Thursday, January 21, 2016

Book Review: Disaster Ecology - the bright side of disaster

Seth Reice: The silver lining, the benefits of natural disasters, Princeton University Press 2001, 213 pages, index, photos, graphics.

"The elaborate environmental management system we have created is grounded in an archaic, misguided belief that disturbances are evil and that nature must be controlled. Our history of attempting to control - indeed, to dominate - nature has led to many of the problems we now face.", page 192

                                          wetland meadow with wild irises

           The thesis of prof Reice's book is simple, if revolutionary. Much of what we call "development" or "improvement" (on nature) ain't! We believe we are "improving" on nature when we drain bogs, swamps and marshes and straighten rivers and divert their flow to irrigate crops. We believe that we are reducing economic losses when we erect dikes to contain rivers prone to annual flooding. We believe that, despite the cost and effort of these projects, we gain more than we lose: we expect a positive "return on our investment". Such beliefs reflect, of course, our cultural ideology of faith in Progress (see note 1).

            But is our naive belief in Progress warranted? The state of our global environment tends to suggest otherwise. 

 Half the wildlife has gone missing in the past 40 years?

Guardian: earth-lost-50%-wildlife-in-40-years-wwf

Half of earth's fish stocks have gone missing in the past 40 years?

       Prof Reice teaches Disaster Ecology at the University of North Carolina. Disaster Ecology studies the impacts, positive and negative, of natural or human disasters on ecosystems, their structure and dynamics. The results of this research are surprising, often counter-intuitive.

"Disturbances help generate the mosaic makeup of the habitat. A fire burns out a patch of forest and open it up to sunlight. Now, small plants, which had been suppressed by the shade of the trees, can thrive, and then a meadow can develop. Every organism is uniquely adapted to a particular type of habitat and a diverse array of habitats can support many more species than a uniform habitat. A variety of habitat patches, in turn, supports a diversity of species and communities. This biodiversity is the foundation of the natural ecosystem services upon which all life depends. Contrary to common thinking, disturbances are not bad, but rather they are valuable - indeed, they are essential for healthy ecosystems.. The nature of nature is change." Page 3 (emphasis added)

            Natural "disasters" therefore possess a hidden - unsuspected - face. They, paradoxically, are necessary for the optimal functioning and resilience of many, if not most, ecosystems. In extreme cases, some ecosystems actually require quasi-periodic "disasters" - fire, flood, storm damage.. - in order to exist and persist over time. The dominant tree species in some conifer based forest ecosystems have died off as a result of human attempts to suppress forest fires. The trees require singeing heat to release seeds from pine cones; the seeds, in turn, may require a forest floor free of competing vegetation and covered in mineral rich ash in order to germinate.

plants requiring fire to germinate: chapparal

                           Lodgepole pine cone needs fire to open and germinate

                It is now evident that such ecosystems evolved with, through and by their interaction with fire. Robbing them of essential, quasi-periodic fires leads to their decline and death (replacement by competing forms of vegetation and their associated ecosystem types) Since the original - fire-evolved - ecosystem was optimally adapted, through aeons of evolution, to the regional climate, local micro-climates and hydrology, primary biological productivity will fall off. Species diversity will drop, some locally adapted species may go extinct. The new ecosystem created by well intentioned human attempts to "improve on nature" will likely be less resilient, less robust in its response to major disasters in the future. This should be a cause for concern in a world challenged by anthropogenic climate change. Now, more than ever, we need healthy ecosystems to withstand the coming changes. Instead we weaken the surviving ecosystems we have left..

              Disaster Ecology teaches that what we call "natural disasters" are actually part of the normal functioning of ecosystems. Suppressing disasters - with dikes, dams, irrigation, fire suppression - disrupts ecosystems, weakening, sickening, even destroying them. The "ecosystem services" provided by these ecosystems - clean air, clean water, fertile soil, natural crops (wood, fish, game, mushrooms, berries..) - will suffer as a result of our meddling. The result of "improvements" can be, paradoxically, increased economic losses, increased risks to life and the aesthetic deterioration of natural scenery. Natural fish stocks may plummet, wiping out livelihoods and forcing migration of impoverished populations. Floods or fires may be reduced in frequency but, when they do inevitably occur, will be devastating holocausts in terms of lives and economic losses.

