The Thirteenth Tipping Point

News: 12 global disasters and 1 powerful antidote

By Julia Whitty

November/December 2006 Issue

WE'VE BEEN DIVING SHIFTS through the night for a week, donning clammy wet suits long after bedtime in order to hover above coral heads and peer into the pools of light from handheld strobes. We are examining the coral polyps, those goose bump-like swellings decorating staghorn, elkhorn, brain, fan, lettuce-leaf, and plate corals. Virtually all of the scleractinian, or reef-building, corals are readying themselves for the greatest sex show on earth, preparing to unleash an orgy of fertilization, self-fertilization, hybridization, and every other manner of fruitful and unfruitful coupling Mother Nature can dream up.

The pink and orange gamete bundles that look like caviar eggs but are actually hermaphroditic clusters of eggs and sperm are migrating up the polyps toward the oral cavities, the corals' single, multi­purpose orifices. Each night these bundles have been growing and stretching the polyps until they resemble nothing so much as minuscule pregnant bellies. On this night, the fourth night after the full moon of the austral springtime, the gametes are beginning to crown, like human heads in their birth canals.

I check my watch. When I glance back to the coral, the ocean is transformed. I blink, thinking I'm seeing things. But it's really here—the black water engulfed in a pink and orange blizzard flowing toward the surface. Within seconds, countless billions of magenta and tangerine gamete bundles have been birthed from their polyps and are floating upward on the buoyancy of the fatty eggs.

Those of us underwater at this moment are also transformed by the bundles, which collect under the folds and angles of our wet suits, buoyancy control devices, dive masks, and regulators. Colorful gametes tangle in our hair. If we could breathe water, we'd be breathing them. The rate of the blizzard amplifies until the light from the strobes blinds us. Clicking to a lower setting, I see eruptions of milky white sperm pulsing rhythmically from nearby sponges and sea cucumbers, polychaete worms and giant clams.

On this night, as many as half of the reef-building corals—perhaps 150 species—plus a host of other invertebrates inhabiting the 1,200 miles of Australia's Great Barrier Reef, are spawning. It's an ancient ritual, maybe as old as the 200 million-plus years that scleractinian corals have been alive. These corals emerged in the darkest days after the Permian-Triassic extinction, when the planet was impoverished nearly beyond repair by massive global climate change, and when almost all life died in hot, dry, and iceless conditions. Since then they have survived two subsequent mass extinctions, including the one that killed the non-avian dinosaurs.

Already, manta rays with six-foot wingspans are sailing into view, mouths open, filtering the eggs from the water. At the outer range of our strobes, reef sharks are circling, preparing to gorge on those that have come to feast. From the cold and perpetually dark reaches of the deep known as the mesopelagic, fish that glow in the dark, and live a mile or more below the tidal, lunar, and seasonal influences that trigger the mass spawning, are rising toward it now, preparing to devour the bonanza they have perceived in ways we can't.

No modern human knew of the mass spawning of corals on the Great Barrier Reef before 1982, when marine biologists accidentally happened upon it. Since then, other spawnings adhering to their own unique schedules have been discovered on many reef systems. Somehow, spineless, brainless, eyeless, earless, immotile marine animals that meet all our criteria for zero intelligence manage to synchronize their activities to ensure survival. Otherwise, all their gametes—a year's investment in energy—would launch off into open water without ever finding suitable partners. While an individual animal might survive such behavior for the term of its natural life, the species could not.

12 ASTEROIDS AND EVOLVING INTO WISDOM



IN 2004, JOHN SCHELLNHUBER, distinguished science adviser at the Tyndall Centre for Climate Change Research in the United Kingdom, identified 12 global-warming tipping points, any one of which, if triggered, will likely initiate sudden, catastrophic changes across the planet. Odds are you've never heard of most of these tipping points, even though your entire genetic legacy—your children, your grandchildren, and beyond—may survive or not depending on their status.

Why is this? Is it likely that 12 asteroids on known collision courses with earth would garner such meager attention? Remarkably, we appear to be doing what even the simplest of corals does not: haphazardly tossing our metaphorical spawn into a ruthless current and hoping for a fertile future. We do this when we refuse to address global environmental issues with urgency; when we resist partnering for solutions; and when we continue with accelerating momentum, and with what amounts to malice aforethought, to behave in ways that threaten our future.

