Fighting through the static to detect real environmental and climate trends. Part I

Posted by on August 17, 2016
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Donald Trump, that peculiarly coiffed symbol of our collapsing ability to think rationally, has called repeatedly for a ban on entry of Muslims to the United States “until our country’s representatives can figure out what is going on.”  In saying so he is admitting that it can be difficult to discern what is happening in our complex world.

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Donald Trump; not known for the impeccability of his logic.

While Trump reveals little evidence of attempting to figure out anything more complex than how many words can fit into a tweet, I believe that we all face an increasingly difficult task if we attempt to figure out what is really happening in society, in politics, in international relations, or in almost anything else.  This difficulty extends to our attempts to interpret reports of scientific advances, whether we rely on secondary sources such as the media, or go directly to the technical reports in the scientific literature or presentations at conferences.

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It is not surprising that many people get confused about climate change.  It is a complex, long-term, broad-scale, slow-acting change, and the diversity of messages about it is sufficient to numb many minds.

I don’t think for a moment that this difficulty is solely responsible for what may be a growing problem in translating scientific understanding into sound policy.  However, I think we have an unrecognized problem in understanding what science is telling us, and that problem is growing.  I’ll not spend time on what are now highly politicized controversies, such as whether or not climate change is occurring, whether it is possible to largely eliminate our burning of fossil fuels without collapsing the global economy, or whether our growing pressures on the biosphere are pushing the Earth system outside planetary boundaries that define the limits within which it can continue to function ecologically.  Instead, I’ll consider some ‘smaller’ questions from the world of coral reefs; ones that might be considered more tractable, less politicized, more readily answerable.  I’ll propose some reasons for our difficulty in “figuring out what is going on”, and I’ll close with some suggestions for what scientists could do to better ensure the public gets access to accurate, up-to-date science.

Has the recently ended el Niño resulted in substantial damage to coral reefs worldwide?  I think most people who follow environmental news would answer ‘yes’, but if asked how substantial that damage has been, the responses would cover a broad spectrum from ‘it’s happened before, and it will happen again’ to ‘this is just the latest nail in the coffin of coral reefs as a living ecosystem on this planet’.  Most people would be hard-pressed to specify the extent of mortality of corals, or any other quantitative measure of the extent of the impact, yet they would differ widely in evaluating its severity.

If the discussion moved to more specific questions concerning what may or may not be happening to coral reefs, responders would reveal similarly fuzzy yet quite divergent views.  Are the consequences of ocean warming for coral reefs since 1981 (the first, well-documented mass bleaching events in Panama and the Galapagos) the largest anthropogenic threat to their sustainability?  Will corals evolve greater tolerance to warmed water?  If we reduce other stresses on reefs from overfishing and pollution will that confer on them a greater capacity to withstand warmed water?  Is the propagation of coral fragments in nurseries for planting out in locations affected by bleaching an appropriate solution to the effects of warming on reefs?  Views on the societal consequences of loss of coral reefs will be equally wide-ranging, even among those individuals whose own experience makes them best able to evaluate societal benefits of coral reefs.  For many people outside the research community, of course, many of these more precise questions would fall outside the range of topics on which they could form views of any specificity at all.

northern GBR bleaching COE image[11]

The recent bleaching of the northern Great Barrier Reef, the worst in its history, raises difficult questions about whether good local management of reefs confers protection against (builds resilience to) effects of ocean warming.  The true extend of the damage, in terms of coral killed, is not yet known because mortality due to the bleaching is still taking place.
Photo © ARC COE Coral Reef Studies.

The present is a time in which more scientific discoveries are being made than ever before.  Information about those discoveries, whether the technical reports by the scientists making the discoveries, or coverage of them in the general information media, is more available, to more people, than ever before.  And commentary on the discoveries is extensive in both print and electronic media, readily accessible by anyone with access to the web.  Yet, as the availability of information grows, the clarity of messages gets diminished, and people find themselves listening to a cacophony of mixed messages, unable to extract any coherent theme.  Why is this so?

I think this wide-spread perception of a static-filled, cacophonous stream of messages about the environment has several causes that act additively, or perhaps even synergistically.  Some are specific to scientific questions, while others apply to other types of messages that we attempt to decipher.  In this post, I will talk about the nature of science, and the nature of human thought.  In a subsequent post, I’ll discuss how the scientific endeavor is changing, and the role of the media in communicating science.  Then I’ll tie it all together with some comments on a recent pair of articles dealing with global patterns of coral reef degradation.

The nature of science

To begin with, there is the nature of the scientific process, a process of creative destruction of one hypothesis after another.  Science proceeds by inventing hypotheses to explain observations.  Then further observations and experiments are done to ‘test’ each hypothesis.  Testing is an effort to prove the hypothesis incorrect, and when a hypothesis falls, a new one, or better, several new ones are created to take its place.  The creativity of science lies in a scientist’s ability to imagine novel explanations (new hypotheses), and in his/her capacity to design experiments or observations that potentially can prove a hypothesis incorrect.  This strange approach to building understanding has evolved because you can never prove, beyond a shadow of a doubt, that an explanation for an observed phenomenon is correct.  You can only prove it is not correct, or at least, that it is substantially unlikely to be correct.

