The Earth's Biosphere : Evolution, Dynamics, and Change

Rating:
Summary: A very useful reference on the Earth's biosphere
Review: This is a very readable book about the history and nature of the Earth's biosphere, and ideas about its future.

Smil begins with some fascinating material on the the nature and origin of early life on Earth. That includes a discussion of stromatolites (early life), and some interesting comments about guesses of the odds of life appearing in a stellar system in the Galaxy. While estimates that hold the chances to be small are taken seriously, Fred Hoyle's argument that the chance is outrageously small is shown to be silly.

The author then describes the nature and diversity of life in general, and its resiliance to a variety of natural catastrophes, including bolide impacts and supernovae.

Smil tells us about how the biosphere is energized, by solar radiation and the Earth's internal heat. And we then see the flows of water and materials, including carbon, nitrogen, sulfur, and other mineral cycles. The next two chapters deal with the extent of the biosphere and the biosphere's mass and productivity. There are organisms that range up to 50 km above the surface of our planet, or to the bottom of the oceans, nearly 11 km down. To tens of meters below the land surface. And at temperatures ranging from 110 degrees Celsius to minus 50. pH ranges can be from 1 to 11. Meanwhile, the biomass may be anywhere from 2200 to 4000 Gigatons of Carbon.

There is a chapter on the dynamics and organization of the biosphere, including the quarter-power scaling of animal and plant metabolism "that applies across an entire range of body sizes and metabolic pathways."

After that, Smil discusses the transformation of the biosphere due to human actions, such as the release of sulfur, nitrogen, and carbon into the atmosphere. The book concludes with some ideas about the future of the biosphere. He speculates that the Earth's population will stabilize at well below 10 billion people and that there needs to be a transition "from fossil fuels to solar radiation as the dominant source of human energy needs." Meanwhile, there are problems to face: we humans are awfully prone to violence, there may be a new ice age, we could be hit by a big bolide, and so forth. Still, the author is mentions that the biosphere might prove surprisingly resiliant to what is being done to it at present.

There are a few useful appendices, covering milestones in the evolution of the Earth and its biosphere, sizes and masses of organisms, chemical reactions in the carbon, nitrogen, and sulfur cycles, and ocean and land estimates of the biosphere's phytomass, heterotrophic biomass, and net primary productivity, There's also a list of useful websites.

I highly recommend this book to anyone interested in the topic.

Rating:
Summary: Rich with connections between ideas
Review: This less a review of the book then a plea for more people to read it. Like an idiot, I loaned my new copy of this book to a friend after just reading through it once. I'll be buying another, and keeping it.

Smil connects so many ideas together here that you might find yourself thinking that the dynamics of an interconnected biosphere are obvious. I suppose that's the highest praise I can offer. Complex interactions within geology, geography, chemistry and evolution are made clear in this book. The writing is bright, interesting and yet dense with information. This is large scale popular science writing at its best.

Rating:
Summary: A Masterful Survey
Review: Vaclav Smil is a geographer, and tries to get some perspective on the life of our planet by taking the large view. This entails a sacrifice of depth to get the necessary breadth. But the task he has set himself is still to provide sufficient rigorous detail on the topics he includes (bichemistry, energetics, geology, geochemistry, etc.) to give the reader a basis for useful understanding of the complex thing that is the biosphere. It is necessary, as he asserts in his preface, to synthesize rather than specialize if we are to address the pressing questions about our living environment, which sprawls -- physically and intellectually -- over the whole world. And if you follow the references -- or just leaf through the bibliography -- you must come to realize the immense amount of learning and research that undergird this presentation.

The patron saint of this volume is the early 20th-century Russian scientist Vladimir Vernadsky, who was the first to use the term "biosphere" (actually, "biosphera") in the grand and inclusive way that the rest of the world is now getting around to doing. He calculated (or estimated or guessed) the primary productivity of the green world, the standing biomass divided into its varous categories of land and water autotrophs and heterotrophs, the interrelationships between life, the sun's energy, the composition and behaviors of sea and air, and the grand geochemical cycles. And Vernadsky was hopeful: he expected a planet-wide consciousness to arise that would manage the biosphere intelligently.

Since then, hope has waned as our knowledge and power have grown. Humanity is stressing the systems of life as much, perhaps, as any catastophe in Earth's long history. Yet this book is a hopeful gesture: it is an attempt to get a grip on the issues in play so we can act with some effect to reverse or slow the degradation of the air, land, and waters, and to restore nature to a state of robust health -- or at least to give nature some breathing room. Smil has chosen to treat in detail the questions of the origins of life, its possible existence elsewhere, and its fundamental biochemistry. He talks about life in the mass -- as a storehouse for sunlight, and as a participant in the great cycles of material through the atmosphere, waters, within the mantle of the earth, and out again. He talks about the physical constraints on life's productivity, the dynamics and organization of the biosphere. And always he is concerned with magnitudes and their relationships: it is not enough to discuss the amount of plankton in the oceans as an isolated fact. Rather, its mass and its turnover, its powers of energy sequestration, should be compared to those of land plants, and productive and unproductive sea areas contrasted.

It is implicit in this approach that the numbers matter. We must know the size and extent of things that we wish to affect or to stop adversely affecting. After all, without some sense of the magnitude of the particular flows of material or requirements of particular facets of the living world, we can waste our efforts on what amount to side issues. However, I wish the presentation had been more user-friendly: many of the charts and graphs were lifted from technical publications, and the others had that feel. The ultimate goal of all this numerizing should be -- let's face it -- a sort of pictoral understanding. To that end, I would have liked some synthesizing graphics that showed (maybe with fat arrows and thin arrows, big, little and even teeny-tiny barrels (or trees or bugs...)) how facets of the system compared, and at a glance showed the relative "importance" of things.

I know that mere magnitude is not always a safe guide to how important something is in the workings of the world. A rather small quantity of CFC's in the stratosphere has had immense effect, for counterexample. Small amounts of bottleneck chemicals like phosphorous control the richness of life in otherwise productive areas. And how unimportant is a rare -- and biospherically useless -- species?

Anyway, I cheer this parade of fact backed by much research and aided immensely by our current generation of planet-spanning monitoring devices. This is hard science, and it gives us baselines and error ranges, without which all discussion finally devolves into opinion and political posturing. Yet, when the last graph is in place, we go right on despoiling the world. The problem is not so much a technical difficulty as it is a matter of societal will. Smil admits as much in his last chapter. All that has gone before is not even really prelude. Without the active cooperation of the political entities that partition this vast human herd the environment cannot be saved. This is the hard part. It is rather a letdown, getting to this point in the book, to realize that science is powerless in the face of a desire to ignore it.