A 2005 study by Anthony Leiserowitz, published in Risk Analysis, found that while most Americans are moderately concerned about global warming, the majority—68 percent—believe the greatest threats are to people far away or to nonhuman nature. Only 13 percent perceive any real risk to themselves, their families, or their communities. As Leiserowitz points out, this perception is critical, since Americans constitute only 5 percent of the global population yet produce nearly 25 percent of the global carbon dioxide emissions. As long as this dangerous and delusional misconception prevails, the chances of preventing Schellnhuber's 12 points from tipping are virtually nil.

So what will it take to trigger what we might call the 13th tipping point: the shift in human perception from personal denial to personal responsibility? Without a 13th tipping point, we can't hope to avoid global mayhem. With it, we can attempt to put into action what we profess: that we actually care about our children's and grandchildren's futures.

Science shows that we are born with powerful tools for overcoming our perilous complacency. We have the genetic smarts and the cultural smarts. We have the technological know-how. We even have the inclination. The truth is we can change with breathtaking speed, sculpting even "immutable" human nature. Forty years ago many people believed human nature required blacks and whites to live in segregation; 30 years ago human nature divided men and women into separate economies; 20 years ago human nature prevented us from defusing a global nuclear standoff. Nowadays we blame human nature for the insolvable hazards of global warming.

The 18th-century taxonomist Carolus Linnaeus named us Homo sapiens, from the Latin sapiens, meaning "prudent, wise." History shows we are not born with wisdom. We evolve into it.

CLIMATE CLIQUES AND NAYSAYERS

EISEROWITZ'S STUDY OF risk perception found that Americans fall into "interpretive communities"—cliques, if you will, sharing similar demographics, risk perceptions, and worldviews. On one end of this spectrum are the naysayers: those who perceive climate change as a very low or nonexistent danger. Leiserowitz found naysayers to be "predominantly white, male, Republican, politically conservative, holding pro-individualism, pro-hierarchism, and anti-egalitarian worldviews, anti-environmental attitudes, distrustful of most institutions, highly religious, and to rely on radio as their main source of news." This group presented five rationales for rejecting danger: belief that global warming is natural; belief that it's media/environmentalist hype; distrust of science; flat denial; and conspiracy theories, including the belief that researchers create data to ensure job security.

We might wonder how these naysayers, who represent only 7 percent of Americans yet control much of our government, got to be the way they are. A study of urban American adults by Nancy Wells and Kristi Lekies of Cornell University sheds some light on environmental attitudes. Wells and Lekies found that children who play unsupervised in the wild before the age of 11 develop strong environmental ethics. Children exposed only to structured hierarchical play in the wild—through, for example, Boy Scouts and Girl Scouts, or by hunting or fishing alongside supervising adults—do not. To interact humbly with nature we need to be free and undomesticated in it. Otherwise, we succumb to hubris in maturity. The fact that few children enjoy free rein outdoors anymore bodes poorly for our future decision-makers.

Another study, this one from the Earth Institute at Columbia University, found an ominous silence when it comes to educating American K-12 students on the relationship between our personal behavior and our environment: that the size and inefficiency of our cars, homes, and appliances, our profligate fuels, our love of disposables, and the effects of buying more than we need actually undermine our prospects on earth. Slightly more time is spent teaching kids how the environment can affect us, overpowering humanity with floods, droughts, storms, earthquakes, climate change. But in our overall failure to illuminate the interdependence between Homo sapiens and earth we withhold critical knowledge from those whose lives depend upon it most.

Many of today's kids recreate in the unwilderness of the shopping mall, where messages of prudence and wisdom are overwhelmed by the consumerism that feeds global warming. We send our kids to the mall because we fear the dangers outside. We could hardly be more wrong in our assessment of risk.

THE ALARMISTS AND THE ACROBAT

ON THE OTHER END of Leiserowitz's spectrum of perception regarding global warming is an interpretive community he calls the alarmists, generally comprised of individuals holding pro-egalitarian, anti-individualist, and antihierarchical worldviews, who are supportive of government policies to mitigate climate change, even so far as raising taxes. Members of this group are likely to have taken personal action to reduce greenhouse gas emissions. Collectively, alarmists compose 11 percent of Americans, with the remaining interpretive communities falling considerably closer to the alarmists than the naysayers in the spectrum—suggesting the gap might be cinched by sustained public education on the neighborhood dangers likely to arise in a changed global climate.

