Part 9 (1/2)

That's not the only way birds cope with human noise. In 2007 Richard Fuller and two other scientists at the University of Sheffield in the United Kingdom discovered that European robins liv ing in noisy urban areas have radically departed from their normal behavior of singing during the day. Now they sing almost exclusively at night, presumably to evade interference from the human din. If you hear a bird singing on your way home from a night at the pub, it's probably a robin, Fuller says.

In Berlin, nightingales have taken a different approach, raising their singing volume in response to traffic noise, according to a study by Henrik Brumm of that city's Free University, published in the Journal of Animal Ecology. In what is known as the Lombard effect, where a singer or speaker raises his voice to be heard, the nightingales try to counteract rush-hour clamor by singing louder on weekday mornings than on weekend mornings.

Most research on the impact of human sounds has focused on birds, but there is growing evidence that what's happening in the avian world is playing out across the animal kingdom, even in remote places that might seem impervious to human soundsa”places like the deep ocean.

Cities are getting louder, but underwater noise is increasing even faster. There are about twice as many s.h.i.+ps plying the world's oceans now as in the 1960s, and these s.h.i.+ps are faster, more powerful, and collectively far noisier than their predecessors. When scientists at the Scripps Inst.i.tution of Oceanography and the Colorado-based company Whale Acoustics compared sound levels west of California's San Nicolas Island in 2003 and 2004 with measurements made during the 1960s at the same site, they found that ambient noise levels had increased about tenfold. And this area may be representative of the entire northeast Pacific, the scientists say in a report published in the Journal of the Acoustical Society of America.

Instead of containing this noise within s.h.i.+pping lanes or coastal areas, the ocean's unique dynamics actually help the sounds travel hundreds or even thousands of kilometers. The so-called ”deep sound channel” is a layer of water where sound travels slowly but encounters little resistance or interference. Some scientists suspect that humpback whales dive down to this channel and then sing into it, communicating with other humpbacks hundreds of kilometers away. And when noises from commercial s.h.i.+pping, offsh.o.r.e drilling, and other human activities get caught in the channel, they too are carried far from the original source.

Researchers have only just begun investigating these sounds' exact impacts, but a few studies suggest man-made noise is forcing marine mammals to respond in much the same way as birds do. Scientists at the Inst.i.tute of Ocean Sciences in Sidney, Canada, have shown that beluga whales change their vocal patterns in response to the presence of icebreakers, whose systems interfere with the belugas' preferred frequencies. Belugas also switch the frequencies of their echolocation clicks when background noise increases. Elsewhere, orcas in the Pacific Northwest have changed their calls, perhaps in response to increased traffic by commercial s.h.i.+ps and whale-watching boats.

In more extreme cases, human sounds have forced whales to abandon their preferred habitat. For instance, gray whales have long used Baja California's Guerrero Negro lagoon as a calving ground. But when construction at a nearby salt factory spurred increases in s.h.i.+p traffic and dredging activities, the whales stayed away from the lagoon for several years, returning only after construction ebbed.

Some researchers interpret these adaptations as a heartening sign, pointing out that some animals will simply change along with the soundscape. But Slabbekoorn cautions that some species could be wiped out by the human din.

Because low-frequency traffic noise accounts for most of humans' clamor, animals that use low-frequency calls and can't switch to higher frequencies are threatened most. Slabbekoorn says birds such as orioles, great reed warblers, and house sparrows fit this category. Populations of house sparrows are declining throughout Europe; researchers haven't pinpointed the cause, but Slabbekoorn suspects human noise is a factor.

Bernie Krause has witnessed a similar phenomenon among spadefoot toads in the Mono Lake basin east of Yosemite National Park. Using its big front claws, the toad buries itself one meter below the desert floor and can survive there for up to six years. When rain finally comes, the toad emerges and joins others to sing in chorus, which makes it harder for predators such as owls and coyotes to get a bead on where the sound is coming from.

The problem is that during nighttime periods when the toads do their singing, military jet planes often use the basin for training. Flying only one hundred meters above the ground, the planes are so loud that the toads can't hear each other. Even after the planes leave, it takes twenty to forty-five minutes for the toads to resume their synchronized chorus, and in the meantime they're vulnerable to predators. Krause believes the noise is partly responsible for a precipitous decline in spadefoot populations, which he has studied since 1984.

Even adaptable species may be altered in fundamental ways. For instance, if changing calls or switching frequencies helps male birds be heard, they could earn an advantage when it comes to attracting female mates. Over time, this dynamic could force evolutionary changes, splitting populations of birds into localized species with specialized reactions to the sounds in their vicinity.

