Review by PAUL KRUGMAN, The New York Times
Published: May 7, 2006

ECONOMIC ideas play a large role in shaping the world. “Practical men, who believe themselves to be quite exempt from any intellectual influences,” John Maynard Keynes said, “are usually the slaves of some defunct economist.” So it’s odd how few popular books have been written describing the social and personal matrix from which economic ideas actually emerge. There have been no economics equivalents of, say, James Watson’s book “The Double Helix,” or James Gleick’s biography of Richard Feynman.

David Warsh has now made a major effort to fill that gap. “Knowledge and the Wealth of Nations” is the story of an intellectual revolution, largely invisible to the general public, that swept through the economics profession between the late 1970’s and the late 1980’s. I’ll come back to the question of how important that revolution really was. But whatever one thinks of the destination, Warsh, a former columnist for The Boston Globe who writes the online newsletter Economic Principals, takes us on a fascinating journey through the world of economic thought — and the lives of economists — from Adam Smith to the present day.

I should mention here that I was a prominent player in some of the events Warsh describes. My closeness to it all makes me aware of, and perhaps oversensitive to, the things Warsh doesn’t get quite right. But let me focus on the book’s virtues before I talk about its minor flaws.

Warsh tells the tale of a great contradiction that has lain at the heart of economic theory ever since 1776, the year in which Adam Smith published “The Wealth of Nations.” Warsh calls it the struggle between the Pin Factory and the Invisible Hand. On one side, Smith emphasized the huge increases in productivity that could be achieved through the division of labor, as illustrated by his famous example of a pin factory whose employees, by specializing on narrow tasks, produce far more than they could if each worked independently. On the other side, he was the first to recognize how a market economy can harness self-interest to the common good, leading each individual as though “by an invisible hand to promote an end which was no part of his intention.”

What may not be obvious is the way these two concepts stand in opposition to each other. The parable of the pin factory says that there are increasing returns to scale — the bigger the pin factory, the more specialized its workers can be, and therefore the more pins the factory can produce per worker. But increasing returns create a natural tendency toward monopoly, because a large business can achieve larger scale and hence lower costs than a small business. So in a world of increasing returns, bigger firms tend to drive smaller firms out of business, until each industry is dominated by just a few players.

But for the invisible hand to work properly, there must be many competitors in each industry, so that nobody is in a position to exert monopoly power. Therefore, the idea that free markets always get it right depends on the assumption that returns to scale are diminishing, not increasing.

For almost two centuries, economic thinking was dominated by the assumption of diminishing returns, with the Pin Factory pushed into the background. Why? As Warsh explains, it wasn’t about ideology; it was about following the line of least mathematical resistance. Economics has always been a discipline with scientific aspirations; economists have always sought the rigor and clarity that comes from using numbers and equations to represent their ideas. And the economics of diminishing returns lend themselves readily to elegant formalism, while those of increasing returns — the Pin Factory — are notoriously hard to represent in the form of a mathematical model.

Yet the fact of increasing returns was always a conspicuous part of reality, and became more so as the decades went by. Railroads, for example, were obviously characterized by increasing returns. And so economists tried, again and again, to bring the Pin Factory into the mainstream of economic thought. Yet again and again they failed, defeated by their inability to state their ideas with sufficient rigor. Warsh quotes Kenneth Arrow, who received a Nobel in economic science for work that is firmly in the Invisible Hand tradition: increasing returns were an “underground river” in economic thought, always there, yet rarely seeing the light of day.

The first half of “Knowledge and the Wealth of Nations” is a history of economic thought from the vantage point of that underground river. It describes how great economists chose to exclude increasing returns from their analyses, even though many of them understood quite well that they were leaving out an important part of the story. It also tells the tale of economists, most notably Joseph Schumpeter, who decided that if increasing returns couldn’t be modeled rigorously, so much the worse for rigor — and who found their literary, nonmathematical versions of economics simply ignored. (Schumpeter was a sad figure in his later years; his canonization as a patron saint of economic growth — based largely on his famous phrase, “creative destruction” — came long after his death.) The second half of the book describes how the underground river finally fountained to the surface.