Hurricane Katrina provided a wake-up call for how bad it can get in the neighborhood, and may prove a tipping point itself. Yet long before its rampage, American kids were coloring pictures of the first icon of global environmentalism, the Amazon. Its billion-plus acres of rivers and rainforest—its trees collecting and containing excessive greenhouse gases from the atmosphere—were our primer for the revolutionary notion that the earth's neighborhoods are interdependent.

Today Amazonia is the most famous of Schellnhuber's tipping points. For a generation, kids have grown up learning that the Amazon is at risk from massive deforestation. But even if clearcutting were to halt, climate models forecast that a warming globe will convert the wet Amazonia forest into savanna within this century, and the loss of trees will render the region a net CO2 producer, further accelerating global warming.

Amazonia's tipping point might be fast approaching. The year 2005 saw the driest conditions in 40 years, with wildfires raging unabated, and 2006 is looking worse, raising alarms that environmental synergism is already in play as changes become self-sustaining and reinforce one another. Dan Nepstadt of the Woods Hole Research Center in Massachusetts questions whether the warming of the Atlantic (the tropical North Atlantic rose 1.7 degrees Fahrenheit above the 1901-1970 average in 2005) is affecting airflow over the Amazon, leading to drier and fierier conditions there.

Changes in the currents of the North Atlantic constitute another tipping point. As the Atlantic warms, ice caps melt, diluting the ocean and potentially shutting down its thermohaline circulation (THC), the oceanic river currently delivering the thermal equivalent of 500,000 power stations' worth of warmth to Europe. A 2005 study published in Nature found that after 50 years of monitoring, a critical component of the THC had suddenly slowed by 30 percent.

The fate of this circulation is closely linked to one of Schellnhuber's more notorious tipping points, the Greenland Ice Sheet. Encompassing 6 percent of the earth's freshwater supply, this ice, if melted, would raise sea levels by about 23 feet worldwide—not counting ice loss from the rest of the Arctic and the Antarctic. A study by NASA and the University of Kansas showed the decline of Greenland's ice unexpectedly doubled between 1996 and 2005, as glaciers surged into the sea with unpredicted speed. More worrying, the area of melt shifted 300 nautical miles north during the last four years of the study, indicating the warmth is spreading rapidly.

One tipping point affects the other in a balance as delicate as that of an acrobat's spinning plates. Greenland's increasing freshwater flow into the North Atlantic will certainly impact the THC. Warm water recirculating within the central Atlantic may further rearrange airflow over the Amazon, accelerating its dry-down and tree loss, and potentially freeing as much carbon dioxide from its enormous reservoir as the 20th century's total fossil fuel output. A sudden Amazonian release would surely melt whatever of Greenland hadn't already melted, crashing the THC and drastically cooling Europe—in the worst-case scenario, freezing it solid. Although we like to compartmentalize, nature does not. Biology and climatology are the indivisible warp and weft of earth's living fabric.

SOCIAL FACILITATION, REWARDING PRUDENCE

A VARIETY OF FACTORS enable tiny coral animals to coordinate spawning with pinpoint precision. Many synchronize to inescapable environmental factors—maximum water temperature, for instance, fine-tuned to moon phase and tides. Spawners also stimulate the spawning of their fellows by the presence of their eggs in the water. Thus, among some species, local spawning triggers a cascade of spawning down current, night after night, as the gamete cloud passes overhead.

Many animals coordinate their activities through what is known as social facilitation. The howling of wolves, the twittering choruses of African wild dogs, the cawing of crows when settling to roost, all serve to synchronize the group, and perhaps to spur individuals to their best performance. In human psychology, social facilitation is defined as the tendency for individuals to perform better at simple or well-known tasks when they know they are being observed.

Interestingly, research out of the Max Planck Institute in Germany found that people are more likely to take action to protect the climate when they are seen to be doing so. Manfred Milinski and his cohorts used a variation on game theory, a tool born from mathematics and economics, now used across many disciplines to analyze optimal behavior strategies when the outcome is uncertain and is dependent on the choices of others.

In Milinski's version of the game, players were asked to contribute money—in some rounds anonymously, in other rounds publicly—to a common pool used to pay for a magazine advertisement warning the public of the dangers of global warming and listing simple means to limit individual carbon dioxide emissions. Some rounds enabled players to reward or not reward fellow players whose "reputations" as donors from previous rounds were revealed. Some groups received scientific information on the causes and consequences of climate change; others did not.