            It is only with the last few decades that ecologists have grasped the essential role of natural disasters in promoting ecosystem health, diversity, productivity and resilience. Much of our thinking has undoubtedly been influenced by the Darwinian Evolutionary School and their battles with the Creationist of their time. 

            Religionists argued that Bible stories of the Creation, the Deluge and the promised Kingdom of God at the End of Days were confirmed by the "episodic" nature of fossil strata. The fossil record seemed to indicate that the world's history was divided into Epochs, each stage initiated and terminated by Divine Intervention. Some argued that the "antediluvian monsters" were punished by God for sin of greed: God allowed them to perish in the Deluge. Others held that dinosaurs were simply too big to fit on Noah's ark..

                Darwin and his followers were, in retrospect, seriously hemmed in by ideological constraints. To differentiate the emerging "scientific worldview" from "creationist obscurantism", the Darwinists contended that the processes of nature were slow and steady, change was gradual. There was no need to seek Divine Intervention in our attempt to understand - and control - nature. Human reason, science, would eventually prove competent to explain / control human destiny. God was, in their eyes, an "unnecessary hypothesis" (Laplace).

               Today, with advances in the earth and life sciences, we have come to understand the Darwinian / Creationist debate of the 19th century in a new light. We see that the Creationists were right but for the wrong reasons. Nature is violent, the earth's biological history is episodic but God had no hand in all that. The Darwinists were wrong but for the right reasons: nature's "gradualism" is punctuated by periods of accelerated - even catastrophic - change but the hand of God is, indeed, nowhere to be found.
               Unfortunately, our treatment of nature remains founded on false "equilibria theories" inspired by wrong-minded Darwinian gradualism. Ecology itself has utterly failed till recently to understand the creative roles "disasters" play in healthy ecosystems. The economic and sociopolitical consequences of our misguided conceptions of nature are now becoming increasingly disastrous in their own right..

              For example, it is now known that only a small fraction of the species capable of living in a space actually live there. Why? Darwin's "survival of the fittest"! Competition between species competing for the same ecological niches actually tends to reduce biodiversity as the species best adapted to local conditions drive their competitors out of business. This, in turn, has unfortunate consequences given nature's catastrophic tendencies. If predator species A, B and C compete for the resources of a locality and A is a bit better adapted, A will tend to drive out the other two. Then comes a spate of bad weather, a random or periodically occurring fluctuation in regional climate. What happens to the ecosystem if it turns out that species A - the winner of the Darwinian survival sweepstakes - is "overspecialized": it eliminated its competitors, recall, exactly because it was better adapted to local conditions. But now these conditions no longer hold! If B and C were still present they, in theory, might possess capabilities of adapting to the new conditions (each species has its own skill set..) Alas! B and C are gone and now, under changed climatic conditions, A bites the dust too. If A was a "keystone species" - the bit that holds the whole ecosystem together (say, because it prevented herbivores from overgrazing..), then the entire ecosystem will collapse, biomass productivity will fall precipitously, many species will die off in a "domino effect" cascade. The disappearance of key plant species - from overgrazing by goats in arid environments - may result in catastrophic degradation of the soil with attendant aridification and terminal desertification. In our example, all this might have been avoided  with a more diverse selection of apex predators - to control those overgrazing goats.. Moral: lack of biodiversity kills! 

              Interestingly, natural disasters maintain essential, resilience building biodiversity. Disasters build diversity in several ways. By eliminating competitors in a small region, disasters allow "migrants" from neighboring regions to enter and set up shop. In the case of aquatic ecosystems with flowing water (river, seas coast), the migrants may arrive from quite a distance but formerly were not equipped to deal with a dominant species, fortunately now greatly reduced in numbers. A quasi-regular regime of disaster (recurrent flood, fire, drought, frost, deep snow..) tends, therefore, to maintain biodiversity as it prevents any one species from establishing a monopoly. This, in turn, enhances resilience, the capacity to rebound after a disturbance. A biologically diverse ecosystem has more cards in hand hence more hands to play - more adaptive options to play..

             Increased biodiversity has other advantages than increased resilience in the face of disturbance. By increasing the number of species "working" the land, more ecological niches are created with a generalized increase in total annual biomass production. Diverse ecosystems are more resilient and productive and because there is more biological activity going on. They are better able to provide vital ecosystem services such as water retention and purification, soil production and retention, nutrient transport, etc.