Nor do scientists work in isolation.  A ‘hot’ topic will be being explored by multiple scientists in multiple labs testing multiple hypotheses.  The process of building scientific understanding is done by many scientists working collaboratively, cooperatively and competitively, and while it is not quite as messy as the sausage making that is politics, it is not a straight-arrow path towards ultimate truth.  At any moment there can be multiple explanations for the observations or processes being studied.  Looking at the results as they appear, hot off the press, or even earlier, as they are announced during conferences, or even sooner as they are tweeted, posted, or e-mailed among colleagues presents the outsider, seeking to understand, with a lot of red herring ideas destined to fall when the next set of experimental results shows them to be wrong.

Complicating this picture slightly is the fact that scientists generally work within conventional paradigms – sets of related ideas about how the world works that have stood the test of time and represent the conventional understanding of the community to which a scientist belongs.  Such internally coherent sets of not-yet-disproven hypotheses provide the essential framework on which scientists build their new ideas.  Usually, all is well and the paradigm persists, becoming continuously strengthened by new observations and experiments.  But sometimes paradigms collapse when the evidence against their weaker links becomes sufficient.  Because scientists want to believe they are building on a sound foundation of established understanding, there is often a tendency to cling to paradigms that should really be radically revised or put aside.  When such paradigms are eventually discarded, the change in understanding of the system can seem sudden and profound.  This adds to the non-linearity of scientific progress.

As an example of what I mean, coral reef science is currently witnessing a minor paradigmatic readjustment in connection with the control of the competition between corals and algae.  Before saying more, I must digress to talk about reef ‘health’.  A coral-dominated reefscape is highly productive, highly diverse, and can support lots of people through the fishery products it yields.  For some or all of these reasons, people mostly value reefs of this type.  Conversely, there are reefs with very little living coral now present, which are dominated by fleshy macro-algae (macroscopic seaweed growing attached to the substratum, not algal symbionts living within corals or phytoplankton in the water column).  These support less biological diversity, and seem to be less productive – both primary production and production of fishery products.  Mostly we consider reefs of this type less desirable.  We call the coral-dominated reefs ‘healthy’ because we value them, and we speak of ‘degradation’ if a coral-dominated reef changes to become dominated by algae.  This use of the word ‘health’ has nothing to do with disease, and everything to do with subjective value judgements.  There is no agreed way to measure this ‘health’, but we know it when we see it.  On such silty concepts, coral reef science is built!

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Most reef scientists, and most people, prefer coral-dominated reefs such as the one on the left to algae-dominated reefs like the one on the right.  We call coral-dominated reefs healthy.  If I were a fish that fed on algae, I’d likely prefer the one on the right.  Still, since we prefer the coral-dominated ones, it’s OK to explore why such reefs sometimes become algae-dominated.
Photos of Line Island sites © Scripps Institution of Oceanography.

Getting back to corals and algae, both corals and fleshy algae need space on the reef in which to grow.  Most reefs that we would consider ‘healthy’ are dominated by corals with algae quite sparse, but sometimes ‘degraded’ reefs, low in coral cover, become heavily dominated by algae, to the extent that corals can be effectively excluded.  This occurs either because their larvae cannot find suitable places to settle and attach, or because they die weeks after settling because they are shaded out by algae early in juvenile life.  Observations  and experiments beginning in the 1980s, particularly though not entirely in Jamaica, where reefs had been severely overfished, led by the late 1990s to what seemed a robust model, a paradigm of the regulation of the conflict between corals and algae.  This model was generally supported in reviews up until recently.

bolbometapon UC Berkeley

Not the most beautiful parrot, but Bolbometapon muricatum, the bumphead parrot fish is the largest, most voracious grazer on Pacific coral reefs.
Photo © UC Berkeley

In essence, this model considers corals, algae and herbivores as three actors in a classic, top-down regulatory process, in which herbivory limits algal growth permitting coral dominance.  Loss of herbivory allows algae to grow in abundance, shade out corals, and take over living space.  The result is a rapid phase-shift from coral-dominated to algae-dominated reef.  The management inference drawn is to protect herbivorous fishes from overfishing, as a way of preventing reefs becoming dominated by algae.

This model is attractively simple and easy to understand.  With just three actors, there are only three states and six interactions to worry about.  It ties an ‘undesirable’ change in a reef-scape – the phase-shift to algal domination – with a simple, feasible management action, controls on fishing of parrotfishes.  It is a hypothesis potentially explaining many examples of phase-shifts in the Caribbean, while offering an understandable, new argument for controls on the frequently rampant overfishing.  Perhaps not surprisingly, it became simplified into a useful new axiom for reef managers: cut fishing of parrotfishes and prevent algae from overrunning your reefs.

