March of the Tourists

Polar Earth is thawing. Does it matter if the visiting hordes don't understand?

July/August 2008 Issue

If not for the wind, it would be another hot day in Antarctica. But the 20 knots blasting around the shoulders of Penguin Island are stripping us of sweat and what feels like our clothes. I'm shivering hard, and working hard to keep up with Heather Lynch, 5 feet 4 inches of science dynamo, robin's-egg-blue rubber boots pistoning through knee-deep snow with manic determination. She turns 30 this July and is training for a 19-mile wilderness run in Vermont billed as the hardest for its distance anywhere.

We're in the Antarctic Peninsula, that Sistine Chapel of the geologic world, with its godlike finger of mountains reaching across the Drake Passage toward South America's mountains of men. Training helps. We have only a couple of hours ashore to count an expected two or three thousand penguins, with a few cross-country miles to hike to and from the rookery across unknown terrain, orienteering via a hand-drawn map that might as well say here be dragons for all it's worth. Ordinarily, penguin rookeries aren't cryptic places. They advertise through a landscape of jittery, methlike overactivity, a soundscape of braying, buzzing, and honking, and a scentscape reeking of guano and treacly dead things.

Except we can't find this one, and resort to sniffing over sea cliffs 150 feet high. Below, icebergs rear like Mormon temples from the battleship-gray waters of the Bransfield Strait. A few weeks back, a smaller version of one of these white behemoths sank the venerable Antarctic tour ship the Explorer in view from here, stranding 154 passengers and crew in lifeboats for four hours. The first ship to the rescue was the National Geographic Endeavour—Lynch's and my ride, anchored offshore now.

We power hike until the snowfields give way to desolate, burnt slopes of ejected volcanic boulders. The island has the feel of a tensed muscle overdue for another tectonic release. The last eruption here was estimated by the dating of lichens as 1905—the same year French polar explorer Jean-Baptiste Charcot began to amass 32-plus volumes of observations on the Antarctic Peninsula, a treasure chest of data that Lynch and her colleagues still mine today.

In the lee of the island's summit we finally spy a scattering of a few hundred Adélie and chinstrap penguins where we were expecting thousands. They're subdued, with nary an ecstatic display to be seen, that head-craning, chest-pumping, flipper-flapping performance complete with hee-hawing calls. The Adélies are clustered on empty nests, with only 11 chicks among them. A pitiful tally for an entire year's breeding effort.

Hiking back into radio range, we hear from Ron Naveen, counting southern giant petrel nests on the other side of the island. It's terrible here, he reports, just awful. At first I picture him befouled by stomach-oil spit from the bellies of the huge albatrosslike birds the whalers called stinkers. But his concern is that he's found only 75 nests in a colony that once housed more than 600. Worse, it appears all the petrels are sitting on eggs, far too late in the season for the chicks to survive. The whole island is a bust.

Breeding success in Antarctica is highly variable. Local events—rain, heat, snowfall—can crash an entire season. In East Antarctica, southern giant petrels have been found dead on their nests, a single egg nestled in the brood patch, the birds having succumbed to enormous, burying snows. Yet what's happening now is indicative of a larger meteorological reality. The western Antarctic Peninsula is warming faster than any place on Earth. Wintertime temperatures have risen a staggering 9 degrees Fahrenheit in 50 years. What was once a cold, dry place has become a warm, wet place. The wildlife is reeling from the chaos, some finding opportunity, others catastrophe. On Penguin Island, Adélie populations have plummeted 75 percent since 1980.

Returning across the high flanks of the island, Lynch and I pass a pair of chinstraps—chinnies, as they're affectionately known—waddling toward the distant colony, wings cranked open for balance, lurching from one webbed foot to the other, climbing hard. It's an impressive feat of penguin mountaineering. The pair rests, facing each other, as if conferring on their own adventurous conundrum. We chuckle, though we're puzzled as to why they don't just swim to their front doorstep on the far side of the island.

Of course, there's no telling why penguins make one decision versus another, why they elect a long and difficult path when an easier way is obvious. Any more than we can figure the bizarrely perilous choices of our own kind.

polar peril

It's not just penguins and other Antarctic animals that are in trouble. A sampling of Arctic species reeling from climate change. —J.W.

