      So using their conclusion against them, no wind farms (bird choppers), no hydroelectric production, no solar thermal plants or farms, and no biofuels as the environmental changes involved could be catastrophic, have I got that right?

    • ” in such a world, one would never step outside of the house, because of the risk.”

      Who would be allowed to build a house, for heaven’s sake?

  5. When focussing on tipping points, scientists and policy makers may thus risk overlooking the negative impact of gradual changes on ecosystems – with potentially disastrous consequences.

    So, they’re going for linear no-threshold. Niiice. It works so well for radiation. Not

    • Yes, I read that sentence too; several times; trying to make some sense out of it.

      My eventual conclusion is that what it means is: if we apply sufficient small changes then eventually the system (however defined) can end up quite different. ie it can change without ever having a “tipping point” in which the change is large and irreversible and obvious.

      I can’t decide whether that is a profound statement, or just a statement of the bleeding obvious !

      To qualify as science, a theory must be testable. If it is not testable, then it is not science it is just philosophical speculation. As MarkW says below, they carried a meta analysis of 36 meta analyses, and didn’t find anything useful. I’m not convinced that that approach qualifies as science. It seems to be little more than: “if we look at these 36 data sets can we draw any conclusions?”

      The answer was “No”, so they wrote it up in a way that they hope will make them look really smart guys, finding a general purpose get-out-of-jail-free card for any climate scientist to use when one of his predictions fails to come true (and at the same time giving them something publishable to use as the basis for appeals for further public funding for more “research”.)

  6. I am becoming very clinical about the direction of Science and the over use of models and statistics. What ever happened to getting out and studying the environment. I have not seen any “model ” that fully captures the complexity of the most simple system.

    • Beninger, P. G., I. Boldina and S. Katsanevakis. 2012. Strengthening statistical usage in marine ecology. J. Experimental Marine Biology Ecol. 426-427. 97-108. https://doi.org/10.1016/j.jembe.2012.05.020
      Beginning of abstract–
      “Although within their own disciplines, the statistical, social science, medical, and terrestrial ecology literatures are replete with accounts of the widespread misapplication and misuse of statistical testing and interpretation, awareness of these issues is weak among marine scientists who are not statisticians, but whose work is nonetheless situated within the expanse of marine ecology.”

      Too much literature to digest, takes more time than a model. Funny thing is that they must know something about stats to do a model??

      • Aren’t climate models proof of something that might be stated as
        “making a model requires some specific skills, perhaps especially computer software related skills, but does not require understanding the field of study for which the models are intended”?

  7. First line:
    “Large data analysis reveals pitfalls of focusing on abrupt ecosystem chances”

    Perhaps you meant “changes”?

  8. “used information from 36 meta-analyses,”

    So they did a meta-analysis of meta-analyses?

    Climate scientists don’t like to work with real data, do they?

  9. THE STUDY BY HILLEBRAND AND CO-AUTHORS WARNS THAT THE REACTION OF NATURAL ECOSYSTEMS (HERE: A FLOODPLAIN FOREST IN LOWER SAXONY, GERMANY) TO MINOR ENVIRONMENTAL CHANGE SHOULD NOT BE UNDERESTIMATED.

    Sounds like just an excuse/justification to scare-monger.

  10. I just came across a neat video on another interesting source of ‘diversity’ – frequency dependent balancing selection. It operates at many levels, from genes to ecosystems. All the ecological examples given concern tropical forests, and I wonder how it is expressed in our species poor northern forests.

    • The diversity of human life is a color judgment. For example, a class-based taxonomic system, process, or belief based on low-information attributes, not limited to racism, sexism.

  11. Quoting: “In his view, scientists and policy makers should therefore rather focus on the size and lifetime of random fluctuations and their possible consequences to be able to act according to the precautionary principle.”

    How in the world can we “focus on ..random fluctuations” and their consequences? If they are random (or Chaotic), they are still unpredictable. If they can not be predicted, how can we act “according to the precautionary principle”?

    • It’s deterministic or stochastic within a limited frame of reference (the scientific logical domain). It is chaotic or nonlinear, not differentiable, and, from our perspective, discontinuous, outside, due to incomplete or insufficient characterization and unwieldy computations. Random can be modeled, and estimated with statistics. A prototypical example of a chaotic process is human life. From our perspective, a scientific perspective, we know the beginning: conception, and the end: death, perhaps a progressive decomposition of coherent function, but, because of the semi-stable system (e.g. quasi-isolation, independence from the environment), we can forecast and predict our function in the interim.

  12. The use, by Climate activist progressive liberals (which certainly does include the UN organizations (UNFCC) along with countless economists in publishing papers of theoretical studies of tipping points), of “tipping points” is unjustified and improper and aim to attract others to point of view. The tipping point is defined by the outcome and not the likelihood of occurrence and is defined in the abstract to garner attention by back calculating the impact of some theoretical event. If the event in question has actually occurred in the past it can be considered a legitimate case but otherwise it’s a theoretical abstraction done with a purpose in mind. In short, we should stick to “science” not fiction writing.