The results showed that almost no one was willing to donate money anonymously. Those who did had received the scientific education. Overall the largest donors were those both tutored in the science and able to donate publicly. In the reputation rounds, players generally only rewarded fellow players who were known to be donors. Clearly, we are inclined to behave as better citizens when we are educated and when our actions are visible. Perhaps if we're vigorously informed of the neighborhood dangers of global warming, we'll make sustainable and sensible lifestyle choices. Abetted by knowledge, social facilitation might begin to reward prudence.

SOCIAL LOAFING, THE MEDIA, THE OZONE HOLE

EVEN WELL-INTENTIONED CITIZENS feel helpless in the face of looming global calamities and respond by circling the wagons and focusing on family-size problems. The end result is that most of us practice denial, which appears in the culture at large as indifference, and which collectively enables us to embrace the dark sister of social facilitation: social loafing.

Social loafing is the tendency of individuals to slack when work is shared and individual performance is not assessed. There may be no better example of social loafing than in the U.S. Congress, where members cloak their lethargy regarding global climate change behind the stultifying inactivity of their fellows. And why not? After all, who's watching?

Not the media. For example, on the day the National Oceanic and Atmospheric Administration (NOAA) announced that the first half of 2006 was the hottest on record in the United States, the news vaporized in the explosions of the Israeli-Lebanese conflict. Though the media would never ignore another round of Middle East bloodletting by rationalizing that we've heard all that before, this is exactly what it does with environmental news.

Part of the reason is that the organizations responsible for bringing us the news fail to assess that new science stories are not the same global warming story rehashed from last week/month/year but worrisome new data. Combined, the growing body of scientific knowledge gains heft and power. But the public rarely hears it, reinforcing our denial and indifference.

A 2005 workshop at the Tyndall Centre assessed the performance of the media and found that its sensationalist approach simplified complex issues, while its "balanced" coverage ignored the consensual scientific view, awarding a few skeptics equal billing. The workshop also noted a seminal study from Philadelphia's Drexel University, which found the U.S. media subservient to (at least) or controlled by (at worst) the fossil fuel industry.

A classic example of the bad marriage between a compromised media and a slacking public fuels another of Schellnhuber's tipping points. We've known since 1985, when scientists first reported a "hole" above Antarctica, that chlorofluorocarbons deplete ozone in the stratosphere. Two years later the world mobilized to sign the first Montreal Protocol phasing out ozone-destroying chemicals.

All seemed well enough. Kofi Annan called the Montreal Protocol one of the undoubted success stories of international cooperation. Yet along with the hole over the Antarctic, and the newer ozone dimple over the Arctic, a general thinning is under way everywhere else on earth at the rate of about 3 percent per decade. Schellnhuber calls the ozone hole the mother of all tipping points since it tips even as we declare victory.

In June 2006 researchers from NASA, NOAA, and the National Center for Atmospheric Research announced findings that the hole will take 20 more years than previously predicted—that is, until 2018—to begin significant healing. This is partly the result of a paradoxical effect of global warming: It actually makes the stratosphere cooler, and a cooler stratosphere slows ozone repair. Yet the critical new findings, the snowballing data, go largely unreported.

Similarly, we hear about the connection between ozone depletion, skin cancers, and cataracts but very little about the fact that increased ultraviolet radiation will also impair or destroy phytoplankton. Without these tiny marine plants turning inorganic sunlight into organic life, none of us would or will be here.

Although they live underwater, phytoplankton mitigate atmospheric carbon dioxide more powerfully than any other known agent. They are critical counterweights to another tipping point: the Antarctic Circumpolar Current (ACC), which circulates 34 billion gallons of water around Antarctica every second, carrying nutrients from the depths to the surface.

A 2006 Princeton study identified this current of the Southern Ocean as the key global player in the balance between the nutrient and carbon cycles of our planet. Put simply, the more nutrients in Antarctic waters, the less carbon dioxide in earth's atmosphere, because the nutrients fuel the phytoplankton that absorb CO2. Moreover, when these phytoplankton die, they sink, taking their CO2 load with them to the cold bottom of the ocean and sequestering it there. But global warming is predicted to slow the nutrient upwelling, affecting phytoplankton populations in the Pacific, Indian, and Atlantic oceans, too.

Just as the oceans affect the atmosphere, so the land affects the oceans. In another of Schellnhuber's tipping points, global warming is expected to shrink the Sahara by increasing rainfall along its southern border. A greener Sahara will emit less airborne desert dust to seed the Atlantic and feed its phytoplankton, to suppress hurricane formation, and to fertilize the CO2-eating trees of Amazonia. Hardly a neighborhood on earth will look the same if Africa tips.

