The Weather Makers
eBook - ePub

The Weather Makers

How Man Is Changing the Climate and What It Means for Life on Earth

Tim Flannery

Partager le livre
  1. 400 pages
  2. English
  3. ePUB (adapté aux mobiles)
  4. Disponible sur iOS et Android
eBook - ePub

The Weather Makers

How Man Is Changing the Climate and What It Means for Life on Earth

Tim Flannery

DĂ©tails du livre
Aperçu du livre
Table des matiĂšres

À propos de ce livre

The #1 international bestseller on climate change that's been endorsed by policy makers, scientists, writers, and energy executives around the world. Tim Flannery's The Weather Makers contributed in bringing the topic of global warming to worldwide prominence. For the first time, a scientist provided an accessible and comprehensive account of the history, current status, and future impact of climate change, writing what has been acclaimed by reviewers everywhere as the definitive book on global warming. With one out of every five living things on this planet committed to extinction by the levels of greenhouse gases that will accumulate in the next few decades, we are reaching a global climatic tipping point. The Weather Makers is both an urgent warning and a call to arms, outlining the history of climate change, how it will unfold over the next century, and what we can do to prevent a cataclysmic future. Originally somewhat of a global warming skeptic, Tim Flannery spent several years researching the topic and offers a connect-the-dots approach for a reading public who has received patchy or misleading information on the subject. Pulling on his expertise as a scientist to discuss climate change from a historical perspective, Flannery also explains how climate change is interconnected across the planet. This edition includes a new afterword by the author. "An authoritative, scientifically accurate book on global warming that sparkles with life, clarity, and intelligence." — The Washington Post

Foire aux questions

Comment puis-je résilier mon abonnement ?
Il vous suffit de vous rendre dans la section compte dans paramĂštres et de cliquer sur « RĂ©silier l’abonnement ». C’est aussi simple que cela ! Une fois que vous aurez rĂ©siliĂ© votre abonnement, il restera actif pour le reste de la pĂ©riode pour laquelle vous avez payĂ©. DĂ©couvrez-en plus ici.
Puis-je / comment puis-je télécharger des livres ?
Pour le moment, tous nos livres en format ePub adaptĂ©s aux mobiles peuvent ĂȘtre tĂ©lĂ©chargĂ©s via l’application. La plupart de nos PDF sont Ă©galement disponibles en tĂ©lĂ©chargement et les autres seront tĂ©lĂ©chargeables trĂšs prochainement. DĂ©couvrez-en plus ici.
Quelle est la différence entre les formules tarifaires ?
Les deux abonnements vous donnent un accĂšs complet Ă  la bibliothĂšque et Ă  toutes les fonctionnalitĂ©s de Perlego. Les seules diffĂ©rences sont les tarifs ainsi que la pĂ©riode d’abonnement : avec l’abonnement annuel, vous Ă©conomiserez environ 30 % par rapport Ă  12 mois d’abonnement mensuel.
Qu’est-ce que Perlego ?
Nous sommes un service d’abonnement Ă  des ouvrages universitaires en ligne, oĂč vous pouvez accĂ©der Ă  toute une bibliothĂšque pour un prix infĂ©rieur Ă  celui d’un seul livre par mois. Avec plus d’un million de livres sur plus de 1 000 sujets, nous avons ce qu’il vous faut ! DĂ©couvrez-en plus ici.
Prenez-vous en charge la synthÚse vocale ?
Recherchez le symbole Écouter sur votre prochain livre pour voir si vous pouvez l’écouter. L’outil Écouter lit le texte Ă  haute voix pour vous, en surlignant le passage qui est en cours de lecture. Vous pouvez le mettre sur pause, l’accĂ©lĂ©rer ou le ralentir. DĂ©couvrez-en plus ici.
Est-ce que The Weather Makers est un PDF/ePUB en ligne ?
Oui, vous pouvez accĂ©der Ă  The Weather Makers par Tim Flannery en format PDF et/ou ePUB ainsi qu’à d’autres livres populaires dans Biological Sciences et Environmental Conservation & Protection. Nous disposons de plus d’un million d’ouvrages Ă  dĂ©couvrir dans notre catalogue.