Lemming Lemming
Reports of mass suicide are erroneous, but some species of these rodents are in danger of extinction from climate change and habitat loss. Many Arctic land species—from flowering plants to insects to birds—are now forced to cope with springtime arriving 30 days earlier than 10 years ago.

Arctic Fox Arctic Fox
A seminal study of Arctic fox dna upends the presumption that animals are able to chase after their range when it dwindles or moves. In fact, Arctic foxes in Europe failed to track northward with the ice melt at the end of the last ice age, dooming their genetics to oblivion. Siberian foxes likely moved east and now largely depend on lemmings for food.

Polar Bear Polar Bear
Among the most ice dependent of all marine mammals. A 23-year study recently found that Hudson Bay polar bears have declined—along with the ice—more than 20 percent in 20 years. Desperate for food, bears are drowning and turning to cannibalism. In 2006 the world's foremost conservation scientists rated the bears as "vulnerable," noting, "It seems unlikely that polar bears will be able to adapt to the current warming trend in the Arctic."

Walrus Walrus
To rest, walruses need to haul out on ice, yet they found so little in 2007 they were forced ashore in record numbers—40,000 on Russia's Arctic coast, where up to 4,000 died in stampedes. Experts worry that as walruses become more land based, they'll strip coastal waters of food, dooming themselves to starvation.

Ribbon Seal Ribbon Seal
A species that needs sea ice because they almost never come ashore. Their future is of such concern due to global warming that in 2007 the Center for Biological Diversity requested federal protection under the Endangered Species Act.

Narwhal Narwhal
The most specialized of all Arctic whales and dolphins, narwhals are believed to fast most of the summer and feed all winter on halibut living beneath the ice. A recent assessment found narwhals more sensitive to climate change than polar bears.

Hooded Seal Hooded Seal
Completely dependent on sea ice for whelping, molting, and mating. A small worldwide population and limited range make this species as vulnerable as polar bears.

Beluga Whale Beluga Whale
Like narwhals, belugas are being infected by diseases such as brucellosis that are traveling north in warming waters.

Musk Ox Musk Ox
Four years ago, 20,000 starved in Canada, victims of a likely climate-change-related, late-autumn rainfall that froze the ground solid and prevented the herd from feeding all winter.

In 1774, after enduring tempests, gales, and fogs, Captain James Cook came up hard against the Antarctic ice sheet and turned back. He never saw the land beyond, land he thought "doomed by nature to everlasting frigidness...whose horrible and savage aspect I have no words to describe." He predicted another explorer would, though "I shall not envy him the honour of the discovery but I will be bold to say that the world will not be benefited by it."

It's still a hard sell, the notion that this frozen continent and its frozen-ocean partner to the north have much relevance to our temperate world. Naveen and Lynch are here to count dwindling numbers of penguins—because, Naveen says, doing so is like looking into a crystal ball and seeing our own future beset by climate change. They're censusing three species (Adélies, chinstraps, gentoos), plus two seabirds (blue-eyed shags, southern giant petrels), at 123 sites in a long-term research project known as the Antarctic Site Inventory. It's a daunting undertaking, facilitated in part by Lindblad Expeditions, which donates one cabin, two bunks, and all meals for two researchers aboard the Endeavour for the entirety of the Antarctic season—a contribution worth a minimum of $200,000 a year. Naveen and Lynch have no control of the ship's itinerary, but are grateful to piggyback on the travels of the tourists.

Ron Naveen's history as a Lindblad lecturer dates back a quarter century. He's also the founder and president of Oceanites (OH-shun-AYE-tees), the nonprofit funding organ for the Antarctic Site Inventory. Heather Lynch, who looks, in her own words, to be 17 years old, is a newcomer to the project, with two Antarctic seasons under her belt. She brings 21st-century science to the table, introducing überstatistics to often-incomplete datasets as a way to fast-forward to results.

I'm hitchhiking on their ride, sharing their tiny, two-bunk cabin, sleeping on a ledge below the porthole. My goal is to report on the International Polar Year, a 63-nation enterprise launched because the poles "are presently changing faster than any other regions of the Earth, with regional and global implications for societies, economies and ecosystems." Written between the lines of the mission statement is the understanding that the frozen poles are Earth's own doomsday vault, our last nest egg of vitals: freshwater, minerals, oil, oceanic currents, climate control, and who knows what else. Vaults we don't want to open.