I’ve never seen anyone write as well as Warsh about the social world of economic research, a world of brilliant, often eccentric people who bear no resemblance to the dreary suits you see discussing the economy on CNBC. It’s a world of informal manners yet intense status competition, in which a single seminar presentation can suddenly transform a young man or woman into an academic star.

For about a decade, starting in the late 1970’s, many of those star turns involved increasing returns. Economists had finally found ways to talk about the Pin Factory with the rigor needed to make it respectable. One after another, fields from industrial organization to international trade to economic development and urban economics were transformed.

Warsh does a superb job of conveying the drama of it all. He also tells us about a number of remarkable people and what they did later in their lives — because many of the once-young men (alas, there are few women in the story) who made that revolution have had very interesting second acts.

There are some flaws. The work of the economists who brought increasing returns to international trade, a group that included yours truly, receives flattering treatment, yet Warsh’s account misrepresents that work in subtle but important ways.

Maybe that slight sloppiness reflects Warsh’s relative lack of interest in applications of increasing returns other than the one he believes to be most crucial: as an explanation of economic growth. He portrays a famous 1990 paper about increasing returns and growth by Paul Romer of Stanford University as a sort of pivot around which the whole way economists see the world changed.

Now “Romer 1990” is a terrific paper — I wish I had written it, which is the highest praise one economist can give to another. Yet I don’t think it can bear the weight Warsh places on it. Nor is it clear that increasing returns really did transform our understanding of economic growth. In fact, Warsh seems to concede as much. “So there is a new economics of knowledge. What has changed as a result? The answer, it seems to me, is not much.”

Never mind. If you like reading stories of high intellectual drama, if you want to know the origin of ideas that, as Keynes said, “are dangerous for good or evil,” this book is for you.

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An Ocean of Air

八月 3, 2007

Books of The Times (New York Times)

By WILLIAM GRIMES
Published: August 3, 2007

As a metaphor for absence and nothingness, air has performed admirably for centuries. It has pulled off one of the great con jobs in human history, concealing endless complexities behind its bland, transparent facade. Layer by layer, from the ionosphere to the Earth’s surface, Gabrielle Walker exposes the Earth’s atmosphere for what it is, a restless, electrically charged, dynamic superhero, entrusted with the sacred mission of protecting our planet, nurturing life and even, when looked at from a certain angle, making love possible.

Ms. Walker, a chemist by training and a science journalist by profession, finds that angle in “An Ocean of Air,” her perkily popular take on air, wind, atmosphere and the scientists who unraveled their mysteries, from Galileo onward. It starts with oxygen, creator and destroyer, foundation of the atmosphere, the revolutionary element that quickens life and hastens death through its ferocious reactivity, and requires two sexes. Oxygen-burning, ever-aging mitochondria from the male expend energy seeking out cool, unaged mitochondria in the female egg, which guarantee that the human embryo’s biological clock starts at zero. Romance is in the air.

Like Dava Sobel in “The Planets,” Ms. Walker writes for a general audience and seems to assume something close to scientific illiteracy in her readers. There is plenty of gee-whiz and tee-hee in her merry tale, a colorful blend of anecdote, personality and pure science explained in the simplest terms. Every fact is chased with a sweetener to make it go down a little easier, and each turn in the narrative ends with a cliffhanger.

At times Ms. Walker can be absolutely shameless in her efforts to keep readers on the edge of their seats. A straightforward account of Marconi’s experiments with radio waves leads right into a taut recounting of the Titanic’s last hours as experienced from the ship’s telegraph room. This is completely beside the point but forgivable, first, because it is undeniably stirring, and second, because Ms. Walker has put the reader on an addictive drip-feed of asides and digressions

She starts early. After carefully explaining Galileo’s efforts to measure the weight of air, Ms. Walker leans forward from her lectern, as it were, and poses a simple but intriguing question: How heavy is it? Well, imagine an empty space, say, the inside of Carnegie Hall. Take a guess. Ten pounds? A hundred? Five hundred? Try 70,000 pounds.