THE GAME THEORY OF COCKROACH DEMOCRACY

Recent research out of the Université Libre de Bruxelles in Belgium shows that cockroaches live in a democracy composed of individuals with equal standing that consult to reach consensus on decisions affecting the whole group. These decisions are made nonhierarchically and in the absence of perfect knowledge. Somehow these simple creatures balance the inevitable conflicts between cooperation and competition in ways that benefit all.

Some dolphins manage this social dilemma ingeniously, too. At 5.5 feet long and 150 pounds, Tahitian spinner dolphins are among the world's smallest cetaceans, inhabiting the tropical waters of the globe, often in close proximity to coral reefs. They live in flexible, ever-changing groups composing what the late Ken Norris of the University of California-Santa Cruz called "a society of remarkably cooperative friends."

This day in French Polynesia, a group of about 25 spinner dolphins is sleeping behind the barrier reef protecting Moorea's lagoon from the open sea. Like all dolphins, they remain conscious during sleep, resting only the hearing parts of their brains while relying on their sight to identify predators. In this state, they move as stealthily as ghosts, surfacing quietly, breathing low. But by the late afternoon the school begins to awaken and the dolphins pick up speed, with individuals bursting through the surface to perform the dramatic aerial leaps and spins for which the species is named.

Then almost as quickly as they awoke, the dolphins slow down again. The spinners have entered the phase of their day Norris and colleagues dubbed "zigzag swimming," with the group oscillating between sleep and wakefulness, as some individuals wish to awaken and others wish to lounge abed in the lagoon a while longer.

Underwater, the split in intentions is even more obvious. When the group is persuaded to sleep, the dolphins fall silent. When the group is urged to awaken, the sea explodes with the whistles, clicks, quacks, moos, baahs, barks, and squawks of their varied calls. In short order, these sounds are accompanied by an artillery barrage of dull booms and hissing bubble trains: the percussion of belly flops and back flops at the surface.

Like howling wolves and cawing crows the spinners are consolidating their intentions, using zigzag swimming to cast and recast their votes until consensus is reached. As the afternoon progresses, their phonations grow louder, eventually merging into the congested cross talk that Norris et al. jokingly called the Yugoslavian News Broadcast. This is the buoyant clamor of true democracy. Since there is no leader or hierarchy in this or any other aspect of spinner life, every dolphin is awarded the same voting power. However many individuals reside here today is the same number that must now agree on when to leave and where to go.

It's no easy decision. At stake are their lives. By leaving the lagoon the spinners face real danger. To catch fish they must venture offshore and dive alone or in mother-calf pairs to depths of 1,000 feet or more in the nighttime sea. They will be hunting alongside many larger predators, including sharks hunting them.

Throughout the night the school maintains auditory contact as members share information (location of a food source) and resources (the food), even when that sharing might diminish their own wellbeing (less food left for them). This trade-off enables individuals to survive conditions they could not survive alone.

Curiously, cockroaches and spinner dolphins have learned to share in ways both prudent and wise—despite the predictions of game theory, which in its simplest guise posits that cheaters will beat altruists every time. Clearly, nature knows otherwise.

A recent study hints at the evolution of altruism. A team of Swiss and American mathematicians and population biologists ran a variant of game theory known as a public goods game, in which players contribute money to a common pot that an experimenter doubles, divides evenly, and returns to the players. In ordinary play, if all players contribute all their money, everyone wins big. If one player cheats, everyone wins small. If an altruist and a cheater go head-to-head, the cheater wins consistently. This paradox is known as the Tragedy of the Commons.

But in the new computer variant, population dynamics were introduced into the game. Players were divided into small groups that played among themselves. Each player eventually "reproduced" in proportion to the payoff received from play—thereby passing her cooperator or cheater strategy to her offspring. Mutations and dispersions were introduced, creating a shifting population of individuals divided into groups of changing sizes and allegiances.

After 100,000 generations, the results were surprising. Rather than succumbing to the cheaters, the cooperators overwhelmed them.

This is because cooperators flourish in smaller groups where their high investments begin to pay off, says Thomas Flatt, one of the study's authors. They reproduce at higher rates, gain a toehold in a group, eventually come to dominate it, then launch their offspring to spread their altruism to other groups.