Meanwhile, scientists were noting that the world was not quite so simple as this model presumed.  There are many species of corals, algae and herbivorous fishes, and they do not act identically.  There are many overfished reefs in the world that have not undergone a phase-shift to become dominated by fleshy algae.  There are some reefs, for example the Abrolhos Reefs of Western Australia, in which corals flourish along-side abundant fleshy algae and abundant herbivorous fishes.  Even in the Caribbean sites that had provided the data that led to formulation of this model, many other changes had taken place in the past at the same time as fish were being over-exploited.  Reality did not simplify into the three-actor system of the model.

There are still reef managers (and reef scientists) advocating restrictions on the fishing of herbivores like parrotfishes as a useful tool for maintaining coral reefs in ‘healthy’ condition.  Undoubtedly, curtailing over-exploitation of reef fishes will be useful in places where they are heavily fished – for fishery economics (higher catch per unit of effort), for fish conservation, and for the suite of ecosystem services that fish provide to a reef, including, in some cases, control on algal abundances.  But the simple, three-actor rule is now seen by a growing number of scientists and managers as not based on rigorous scientific understanding.  Reefs are complicated places, and this model was too simple!  That it ascended to prominence and endured as long as it did is testament to the notion that science stumbles towards the truth.  Science is not choreographed.

The way people think

One of Marshall McLuhan’s less well-known aphorisms is “If I had not believed it, I never would have seen it.”  Artfully, he captured a fundamental truth about human thought processes.  The nature of human perceptual abilities and thought processes is a second factor making scientific discoveries difficult to interpret and understand.  We do not see what is in front of us, and we do a lot of interpreting of the sensory stream.  We think dichotomously, in black and white instead of in the shades of gray that reality presents to our senses.  We emphasize edges and discontinuities as a way of classifying the information stream into discrete categories, such as all corals, all algae and all herbivores, while avoiding the rich detail in the raw information.  As well as simplifying in these ways, we are only really able to count to three or seven (depending on which psychologist you believe), so that few of us can think about more than one or two processes at a time, even when we know we are dealing with complex environmental systems involving many different actors and numerous interactions.  Finally, we only think short term, and we shift baselines continuously, so that long-term, gradual processes and changes are not even noticed.

It is only since the global bleaching episode of 1997-8, or perhaps the die-off of Diadema sea urchins across the Caribbean in the early 1980s, that coral reef ecologists have begun to recognize that the reefs of the world could be travelling on a long, slow journey from the state(s) they were in in the 1950s to the state(s) they will be in in the 2050s and beyond.  (I know I was not the only coral reef ecologist in the 1970s who assumed that the processes he was unravelling were ones that had been operating on reefs long before humans arrived on nearby shores, and would continue operating into the future.)  Reef geologists do a somewhat better job of thinking about deep time, which is one of the reasons it is good for reef ecologists and geologists to talk to each other.

Come to think about it, back in the 1970s, when I was doing field research which led me to emphasize the lack of predictability in outcomes of competition for habitat among territorial reef fishes, I had to struggle hard to prevent my colleagues characterizing my ideas simplistically,  They tended to characterize my work as claiming that ‘competition among territorial reef fish species is a chaotic process’ as opposed to the conventional view that competitive interactions among coexisting species were tightly structured as hierarchical systems with predictable winner and loser species.  They were thinking dichotomously, and were simplifying my message into something it clearly was not, and some never did see what I was trying to say.

I see this as my failure, even though I tried very hard to state my ideas explicitly.  We argued back and forth for a while, but fortunately, the discovery that, much of the time, territorial reef fish were not being limited by a shortage of space, even though they fought aggressively over space, seemed to be using all available space fully, allowed us to end that controversy gracefully, while conveniently neglecting that none of us had previously suspected that there could be unused resources on a reef.  We glided gracefully to a new model!

We all turned our attention to recruitment limitation – the idea that the delivery of larval fish to reefs is normally insufficient to saturate the resources available on the reef.  In such circumstances, multiple species, using the same reef resources can coexist indefinitely without one out-competing the others.  (And of course, there were some among us who persisted in believing that recruitment was ‘always’ sufficient – I sometimes wish I lived in such an orderly universe.)  Still, I fear that today, should someone want to go back and figure out what so many reef fish ecologists were arguing about back then, they would have a difficult time interpreting the publications that appeared.  We certainly were not moving linearly towards ultimate truth.  Only with knowledge of the people and the ideas could a clear story be told (and that knowledge is disappearing as each year passes).

These seldom talked about features of our ways of thinking mean that we are all continuously shaping the information we receive, fitting it into our own personal view of reality.  Further, while some of us like to think that we are rational beings, our evaluation of information we receive – whether a new technical report, a media news item, or something conveyed by a friend in an e-mail – is not completely logical.  Emotional responses, subconscious preferences lodged deep in memory, and logical analysis all play their roles, and we are all capable of simultaneously holding contradictory opinions.  What we notice is colored; so too is how we understand it.  We don’t all see the dancing gorilla in the center of the room.  To make effective headway in understanding the science that is being reported, we have to work hard to minimize the filtering and coloring that our own ways of thinking introduce.

Coming next, the changing nature of science and the role of the media.

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This still from a Youtube video demonstrates our failure to experience what is in front of our eyes.  Any wonder that we do not always grasp the significance of complex scientific data?
Image and video © Daniel J Simon.

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