The fun facts keep on coming. Simply breathing air for one year is equivalent to being bombarded by the radiation from 10,000 chest X-rays. It’s that reactive oxygen again. Every year green plants convert carbon dioxide into 100,000 million tons of plant material, otherwise known as food, using up 300 trillion calories of energy from the sun, which is 30 times the energy consumption of all the machines on Earth.

Somewhat less dramatically, John Tyndall, the Victorian scientist who first discovered the link between carbon dioxide and infrared radiation, drew such large crowds to his lectures at the Royal Institution in London that Albemarle Street had to be made a one-way thoroughfare — Britain’s first — to accommodate the carriage traffic.

Tidbits like this should not disguise that Ms. Walker, while cruising along at a breathtaking clip, manages to explain with exemplary clarity the chemistry of the atmosphere, the mechanics of wind and the role of the enveloping layers that swaddle the Earth, protecting it from the sun and occasionally putting on a grand show, like the northern lights.

She ties her discoveries to personalities, and three of them obviously capture her heart and imagination. The first is William Ferrel, a poor, mostly self-taught farm boy from West Virginia who collated random observations on prevailing winds and used them to explain the relationship between the rotation of the Earth and the movement of air across its surface.

Ms. Walker’s second hero, Oliver Heaviside, is almost too good to be true, from his name to his eccentricities. “Tales of his oddities were legion,” Ms. Walker writes. “He furnished his rooms with blocks of granite; he dyed his hair black and then wore a tea cozy on his head until it was dry; he kept his nails exquisitely manicured and painted them cherry red.” He also explained what Marconi never understood, that radio signals can overcome the curvature of the Earth even though they travel in a straight line because an electrical layer in the sky, now known as the Heaviside layer, acts as a mirror, bouncing the waves back to Earth.

The third star in Ms. Walker’s twinkling constellation is Kristian Birkeland, a Norwegian scientist whose fascination with the northern lights led him to a discovery that, had anyone paid attention, would have made it less of a surprise when American scientists found that space is radioactive.

Ms. Walker takes her title from Evangelista Torricelli, an Italian mathematician and colleague of Galileo’s who, marveling at the power and weight of the atmosphere, exclaimed in a letter in 1644, “We live submerged at the bottom of an ocean of air.” This sense of wonder, transmitted down through the ages through generations of scientists, animates Ms. Walker’s high-spirited narrative and speeds it along like a fresh-blowing westerly. It may be science lite, but out of thin air, Ms. Walker conjures marvelous shapes and forms.

Books of The Times

By MICHIKO KAKUTANI
Published: July 19, 2007

So, here it is at last: The final confrontation between Harry Potter, the Boy Who Lived, the Chosen One, the “symbol of hope” for both the Wizard and Muggle worlds, and Lord Voldemort, He Who Must Not Be Named, the nefarious leader of the Death Eaters and would-be ruler of all. Good versus Evil. Love versus Hate. The Seeker versus the Dark Lord.

J. K. Rowling’s monumental, spellbinding epic, 10 years in the making, is deeply rooted in traditional literature and Hollywood sagas — from the Greek myths to Dickens and Tolkien to “Star Wars.” And true to its roots, it ends not with modernist, “Soprano”-esque equivocation, but with good old-fashioned closure: a big-screen, heart-racing, bone-chilling confrontation and an epilogue that clearly lays out people’s fates. Getting to the finish line is not seamless — the last part of “Harry Potter and the Deathly Hallows,” the seventh and final book in the series, has some lumpy passages of exposition and a couple of clunky detours — but the overall conclusion and its determination of the main characters’ story lines possess a convincing inevitability that make some of the prepublication speculation seem curiously blinkered in retrospect.

With each installment, the “Potter” series has grown increasingly dark, and this volume — a copy of which was purchased at a New York City store yesterday, though the book is embargoed for release until 12:01 a.m. on Saturday — is no exception. While Ms. Rowling’s astonishingly limber voice still moves effortlessly between Ron’s adolescent sarcasm and Harry’s growing solemnity, from youthful exuberance to more philosophical gravity, “Deathly Hallows” is, for the most part, a somber book that marks Harry’s final initiation into the complexities and sadnesses of adulthood.