Cockroaches have been on earth about 300 million years and dolphins about 50 million years—what amounts to millions of rounds of play. During those eons they have evolved what ethologists call "obligate cooperation": an evolutionarily stable strategy that reflects the individual's inescapable dependence on the group.

Somewhere along the way, these two very different life-forms found the tipping point and slipped from selfishness toward altruism, transforming what we perceive as the Tragedy of the Commons into something more like a triumph.

SEQUESTERED KNOWLEDGE AND SNOW MIRRORS



KNOWLEDGE CAN BE VIEWED as a commons. At the moment, science knows far more than it "tells" to the larger world, in effect hoarding its resource. Not all scientists agree with this strategy, leading the community to play out its own version of zigzag swimming.

At a recent meeting of the Society for Conservation Biology, members argued over whether they should simply publish their findings in their scientific journals or advocate solutions—by forcing their results, conclusions, and suggestions in front of lethargic policymakers and the press. Some vigorously oppose the proactive approach as one that sullies research. Others believe the time has come for the man behind the curtain to step forth. A survey in the wake of the conference found that 70 percent of the 300 members favored increased advocacy. At the moment, however, the behavior of most researchers is still largely non-advocatory, depriving the lay world of the right to zigzag on its own through global warming issues.

Sequestering scientific knowledge is the equivalent of piling lead weights on the scales of the tipping points we hear little or nothing about. Take another tipping point: the Tibetan Plateau, a million square miles of steppe, mountains, and lakes. This roof of the world is home to fewer people per square mile than any land besides Greenland and Antarctica. Rising an average of 15,000 feet above sea level, its snowy heights act like an enormous mirror reflecting the sun's warming rays back to space. But global warming is forecast to melt these snows and uncover dark soils ideal for absorbing sunlight and warming the earth in a positive feedback loop.

The Tibetan Plateau acts like a powerful chimney between earth and the sky, connecting tipping points in both places. It cools the stratosphere by drawing water vapor and chemicals upward via thunderstorms. A cooler stratosphere rearranges the jet stream, resulting in warmer winters in North America and Europe, and exacerbating the Greenland and ozone-hole tipping points.

The source of Tibet's thunderstorms is the Asian monsoon, which drives oceanic moisture up the flanks of the Himalayas. Geoscientists expect a warming climate to either weaken or strengthen the monsoon, perhaps one after the other. Either effect is potentially catastrophic for the more than half the world's population adapted to and reliant on the monsoon as it currently exists. For this reason, the monsoon is another of Schellnhuber's tipping points.

The health of the monsoon is critically connected to the ocean, notably the faraway North Atlantic thermohaline circulation. Working with fossilized plankton and ancient iceberg debris, scientists from India and America have concluded that periods of a cooler and less salty North Atlantic corresponded to—or else produced—weaker monsoons. This suggests a warming climate might strengthen the monsoon, perhaps ruinously, then weaken it below present levels if and when the THC shuts down.

Other studies hint that the connective tissue between the monsoon and the North Atlantic is none other than the Tibetan Plateau. Normally, spring warms the air above Tibet and powers the pressure gradient driving the monsoon. But a cooler North Atlantic might cool the plateau lying downwind, stalling the monsoon's ignition.

No matter how badly it manifests for us, nature evolves toward efficiency, balancing the spinning plates at the point of minimum effort, rearranging them with ruthless dexterity.

THE RECIPROCAL ALTRUISM OF VAMPIRE BATS

AN ASSESSMENT BY the World Health Organization concluded that the effects of climate change since the mid-1970s likely caused more than 150,000 deaths in the year 2000. Other analyses estimate 160,000 deaths a year since then. In contrast, terrorism caused 56 American deaths in 2005, the same year we spent about $100 billion fighting it and its shadow oil war—even as these investments fantastically increased the real threats to our homeland security.

To mitigate and survive the global changes coming our way, we need to cooperate in unprecedented ways. Biologists have long struggled with the notion of cooperation, which was once seen as benefiting the "survival of the species"—until geneticists pointed out that, evolutionarily speaking, there is no mechanism in place for species survival, only individual survival. William Hamilton's work on colonial-living insects advanced the radical idea that related individuals might act altruistically because they share genes.

Eventually, scientists surmised that individuals act altruistically toward even unrelated others in expectation of an equivalent reciprocal act at some time in the future. A now-classic example was found among vampire bats. Gerald Wilkinson of the University of Maryland discovered that on any given night, 7 percent of adult vampire bats and 33 percent of juveniles fail to find a blood meal. They rarely go hungry, however, since well-fed bats regurgitate blood to them upon return to the roosting colony.