Grove Press



There must be an intricate security system to ensure that exotic outlaw species do not evolve into rampantly criminal syndicates ...
When a species ... produces a poisonous substance, it may well kill itself. If, however, the poison is more deadly to its competitors it may manage to survive and in time both adapt to its own toxicity and produce even more lethal forms of pollutant.
—James Lovelock, Gaia
Until a black mood takes her and she rages about our heads, most of us are unaware of our atmosphere. The “atmosphere”: what a dull name for such a wondrous thing. And it’s hardly specific. I remember, when I was a child, my great-aunt sitting with my mother at our kitchen table, a cup of tea in hand, saying meaningfully, “You could have cut the atmosphere with a knife.” If we took the same linguistic approach to things maritime, we would use the catchall word water to replace sea and ocean, leaving us with no way to indicate whether we meant a glassful or half a planet’s worth of hydrogen oxide, as H2O is properly known.
It was Alfred Russel Wallace, cofounder with Charles Darwin of the theory of evolution by natural selection, who came up with the phrase “the Great Aerial Ocean” to describe the atmosphere. It’s a far better name, because it conjures in the mind’s eye the currents, eddies, and layers that create the weather far above our heads, and that are all that stand between us and the vastness of space. Wallace’s phrase was born of a romantic era of scientific discovery when both amateurs and professionals were making significant contributions toward understanding why cyclones rage in certain regions of the globe, and how “carbonic acid,” as carbon dioxide was sometimes described, affects the distributions of plants and animals.
Reading such work, you get the sense that their discoveries caused as much excitement as did the dredging up of monsters from the deep or, more contemporarily, pictures sent from Mars. Staid scientists would write rapturously of atmospheric dust: What an astonishing thing it is, Wallace mused, that without dust, sunsets would be as dull as dishwater, our glorious blue sky would be as black and uniform as ink, and shadows would be so dark and razor edged as to be as impenetrable as concrete to our sight.
Today the wonders of the atmosphere are often reduced to dry facts that, where they are known at all, are learned by rote by bored school-children. Despite having been forced to swallow them when at school, I still find the workings of the atmosphere fascinating. It connects everything with everything else and thus performs many services that we take for granted.
It is in our lungs that we connect to our Earth’s great aerial bloodstream, and in this way the atmosphere inspires us from our first breath to our last. The time-honored customs of slapping newborns on the bottom to elicit a drawing of breath, and the holding up of a mirror to the lips of the dying are bookmarks of our existence. And it is the atmosphere’s oxygen that sparks our inner fire, permitting us to move, eat, and reproduce—indeed to live. Clean, fresh air gulped straight from the great aerial ocean is not just an old-fashioned tonic for human health, it is life itself, and thirty pounds of it are required by every adult, every day of their lives.
The great aerial ocean, indivisible and omnipresent, has so regulated our planet’s temperature that for nearly 4 billion years Earth has remained the sole known cradle of life amid an infinity of dead gases, rock, and dust. Such a feat is as improbable as the development of life itself; but the two cannot be separated, for the great aerial ocean is the cumulative effusion of everything that has ever breathed, grown, and decayed. Perhaps it is the means by which life perpetuates the conditions necessary for its existence. If this is so, two profound questions naturally arise: How can the individual components that constitute life coordinate their efforts; and (more immediately relevant to ourselves) what can be said of species that threaten that equilibrium?
In 1979 the mathematician James Lovelock published a book, Gaia, that delved deeply into these questions.1 Lovelock argued that Earth was a single, planet-sized organism, which he named Gaia after an ancient Greek earth goddess. Anyone who has lived close to nature will recognize the thing Lovelock was describing, but because his arguments seemed mystical, they discomfited many scientists.
The atmosphere, Lovelock concluded, is Gaia’s great organ of interconnection and temperature regulation. He describes it as “not merely a biological product, but more probably a biological construction: not living, but like a cat’s fur, a bird’s feathers, or the paper nest of a wasp, an extension of a living system designed to maintain a chosen environment.”2 This notion was considered heretical by many, and until Carl Sagan accepted Lovelock’s manuscript for the journal Icarus, it faced the prospect of remaining unpublished. In truth, Lovelock had few examples to explain how life might act to regulate Earth’s temperature. About the best he could offer was the instance of some microorganisms that inhabit salt marshes where the salt crystals, by reflecting light back to space, keep them cool. These microorganisms turn black as winter approaches, thereby absorbing heat and warming Earth.
More important to his argument than such flimsy evidence was a profound paradox. The sun, like all stars, has become more intense as it has aged. Since life evolved, its rays have increased in intensity by 30 percent, yet the temperature of the surface of our planet has remained relatively constant. A drop of one tenth of 1 percent in the solar radiation reaching Earth can trigger an ice age; so Earth’s long-term climatic stability, Lovelock argued, could not have resulted from mere chance.
One reason biologists were so resistant to the concept of Gaia was that they could not imagine species cooperating globally to achieve such an outcome. Indeed, driven by Richard Dawkins’s selfish gene theory, most biology was going in the opposite direction—toward a concept of the world wherein even individual genes were at war with each other. The most devastating rebuttal of the Gaia hypothesis is that it is teleological. Lovelock asserted that the likelihood of Earth’s surface temperature resulting from chance was about the same as surviving a drive through peak-hour traffic blindfolded, to which the biologist W. Ford Doolittle replied:
I think he is right; the prolonged survival of life is an event of extraordinary low probability. It is however an event which is a prerequisite for the existence of Jim Lovelock and thus for the formation of the Gaia hypothesis... . Surely if a large enough number of blindfold drivers launched themselves into rush-hour traffic, one would survive, and surely he, unaware of the existence of his less fortunate colleagues, would suggest that something other than good luck was the cause.3
It’s a fair enough view, but before accepting it, let’s look at what evidence in favor of Lovelock has been produced since 1979.
