If the annoyances of everyday life get to you, take comfort in the fact that these details won't matter in the long run. When our sun turns into a red giant star, all life on Earth will be burned to a crisp anyway. So cheer up! Many scientists have the ability to get out of themselves, and to think, not in terms of wristwatch time, but in geological or cosmological time. In their latest book, two University of Washington scholars, paleontologist Peter D. Ward and astronomer Donald Brownlee, exhibit the ability to think in a scale of time that ticks, not in seconds or heartbeats, but in epochs and eons. 
In The Life and Death of Planet Earth even the scale of centuries and millennia is the short term. Over centuries, we will probably see global warming due to the consumption of fossil fuels and the emission of greenhouse gases. After glaciers melt and the sea rises, coastal cities will be underwater. Spanning millennia, the Earth will have run out of fossil fuels and the next ice age will will occur. [Pages 69-86] Everywhere in the world except for the lowest latitudes will have climates comfortable only to penguins and polar bears. But millennia are short term increments -- What will we experience over millions and billions of years? The sun will expand in diameter until it engulfs the planets, one at a time. What was Mercury will be inside the sun, and Venus will be the next to go. Temperatures on Earth will rise sharply, and the oceans will evaporate. By the time the sun swallows the Earth, our planet will already have become uninhabitable long before. Ward and Brownlee define their field: "Astrobiology is a discipline that is useful for predicting the kinds of planets that could harbor life, to search for such life, and to understand the life cycle of our own world. The authors of this book are astrobiologists and our thesis is simple: Earth's future -- and its perilous present -- can be understood for the first time by studying its past and our neighbors in space." [6] All that we see around us is "our blink in time." The "constancy" and "stability" of nature are apparent. [11] The irony is that the next few days are more uncertain than the next billion years. We can't get a reliable five day weather forecast, but studies of many other stars in the galaxy leave no doubt about the ultimate fate of this solar system. I've got some good news and some bad news. The good news is that astrophysicists have now determined that our sun will never explode into a supernova. [159] The bad news is that it will become a red giant star, which will be no more survivable for living things on Earth than the previous option. Can we do anything about it? The authors observe, "Humans have a habit of moving on when things get bleak." [199] Ward and Brownlee take a careful look at the proposal for our species to migrate to Mars, which is 50% further from the sun than our own planet. Mars is eventually doomed also, but that "Great Escape" [201] would give us a reprieve of millions of years, possibly allowing us the time to devise something else. But no science fiction or fantasy is offered here. Ward and Brownlee cautiously assess the technical problems associated with mass production of reliable spacecrafts that can travel for more than a year to make the voyage, and the real challenges of terraforming Mars to make it livable. [201] The authors write, "Perhaps the solution is not to try to replicate the Earth on a planet or moon, but to move the Earth." [204] There are several proposed methods to gradually nudge our entire world into orbits of greater diameter, compensating for the continuous rise in temperature. Even this long shot is more realistic than counting on interstellar travel. [206-208] Perhaps the real top-down perspective is that life throughout the universe will go on. Maybe Earth life will vanish after all, but life appears and reappears independently elsewhere. The authors reconsider the famous Drake equation for estimating the number of intelligent species in the universe [189] and they propose a few modifications to the terms of the equation [194] to make it more precise. If that is the real issue, one may wonder, "What trace will we leave?" [179] It could be that our final legacy will be the communications we send outward to be found someday by extraterrestrials. This tendency to send messages to whomever may someday find them began with the plaque placed aboard Pioneer 10 in 1972. [182] In this way, some basic philosophical questions accompany the scientific education imparted in the book -- the explanations interconnecting the subjects of the creation of a planet and organisms, plate tectonics, glaciers and ice ages, red giant stars, and the search for extraterrestrial life. Quite apart from "doing" science, questions about the ultimate meaning and purpose of life are placed on the table. If our distant descendents prepare to and are able to make an exodus on spaceships, or save themselves by some other means, the publication of this book may be remembered by them as the incident that provided the earliest warning for humankind to begin the preparations. Book review by Mike Lepore for crimsonbird.com 256 pages: prologue, 13 chapters, epilogue, 12 pages of sources, 12-page 2-column index. B&W illustrations. |