From his first days at Hogwarts, the young, green-eyed boy bore the burden of his destiny as a leader, coping with the expectations and duties of his role, and in this volume he is clearly more Henry V than Prince Hal, more King Arthur than young Wart: high-spirited war games of Quidditch have given way to real war, and Harry often wishes he were not the de facto leader of the Resistance movement, shouldering terrifying responsibilities, but an ordinary teenage boy — free to romance Ginny Weasley and hang out with his friends.

Harry has already lost his parents, his godfather Sirius and his teacher Professor Dumbledore (all mentors he might have once received instruction from) and in this volume, the losses mount with unnerving speed: at least a half-dozen characters we have come to know die in these pages, and many others are wounded or tortured. Voldemort and his followers have infiltrated Hogwarts and the Ministry of Magic, creating havoc and terror in the Wizard and Muggle worlds alike, and the members of various populations — including elves, goblins and centaurs — are choosing sides.

No wonder then that Harry often seems overwhelmed with disillusionment and doubt in the final installment of this seven-volume bildungsroman. He continues to struggle to control his temper, and as he and Ron and Hermione search for the missing Horcruxes (secret magical objects in which Voldemort has stashed parts of his soul, objects that Harry must destroy if he hopes to kill the evil lord), he literally enters a dark wood, in which he must do battle not only with the Death Eaters, but also with the temptations of hubris and despair.

Harry’s weird psychic connection with Voldemort (symbolized by the lightning-bolt forehead scar he bears as a result of the Dark Lord’s attack on him as a baby) seems to have grown stronger too, giving him clues to Voldemort’s actions and whereabouts, even as it lures him ever closer to the dark side. One of the plot’s significant turning points concerns Harry’s decision on whether to continue looking for the Horcruxes — the mission assigned to him by the late Dumbledore — or to pursue the Hallows, three magical objects said to make their possessor the master of Death.

Harry’s journey will propel him forward to a final showdown with his arch enemy, and also send him backward into the past, to the house in Godric’s Hollow where his parents died, to learn about his family history and the equally mysterious history of Dumbledore’s family. At the same time, he will be forced to ponder the equation between fraternity and independence, free will and fate, and to come to terms with his own frailties and those of others. Indeed, ambiguities proliferate throughout “The Deathly Hallows”: we are made to see that kindly Dumbledore, sinister Severus Snape and perhaps even the awful Muggle cousin Dudley Dursley may be more complicated than they initially seem, that all of them, like Harry, have hidden aspects to their personalities, and that choice — more than talent or predisposition — matters most of all.

It is Ms. Rowling’s achievement in this series that she manages to make Harry both a familiar adolescent — coping with the banal frustrations of school and dating — and an epic hero, kin to everyone from the young King Arthur to Spider-Man and Luke Skywalker. This same magpie talent has enabled her to create a narrative that effortlessly mixes up allusions to Homer, Milton, Shakespeare and Kafka, with silly kid jokes about vomit-flavored candies, a narrative that fuses a plethora of genres (from the boarding-school novel to the detective story to the epic quest) into a story that could be Exhibit A in a Joseph Campbell survey of mythic archetypes.

In doing so, J. K. Rowling has created a world as fully detailed as L. Frank Baum’s Oz or J. R. R. Tolkien’s Middle Earth, a world so minutely imagined in terms of its history and rituals and rules that it qualifies as an alternate universe, which may be one reason the “Potter” books have spawned such a passionate following and such fervent exegesis. With this volume, the reader realizes that small incidents and asides in earlier installments (hidden among a huge number of red herrings) create a breadcrumb trail of clues to the plot, that Ms. Rowling has fitted together the jigsaw-puzzle pieces of this long undertaking with Dickensian ingenuity and ardor. Objects and spells from earlier books — like the invisibility cloak, Polyjuice Potion, Dumbledore’s Pensieve and Sirius’s flying motorcycle — play important roles in this volume, and characters encountered before, like the house-elf Dobby and Mr. Ollivander the wandmaker, resurface, too.

