The subtitle for "The Medea Hypothesis" is "Is Life on Earth Ultimately Self-Destructive?" Peter Ward's answer is yes. Medea, the trophy wife of Jason the Greek Argonaut, who murdered her own children in order to revenge herself on her cheating husband, is indeed the operating paradigm for planet Earth, not Gaia the loving Earth goddess.
The main thrust of the book is to falsify the Gaia Hypothesis posed by James Lovelock that life makes conditions better for itself and that life is self-regulating. The first eight chapters are wholly devoted to the falsification of this benevolent idea. Using the very latest research on mass extinctions in particular, Peter Ward's attempts to falsify the Gaia Hypothesis are satisfying and would, I think, put a dour smile on the lips of Schopenhauer were he alive today and if Ayn Rand were alive today, she would have to weep. (Rand's concept of a benevolent universe wouldn't be rationally supportable through the science Peter Ward uncovers here.) Only one of the six mass extinctions on this planet was due to an extraterrestrial cause (asteroid). Planet earth poisons and/or deadens itself periodically through high and low temperatures. Life contains within it its own ability to destroy itself; life, indeed, is in conflict with itself and is self-destructive, and life includes man himself or herself. Peter Ward demonstrates quite clearly, for example, how life increases to the point where it uses up all resources, whether phytoplankton or humanity. (Ronald Wright in "A Short History of Progress" thematizes this self-same idea historically.)
Chapter 9, only two pages long, summarizes Peter Ward's four chief points on the matter.
Chapters 10 and 11, the last two chapters of this short book, wax both philosophic environmentally and futuristic technologically. Both are weak offerings in that Peter Ward is no philosopher at all and with regard to the future, he cannot posit any engineering solution to life on this planet as we know it. We're simply and hopelessly stuck, science-fiction notions about colonizing space notwithstanding.
I was interested to learn how the author might understand the following conflict: science shows carbon dioxide will decrease in the long run, across the next billion years (and there are graphs in the book to illustrate this fact) and yet global warming (an increase in carbon dioxide) will destroy the planet as we know it. Peter Ward, however, doesn't concern himself with any scientific proofs about global warming. He merely asserts that global warming is a fact and those who aren't convinced of it are either intellectually deficient or politically biased. He never addresses the dichotomy between these two scientific positions, positions he himself poses within the book.
In terms of style, structure and language for this book, it requires a dictionary first of all and then some patience. The talented layperson has a fighting chance of understanding this text with the help of a good dictionary for vocabulary, but a biologist or an earth science professor will definitely have an even easier time of it altogether. It's helpful (but not wholly necessary) if you know, for example, what is a C3 docot from a C4 monocot in terms of vegetation. It's definitely worthwhile to grab that dictionary and look up what are eukaryotes and prokaryotes as well, not to mention such scientific terms as eutrophication, adiabatic, anoxic, albedo, biomass, and hypocapnia.
The sentences one encounters in this book are also full of parenthenticals, most of which appear in the middle of the sentence, interrupting the main thought with nearly irrelevant details, parentheticals that could have been added instead at the very end of the sentence in order to keep cognitive integration focused and steady. When I read on page 78, Chapter 5, that the bacteria in the Canfield ocean "could care less" about nitrogen, knowing the phrase ought to be "couldn't care less" and laughing at the fact that this scientist was suddenly and inexplicably anthropomorphizing bacteria, I knew I clearly wasn't in the hands of a master of nonfiction prose.
My sense of order for this book is that it wasn't written in a steady, logical development or logical progression, nor was it even written with an overall design or plan in mind, but consisted in a (somewhat repetitive) series of efforts, essays, perhaps, and/or technical "pushes" in certain directions in order to do away with various levels of the Gaia Hypothesis. On the whole, I thought this disappointing book needed to be rewritten and edited in which case it probably would have been published only as a pamphlet or a long magazine article.