The most compelling proof has to do with the idea that, as life has diversified, Gaia has become better at regulating Earth’s temperature. For nearly half of its existence—from 4 billion to around 2.2 billion years ago—Earth’s atmosphere would have been deadly to creatures such as us. Back then all life was microscopic—algae and bacteria—and its hold on our planet was tenuous. By around 600 million years ago oxygen levels had increased enough to permit the survival of larger creatures—ones whose fossils can be seen with the unaided eye. These early organisms lived during a period of momentous climate change, when four major ice ages gripped the planet, indicating that back then Earth’s thermoregulation was not as effective as it is today. Carbonate deposited in rocks (thus taking CO2 out of the atmosphere) indicates that there was something odd about the carbon cycle back then. Organic matter was being buried at an unprecedented rate. Maybe the breakup of the early continents opened troughs in the ocean floor that rapidly filled with organic-rich sediment, and this led to a runaway refrigeration of the planet. Whatever the case, with less CO2 in the atmosphere, Earth began to get very cold. Twice—around 710 million and again at 600 million years ago—Earth crossed a threshold that all but exterminated life, freezing our planet right to the equator.4
Whatever its ultimate cause, Earth’s deep freeze must have been aided by a powerful mechanism known as Earth’s albedo. Albedo is Latin for “whiteness,” and of course a snow-covered Earth is a lot whiter than one that isn’t. The importance of this can be seen from the fact that one third of all energy reaching Earth from the sun is reflected back to space by white surfaces. Fresh snow reflects the most light (80–90 percent), but all forms of ice and snow reflect far more sunlight than does water (5–10 percent). Once a certain proportion of the planet’s surface is bright ice and snow, enough sunlight is lost that a runaway cooling effect is created, which freezes the entire planet. That threshold is crossed when ice sheets reach around 30 degrees of latitude.
Around 540 million years ago living things began to build skeletons of carbonate, and to do this they absorbed CO2 from sea water. This affected CO2 levels in the atmosphere, and ever since then ice ages have been rare. Only twice—between 355 and 280 million years ago, and for the past 33 million years—have they prevailed. An ingenious theory to explain why this might be so has been put forward by Andy Ridgwell of the University of Riverside, California, and his colleagues.5 They argue that the evolution of tiny, shell-forming plankton more than 300 million years ago was a crucial step in stabilizing Gaia’s thermostat. Before that, if Earth’s temperature dropped for any reason, ice would form and the level of the ocean would fall, exposing the continental shelves. This in turn disrupted the carbon cycle, allowing the oceans to draw ever greater amounts of CO2 from the atmosphere, which drove temperatures ever lower. The planktonic calcifiers changed all that because they were not tied to the continental shelves. Instead, they floated in the open ocean, so the cycling of carbon through their bodies and into the ocean sediments was not as influenced by exposure of the continental shelves. As a result, the oceans were prevented from absorbing too much carbon dioxide from the atmosphere, thereby breaking the self-reinforcing cycle that hitherto had turned a slight chill into a full-blown ice age.
If there was ever a single great advance in the establishment of Gaia, the evolution of the planktonic calcifiers was certainly it; but at around the time they were proliferating, other changes were occurring that would also have a profound impact on Earth’s thermostat. This was during the Carboniferous Period, when forests first covered the land, and when most of the coal deposits that now feed our industry were laid down. All of the carbon in that coal was once tied up in CO2 floating in the atmosphere, so those primitive forests must have had an enormous influence on the carbon cycle.
Other evolutionary events are likely to have influenced the carbon cycle, but, because most have not been studied in detail, we cannot be sure about whether they refined Gaia’s thermostatic control. The evolution and spread of modern coral reefs around 55 million years ago drew unimaginable volumes of CO2 from the atmosphere, further altering Gaia; the evolution and spread of grasses around 6–8 million years ago may have changed things in a very different way. Computer simulations reveal that forests would be far more widespread were it not for grasses and the fire they engender. Forests contain much more carbon than does grass, and they also absorb more sunlight (having a different albedo) and produce more water vapor, which affects cloud formation. All of these things influence Gaia’s capacity to regulate temperature.6 Another likely influence on Gaia’s thermostat is the elephant, a great destroyer of forests. Like humans, its original homeland was Africa, and as it spread across the planet around 20 million years ago (only Australia escaped colonization), it too must have affected the carbon cycle.
Despite the growing sophistication of our understanding of how life works to affect Earth’s temperature and chemistry, there is still much debate about Lovelock’s Gaia hypothesis. Does it really matter whether Gaia exists or not? I think it does, for it influences the very way we see our place in nature. Someone who believes in Gaia sees everything on Earth as being intimately connected to everything else, just as are organs in a body. In such a system, pollutants cannot simply be shunted out of sight and forgotten, and every extinction is seen as an act of self-mutilation. As a result, a Gaian worldview predisposes its adherents to sustainable ways of living. In our modern world, however, the reductionist world-view is in the ascendant, and its adherents often see human actions in isolation. It is a reductionist worldview that has brought the present state of climate change upon us.
This is not to say that a Gaian philosophy inevitably makes for good environmental practice. I frequently hear people say that all will be okay with climate change because “Gaia will sort it out.” When Lovelock argued that “there must be an intricate security system to ensure that exotic outlaw species do not evolve into rampantly criminal syndicates” that disrupt Gaia’s thermostat, he seems to agree. Yet notwithstanding the destruction of human civilization through the agency of climate change, it’s difficult to imagine just how Gaia would “sort it out.” And even if she does manage to rid herself of us, we would take so many other species with us that the repair job to Earth’s biodiversity would take tens of millions of years.
The eminent biologist John Maynard Smith said of the debate between Gaian adherents and the reductionists, “It would be as foolish to argue about which of these views is correct as it would be to argue whether algebra or geometry is the correct way to solve problems in science. It all depends on the problem you are trying to solve.”7 And this is the view I will take here, for the questions I wish to address are more amenable to a Gaian approach than to a reductionist one. So let’s use the term Gaia as shorthand for the complex system that makes life possible, while recognizing all the while that it may result from chance.