The world of Harry Potter is a place where the mundane and the marvelous, the ordinary and the surreal coexist. It’s a place where cars can fly and owls can deliver the mail, a place where paintings talk and a mirror reflects people’s innermost desires. It’s also a place utterly recognizable to readers, a place where death and the catastrophes of daily life are inevitable, and people’s lives are defined by love and loss and hope — the same way they are in our own mortal world.

By COREY S. POWELL
Published: May 20, 2007

In the ocean of biographies, Albert Einstein is the white whale: impossible to ignore, almost as difficult to capture, symbolic as all hell. Who could resist going after the man whose name and face have become synonymous with genius?

And go after him they do, those literary Ahabs. Amazon.com already lists more than 200 Einstein biographies and memoirs, including the superlative 1971 portrait by Ronald Clark. And here come two more. Walter Isaacson, the former managing editor of Time magazine, concocts a hearty, slightly populist take on Einstein. Jürgen Neffe, a German journalist and biochemist, embarks on a more probing, if somewhat dour, exploration in an expanded version of a biography originally published in Germany in 2005, here crisply translated by Shelley Frisch. Both authors justify themselves in part by incorporating recently unearthed bits of Einsteiniana, including a trove of personal letters released by Hebrew University last year. At a deeper level, though, these books owe their existence not to new scholarship but to an old frustration. A half-century after Einstein’s death, his theories and the mind that spawned them remain as baffling as ever to most of the public.

Isaacson opens by introducing the five landmark papers Einstein published in 1905, when the 26-year-old Bern patent clerk turned the world of physics on its head. Two of the papers put forward novel analyses of the size and motion of atoms — clever, but a sideshow to the March 1905 “On a Heuristic Point of View Concerning the Production and Transformation of Light,” which established the basis of quantum mechanics. Five years earlier, Max Planck had suggested that objects emit and absorb radiation in discrete units of energy, or quanta, but he had treated the idea primarily as a mathematical formalism. Einstein showed that, applied literally, Planck’s quanta would explain a mystery called the photoelectric effect, by which light drives electric current out of certain materials (think of a solar cell). This proposal was far more incendiary than it sounded — “a flame that would consume classical physics,” in Isaacson’s words. If light is made of particles, then its behavior can be treated statistically and the world can no longer be described by strict laws of causality — a concept so unsettling that Einstein later recoiled from it with his protest that God “does not play dice” with the universe.

The fourth 1905 paper, which introduced Einstein’s special theory of relativity, was inspired by a thought problem he had stewed over since adolescence: what would a light beam look like if you could catch up and ride alongside it? The standard thinking suggested that you would see a bizarre bit of electromagnetic field frozen in place but oscillating like mad — an answer that made no sense to him, because it suggested that the behavior of light would depend on an observer’s motion relative to some unknown, unseen frame of reference. Instead, Einstein proposed a radical solution. No matter how fast you move, he reasoned, the beam of light always appears to be fleeing at the speed of light. This argument applies across the board: the laws of physics are the same to all observers, regardless of their state of relative motion. Such a thing is possible only if space and time can bend to preserve the consistent appearance of physical laws. There is no absolute grid that defines “here,” no universal definition of “now.” Issacson quite aptly calls this “one of the most elegant imaginative steps in the history of physics.”

Neffe locates the defining moment of Einstein’s life at a later point: Nov. 6, 1919, the day when a joint session of Britain’s Royal Society and Royal Astronomical Society announced it had confirmed Einstein’s grandest idea, the general theory of relativity. According to the theory, gravity has the power to bend light, so two teams of astronomers had attempted to measure the effect on stars adjacent to the sun during a solar eclipse. Sir Frank Dyson, the Astronomer Royal, announced that the results left “no doubt” about the validity of Einstein’s prediction. (Years later it came out that the results in fact left considerable doubt, but Einstein’s boosters — like the man himself — intuitively felt that the theory must be correct.) The Times of London declared the finding “one of the most momentous, if not the most momentous, pronouncements of human thought.” Within days other salivating media around the world followed suit. In an instant, Neffe writes, “Albert Einstein was reborn as legend and myth, idol and icon of an entire era.”

