The Australian documentary “Crude” was an impressive effort. I wanted to verify the claims presented in the documentary. For that reason I visited the Science Library at the U. of of O., found the QH 344 shelf (Library of Congress system, common to university libraries) which contains material relating to the ‘Carbon Cycle’. There are, of course, those who dismiss climate change as something that happens and don’t worry about it. True, it has happened before, but not to worry????

At any rate, I brought home with me “The Changing Carbon Cycle: A Global Analysis,” published in 1986, which I thought somewhat mis-titled. I thought it more of an examination of what additionally needed to be known at that time, and what kind of computer model would be needed to deal with the massive inflow of information. It is also the book that contains a first chapter by Senator Albert Gore of Tennessee. Seems he and the folks out at Oak Ridge National Laboratories got on famously. Still do, from the looks of things. The book is the work of 52 authors, not all from Oak Ridge, because that’s not where oceanographers congregate, for example, and the oceans are quite important to the story.

The story is essentially about the freewheeling nature of carbon, the fourth most common elements on earth. Carbon is prevalent, it is changeable, and the changes may well show up in atmospheric concentrations of carbon. The presence of carbon in the atmosphere affects the temperatures felt at the earth’s surface, and that in turn affects the earth’s “albedo”, the degree to which the surface absorbs or reflects energy. Since they want to know how to interpret changes, the scientists must gain a clear understanding through the use of computer models (nothing less can deal with the huge number of independent variables.) The book is heavily involved with discussions on how to formulate the model. Much of that discussion flew clean over my head.

The book was published in 1986, we know more now than we used to, computers and models are considerably advanced, but both are still works in progress. Consider medicine or the weather – not everything is yet known about either. Works in progress. Perfection may never be realized, but it would be a mistake for the captain of a small vessel to leave port when storm watches are posted, or for the owner of an orange grove to disregard freeze warnings.

The second book that I found in the Science Library proved to be more readable, enjoyable even. It’s “Vegetation and the Terrestrial Carbon Cycle: Modeling the first 400 Million Years.” by Beerling and Woodward, a couple of British scientists whose work has added significantly to the science. The book (Published 2001) was written a decade and a half after ‘The Changing Carbon Cycle, and reflects the considerable progress made by scientists, at least in the area of vegetation.

Challenged by this book I looked into how photosynthesis worked. We associate it with leaves on terrestrial vegetation, and that in itself is interesting. A leaf is a far more complicated mechanism that I had supposed (bear in mind that I came to this completely innocent of any knowledge of biology.) A leaf breathes, as you and I do, but the process is directly the reverse. The leaf inhales carbon dioxide and exhales oxygen. To do that, it possesses a variable number of “stoma” Carbon Dioxide and water (from the root system) are conveyed to the chlorophyl molecules, which contains a substance called ‘rubisco.’ which is an enzyme that magically converts the sun’s radiant energy, carbon dioxide and water into a fundamental form of alcohol, which the plant then transforms into whatever the plant needs to grow and multiply. Forests and meadows grow, fauna develop to take advantage of nature’s bounty, and king of the whole business is us. For a little longer only, perhaps.

The number of stoma in the leaf varies depending upon carbon dioxide levels. The plant must maintain moisture to survive, too many stoma may kill the plant because water lost to exhalations might overwhelm the root system’s ability to collect moisture. But it needs enough carbon dioxide to grow and multiply. So the leaf is sensitive to carbon dioxide, heat and relative humidity and adjusts its breathing apparatus (stomatic density) accordingly. That is readily verified in laboratory experiments. What the labs learn can be used to determine ancient climates. That permits models to determine carbon dioxide levels in previous eras. That was claimed in “Crude,” that is verified in Beerling and Woodward.

The book begins with the first vegetation becoming established on land, draws inferences from fossils to develop a picture of circumstances of the time. For our purposes, the Carboniferous of 300 million years ago is important; vigorous plant growth in foetid swamps, where the plant materials might be buried in sediment, preventing decomposition antimately creating coal. And where sometimes fossil evidence is preserved. The Triassic followed, then the Jurassic. The change from one era to another is called a “boundary event.” Boundary events bookend the Jurassic period, in which I am most interested. We are headed quickly and squarely into the same levels of carbon dioxide (not seen for the past 200 million and more years ago.) The change from Triassic to Jurassic resulted in the greatest species extinction ever and was possibly caused by the breakup of the massive continent ‘Pangaea’, which included all the continents which exist today. The breakup is thought to have caused the release of great quantities of volcanic gases. The change from Jurassic to Cretaceous saw an ‘Anoxic Event,’ in which marine areas became toxic because of the inability of the seas to digest the dead organic matter it contained because of the lack of oxygen in the water. That permitted the growth of the type of bacteria which cannot stand oxygen, and whose byproduct is hydrogen sulfide, deadly to organisms if present in any quantity. High temperatures are the key factor in the event. Without polar ice the seas become stagnant, the seas near land are richly fertilized by material carried in by continuous terrestrial flooding, a rich sea life results with that which should be decaying simply piling up on the sea bed.

Of compelling interest to me was a chart on page 31, “Postulated change in atmospheric carbon dioxide concentrations over the past 500 million years.” It shows a beginning, 500 million years ago, concentration of about 5000 ppm, declining to somewhere around 300 ppm about 300 million years ago, then rising again to perhaps 1800 ppm in the Jurassic period beginning around 270 million years ago. One of the conjectures noted the breakup of the super-duper continent of Pangaea, which then became two super continents Laurasia in the northern hemisphere, and Gondwana in the southern. It is postulated that heavy volcanic activity during the breakup of Pangaea released volumes of carbon from the earth’s core at high temperatures, creating elevated carbon dioxide levels. Glacial ice melted, the seas rose to their maximum depth, and the massive annihilation of species occurred. In the late Jurassic, decreases of carbon dioxide are thought due in large part to carbon transferring from air to phytoplankton or leaves, digestion into carbohydrates with oxygen-free bodies of water causing the interment of carbon beneath sediment. We are enjoying a reverse process. We dig the stuff up and burn it, increasing atmospheric carbon. At the rate at which we are doing that, we will have achieved the level of the early Jurassic just after the middle of this century. After we have done our thing it will take the natural carbon cycle some tens of millions of years (it was more like 200 million years to subdue Jurassic carbon dioxide levels) to put things to right again, right being that which enables human life.

It’s a good book. More of a text-book than “The Changing Carbon Cycle,” which I believe to have been written by scientists for scientists. I’m not one, so I found that volume tough sledding.

But between them they satisfied me that the producers of “Crude” did a splendid job of presenting the science. I detected no exaggeration, no skirting of issues.

I’m hearing a lot from people who demand “good science.” I wonder how many have read the book. I thought it pretty good science myself, inasmuch as the authors can prove what they say.

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