Wilkinson's experiments showed that bats are more likely to share blood with a bat that has previously fed them. Without these reciprocated favors, he wrote, "annual mortality should exceed 80 percent, but female vampire bats are known to survive more than 20 years in the wild." In other words, because they share a little every day, vampire bats increase their longevity over a lifetime. Those that don't share die young.

The notion of reciprocal altruism is tested in game theory through the Prisoner's Dilemma, in which two players pitted against each other choose to cooperate or not cooperate (cheat). Cheaters always win—except when the same players engage in repeated rounds together. Iterated play eventually produces a tit-for-tat response, until the players learn to cooperate, lest they both lose. In this way, punishment for cheating leads to cooperation.

A Prisoner's Dilemma variant run by Stuart West of the University of Edinburgh found that small groups of people are more likely to come together and cooperate (share resources) when engaged in repeated interactions, and when the competition for resources occurs on a more global than local scale. His study took place over two years, engaging undergraduate classes of 12 or 15 students broken into groups of 3. West's results suggest that manipulating how the players perceive competition alters the level of cooperation. He suggests this insight could be used to encourage altruism. One way would be to reward local cooperation. Another would be to create a common enemy who must be competed against globally.

Since we already have our common enemy, global warming, perhaps we can bring it to life. Picture a fiery monster consuming our neighborhoods. It's big and scary yet vulnerable to the Lilliputian arrows each of us wields with personal lifestyle choices. However, the hybrid car is not enough. Wielding the big stick of consumer choice, we can batter the fiery monster more convincingly if we persuade the corporate world that we are serious and, collectively, powerful. We can buy or not buy. We can invest or not invest. Business can survive by becoming green and sustainable.

How might we get these messages across? Imagine a lottery funding advertising about the fiery monster, the Lilliputian arrows, the neighborhood dangers. Ideally these advertisements would be big and splashy and persistent enough to awaken us from our slumber in the televised lagoon.

Instead of a ticket, we'd buy a web listing displaying our commitment to the battle as well as our marksmanship rating: a number reflecting how much money we'd donated, the efficiency of our car, home, appliances. The highest-rated players would earn high-visibility web pages. Low-rated players could improve their ratings by following a list of lifestyle amendments. The higher our rating, the greater our chances in the lottery. Every week someone would win.

Would we play?

THE CLATHRATE GUN HYPOTHESIS

HERE'S WHAT HAPPENS when we don't. Left to governments alone, the troubles breed and fester. For example, the Kyoto Protocol, ratified by 165 nations (but not the United States), requires its signatories to report their greenhouse gas emissions. A 2004 study by the European Commission Joint Research Centre in Italy found this voluntary reporting to be grossly inaccurate. The United Kingdom, for instance, which advertises itself as a leader in the global warming fight, actually emits up to 92 percent more methane than reported. Other enormous discrepancies were found in Germany, China, and France.

Methane is one of the three greenhouse gases reported under Kyoto (along with carbon dioxide and nitrous oxide). Twenty times as powerful a greenhouse gas as carbon dioxide, methane has more than doubled in the atmosphere in the last 150 years until today it totals about half the greenhouse effect caused by carbon.

Worse, methane emissions increase rapidly in a warming climate. So even as methane alters climate, it is also affected by climate—another dangerous positive feedback loop. Methane garners its own tipping point in the form of methane clathrates, the 1- to 2.5-trillion-ton reservoir of frozen methane underlying the ocean floor and the Arctic permafrost.

Some scientists believe that the sudden melting of clathrates in the past released massive "burps" into the atmosphere, catastrophically amplifying global warming. The Clathrate Gun Hypothesis posits that a big burp of methane triggered the Permian-Triassic extinction 250 million years ago. Schellnhuber and others fear this could happen again as ocean temperatures warm, and as the permafrost melts. A recent study in Nature reported that the Siberian and Alaskan permafrosts are rapidly melting, releasing five times more methane than expected.

Exacerbating those problems, a study by Russian and American researchers in Science published in June announced, is a heretofore unknown global carbon source in a deep layer of permafrost known as loess, which contains an estimated 500 gigatons of carbon. The loess has never been accounted for in climate warming models.

