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48 of 49 people found the following review helpful:
5.0 out of 5 stars
The Eschatology of Earth, February 7, 2003
The Life and Death of Planet Earth This book by Ward and Brownlee is the follow up to their previous work, Rare Earth. In that book, the authors argued persuasively that Earth is indeed far different than the great majority of planets: complex life arose and flourished. They contend that simple life, bacteria, is fairly common and developed early in the life of this planet. Complex life, plants and animals, is exceedingly rare. It came about four billion years after the planet formed. In the sequel, the Life and Death of Planet Earth, Ward and Brownlee argue that complex life is now in the long process of dying out. They describe how the various complex processes that drive the ecology of Earth will die out leaving progressively simpler organisms behind. The authors describe how evolutionary progress from hardy bacteria to humankind will recapitulate itself to last days when the last fragment of life ends with the red giant phase of the Sun. There are three major climatic events in the future history of the earth: the continuing ice age that we are in. The present warm phase is now being temporarily put on hold by the rapid increase in carbon dioxide due to human activity. This will end with then next round of glaciations will end human civilization. This glacial phase will end around five million years from now. It will end permanently when the plate tectonics will push the northern continents away from the poles. The next event will be the recombination of the continents to form the super-continent once again. The recreation of Pangaea will cause the greatest extinction in the planets history due to the disastrous effect it will have on climate. This will end the reign of complex life. The last great event will be the continuous brightening of the Sun as it reaches it end in life. The oceans will disappear. Finally in the most remote parts of the polar areas the last flicker of simple, bacterial life will die. The Sun, now in its red giant phase, will finally consume the remains of earth in its distended atmosphere. Not only will complex life be ended on earth, it may be ended in a vast section of the galaxy if not the universe. In a surprise, Ward and Brownlee contend that it will be the lack of carbon dioxide not its surplus will be the culprit in the destruction of complex life. It is being inexorably being locked up in limestone and other carbonates. Already plant life has attempted to adapt to the slow drop in carbon dioxide levels by adapting to new form of photosynthesis called C-4 (used by grasses, cacti, and palm trees). The older form of photosynthesis C-3 used by conifers, flowers, and vines will asphyxiate first leaving a bizarre new world. However, adaptation will end and plants will die out completely cutting off the oxygen supply for animals. At the same time, the diversity of life has been declining for the last two hundred million years. It will continue to decline as the world continues to become more hostile. The book is exceptionally well written. Ward uses the death of his mother from old age to describe how, while not "living", the Earth is the machine of many complex processes and as death comes each process gives out finally failing altogether. The authors don't describe anything radical, just the obvious conclusions from the evidence found by them and other scientists. Against this background, as the authors made the case in Rare Earth, there will be no salvation from the stars. We'll die alone in this solar system. My criticism is they offer no fixes to this. All alternatives are radically too expensive and difficult for humanity to do. Travel to and terraforming of another planet is and always be out of the question. They even assume that somehow humankind manages to hang on for the billion or so years final processes take place. They do advocate trying to leave a legacy to other civilizations. But really are there any other civilizations in the Universe to read our tombstone?
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38 of 39 people found the following review helpful:
5.0 out of 5 stars
Bleak but fascinating, May 31, 2003
It might be that professors Ward and Brownlee are working on a new genre: non-fiction science fiction. Instead of speculations embedded in story form they speculate about the future in a narrative without plot or characterization or other elements of the story form. Of course they are not the only writers doing this, but they are among the best in a growing industry. Well, what about it? I gave up reading most science fiction years ago because either the story elements were wooden or the science was ridiculous (or both). It is not easy to be simultaneously a master story teller and a polymath of science. We know that (e.g.) Asimov, Clarke and Sagan were exceptions and were able to combine both tale and cutting edge knowledge very well, and in some cases spectacularly well. But their world is gone. Today's science is much more complex. To write convincingly about the future it is not enough to be a world expert in one's chosen field. The future is influenced by science of all kinds; consequently it is requisite that one be an expert in a number of scientific disciplines just to avoid naive projections. So it is natural that Peter Ward, who is a geologist and zoologist, (and, by the way, a sometimes poetic prose stylist, witness his expositions in Future Evolution [2001]), and Brownlee, who is an astronomer and NASA scientist, might join forces to augment their individual expertise; and that they might eschew the story form in writing about the future. At any rate, this is an excellent book of speculation about the future of our planet aimed at a general readership. It is a fine follow-up to their Rare Earth: Why Complex Life Is Uncommon in the Universe (2000). As in that book their conclusions are pessimistic. They concluded in Rare Earth that we are probably alone in the galaxy; here they conclude that we will go extinct without getting beyond our solar system. This bleak prognosis should not unduly trouble us however since our demise by their calculation is at least millions of years in the future, possibly hundreds of millions of years. In fact their scenario reverses the biological experience of the planet: things will get hotter and drier until life necessarily retreats back into the ocean, and then as the oceans evaporate, life forms regress from the complex to the simple until the only life left on the planet is single-celled, as it was three billion years ago. And then of course the sun expands into a red giant and the earth is burned to a crisp. Is there any escape? Not according to Ward and Brownlee who argue effectively that it is unlikely that we will acquire the ability and the will to even terra form Mars