The great aerial ocean which surrounds us, has the wonderful property of allowing the heat-rays from the sun to pass through it without its being warmed by them; but when the earth is heated the air gets warmed by contact with it, and also to a considerable extent by the heat radiated from the warm earth because, although pure, dry air allows such dark heat-rays to pass freely, yet the aqueous vapour and carbonic acid [CO2] in the air intercept and absorb them.
—Alfred Russel Wallace, Man’s Place
in the Universe
If we are to understand climate change, we need to come to grips with three important yet widely misunderstood terms. The terms are greenhouse gases, global warming, and climate change. Greenhouse gases are a class of gases that can trap heat near Earth’s surface. As they increase in the atmosphere, the extra heat they trap leads to global warming. This warming in turn places pressure on Earth’s climate system and can lead to climate change. Likewise, it’s important to have weather and climate sorted out. Weather is what we experience each day. Climate is the sum of all weathers over a certain period, for a region or for the planet as a whole. And all, of course, are generated in the atmosphere.
The atmosphere has four distinct layers, which are defined on the basis of their temperature and the direction of their temperature gradient. The lowest part of the atmosphere is known as the troposphere. Its name means the region where air turns over, and it is so called because of the vertical mixing of air that characterizes it.
The troposphere extends on average to seven miles above the earth’s surface, and it contains 80 percent of all the atmosphere’s gases. Its bottom third (which contains half of all the gases in the atmosphere) is the only part of the entire atmosphere that is breathable. The key thing about the troposphere is that its temperature gradient is upside down—it is warmest at the bottom. At first sight this appears contrary to common sense, for you would expect the air nearest the sun (the ultimate source of heat) to be the warmest, but this peculiarity accounts for the well-mixed nature of the troposphere—after all, hot air rises. Another peculiarity is that the troposphere is the only portion of the atmosphere whose north...

Table des matiĂšres