  13. The article states, “If an impact, such as biodiversity loss, becomes too large, an ecosystem might flip into a different often less desirable state.” There is no definition of what a desirable state is. The unstated assumption is that the preexisting state is the desired one! There is a strong conservative bias against change inherent in that assumption. Funny how political progressives often have conservative attitudes about Nature.

  14. The notion of “tipping points” arose in the social sciences and is being misapplied to the earth sciences. Some scholars have looked at the limited usefulness of this importation.

    “The increasingly frequent use of the concept of tipping points in both the natural and social sciences could be scientifically questionable: sociological and political tipping points might be very different phenomena than climatic tipping points, even if both natural and social systems may be subject to rapid qualitative change. If institutional tipping and ecosystem tipping are different ‘things in nature’— different ontological entities—scientific language should not treat them as the same. Scientific language should clarify rather than veil potential differences between tipping points in different fields.”

    “Phenomena in nature—the objects of tipping point research Different fields of science deploy tipping point terminology to study vastly different real-world phenomena. In the natural sciences (Ecology, Climate and Earth System Science), scholars are primarily interested in the tipping of ecological systems, e.g. the eutrophication of lakes, and of larger Earth System components, also called climate tipping elements (e.g. Arctic ice sheets). This research crosses multiple scales of interest, but focuses on a shared mechanism of change: positive, self-reinforcing feedbacks moving a system into a different stability domain. Key research challenges include the limited reversibility of a system to its previous state and significant predictive challenges related to tipping points.”

    “Gladwell’s argument, like all pseudoscience, is a closed loop–if something tips then it hit a Tipping Point; if it doesn’t, then it didn’t. Rather than explaining what happened, the metaphor, once accepted, stifles intelligent analysis. The fact that something happened comes to seem a sufficient explanation and a justification for saying that the process occurred; the actual elements of this theoretical process need never be demonstrated, nor tested; it’s as if the circular beauty of the metaphor precludes questioning its validity.”

    Finally, as the critique shows, tipping points are like climate change itself: Applying labels to something that has already happened, with no predictive utility.

    https://rclutz.wordpress.com/2019/12/04/tipping-points-confuse-social-and-earth-science/

  15. In climate change junk science a tipping point is someone’s wild guess of when something bad will happen, used to frighten people who think it is real science.

    In real life a tipping point is when a patron at a bar has had too much to drink and falls off the bar stool. Our moderator, whose office is a bar stool, is writing a book on this subject. He expects it to be a best seller.
    Moderator bait.

  16. “Tipping Points” only make sense when based on actual science – not modeling, guesswork, or hysteria. It is next to impossible to predict most natural “tipping points” because nature is very chaotic in behavior.

    If it has been scientifically observed and measured in the past, then your odds of getting one right go up. If proxies and especially models are used, your odds go way, way down as most proxies are not nearly as simple and straightforward as the people using them think they are and models are just a bunch of guesswork until tested and adjusted for all the things they get wrong.

  17. Observation shows that earth’s climate is extremely stable with historical evidence of only two states, namely glacial and inter-glacial. There is no historical evidence of a tipping point to a distinctly hotter regime and such a hotter regime is likely impossible in the astronomical short term (Milankovich) because of the Stefan-Boltzmann equation. Fabled tipping points to a hotter regime are the deus ex machina of climate alarmists and their gambit goes hand-in-hand with the vile “precautionary principle’.

  18. Such a profound concept, the tipping point.

    Lean too far, tip over.

    Can you grasp that? OK, then you’re ready for this extraordinary piece of deep wisdom:

    Things tip over, therefore climate change.

    Next week: how to get out of bed.

  19. “If we wait to see clear tipping points in response to any of the major human-induced environmental changes such as warming or biodiversity change, we risk overlooking the small gradual changes which sum up to a shifting baseline over time, that is a shift in the perception of what a healthy ecosystem looks like”, Hillebrand adds. In his view, scientists and policy makers should therefore rather focus on the size and lifetime of random fluctuations and their possible consequences to be able to act according to the precautionary principle.
    ________________________________________________

    The one and only, ready made in the Greek Iron Age found answer

    to the newly called “tipping points desperate searched for” question is, Tata:

    https://www.google.com/search?q=catastrophe+meaning&oq=catastrophe+&aqs=chrome.

    ________________________________________________

    The good news is – Environmentalists never stop searching troubles.

  20. My fault – searching, troubles –>

    “If we wait to see clear tipping points in response to any of the major human-induced environmental changes such as warming or biodiversity change, we risk overlooking the small gradual changes which sum up to a shifting baseline over time, that is a shift in the perception of what a healthy ecosystem looks like”, Hillebrand adds. In his view, scientists and policy makers should therefore rather focus on the size and lifetime of random fluctuations and their possible consequences to be able to act according to the precautionary principle.
    ________________________________________________

    The one and only, ready made in the Greek Iron Age found answer

    to the newly called “tipping points desperate searched for” question is, Tata:

    https://www.google.com/search?q=catastrophe+meaning&oq=catastrophe+&aqs=chrome.

    ________________________________________________

    The good news is – Environmentalists never stop searching. For. Troubles.

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