Naveen, Lynch, and I join 110 passengers aboard the 294-foot Endeavour on their vacation of a lifetime. Fifty years ago there was no infrastructure for tourists in Antarctica. This year, 40,000 will visit aboard more than 58 vessels, with the number predicted to rise to more than 80,000 tourists by 2010. The only obstacles to visitation these days are financial—Lindblad's cheapest berths aboard the Endeavour cost $10,250, plus hefty airfares—though clearly it's worth it. After all, we're all here, tourists, explorers, researchers, writers, sharing similar concerns about a frozen world necessary for our well-being.

We all know how the febrile Arctic is melting toward an ice-free state—while the Antarctic, that mother lode of ice that as recently as 2001 was thought invulnerable in the 21st century, is leaking at the seams. We know that since 2000 atmospheric carbon dioxide levels have increased 35 percent faster than expected, despite the pledges of 180 nations to rein them in. We're aware that polar seas are defying the laws of expectation, warming, in places, a staggering 9 degrees Fahrenheit since 1995, opening the door for nonnative plants and animals to cross the polar thresholds and claim new waters for themselves. We get that all this bodes poorly for penguins and humans alike.

Don't we?

After two days of warm, sunny weather, when I suggest we might expect a change to sleet or snow, one of the guests aboard the Endeavour snorts: Snow? Nobody told us to expect that. More than a few express surprise at snow on the frozen continent. Others, with the stunned look of people booked on the wrong tour, self-medicate at the bar, and don't seem to notice the weather at all. We share meals in the ship's glass-walled dining room, with its gliding panoramas of snow, ice, icebergs, sea, sky, whales, and seabirds, and I hear more than a few guests describe how they came to be here—struck by spontaneous wanderlust after viewing that paean to snow and fatherhood, March of the Penguins.

It's blizzarding the day we arrive at Petermann Island—Oceanites' Antarctic field station and home to three researchers collecting data on penguin breeding efforts. After a brief Zodiac ride, Naveen, Lynch, and I land ahead of the guests and are welcomed ashore by the resident scientists based there for the winter. The greetings are heartfelt and effusive and involve the bestowing of gifts of chocolate and booze and fashion magazines laden with perfume swatches. (There's no shower here.)

We trudge through oversized snowflakes butterflying through the air, past nesting gentoo penguins and their pink guano latrines, to the Arctic Oven, a 20-by-10-foot blimp of a yellow tent built for the cold extremes of the world. It's part kitchen, part science lab, anchored to the ground with a dozen 60-pound "deadmen" bags filled with rocks, now disappearing into the blizzard.

We undress in the sulfur light inside the vestibule, removing every square inch of our sodden, guano-splattered outer clothing before climbing through the tent's zippered hatch. Or, rather, Lynch and I do. Naveen doffs only jacket and boots and steps through with dripping hat and rain pants. Both he and Lynch are giddily happy to be back in their field home—Naveen too much so to be mindful, shuffling in his socks on the cold floor, reaching out to touch everything: the laptop, the satellite phone, the raunchy cards, inflatable flamingo, and weather-beaten maps hanging on the interior clothesline. He's running a monologue about penguins and punctuating his thoughts by tossing back peanut M&Ms pilfered from a bowl on the kitchen table.

Hey, Lynch reminds him, we're on a ship full of goodies. The Petermann gang hardly has any.

But this is The House That Ron Built, so he squirms good-naturedly and eats another handful anyway. It's the first season Naveen hasn't been resident for at least one of two annual five-week stints here, because, he says sadly, things get done faster when he stays home.

He's referring to fundraising, and home is Washington, DC, where he manages the business of collecting charitable contributions and writing science grants that sustain the efforts on Petermann Island, while facilitating 784 visits to 123 bird rookeries across Antarctica since 1994.

The research is daunting. Compounding the difficulties of getting boots on the ground in remote seabird rookeries is the fact that some sites are too big to count. Or too steep. Or too locked in by ice. Or too dangerous due to 70-knot winds on the day of the visit. Furthermore, counts are most useful during only two short windows each season: one at the peak of egg laying, the other at the peak of crèching (the time after hatching when penguin chicks congregate in downy flocks, leaving both parents free to hunt for food). The difference between the number of eggs laid and the number of chicks surviving to crèche is a reliable indicator of how well the species is doing from one year to the next.

