Friday, August 2, 2013

Book Review: Under a Green Sky by Peter Ward

Peter D Ward: Under a Green Sky (Collins, 2007, NY), 204 pages plus bibliography and index

Abbreviations used in this article: CC - climate change, CO2 - carbon dioxide, GHG - greenhouse gas(es), GW - global warming, MYA - millions of years ago, THC - Thermohaline Circulation

             Ward is a paleontologist specializing in the study of mass extinction events such as asteroid impact which killed the dinos 65 million years ago (MYA) and the "greatest mass extinction in earth's history", the Permian mass extinction, 250 MYA.

             Green Sky gives a synopsis of an emerging (or newly emerged) consensus among earth scientists and evolutionary biologists: climate change (CC) is the major driver of biological evolution on earth.

             With a decent flair for story telling, Ward takes us through the early Creationism - Darwinism debates following the publication of the Origin of Species in 1859. The Darwinists successfully opposed the creationists and established the intellectual credentials of their new science. They also introduced a new scientific "meta-paradigm" - or general Worldwiew - for the life sciences in general. In retrospect, their victory had some curious ideological blow back. Creationists in Darwin's day had argued that the fossil history was discontinuous and "episodic" in nature because God had intervened in the World Historical Process, alternately creating and destroying "worlds" or creations in order to punish or rectify sinful mankind. They argued that dinos disappeared because they were too big to fit on Noah's ark..

            Darwin - "paradoxically" it might seem to us today - held that the fossil record was simply incomplete and that we "must have faith" - despite visual evidence to the contrary! - that the World Historical Process was, in reality, continuous. For Darwin, the apparent "gaps" and disconnected "episodes"  of fossil history do not represent divine intervention but mere physical discontinuities: an ocean bed uplifted by an episode of mountain building erodes away and destroys the record of past life. Darwin's crowd, the historical winners of this first round of "debates" between science and creationism, argued that divine intervention does not exist, that only physico-chemical processes acting GRADUALLY over time produce change in the living and fossil world. This notion - called "Uniformitarianism" in opposition to the "Catstrophism" of the creationists - became, in time, an unchallenged, even unchallengeable, dogma. This dogma dominated scientific thinking about evolution and "earth changes" for the better part of a century, at least.

              Then things changed in 1980 when the father-son Alvarez team made waves in scientific and media circles by proposing that the dinos were killed off my an "impactor" (giant comet, asteroid or meteor) striking earth, 65 MYA. This hypothesis was vigorously opposed, challenged, tested and finally verified. It is now accepted by the majority of earth scientists. That's how science is supposed to work: observation, followed by hypothesis building and testable predictions, followed by rigorous testing of those predictions (via lab experiment or observation of the natural world).

              What followed acceptance of the Alvarez Impactor Hypothesis is not edifying and still, to me, a bit unexplained. Scientists, being human, overgeneralize like the rest of us, I guess. Uniformitarianism fell out of favor and all extinctions were now (too often) seem as rapid and, worse, all were believed to be caused by impactors. Ward walks us through the aftermath of the Alvarez Impactor Hypothesis in a focused, easy to follow fashion, perhaps one of the strong points of the book.

               The 20th century has witnessed remarkable technical advances in the measurement of both ancient time and of ancient climate conditions (particularly temperatures and indicators of the state of ecosystemic health). In large part these gains are due to new technologies employing isotopes (radioactive and non-) and "biomarkers" (molecular fragments identifying the presence of life and which kinds of life: oxygen breathing or not, early or advanced bacterial life, etc..) This improved understanding of "life in time" has led to what I call the "contemporary consensus", not yet universal, but emerging strongly: CC is the major driver - or cause - of biological evolution, including mass extinction events, on earth.

              What is most interesting about Green Sky is not the science (it has been exposed elsewhere in more technical detail, the works of Prof Tony Hallam, for example: Catastrophes and other Calamities, not to mention peer reviewed papers and science blogs). What is most interesting is Ward's reaction - "as a father"  - to his research. He began to understand that human beings through our interaction with the environment are setting up the conditions for a near future mass extinction event which may include ourselves as an extincting species. He  draws this "alarming" conclusion from the REPEATED co-incidence of

- Climate Change (CC),
- rises in atmospheric carbon dioxide (CO2) levels,
- bouts of ocean anoxia (dead zones) and
- mass extinction events on land and sea.

              This new science that is emerging - it has no name yet - is "interesting" in at least three senses of the word. "Interesting" scientifically, intellectually - as a puzzle - but also "interesting" in the sense of "involving" or "engaging" as our own self-interest as a species and as individuals IS implicated. There is also the ironic tone of the ancient Chinese curse: "may you live in interesting times!" Times, that is, "interesting" to future historian's. Civilized periods are boring for historians, Much more interesting are periods of chaos, war, calamity and transition - except, of course, for the poor devils that actually have to live in those "interesting" epochs.

              Ward feels that as a man, a father, as well as a scholar, it is time to stand up and sound the alarm. Alert the public so they, acting through the democratic process, can change the course of history, directing the Historical Process in a saner direction. (For this reason, this text is recommendable as a gift or suggestion for young people who are either worried about the future - or should be - and have a decent grasp and / or respect for science).