The general theory of relativity was a stunning elaboration on special relativity. The first theory applied only to observations made by someone moving at a constant speed. Its successor allowed for the way the laws of physics appear to someone accelerating or decelerating — the more “general” case. Again, a thought problem proved crucial. When a worker falls off the roof, he momentarily does not feel the pull of gravity. Why? In that prosaic question, Einstein perceived a stark physical truth, the equivalence between gravity and acceleration. The worker normally feels weight because of gravity, which is really just a constant downward acceleration. If nothing resists it, as during a fall, that feeling goes away. Einstein flipped the situation around and considered a man in an elevator floating in space. Accelerate the elevator upward and he, too, would feel a downward acceleration — not just similar to gravity, but indistinguishable from it. Gravity is not a force pulling us down onto the planet, as Newton pictured it. Rather, it is more accurately thought of as a warp, induced by Earth’s mass, that causes our path through space-time to push us against the ground. “Gravitation is geometry,” in Neffe’s words. It defines the shape of space and time; without matter, space and time would have no meaning.

These are some of the most powerful ideas in all of science, and both Isaacson and Neffe present them with brio and insight. Neffe does an especially thorough job tracing their origins in Einstein’s early obsessions, and he shows how completely the latest cosmic theories are constructed atop general relativity. Unfortunately, his theme-driven structure gets distractingly convoluted in places. Isaacson’s more straightforward chronological approach and conversational style are much livelier. If any 600-page book about relativity can be described as a page-turner, “Einstein: His Life and Universe” is it.

The two books diverge more seriously in their interpretation of the personality behind the science. Isaacson’s Einstein is a resilient humanist who managed to adapt to tough political realities without sacrificing his core beliefs in freedom and social equality. Neffe’s Einstein is more of a naïve idealist, repeatedly drawn to (and burned by) ill-advised causes. After attaining United States citizenship in 1940 and becoming an outspoken one-worlder after World War II, Einstein was closely monitored by J. Edgar Hoover’s F.B.I. To Isaacson, Einstein rose above these suspicions and became a true American, one who “considered his opposition to the wave of security and loyalty investigations to be a defense of the nation’s true values.” To Neffe, who views the United States from a distinctively German perspective, Einstein “shed any illusions about a freedom-loving America” and spent his last years increasingly isolated from both colleagues and countrymen.

The disparate moods extend to the inevitable dishing about Einstein’s love life. We now know that before their marriage, Einstein and his first wife, Mileva Maric, had an illegitimate daughter, named Lieserl, whom he abandoned to an unknown fate. He had multiple affairs, including one with Margarita Konenkova, a reputed Soviet spy. Einstein’s marriage to Maric, a fellow student from the Zurich Polytechnic whose own hopes for a significant scientific career were frustrated, was stormy and at times astonishingly cruel. His second marriage, to his cousin Elsa, was often resolutely pragmatic. Isaacson generally emphasizes Einstein’s compensating warmth, while Neffe focuses on the chill. A telling moment comes in the two accounts of perhaps the most squalid of the recent revelations: a letter from Elsa’s daughter, Ilse, claiming that Einstein had dallied with both mother and daughter and left it to them to decide which would become his bride. Neffe hastily denounces Einstein’s behavior as “one of the most humiliating ways in which a man could treat a woman.” Isaacson has the good sense to examine the sole source of the story: a letter that Ilse wrote to her unsteady boyfriend, whom she quite possibly was trying to bait with a salacious fabrication.

I wish Isaacson had had the courage to take another step back and, in the spirit of Einstein, ask the big underlying question: what do these feet-of-clay stories really tell us about Einstein’s mind, and about the broader nature of genius? Each revelation about his romantic misadventures has generated a chorus of gleefully clucking news coverage. But why is it so thrilling to learn that Einstein was a human being who sometimes made foolish or impulsive decisions? There is a whiff of the Us magazine ethos at work here: “Einstein — he’s just like us!”