Slabbekoorn and his colleague Erwin Ripmeester think these noise-driven evolutionary forces may already be separating European blackbirds into urban and rural subspecies. The two researchers have even begun testing whether rural birds can recognize their urban brethren's hip new calls. If Slabbekoorn and Ripmeester's hunch is correct, it could mean that humans, already powerful conductors of the material world, may be extending their fierce control to the audible one.

ELIZABETH KOLBERT The Catastrophist.

FROM The New Yorker.

A FEW MONTHS AGO, James Hansen, the director of NASA's G.o.ddard Inst.i.tute for s.p.a.ce Studies, in Manhattan, took a day off from work to join a protest in Was.h.i.+ngton, D.C. The immediate target of the protest was the Capitol Power Plant, which supplies steam and chilled water to congressional offices, but more generally its object was coal, which is the world's leading source of greenhouse-gas emissions. As it happened, on the day of the protest it snowed. Hansen was wearing a trench coat and a wide-brimmed canvas boater. He had forgotten to bring gloves. His sister, who lives in D.C. and had come along to watch over him, told him that he looked like Indiana Jones.

The march to the power plant was to begin on Capitol Hill, at the Spirit of Justice Park. By the time Hansen arrived, thousands of protesters were already milling around, wearing green hard hats and carrying posters with messages like POWER PAST COAL and CLEAN COAL IS LIKE DRY WATER. Hansen was immediately surrounded by TV cameras.

”You are one of the preeminent climatologists in the world,” one television reporter said. ”How does this square with your science?”

”I'm trying to make clear what the connection is between the science and the policy,” Hansen responded. ”Somebody has to do it.”

The reporter wasn't satisfied. ”Civil disobedience?” he asked, in a tone of mock incredulity. Hansen said that he couldn't let young people put themselves on the line ”and then I stand back behind them.”

The reporter still hadn't got what he wanted: ”We've heard that you all are planning, even hoping, to get arrested today. Is that true?”

”I wouldn't hope,” Hansen said. ”But I do want to draw attention to the issue, whatever is necessary to do that.”

Hansen, who is sixty-eight, has greenish eyes, spa.r.s.e brown hair, and the distracted manner of a man who's just lost his wallet. (In fact, he frequently misplaces things, including, on occasion, his car.) Thirty years ago, he created one of the world's first climate models, nicknamed Model Zero, which he used to predict most of what has happened to the climate since. Sometimes he is referred to as the ”father of global warming,” and sometimes as the grandfather.

Hansen has now concluded, partly on the basis of his latest modeling efforts and partly on the basis of observations made by other scientists, that the threat of global warming is far greater than even he had suspected. Carbon dioxide isn't just approaching dangerous levels; it is already there. Unless immediate action is takena”including the shutdown of all the world's coal plants within the next two decadesa”the planet will be committed to change on a scale society won't be able to cope with. ”This particular problem has become an emergency,” Hansen said.

Hansen's revised calculations have prompted him to engage in activitiesa”like marching on Was.h.i.+ngtona”that aging government scientists don't usually go in for. Last September, he traveled to England to testify on behalf of anticoal activists who were arrested while climbing the smokestack of a power station to spray-paint a message to the prime minister. (They were acquitted.) Speaking before a congressional special committee last year, Hansen a.s.serted that fossil fuel companies were knowingly spreading misinformation about global warming and that their chairmen ”should be tried for high crimes against humanity and nature.” He has compared freight trains carrying coal to ”death trains,” and he wrote to the head of the National Mining a.s.sociation, who sent him a letter of complaint, that if the comparison ”makes you uncomfortable, well, perhaps it should.”

Hansen insists that his intent is not to be provocative but conservative: his only aim is to preserve the world as we know it. ”The science is clear,” he said, when it was his turn to address the protesters blocking the entrance to the Capitol Power Plant. ”This is our one chance.”

The fifth of seven children, Hansen grew up in Denison, Iowa, a small, sleepy town close to the western edge of the state. His father was a tenant farmer who, after World War II, went to work as a bartender. All the kids slept in two rooms. As soon as he was old enough, Hansen went to work, too, delivering the Omaha World-Herald. When he was eighteen, he received a scholars.h.i.+p to attend the University of Iowa. It didn't cover housing, so he rented a room for twenty-five dollars a month and ate mostly cereal. He stayed on at the university to get a Ph.D. in physics, writing his dissertation on the atmosphere of Venus. From there he went directly to the G.o.ddard Inst.i.tute for s.p.a.ce Studiesa”GISS, for shorta”where he took up the study of Venusian clouds.