The resident team on Petermann Island faces different challenges, including as many as three visiting ships a day, all requiring some aspect of a guided tour. Many days it's hard to get anything done, including the basics. There's no outhouse here, only a rock and the flushing sea, and, if you don't time it right, 100-plus witnesses.

One by one the Endeavour's passengers file up to the Arctic Oven, where the camp manager holds open the hatch to the vestibule so the passengers can peer into the inner workings of a field station. Some seem embarrassed by the zoolike presentation of scientists in their native habitat, and duck away. Others linger with queries, mostly about the living conditions. One woman asks an oft-repeated question, Who does the cooking? We take turns, says Lynch: One person cooks and cleans for a day, followed by two days off. The guest digests this, snow dumping behind her, penguins hee-hawing, wind rattling the guy wires, the fishy stench of guano permeating the air. Huh, she responds: Kind of like a summerhouse on Long Island.

Visitors aren't what they used to be, reports Naveen. The Antarctic aficionados still pilgrimage here, but they're outnumbered these days by doom tourists chasing down the disappearing world and the nouveau riche absentmindedly checking off the premier stop on their grand tour of Planet Earth.

You can't protect what you don't know, said Lars-Eric Lindblad upon first bringing tourists to Antarctica in 1969 (aboard the same Explorer that went to the bottom a few weeks ago). From his pioneering efforts, the notion of ecotourists as ambassadors was born. Nearly 40 years into the training program, the plebes aboard the Endeavour have a ways to go. One guest, when asked after a two-hour onboard lecture on seabird identification whether the bird overhead is a southern giant petrel or black-browed albatross, looks up, shrugs, and admits, I really don't care.

On a day so warm the southern giant petrels are riding thermals rising off icebergs, we sail into the Weddell Sea. The sun is sharp as knives. The air, antiseptically invisible. Islands 50 miles distant seem yards away. Up close, killer whales hunt the floes for sleeping crabeater seals, while cape petrels, those checkerboard flyers of the cold waters, surf the air curls streaming off the ship. I'm wearing flip-flops on deck.

We sail through canyons of ice, enormous tabular bergs colored in sea-glass shades of milk, crystal, turquoise, and cobalt green, shot through with bolts of electric blue. The bergs tower 80 or more feet above us, some the remnants of the 1,264-square-mile Larsen B ice shelf, which in 2002 catastrophically disintegrated at a speed then truly startling to science, but now almost commonplace as both poles and many high elevations summarily liquefy.

As recently as 2000, scientists predicted Arctic summer ice until 2100, whereas some research now suggests its demise by 2013. But even as the bad news from the Arctic mounted, the southernmost continent was considered too big, too remote, too frozen to react with every nuance of changing currents and warming winds. At 5.4 million square miles, it's bigger than Europe, the coldest, windiest, driest place and largest and highest desert on Earth. Much of Antarctica lies more than two miles above sea level; 90 percent of the world's ice and as much as 70 percent of its freshwater are locked in its frozen vault. The prospect of this global Sub-Zero melting anytime soon lies beyond the ken of human imagination, and climate models have long forecast a reassuring stability.

But the certainty of an unshakably frozen South Pole is cracking. The Antarctic Peninsula's thermal sprint is hammering 87 percent of its glaciers into retreat. This past February the Wilkins ice shelf—an area bigger than Connecticut—began to disintegrate, following the familiar script of the Larsen B. In a heartbeat, the northernmost fringe of Antarctica has become more temperate than polar: endowed with snow, but less of it sticking around long enough to become entombed in glaciers, existing glaciers dumping faster into a warming sea. God's finger is growing thin.

The Antarctic landmass is showing the strain too. In 2005, researchers found the first real evidence of massive melting over a multitude of regions previously considered immune, including far inland, at high latitudes, and at high elevations. Put together, these disparate melt zones add up to an area the size of California. Furthermore, whereas scientists were expecting a growth in Antarctica's coastal ice sheets from heavier snowfall, a 10-year study found much of them in mysterious, rapid decline. Losing the coastal ice opens the floodgates for glaciers to surge into the sea, not only raising sea levels but also adding freshwater to oceanic currents fueled by salinity levels, increasing the risks of resetting the currents—Earth's natural thermostat.