or other places in the Solar System. The idea that we might become interstellar travelers is also quashed as being impractical in the extreme. They conclude "Interstellar travel will likely never happen, meaning we are stranded in this solar system forever." (p. 207) While I tend to agree with Ward and Brownlee for the most part, as I did with their conclusions in Rare Earth, I think we should realize that their argument in part is a bit beside the point since in millions of years (at most)--not tens of millions, not hundreds of millions and certainly not billions of years--we will no longer be human anyway. The average life span of a species is something like a million years. Because of the incredibly rapid pace of cultural evolution it is highly unlikely that humans as presently constituted will be around in even a thousand years. Some people think we will be part software and part machine before this century is out. Also as science fiction writers have pointed out, the constraints on our species as presently constituted (in terms of our ability to travel in space and to influence cosmic processes) may not apply to the creatures we are becoming. Ward and Brownlee do not consider this point of view, most likely because it would be extraneous to the scope of their book. So some of their ideas should be considered as stimulative and consciousness-raising, not definitive. As they acknowledge in the epilogue, "Prophecy is a risky business..." (p. 210) Furthermore, most of their material is on the purely physical changes that will take place on planet earth as it evolves toward its ultimate fate, and I have no doubt that the picture that Ward and Brownlee present is as accurate as present knowledge allows. I was especially intrigued by their discussion of the return of the once and future supercontinent, Gondwanaland, and how its reconfiguration will affect earth's climate. Their exposition on the carbon dioxide cycle and the end of plant life when the amount of CO2 in the atmosphere falls below 10 ppm was also fascinating. The chapter asking the question, "What Trace Will We Leave?" really gives the lie to human vanity, reminding me of the sentiments in Shelley's poem "Ozymandias." If anything, Ward and Brownlee are even more pessimistic than the poet, pointing out that our proud "messages in a bottle" sent into interstellar space are not likely to impact "a planet within a trillion years," by which time there won't be any planets. (p. 186) While most of the book is very well written and edited, some of the sentences in the later chapters are less carefully constructed. There are even some gaffs. For example on page 192 they repeat an error from their previous book, stating that there are "between 200 million and 300 million" stars in our galaxy, when the number is more like 100 billion plus. Also on page 194 they give the Drake Equation enhanced with new terms they think appropriate, but in fact the equation is without explanation shorter than Drake's Equation given on page 192.
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19 of 21 people found the following review helpful:
5.0 out of 5 stars
When things get bleak . . ., July 4, 2004
It takes a certain amount of fortitude to confront your own doom. Ward and Brownlee, having acutely described life's beginnings in "Rare Earth", here portray the mechanisms of its end. With the course of life's evolution revealed in the work of many researchers, depicting the finale has rarely been attempted. Recent studies of the past have given the authors the tools for forecasting the future. They use the history of the planet to suggest the "tape of life" will be rerun - backwards. Changing conditions will reduce the options life has to continue surviving. As a swelling sun and dehydrating Earth limit choices, life will revert to simpler, hardier forms. At some point, although far in the future, life's opportunities will end. A bleak barren world will likely be consumed by Sol's energetic transformation into a red giant star. A lifeless planet will either skirt the circumference of that swollen star or be consumed in its fires. Although a fiery conclusion is the ultimate finale, there are many intermediate steps along the path. Ice, which has covered our planet many times in the past, is shown here as one of the major signs of the impending finish. Seas withdraw from coastlines and habitat zones shrink dramatically. Weather patterns undergo massive changes from what we experience. The authors use "time transport" techniques to enable you to envision the impact of these drastic variations. You visit future scenarios where plant life's extinction has taken herbivores with it. Grasses exist for a bit, but it's too desolate for complex grazers to enjoy them. Harsh winds scream across those savannahs, dehydrating the soil until the grasses, too, finally expire. These conditions, Ward and Brownlee contend, have likely already begun. The peak of plant diversity may already be behind us. Animal extinctions, accelerated by our presence, must surely follow. What of humanity, then? Raised with the ideal that we are evolution's "purpose", we believe we can overcome nature's greatest challenges. It's clear that even our esteemed technology must fall short of coping with an overheating Sun. The authors, who have dealt with extinctions in the past, deal ambiguously with the logic of human continuation to a distant future. While most species survive for a few million years, they suggest we will still be present when vast changes begin. They weigh the issues of our possible escape from the doomed planet in terms of will, available resources, advanced technologies and likely havens. All come up somehow short. A bleak prospect indeed. The authors' expressive style captures your attention throughout. Not an academic study, yet still a serious assessment, this book will keep your attention throughout. With the new science of astrobiology as their foundation, little of their narrative is idle speculation. They write with authority, yet present their theme as a drama. Actors come and go, struggle to maintain their roles, but succumb in tragic circumstances. Referring to this book as compelling reading is almost damning with faint praise. While the scenarios are projected billions of years in the future, we can initiate many of the processes through carelessness.
Incorporating many ideas and research information in a mere 200 pages is a major accomplishment. Ward and Brownlee, with their wide knowledge and almost florid style have produced a fine work. As a summary of geology, astrophysics, evolutionary biology and atmospheric sciences, this is a unique and admirable synthesis. If there is anything to fault, it is the strong reliance on the resources used in their previous collaboration - a minor flaw in such a comprehensive study. [stephen a. haines - Ottawa, Canada]
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