              Ward believes that CO2 emissions are dangerous for both our "way of modern life" and, possibly, even our survival as a species. His arguments, while not  ironclad, are compelling, especially if one holds the "precautionary principle" in high regard: one should avoid pleasurable behaviors which carry a small degree of risk of producing devastating consequences: smoking, shooting heroin, road racing, Russian roulette.. Thus we counsel Johnny not to road race even if the chance of an accident is quite low on any given outing, say 1 chance of an accident in 100. But if Johnny races 4 - 5 times each month, his chance of meeting with disaster rises drastically to about even odds for the year. We would also point out the incommensurate nature of the ephemeral adrenaline rush versus the long term (or terminal) consequences of personal death, guilt over killing others, spending life in a wheel chair with a severely impaired brain, etc..

               Ward's professional work has helped to reveal that earth's climate is actually much less stable than the old - now discredited - dogma of Uniformitarianism would allow (or suggest). Climate, with the resolution modern science is able to attain, is now understood to "shift gears" in incredibly short periods of time - of the order of a decade!

              We also know that these "gear changes" can be of large magnitude depending on local conditions: a monsoon may be shifted north or south a few hundred kilometers with devastating - or benefic - impact for a given region. We also now know that earth, while one, responds diversely over its surface. A rise in global temperature of 2 or 3 degrees Celsius might actually cause some regions to cool and some glaciers to advance due to reconfigured air and / or ocean circulation patterns. CC precedes very rapidly at high latitudes but few people live there so little news arises from this part of the world: ignorant southerners may blithely continue to deny the  planet is warming..

              Ward believes that rapidly rising CO2 (and other GHG emissions) are dangerous for several reasons. CO2 is rapidly acidifying the oceans. The rate of increase is especially alarming because  it is overriding the speed of response of natural chemical buffering reactions. We are changing the chemistry of the oceans faster than they  - or the life they contain - can adapt. Acidifying the ocean will deplete photosynthetic plankton with dangerous knock on effects: decreased biomass production (fish) to feed our "burgeoning numbers" and a reduced capacity of the oceans to eliminate CO2 from the atmosphere further accelerating CO2 rises and the CC they bring. This is a classical case of dangerous positive feedback where a noxious process "feeds on itself", intensifying the conditions of its own propagation. Under the worst conditions, we get into science fiction-like scenarios. If the oceans actually "die" - become nearly oxygenless or "anoxic" - the dead water could actually begin spewing GHG and poison gases like hydrogen sulfide into the air. Such events have happened in the past during massive die offs of marine life. If severe enough, even land life will keel over if the wind is blowing the wrong way. Whether or not such scenarios are in our future, only "time will tell", of course. Nevertheless, Ward's evocation of the precautionary principle makes sense: what sane rational being would be doing this to the life support systems of their home planet?

              Another and more plausible potential source of chaos involves the shutting down of the Thermohaline Circulation cycle (THC) in the ocean. Like its namesake, this THC, if badly handled, would be a real mind bender. Shutting down THC would most likely proceed the really nasty stuff mentioned above (dead anoxic oceans spewing poison to kill off life on land and sea). However, even if things did not go so far, shutting down THC would probably shut down industrial civilization in its wake.

             The Gulf Stream is an ocean circulation loop which carries warm water (and heat) from the equatorial zone northward. At high latitudes warm surface waters cool and become dense enough to sink to the ocean floor and begin flowing southward, completing the circulation loop. GW is  causing glacial melt run off and increased precipitation in the north. Thus more fresh water is entering the Arctic sea causing the upper layers of sea water to "freshen", becoming less saline. Reduced salinity reduces the density (weight per unit volume) of the water which, in turn, prevents them from sinking to complete the THC loop. The THC "stalls" and the flow of warm water northward is reduced. Results?

            Firstly, western Europe which, because of prevailing winds, benefits from all that heat carried northward would go into the icebox - despite the fact that world as a whole was warming(!!) Europe would not actually freeze or go into Ice Age conditions but during the period of several decades the transition would take, agricultural output would be profoundly perturbed with unpredictable (geo-)political consequences. We would not die from oceans spewing poisons but there would be war..

            But there's worse - and this is not just "plausible": it's happening now (GW science helps to explain why). Warm water expands and melted glaciers add water to the seas, raising sea levels. A globally warmed world - say 5 degree Celsius or 10 degree Fahrenheit - would flood many populous coastal regions, creating enormous social, political and economic tensions. Once again with unpredictable outcome but ominous import. We proceed at our own risk and danger..

             Green Sky is patently alarmist. Ward intended it that way, so he succeeded. On the whole it is engagingly written with interesting personal insights and anecdotes. It is logically well constructed with nice lead-ins to new subjects. However, the sloppiness of preparation grew irritating during my reading. No book is free of errors but here there were too many syntaxically challenges sentences and dropped words to pass unnoticed. Such sloppiness shows haste or, one fears, lack of respect for the reader (whose respect Ward desperately needs if he is to convince people to jump on his anti-GHG bandwagon!). I found one flagrant misinterpretation of a graphic (British units replaced metric units). Milutin Milankovic, the Serbian founder of the modern theory of Ice Ages was on no less than thee occasions referred to as Russian. This irritates..

             Given the general interest this book presents, the evident passion (and courage) of the author to "do the right thing", his evident writing skills (when not sloppy), this is a worthy book - despite its flaws. I'll still give it a 7 on 10, warts 'n all.

Ref: Overbeck, sea-level change. "future mapping group" University of Arizona.

Be sure to check out their maps. You can adjust the level of sea level rise. Conservative estimates give .5 to 1.4 meter sea level rise by the end of the century.
 The Gulf Stream current is on the left side of the figure

internal blog links 

also check out keyword: climate change (numerous entries)

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