In truth, Einstein was not even like other physicists. “I have no special talents,” he once insisted to his friend Carl Seelig. “I am only passionately curious.” But as Isaacson points out, passionate curiosity was Einstein’s special gift. He brooded over fundamental mysteries of nature that most of his colleagues ignored, and dissected them with the kind of relentless questioning more commonly associated with a small child. He maintained his focus for astounding durations: 10 years on special relativity, eight on general relativity, and more than three decades on the “unified field” theory that he hoped would knit together all of physics.

All of this was not effortless. Neffe’s description of Einstein as a man of “profound, shocking loneliness” may be an exaggeration, but it touches on the very real price he paid for his singular imagination. Isaacson, in a self-proclaimed effort to make Einstein’s ideas accessible to “a responsible citizenry,” writes that the pursuit of science is “an enchanting mission, as the sagas of its heroes remind us.” Einstein’s relentless dedication to the life of the mind was not just enchanting, however; it eroded his marriages, distanced his children, even dissuaded students who could continue his work.

Today’s research environment, with its emphasis on collaboration, consistent publication and competition for funding, is in many ways antithetical to the way Einstein worked. The physicist Lee Smolin has noted that no scientists today call themselves Einsteinians, because “most of us have neither the courage nor the patience to emulate Einstein.” For the few out there who do, the new Einstein biographies can function as a call to greatness. For the rest of us, the most precious thing they offer is a taste of what Einstein called the “cosmic religious sense,” a connectedness to universal truth that he considered the highest expression of being human.

Corey S. Powell is the executive editor of Discover magazine.

Al Gore Revisits Global Warming, With Passionate Warnings and Pictures
By MICHIKO KAKUTANI
Published: May 23, 2006

Lately, global warming seems to be tiptoeing toward a tipping point in the public consciousness. There has been broad agreement over the fundamentals of global warming in mainstream scientific circles for some time now. And despite efforts by the Bush administration to shrug it off as an incremental threat best dealt with through voluntary emissions controls and technological innovation, the issue has been making inroads in the collective imagination, spurred by new scientific reports pointing to rising temperatures around the world and melting ice fields in Greenland and Antarctica. A year ago, the National Academy of Sciences joined similar groups from other countries in calling for prompt action to reduce greenhouse gas emissions.

A Time magazine cover story in April declared that “the climate is crashing and global warming is to blame,” noting that a new Time/ABC News/Stanford University poll showed that 87 percent of respondents believe the government should encourage or require a lowering of power-plant emissions. That same month, a U.S. News & World Report article noted that dozens of evangelical leaders had called for federal legislation to reduce carbon dioxide emissions, and that “a growing number of investors are pushing for change from the business community” as well. And even Hollywood movies like the kiddie cartoon “Ice Age: The Meltdown” and the much sillier disaster epic “The Day After Tomorrow” take climate change as a narrative premise.

Enter — or rather, re-enter — Al Gore, former vice president, former Democratic candidate for president and longtime champion of the environment, who helped to organize the first Congressional hearings on global warming several decades ago.

Fourteen years ago, during the 1992 campaign, the current president’s father, George Herbert Walker Bush, dismissed Mr. Gore as “Ozone Man” — if the Clinton-Gore ticket were elected, he suggested, “we’ll be up to our neck in owls and out of work for every American” — but with the emerging consensus on global warming today, Mr. Gore’s passionate warnings about climate change seem increasingly prescient. He has revived the slide presentation about global warming that he first began giving in 1990 and taken that slide show on the road, and he has now turned that presentation into a book and a documentary film, both called “An Inconvenient Truth.” The movie (which opens in New York and Los Angeles on Wednesday) shows a focused and accessible Gore — “a funnier, more relaxed and sympathetic character” than he was as a candidate, said The Observer, the British newspaper — and has revived talk in some circles of another possible Gore run for the White House.