              Natural disasters tend to increase biodiversity in both space and time. In space, because disasters tend to fragment and break up ecosystems. A flood will produce different degrees of inundation with differential impacts depending on land elevation. A quasi-regular regime of flooding allows different micro-ecosystems to establish themselves and flourish, boosting biodiversity, bioproductivity and resilience.

               In addition, regular flooding provides essential nutrient transport into wetland ecologies, again boosting productivity and diversity. If humans with good intentions prevent regular flooding, reduced nutrient transport will reduce productivity, fish stocks may collapse and fisherfolk starve or be forced to move elsewhere. Some species may disappear completely if they require flooding to migrate or procreate..

               I should point out that prof Reice is not a romantic Luddite tree-hugger. Some human interventions in nature screw things up, others don't. Some interventions - if based on adequate ecological science (and a bit of dumb luck) - may actually enrich natural ecosystems by increasing soil fertility or biodiversity. On the whole, Reice's message is a positive one: humans can learn to live with nature and both parties can thrive.

              Prof Reice proposes several measures which could alleviate some of our more pressing concerns. We could, for example, begin ecological zoning of land use. Insurance premiums should be keyed to ecological reality and take into account the risk of recurrent flood, forest fire, storm surge or drought. Such enlightened policy would discourage building in ecosystem which require periodic disasters to flourish and rejuvenate. Already progress is being made on this front.

infrastructure for extreme weather / Swiss RE 

             Swiss RE is a major "reinsurer", an insurance company which insures insurance companies. This "spreads out the risk" and prevents the smaller client companies from going under if they have to make massive pay outs following a major disaster. Such disasters are becoming more common due to climate change, so it is in Swiss RE's interest to encourage its clients (smaller insurance companies) to adopt enlightened insurance policies.

             Returning wetlands to their natural state in some places will actually result in reduced economic costs since wetlands act as natural buffers against flooding and coastal storm surges: they slow the advance of floods and dissipate their impact over a large surface. It should be noted that the question of wetlands and coastal flooding will become more pressing in coming years due to sea level rise (linked to global warming which causes sea water to expand). Rejuvenated wetlands will - if we are wise - provide a buffer to slow the ingress of rising seas, giving more time for human populations to migrate and / or adapt.

               New York city has recently spent $1 billion to purchase land bordering the Hudson river in order to preserve, or return, ecosystems to their natural state: natural water filtration / purification plants. A tree hugger folly you say? Nay! Economists estimate the dollar cost of equivalent water treatment plants at more than $ FIVE billion. Five versus one billion dollars: a 400% saving!! In addition, the water treatment plants would consume fossil fuel energy both in their construction and operation, further wrecking our climate and ecosystems with greenhouse gas emissions. In this case "letting nature be" is a win - win outcome for everyone. This is a good example of what sound ecologically-based development could accomplish - if we but had the political will..

              The Big Problem at present is that damned lack of political will. For me, the real risk is that by the time environmental disasters become severe enough to change public opinion, it will be too late to mitigate the worst of the damage. This, of course, could have immense - and presently incalculable - effects on the future course of society's evolution. At the limit, we face demographic collapse, exterminatory warfare, universal pauperisation and the effective suicide of civilization as we know it. This choice is up to us, especially the young who will live in the changed world, and the old who choose to dedicate their last years to assuring the worst won't happen..

               Silver lining is an interesting, well written, and above all, an eye opening book. It is written for the public, not for a specialist audience. All essential concepts are well explained, in detail with abundant examples. This is a book recommended for young people and elders who give a damn about the future.


1- Surprisingly, "Progress" turns out to be a new-fangled idea. Earlier cultures generally did not possess our faith in progress and innovation. The goal of traditional societies was to (magically, ritually, ethically) preserve the natural equilibrium upon which human and non-human life depended. Some legendary innovators (the discoverer of fire..) were honored but most innovation was seen as perversion and deviation from an Ideal (metaphysical, spiritual) order. Examples are hunter - gatherer - farmer cultures like the Hopi of N. America or the Australian aboriginal culture. Even relatively "modern" - urbanized, centralized, literate - societies such as China or ancient Rome placed the Golden Age in a Heroic Past, not in some Utopian Future created by technology and the revolutionary establishment of a "Classless Society".

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