By all accounts, including his own, Hansen was preoccupied by his research and not much interested in anything else. GISS's offices are a few blocks south of Columbia University; when riots shut down the campus, in 1968, he barely noticed. At that point, GISS's computer was the fastest in the world, but it still had to be fed punch cards. ”I was staying here late every night, reading in my decks of cards,” Hansen recalled. In 1969 he left GISS for six months to study in the Netherlands. There he met his wife, Anniek, who is Dutch; the couple honeymooned in Florida, near Cape Canaveral, so they could watch an Apollo launch.

In 1973 the first Pioneer Venus mission was announced, and Hansen began designing an instrumenta”a polarimetera”to be carried on the orbiter. But soon his research interests began to s.h.i.+ft earthward. A trio of chemistsa”they would later share a n.o.bel Prizea”had discovered that chlorofluorocarbons and other man-made chemicals could break down the ozone layer. It had also become clear that greenhouse gases were rapidly building up in the atmosphere.

”We realized that we had a planet that was changing before our eyes, and that's more interesting,” Hansen told me. The topic attracted him for much the same reason Venus's clouds had: there were new research questions to be answered. He decided to try to adapt a computer program that had been designed to forecast the weather to see if it could be used to look further into the future. What would happen to Earth if, for example, greenhouse-gas levels were to double?

”He never worked on any topic thinking it might be any use for the world,” Anniek told me. ”He just wanted to figure out the scientific meaning of it.”

When Hansen began his modeling work, there were good theoretical reasons for believing that increasing CO2 levels would cause the world to warm, but little empirical evidence. Average global temperatures had risen in the 1930s and '40s; then they had declined, in some regions, in the 1950s and '60s. A few years into his project, Hansen concluded that a new pattern was about to emerge. In 1981 he became the director of GISS. In a paper published that year in Science, he forecast that the following decade would be unusually warm. (That turned out to be the case.) In the same paper, he predicted that the 1990s would be warmer still. (That also turned out to be true.) Finally, he forecast that by the end of the twentieth century a global-warming signal would emerge from the ”noise” of natural climate variability. (This, too, proved to be correct.) Later, Hansen became even more specific. In 1990 he bet a roomful of scientists that that year or one of the following two would be the warmest on record. (Within nine months, he had won the bet.) In 1991 he predicted that owing to the eruption of Mt. Pinatubo, in the Philippines, average global temperatures would drop and then, a few years later, recommence their upward climb, which was precisely what happened.

From early on, the significance of Hansen's insights was recognized by the scientific community. ”The work that he did in the seventies, eighties, and nineties was absolutely groundbreaking,” Spencer Weart, a physicist turned historian who has studied the efforts to understand climate change, told me. He added, ”It does help to be right.”

”I have a whole folder in my drawer labeled 'Canonical Papers,'” Michael Oppenheimer, a climate scientist at Princeton, said. ”About half of them are Jim's.”

Because of its implications for humanity, Hansen's work also attracted considerable attention from the world at large. His 1981 paper prompted the first front-page article on climate change that ran in the Timesa”STUDY FINDS WARMING TREND THAT COULD RAISE SEA LEVELS, the headline reada”and within a few years he was regularly being invited to testify before Congress. Still, Hansen says, he didn't imagine himself playing any role besides that of a research scientist. He is, he has written, ”a poor communicator” and ”not tactful.”

”He's very shy,” Ralph Cicerone, the president of the National Academy of Sciences, who has known Hansen for nearly forty years, told me. ”And, as far as I can tell, he does not enjoy a lot of his public work.”

”Jim doesn't really like to look at anyone,” Anniek Hansen told me. ”I say, 'Just look at them!'”

Throughout the 1980s and '90s, the evidence of climate changea”and its potential hazardsa”continued to grow. Hansen kept expecting the political system to respond. This, after all, was what had happened with the ozone problem. Proof that chlorofluorocarbons were destroying the ozone layer came in 1985, when British scientists discovered that an ozone ”hole” had opened up over Antarctica. The crisis was resolveda”or, at least, prevented from growing worsea”by an international treaty phasing out chlorofluorocarbons, which was ratified in 1987.

”At first, Jim's work didn't take an activist bent at all,” the writer Bill McKibben, who has followed Hansen's career for more than twenty years and who helped organize the anticoal protest in D.C., told me. ”I think he thought, as did I, If we get this set of facts out in front of everybody, they're so powerfula”overwhelminga”that people will do what needs to be done. Of course, that was naive on both our parts.”