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Book Description from the Publisher A landmark work of science that illuminates the second half of the life of our planet. Imagine our planet far into the future, Carl Sagan's "pale blue dot" reduced to a reddish-brown husk, a mere shell of its former self. It seems like the stuff of science fiction novels, but it is really of science today. We are at a unique moment in our history -- Earth's midlife -- a point at which science has given us the capability to examine the birth of our planet as well as the forces that will bring about its eventual death. Scientists are finally beginning to understand the cycles that make Earth work and to write, for the first time, a biography of our planet. This revolution in thinking, which finds its voice in this book, is as dramatic, in its own way, as the discovery of Earth revolving around the sun. Two brilliant scientists -- Peter D. Ward and Donald Brownlee, a paleontologist and an astronomer respectively -- are helping to bring this groundbreaking work to a popular audience. Vanguards of a new field called astrobiology -- the science of how planets and organisms live and die -- Ward and Brownlee combine the discoveries of astronomers, Earth scientists, and those in other specific disciplines. Astronomers are well-poised to study the ends of other worlds, while paleontologists can tell us about "worlds" that have already ended on our planet, such as the death of dinosaurs and other signposts in the rock and fossil record. Ward and Brownlee present a comprehensive portrait of Earth's ultimate fate, allowing us to understand and appreciate how our planet sustains itself, and offer a glimpse at our place in the cosmic order. As they depict the process of planetary evolution, they peer deep into the future destiny of Earth, showing us that we are living near or shortly after Earth's biological peak. Eventually, the process of planetary evolution will reverse itself; life as we know it will subside until only the simplest forms remain. In time they, too, will disappear. The oceans will evaporate, the atmosphere will degrade, and as the sun slowly expands, Earth will eventually meet a fiery end. At the beginning of the twenty-first century, it is crucial to understand Earth's tumultuous history and probable future. Combining groundbreaking research with lucid, eloquent writing, this landmark book offers fresh and realistic insight into the true nature of our world and how we should best steward our planet for the long-term benefit of our species. About the Authors Peter D. Ward and Donald Brownlee are the coauthors of the acclaimed and bestselling Rare Earth . Don Brownlee is a professor of astronomy at the University of Washington and has been involved in many space experiments; currently he is leading NASA's Stardust mission to collect samples of a comet and return them to Earth. Peter Ward is a professor of geological science and zoology at the University of Washington and the author of nine other books, including Future Evolution , and The Call of Distant Mammoths. Book Reviews "This is the first real biography of the Earth -- not only a brilliant portrait of the emergence and evolution of life on this planet but a vivid and frightening look at Earth's remote future. Peter Ward and Donald Brownlee combine storytelling power with extreme scientific care, and their narrative is as transfixing as any H.G. Wells' fantasies, but more enthralling, for Ward and Brownlee have real power to prognosticate. This is a book that makes one shiver, but also inspires one to wonder how humanity (if we survive in the short term) will fare in the more distant future." -- Oliver Sacks "I have written three biographies and read many others, but who would have thought of a biography of planet Earth and its lifeforms? Ward and Brownlee have introduced the emerging science of astrobiology as a field that is important, exciting, and fun. The different scenarios for the end of life on Earth are provocative; while we cannot prevent some possibilities, the good news is that we can prevent others." -- David H. Levy, discoverer of twenty-one comets, including Shoemaker-Levy 9 "This is beautifully written, provocative book, exploring the long-term future of planet Earth in ways that have never been probed before." -- David Morrison, NASA Ames Research Center |
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Excerpt from the Book
Fire? or Ice? Come with us to the future of Earth, a world that echoes our prehistoric past. Imagine our planet some tens of thousands of years into the future, a stretch of history far longer than the time it has taken our species to develop from hunter-gatherers to industrial civilization. From the vantage point of a derelict and forgotten satellite orbiting far out in space, the reflection of our marbled home is as disquieting as it is dazzling: a reflective, expanding white. The ice of the Poles is creeping steadily equatorward as glaciers advance, and the snows of winter are persisting far longer into the increasingly brief summers. The Alps, the Himalayas, and the northern Rockies are capped year-round with growing tongues of ice. Even at Mount Kilimanjaro and the Mountains of the Moon in central Africa, the glaciers are growing. The sea level that briefly rose at the height of civilization is now dropping, exposing new coastal plains, linking islands, and creating land bridges. Harbors have become meadows. The English Channel and the Bering Strait have become corridors. All the maps have changed. At night the planet no longer glistens with a galaxy of city lights that once stretched from the Arctic to the Southern Ocean. Instead, the Arctic has been abandoned and the Southern Ocean is largely frozen over. The lights that glitter are in a narrower band hugging the equator and midlatitudes. Many are now campfires. It is as if time has not gone forward, but backward. Eerily, the planet is beginning to resemble again the Ice Age world that our primitive ancestors endured. The age of fossil fuels is long over, the planet's reservoir of oil and gas and coal expended in a gluttonous feast of energy