Warming oceans may also trigger the tipping point known as salinity valves—the chemical plugs enabling oceanic bodies to maintain strikingly different ecosystems and biodiversity. These include the Mediterranean, the Red Sea, the Caribbean, the Persian Gulf, the Gulf of Mexico, the Black Sea, the Baltic, and the Java Sea. Warming waters may unbalance the El Niño tipping point, too, which NOAA researchers report could create a persistent El Niño with biblical droughts and floods afflicting half the globe all year, every year.

Finally, the West Antarctic Ice Sheet. Long believed too cold to melt anytime soon, this icy world now confounds the soothsayers. New data from the British Antarctic Survey hint that the slumbering giant is awakening, its 7 million cubic miles of ice thinning dangerously. If melted, the ice sheet will raise sea levels between 16 and 50 feet worldwide.

This recent melt may be caused in part by the Antarctic Oscillation—a kind of on/off switch affecting pressure gradients in the Southern Hemisphere. At its current setting, the Antarctic Oscillation is warming Antarctica, increasing the melt, and accelerating the flow of the Antarctic Circumpolar Current (our earlier tipping point). As we've heard, changes in this current affect plankton populations, which affect atmospheric CO2. Changes in the ACC also affect the global thermohaline circulation, which controls everything from Europe's thermostat to the monsoon.

In the end, all the spinning plates spin or fall together, and the Antarctic Oscillation appears to be triggered by none other than the ozone hole, the wound that refuses to heal. The cooler stratosphere caused by (and causing) the ozone hole produces the weather changes at ground level now threatening to turn Antarctica's icescape into a continent-swallowing seascape.

In less than 200 years, armed with fossil fuels, we've wrested hold of the spinning plates, donned the acrobat's tights, and initiated our own wobbly circus. Nature, impassive and plenipotent, waits to reward or punish us.

LET THEM EAT CO2

THE NATURE OF TIPPING POINTS is that they happen dizzyingly fast. The good news is that history proves we are capable of keeping up. Social scientists once believed it would take decades of government pressure and education for Americans to choose smaller families, since the desire to procreate is an absolute part of the human animal, or so they thought. Yet population radically declined in the course of only three years in the 1970s—one woman at a time, without an ounce of government involvement. Harvard sociobiologist Edward O. Wilson calls the voluntary choice of women around the globe to limit their families an almost miraculous gift to future generations.

We also changed with breathtaking speed in 1941 when we recalibrated the entire economy of the United States in one short year to fight global enemies in Germany and Japan. The effort was promoted by the government but carried forward by individual citizens. Obviously, our powers of transformation are magnified by visionary leaders. Mahatma Gandhi's Salt March in 1930 ignited Indians of diverse religions, languages, and ethnicities to unite in the common cause of independence. Gandhi, in turn, inspired Martin Luther King Jr., Stephen Biko, Nelson Mandela, and Aung San Suu Kyi, who catalyzed their followers to change the world as well.

Leaders can rouse us against them, too. Whether or not Marie Antoinette actually said, "Let them eat cake," she inspired change that reverberated far beyond Europe. Likewise, when George W. Bush says we can't act on global warming until we "fully understand the nature of the problem," we can use his callous disregard as a rallying cry.

The truth is, we can change, and change fast, even in the absence of perfect knowledge. Like cockroaches, our hallmark is adaptability. Long ago, we looked out from the trees and saw the savannas. Beyond the savannas we glimpsed other frontiers. History proves that when we behold a better world, we move toward it, leaving behind what no longer works.

WE ARE THE ANTIDOTE

THIS MORNING, IN THE AFTERMATH of the coral spawning on Australia's Great Barrier Reef, the surface of the sea is slick and pink with eggs. From the air or from afar it looks like an oil spill and smells like a fish kill, drawing in creatures from the deep and creatures from the land, including crocodiles cruising the reefs. Underwater, the fish that make their living picking plankton are hyperactively at work—the day shift toiling alongside the night shift, as lobsters, cuttlefish, and flashlightfish forgo sleep to feast. Above, the air is crowded with seabirds plucking at the surface with pink-stained beaks.

In the coming days the gamete cloud will travel on prevailing currents, triggering the corals below to spawn. Seduced by moonlight, spring, and the tides, stimulated by the chemistry of other spawners, the tiny creatures that build their own world will build it again.

So too with us. The difference between people and corals is that if we build our world poorly, we can rebuild it well. We know what to do. We know how to do it. We know the timeline. We are our own antidote.