But it's a beautiful day aboard the Endeavour. Hatless guests stroll the decks, complementary red parkas flapping open, heads craned back to see the massive icebergs, oohing and aahing in their own ecstatic displays. The ship weaves between a fantastic assortment of bergs melted below the waterline and flipped, revealing the crazed hand of a submarine sculptor, complete with domes, pinnacles, wedges, and weird standing glassy blocks resembling Icehenges. Some icebergs are favored haul-outs for penguins, whose formidable ice-climbing skills allow them to porpoise out of the waves, stab the ice-axes of their bills into sheer walls, then peg with toenail crampons, hammering move after move until they've climbed 50 or more feet to ledges tattooed with sleeping penguins.

There's talk aboard the Endeavour of climate change, including from a vocal contingent of naysayers quoting mythical studies. One woman repeatedly cites a fictional cluster of 19,000 denialistas hunkered down in German institutes of higher learning, until someone asks her to prove it. There are also a surprising number of middle grounders leaking equal parts confusion and skepticism about "this global warming business." The two groups manage to exhibit all five stages of climate-change denial: There's nothing happening; we don't know why it's happening; climate change is natural; climate change is not bad; climate change can't be stopped. The true believers discover each other mostly through shared incredulous silence.

Yet all come together when we happen upon an ancient ice floe topped with a single sleeping emperor penguin. It's a juvenile that has just completed its inconceivable genesis in the dark of the Antarctic winter, perched atop its father's webbed feet, tucked into the brood pouch, enduring 100-knot winds and subzero temperatures. The young bird utters three soft braying calls as we approach, then stands. The motor drives on a hundred cameras whine. Everyone whispers to no one in particular, as all are joined by an invisible thread of respect woven into the collective consciousness by March of the Penguins. You can almost hear the Morgan Freeman narration hang in the air.

Directly ahead lies heavy pack ice, the dividing line between ships and penguins. We turn back, leaving the young bird to its solitude.

The pack ice in the Weddell Sea is the same obstacle that sank Ernest Shackleton's Endurance in 1915, and, like him, we set our sights on Paulet Island, where he hoped and failed to land his men. We can't quite get there either, though Captain Philipp Dieckmann noses the ship in a narrow channel cluttered with big bergs, bergy bits, growlers, and weather-pummeled sea ice, all idiosyncratically on the move with tide and wind, like dancers without a choreographer. Here and there we kiss ice, the ship shuddering at the impact and wailing in a Björklike voice, seductive and violent. Everyone who can be is clustered topside, watching the contest, when a German who speaks excellent English confesses how he and his compatriots have been confused by the constant references to "Adélie" this and "Adélie" that, wondering where in the world is this French woman everyone is talking about.

Naveen and Lynch badly want to get ashore on Paulet and count Adélie penguins and the Antarctic cormorants known as blue-eyed shags. But Matt Drennan, expedition leader and 20-year veteran of the Antarctic, with 80 expeditions under his belt, doesn't like the look of things. Too much ice. Too much tide. Wind coming up. He squints into the glare of memory—things can change too quickly here—and apologizes profusely. No one second-guesses his tough decision because no one wishes to repeat the travails of the 20 men of the Nordenskjöld Expedition who inadvertently overwintered here in 1903 after their ship sank in the Weddell ice. Their tiny stone hut, visible from the Endeavour, looks to be built from stacked headstones.

Paulet is only a mile across, yet its slopes, rising more than 1,100 feet, are so steep and its birds so densely packed that they've never been fully counted, only estimated. The last year conditions enabled an estimate was 1999, when Naveen managed a flyover in a British navy helicopter and calculated between 95,000 and 105,000 Adélie nests, for a total of perhaps 350,000 adults and chicks on the island.

The question of interest today is how many are present this year. Adélies, the most polar of the three penguin species nesting in the peninsula, seem to be suffering the most from climate whiplash, their numbers plummeting 80 percent in places. Exactly why remains a matter of conjecture, though many theories begin and end with krill. Adélies survive almost exclusively on krill, making forays more than 400 miles to and from their nests and dives up to 574 feet deep in pursuit of the shrimplike invertebrates.