As recently as the George W. Bush administration, Hansen was still operating as if getting the right facts in front of the right people would be enough. In 2001 he was invited to speak to Vice President d.i.c.k Cheney and other high-level administration officials. For the meeting, he prepared a detailed presentation t.i.tled ”The Forcings Underlying Climate Change.” In 2003 he was invited to Was.h.i.+ngton again, to meet with the head of the Council on Environmental Quality at the White House. This time he offered a presentation on what ice-core records show about the sensitivity of the climate to changes in greenhouse-gas concentrations. But by 2004 the administration had dropped any pretense that it was interested in the facts about climate change. That year NASA, reportedly at the behest of the White House, insisted that all communications between GISS scientists and the outside world be routed through political appointees at the agency. The following year, the administration prevented GISS from posting its monthly temperature data on its website, ostensibly on the ground that proper protocols had not been followed. (The data showed that 2005 was likely to be the warmest year on record.) Hansen was also told that he couldn't grant a routine interview to National Public Radio. When he spoke out about the restrictions, scientists at other federal agencies complained that they were being similarly treated, and a new term was invented: government scientists, it was said, were being ”Hansenized.”

”He had been waiting all this time for global warming to become the issue that ozone was,” Anniek Hansen told me. ”And he's very patient. And he just kept on working and publis.h.i.+ng, thinking that someone would do something.” She went on, ”He started speaking out, not because he thinks he's good at it, not because he enjoys it, but because of necessity.”

”When Jim makes up his mind, he pursues whatever conclusion he has to the end point,” Michael Oppenheimer said. ”And he's made up his mind that you have to pull out all the stops at this point, and that all his scientific efforts would come to naught if he didn't also involve himself in political action.” Starting in 2007, Hansen began writing to world leaders, including Prime Minister Gordon Brown, of Britain, and Yasuo f.u.kuda, then the prime minister of j.a.pan. In December 2008, he composed a personal appeal to Barack and Mich.e.l.le Obama.

”A stark scientific conclusion, that we must reduce greenhouse gases below present amounts to preserve nature and humanity, has become clear,” Hansen wrote. ”It is still feasible to avert climate disasters, but only if policies are consistent with what science indicates to be required.” Hansen gave the letter to Obama's chief science adviser, John Holdren, with whom he is friendly, and Holdren, he says, promised to deliver it. But Hansen never heard back, and by the spring he had begun to lose faith in the new administration. (In an e-mail, Holdren said that he could not discuss ”what I have or haven't given or said to the President.”) ”I had had hopes that Obama understood the reality of the issue and would seize the opportunity to marry the energy and climate and national-security issues and make a very strong program,” Hansen told me. ”Maybe he still will, but I'm getting bad feelings about it.”

There are lots of ways to lose an audience with a discussion of global warming, and new ones, it seems, are being discovered all the time. As well as anyone, Hansen ought to know this; still, he persists in trying to make contact. He frequently gives public lectures; just in the past few months, he has spoken to Native Americans in Was.h.i.+ngton, D.C.; college students at Dartmouth; high school students in Copenhagen; concerned citizens, including King Harald, in Oslo; renewable-energy enthusiasts in Milwaukee; folk music fans in Beacon, New York; and public health professionals in Manhattan.

In April I met up with Hansen at the state capitol in Concord, New Hamps.h.i.+re, where he had been invited to speak by local anticoal activists. There had been only a couple of days to publicize the event; nevertheless, more than 250 people showed up. I asked a woman from the town of Ossipee why she had come. ”It's a once-in-a-lifetime opportunity to hear bad news straight from the horse's mouth,” she said. For the event, Hansen had, as usual, prepared a PowerPoint presentation. It was projected onto a screen beside a faded portrait of George Was.h.i.+ngton. The first slide gave the t.i.tle of the talk, ”The Climate Threat to the Planet,” along with the disclaimer ”Any statements relating to policy are personal opinion.”

Hansen likes to begin his talk with a highly compressed but still perilously long discussion of climate history, beginning in the early Eocene, some 50 million years ago. At that point, CO2 levels were high and, as Hansen noted, the world was very warm: there was practically no ice on the planet, and palm trees grew in the Arctic. Then CO2 levels began to fall. No one is entirely sure why, but one possible cause has to do with weathering processes that, over many millennia, allow carbon dioxide from the air to get bound up in limestone. As CO2 levels declined, the planet grew cooler; Hansen flashed some slides on the screen, which showed that between 50 million and 35 million years ago, deep ocean temperatures dropped by more than 10 degrees. Eventually, around 34 million years ago, temperatures sank low enough that glaciers began to form on Antarctica. By around 3 million years agoa”perhaps earliera”permanent ice sheets had begun to form in the Northern Hemisphere as well. Then, about 2 million years ago, the world entered a period of recurring glaciations. During the ice agesa”the most recent one ended about 12,000 years agoa”CO 2 levels dropped even further.