As for the book, its roots as a slide show are very much in evidence. It does not pretend to grapple with climate change with the sort of minute detail and analysis displayed by three books on the subject that came out earlier this spring (“The Winds of Change” by Eugene Linden, “The Weather Makers” by Tim Flannery and “Field Notes From a Catastrophe” by Elizabeth Kolbert), and yet as a user-friendly introduction to global warming and a succinct summary of many of the central arguments laid out in those other volumes, “An Inconvenient Truth” is lucid, harrowing and bluntly effective.

Like Mr. Gore’s 1992 book “Earth in the Balance,” this volume displays an earnest, teacherly tone, but it’s largely free of the New Age psychobabble and A-student grandiosity that rumbled through that earlier book. The author’s wonky fascination with policy minutiae has been tamed in these pages, and his love of charts and graphs has been put to good use. Whereas the charts in “Earth in the Balance” tended to make the reader’s eyes glaze over, the ones here clearly illustrate the human-caused rise in carbon dioxide levels in recent years, the simultaneous rise in Northern Hemisphere temperatures and the correlation between the two. Mr. Gore points out that 20 of the 21 hottest years measured “have occurred within the last 25 years,” adding that the hottest year yet was 2005 — a year in which “more than 200 cities and towns” in the Western United States set all-time heat records.

As for the volume’s copious photos, they too serve to underscore important points. We see Mount Kilimanjaro in the process of losing its famous snows over three and a half decades, and Glacier National Park its glaciers in a similar period of time. There are satellite images of an ice shelf in Antarctica (previously thought to be stable for another 100 years) breaking up within the astonishing period of 35 days, and photos that show a healthy, Kodachrome-bright coral reef, juxtaposed with photos of a dying coral reef that has been bleached by hotter ocean waters.

Pausing now and then to offer personal asides, Mr. Gore methodically lays out the probable consequences of rising temperatures: powerful and more destructive hurricanes fueled by warmer ocean waters (2005, the year of Katrina, was not just a record year for hurricanes but also saw unusual flooding in places like Europe and China); increased soil moisture evaporation, which means drier land, less productive agriculture and more fires; and melting ice sheets in Antarctica and Greenland, which would lead to rising ocean levels, which in turn would endanger low-lying regions of the world from southern Florida to large portions of the Netherlands.

Mr. Gore does a cogent job of explaining how global warming can disrupt delicate ecological balances, resulting in the spread of pests (like the pine beetle, whose migration used to be slowed by colder winters), increases in the range of disease vectors (including mosquitoes, ticks and fleas), and the extinction of a growing number of species.

Already, he claims, a study shows that “polar bears have been drowning in significant numbers” as melting Arctic ice forces them to swim longer and longer distances, while other studies indicate that the population of Emperor penguins “has declined by an estimated 70 percent over the past 50 years.”

The book contains some oversimplifications. While Mr. Gore observes that the United States is currently responsible for more greenhouse gas pollution than South America, Africa, the Middle East, Australia, Japan and Asia combined, he underplays the daunting increase in emissions that a rapidly growing China will produce in the next several decades. And in an effort to communicate the message that something can still be done about global warming, he resorts, in the book’s closing pages, to some corny invocations of America’s can-do, put-a-man-on-the-moon spirit.

For the most part, however, Mr. Gore’s stripped-down narrative emphasizes facts over emotion, common sense over portentous predictions — an approach that proves considerably more persuasive than the more alarmist one assumed, say, by Tim Flannery in “The Weather Makers.” Mr. Gore shows why environmental health and a healthy economy do not constitute mutually exclusive choices, and he enumerates practical steps that can be taken to reduce carbon emissions to a point below 1970’s levels.

Mr. Gore, who once wrote an introduction to an edition of Rachel Carson’s classic “Silent Spring” (the 1962 book that not only alerted readers to the dangers of pesticides, but is also credited with spurring the modern environmental movement), isn’t a scientist like Carson and doesn’t possess her literary gifts; he writes, rather, as a popularizer of other people’s research and ideas. But in this multimedia day of shorter attention spans and high-profile authors, “An Inconvenient Truth” (the book and the movie) could play a similar role in galvanizing public opinion about a real and present danger. It could goad the public into reading more scholarly books on the subject, and it might even push awareness of global warming to a real tipping point — and beyond.