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.