consumption that briefly dumped billions of tons of carbon dioxide into the atmosphere. The resulting global warming caused agricultural havoc and erratic climate swings that lasted for several disastrous centuries, but that's but a blink in planetary time. Slowly, the natural processes that seek to balance our planet reabsorbed the carbon out of the atmosphere. The cruelly hot weather dissipated, and for a while our species rejoiced at a return to "normality." But now the climate has dipped toward a more ominous norm. Earth is returning to the conditions that have dominated it for the last 3 million years: a regime of ice. The human civilization that arose in a brief interglacial period is now struggling for survival in a colder and much drier world. The diverse and extensive rain forests of the tropics are being replaced by savanna. The midlatitude grasslands that once helped feed the world, such as the American Great Plains, are becoming dust bowls. Katabatic winds that can reach 200 kilometers per hour howl off the advancing ice sheet and make permanent habitation near its fringe almost impossible. The glaciers are a blue-white wall, gritty on top and at their base, which are grinding forests, towns, and highways into oblivion. Eventually the skyscrapers of Manhattan and the towers of London will be bulldozed by snouts of ice half a kilometer high. Earth has become a planet where humans struggle to feed themselves. Changing climate has made a mockery out of seasons, and the farm crops that predictable seasons allow. Our descendants are starving. Shiver, and go on. Come with us to an even grimmer future. The reign of ice will come again, but will not last forever. Fire will succeed it, in the form of an increasingly hot sun. This time we travel not just thousands of years forward, but hundreds of millions of years: a time more distant from the present era than the ancient seas and primordial swamps that preceded the dinosaurs. The succession of Ice Ages that held the Earth in thrall for millions of years is long forgotten. From space, our planet no longer looks white, or green, or even blue. Its continents are a desolate reddish-brown and its atmosphere thick with windblown dust. Descend in your imagination to an alien world. Picture that we are standing on a seashore, at the edge of a vast, white-capped ocean. The water, at least, is familiar. As it has been since nearly the dawn of time on Earth, the sea is filled with life. Fleet schools of fish arrow through the sunlit surface waters. Below, on the rippled sand of the sea bottom, persist crabs and anemones, flounders and starfish, corals and barnacles. What is different is that the ocean -- once a cradle for the life that crawled onto land -- has become a sanctuary. Animals, hammered by a relentless sun, are retreating into the water. The ocean shore that was once life's beachhead has become its Dunkirk, and the species that cannot readapt to the water are doomed to extinction. The sandy strand we are standing on has become an oven where a hard cadre of animals struggles to exist between the two worlds of warm water and far warmer air. During high tide a few species of hardy crustaceans and mollusks scurry and hunt, feeding and breeding. But during low tide all visible life comes to a stop, the animals hunkered down under parasol-like shells or wedged within the damp crevices of overhanging rocks, trying to survive the murderous rays of the sun. Look up. The sky is grayish-yellow, huge winds carrying storms of sand at galelike velocities. The continents have become deserts of scoured rock and marching dunes. Although imperceptible to the eye, the Sun is slightly brighter and the Moon -- slowly spiraling away -- appears slightly smaller and dimmer. The hottest temperature on record in our own times is the 136 degrees Fahrenheit measured at Le Aziza, Libya, on September 13, 1922. In this future world it reaches that temperature every day, and not just in the Sahara but on midlatitude shores that were once cold and forested. The humidity is 90 percent, the air sticky, oxygen thin. We gasp for breath as if on a high mountain. What life is left? There is no driftwood on this beach, because there are no longer any trees on Earth. Or bushes. Or even grass. The tallest green things left are mosses, found among the more common lichens and fungi that cling to a precarious existence. Even soil is a thing of the past, for when the dying roots of the planet's flora unclenched their grasp on the topsoil, it flew with the wind, leaving behind rock, dust bowl, and dune. The land has become a vast expanse of sand and rock. The rivers are chocolate Colorados carrying eroded land to sea. Some animals persist in this new hell. If we get down on our knees we can see that centipedes and spiders still prowl for insect prey. Ants march in search of wrack worth scavenging. Amphibious lizards watch for food. All of these species conduct their business with alacrity, however, scurrying frantically to finish before the punishing sun reaches its awful noon. Then they too must hide. There are no more birds. Nor mammals, nor amphibians. There is no song and no shade. To try to escape the heat, we too wade into the water, but the surf is uncomfortably hot. We'd have to develop gills and dive deeper to find temperatures that are more comfortable. Yet even the sea will turn out to be only temporary sanctuary for the animals that persist there. The vast oceans themselves are evaporating, their water molecules slowly lost to space. Even they, like all things, will eventually come to an end. The long history of the sea will have left only glistening plains of salt.
Continued .....
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