But krill stocks aren't what they used to be. Despite the fact that wildlife has been protected on Antarctic lands since 1959, the Southern Ocean, which feeds most Antarctic life, is still considered fair game. Industrial-scale krill-fishing fleets arrived here in the 1970s, bent on transforming the keystone species of Antarctica into fish food and omega-3 supplements. In 2007, the Convention for the Conservation of Antarctic Marine Living Resources expanded the catch limit from 450,000 to 2.6 million metric tons in East Antarctica alone. This despite concerns that the stock is already in decline from climate change. Krill need pack ice for feeding, yet the pack in the peninsula has shrunk 80 percent in 30 years, forming later each winter and retreating earlier each summer.

The problems for penguins don't end with krill. Adélies need sea ice as a place to rest while foraging, a kind of polar recovery room, now shrinking. Moreover, the warming climate is producing deep snows and flooding rains that smother or drown their eggs and chicks—changes that may also be fueling outbreaks of ticks severe enough to force some penguins to abandon their eggs and chicks and seek relief in the sea. Now melting glaciers are releasing time bombs of ddt and likely other pollutants once safely frozen in the ice.

In November 2007 researchers at Palmer Station in the Antarctic Peninsula recorded the first extinction of an Adélie colony, which may historically have housed as many as 30,000 birds. "The evidence could no longer be denied," the team wrote, "and it was formally transcribed into our field notebooks and databases...no [Adélie] pairs had arrived to breed on Litchfield Island...the first recorded extinction of an entire colony in the 34-year history of this study."

At first glance, the massive penguin rookery at Brown Bluff looks to be strewn with the carcasses of penguin chicks. But they're not dead, only prostrate with heat—fat, absurdly fuzzy, lying prone on rotund krill-filled bellies, wings outstretched, webbed feet raised in the air behind them, shedding heat through the only unfeathered parts of their bodies. The Adélie chicks hatched earlier than the gentoos on the island, and some are near fledging now, molting their down feathers like penguins emerging from gorilla suits. Most are joining crèches and partaking in the comical affairs known as feeding chases: a parade of chicks besieging any parent returning from the sea, the youngsters chattering loudly of their hunger. The returning parents, bloated with krill, lurch as fast and far away as they can, hoping to winnow their own chicks from the mob. Some feeding chases persist a thousand feet down the beach, a long way for birds with no ankles, says Naveen.

We arrive prepared to count, but are waylaid by the impossibly calm day, the mirrorlike bay with ripples of sinuous leopard seals, the grounded icebergs on shore, and the literally hundreds of adult penguins crowding the waterline. They're restless and hot and hungry. They're also afraid of the leopard seals. Entering the water requires a flock to reach consensus. Before that, they reach many false consensuses, a few birds toppling headfirst into the sea only to U-turn and torpedo out again. This day, as every day, a few will not return with food but instead become food for leopard seals.

We climb a precipitous hill worn to dirt and rock from countless generations of penguin feet. Birds come and go, effortlessly hopping past us on the uphill. Near the pinnacle, scrambling atop a boulder, Heather Lynch snaps photos of the colony in all directions and notes the gps coordinates. There are too many birds to count, except on a digitized image on a computer screen. Next year, conditions permitting, an Oceanites team will return to this same boulder and count again. Such is the way databases in the Antarctic grow, as slowly as lichens.

To compensate for the difficulties inherent in polar work, Naveen hooked up with Bill Fagan at the University of Maryland. Fagan's lab, where Lynch is a postdoc, is a scientific front line combining advanced mathematical theory and off-the-map fieldwork to explore questions critical to life on Earth—including those shaping life naturally (community ecology), and those that save life from ourselves (conservation biology).

Lynch, with a master's in physics and a Ph.D. in biology from Harvard, is representative of what may well turn out to be the distinguishing feature of 21st-century science—the reintegration of the last century's separate disciplines into something beginning to resemble one. What she offers the Antarctic Site Inventory is the bandwidth to crunch relatively sparse population numbers alongside data on sea ice, climate, and ocean productivity—plugging it all into hierarchical Bayesian models—statistical analyses so complex that only recently has the computational power emerged to manage them. (An early Bayesian application in 1968 stretched computers of the day, yet succeeded in locating the sunken nuclear submarine the Scorpion, lost somewhere in the Atlantic.) The work derives from the 18th-century British mathematician and Presbyterian minister Reverend Thomas Bayes and his theorem on the probabilities of the behavior of billiard balls.

Lynch hopes to use Bayesian models to address what Fagan calls the weak-data problem in conservation biology: the persistent dearth of field records over consequential timescales. The statistical tools aren't quite the equivalent of sinking all your pool balls on the break. But they set them up cleanly for your next shot.

At Booth Island, in a heavy snowfall, the naturalists aboard the Endeavour land ahead of the guests and set up orange traffic cones to mark footpaths as close to the action as front-row seats, yet far enough away from penguin trails and colonies to be respectful of their privacy. Along with ice and weather, Naveen and Lynch are also examining the impact of tourism on breeding penguins, though initial results seem to agree with other studies that well-managed tourism enhances penguin survival, possibly by keeping skuas—predatory gulls nearly the size of eagles—away. Good for penguins, bad for skuas, says Lynch.

The first 1,000-passenger liner traveled to Antarctica in 2000, and last year a 3,000-passenger cruise ship visited. Not all make landings, yet the dangers are real, whether people come ashore or not. When the Explorer sank in 2007 it was small enough, and the weather calm enough, that nearby ships could rescue its passengers. And the ship sank cleanly enough that a major oil spill, far from any emergency infrastructure, was averted. In other words, conditions were excellent for a sinking, a reality unlikely to be repeated.

More tourists also change the aesthetic. Matt Drennan spends several hours a day calculating how to keep the Endeavour out of the line of sight of all the other ships competing for space at the 20 or 25 most popular landing sites on the peninsula. Maintaining the illusion of solitude is hectically orchestrated every July during the International Association of Antarctic Tour Operators' online electronic derby. Ignorant of what December or January will hold, ships submit itineraries for which landing sites they'd like to visit on which days. Six months later, the reality of ice and weather hits and the schedules are reshuffled in an undertaking worthy of a Bayesian model. It's a process that's still workable, says Drennan, but only just. He doubts it can absorb twice as many visitors and still maintain the character of a wilderness experience.

Do visitors care? No matter the weather outside, the Endeavour's bow is stippled with a flock of hardcore guests wearing red Lindblad parkas—the $10,000 parkas, they joke—cameras at the ready, eyes tearing from the wind. Those less hardy rest in easy chairs in the library, watching the scenery glide by. Others nap in their bunks. A few anchor the bar. One soul holes up in the windowless computer lab with an everlasting game of solitaire. The old hands aboard, the 12 naturalists, who tally more than 150 years combined Antarctic experience, keep watch for whales from behind the windshield on the bridge. Sometimes a frozen guest joins them. But the inside lacks the raw power of the outdoors, the sensual jolt craved by those who know this is a once-in-a-lifetime experience.

The whales spout. The crabeater seals glance up from their daybeds on the ice floes. The penguins porpoise from the surface like flying minnows. Somewhere between the naturalists' lectures and the uncensored cut of the wind, the stunning landscapes of Antarctica transform into a living, breathing, ongoing story that will follow these visitors back to the other world and whisper in their ears for a long time to come.

Fifty years ago, a bunch of visiting scientists heard the call of Antarctica. The result was the Antarctic Treaty, written in language as stripped-down and clear as the Declaration of Independence, presenting a revolutionary argument for the rights of the uninhabited continent: "Recognizing that it is in the interest of all mankind that Antarctica shall continue forever to be used exclusively for peaceful purposes and shall not become the scene or object of international discord."

Because of the treaty and related agreements, known as the Antarctic Treaty System or ats, the continent enjoys freedoms unparalleled elsewhere on Earth, including freedom from any military presence (though some nations use their military to run their research), freedom of scientific investigation and cooperation, freedom from territorial ownership, and freedom from nuclear weapons. The frozen continent offers a thought experiment as to how an intelligent, informed, curious, energetic, disciplined, and mostly rational human society might operate at some future date.

The Arctic, in contrast, presents a dark glimpse into the past, as disappearing ice awakens piratical instincts in nations seeking heretofore inaccessible minerals, oil, fish, and seafaring riches. New data in the Arctic are already being used to boost increased American territorial claims by 100 nautical miles. Canada is embroiled in sovereignty disputes with the US, Russia, Denmark, and Norway over sites rich with oil and natural gas, and over ownership of the fabled Northwest Passage.

Yet Antarctica may be only temporarily immune from polar fever, since the ats suspends mineral exploration merely until 2048. Seven nations—Argentina, Australia, Britain, Chile, France, Norway, and New Zealand—maintain territorial claims in abeyance, for the time being. Along with 39 other countries, they wait, should the treaty change, poised inside 64 permanent and seasonal scientific bases, some facilitating no science, some facilitating exploitation thinly disguised as science. For better or worse, the research footprint grows far bigger than even the tourist footprint in Antarctica.

It's questionable whether 40 years from now, when the mineral rights prohibition comes up for renewal, the equivalent spirit of enlightenment will prevail. By then, the frozen goodies known to abound under Antarctica's snowfields may well be more accessible. The United States has already completed a controversial 1,000-mile snow road connecting its bases at McMurdo Sound and the South Pole—the road to plunder, should conditions allow. By 2048, the global population will have soared to 9 billion, an increase almost equivalent to the total number of people living on earth in 1959, when the first Antarctic Treaty was signed. Pressures on Earth's resources may well have outgrown our generosity.

In all likelihood we're only an oil shortage away from applauding the 19th-century sentiments of poet Bret Harte on America's original polar aspirations:

Know you not what fate awaits you
Or to whom the future mates you?
All ye icebergs, make salaam
You belong to Uncle Sam!

We make final landfall at Port Lockroy, a weatherproof harbor in the Palmer Archipelago, and historic site of an old British whaling station turned military base turned meteorological station. Whale skeletons line the shores. A pair of tiny black huts marks the line Churchill held against the Nazis in Antarctica. Enormous glaciers ring the bay, punctuated by rocky mountaintops knuckling through the snow. At metronomic intervals, ice calves into the sea, sonic booms marking puffs of snow and ice. Outside the protected harbor, hurricane-force winds blow, while five yachts that braved the Drake Passage moor in faultless calm.

Port Lockroy is crowded with tourists in kayaks, tourists beachcombing, tourists on Zodiac tours of the harbor. The hut's latest persona is as a museum, gift shop, and post office, its rooms crowded with visitors spending all manner of currencies on tea towels, T-shirts, and postcards. It's a snapshot of one Antarctic future.

A passenger aboard one of the moored yachts visits the Endeavour and gives a talk in the lounge. He's a well-known explorer, examining climate change and the impacts of tourism while making a documentary about himself kayaking in the Antarctic Peninsula. He refers to his kayaks as floating ambassadors, and the guests are eager to hear his take on this global warming business. But despite his audience of newly fledged envoys, despite the incomparable backdrop, and the pressing issues, the explorer is reticent, paddling around the touchy subject while waving a drink through the air. Perhaps this is what ambassadors do.

With a few working hours still left in Antarctica, Ron Naveen and Heather Lynch launch into the bird colony at Jougla Point, most of it off-limits to nonscientists, wading shin-deep in muck and slipping and sliding in melt pools on the edges of rocky escarpments. Naveen's no novice and skates nonchalantly along drop-offs; Lynch powers behind, field notebook in hand, hood cinched low. They count and recount, the simplest science imaginable. Much depends on their numbers, including decisions likely to be made about future human visitation here, the outlook for penguins, and, perhaps, a critical data point in the emerging picture of how this unpeopled world sustains us.

Snow sashays onto the nesting gentoo penguins and blue-eyed shags, disguising the pink mire of the colony that has turned their chicks into unrecognizable lumps of filthy down. The birds nest shoulder to shoulder, alongside old winch anchors, mooring blocks, whale skulls, wooden crates, discarded cable. They nest under the old World War II huts and on the cement block holding the British flag. Through every human endeavor that has blossomed here then faded, they've endured, cooing their courtship calls, hissing at intruders, spreading their feathered parasols to keep snow, sleet, rain, and sun from their perfectly hopeful chicks.