A world without ice.

by Henry Pollack, Ph.D.

FOREWORD.

Humanity has arrived at a historic moment of decision. Our home, Earth, is in grave danger. At risk of destruction is not our planet itself, but the unique climatic conditions that have made it hospitable for human life and that help sustain civilization as we know it.

For decades now, scientists have studied Earth's climate, the causes contributing to its warming, and how this rising fever is impacting and will continue to impact our world and way of life. As overwhelming scientific evidence mounted that human activity is the primary cause of dramatic and accelerating global warming, many in the scientific community raised the alarm.

Testifying before elected officials and policymakers, collaborating on international studies, reporting to the United Nations Intergovernmental Panel on Climate Change, consulting with business leaders and speaking out in the media, scientists around the world have worked hard to communicate the severity and immediacy of the challenge before us-a challenge of our own inadvertent making and one requiring urgent, bold, and united action to address.

The consequences of inaction are already becoming more and more apparent: rising sea levels, more severe droughts, increasingly violent storms, the spread of disease, the loss of crops, disappearing wildlife, and politically destabilizing tides of climate refugees.

Still, a small group of climate change naysayers-some with deep financial interests in defending the status quo, and others with philosophical objections to any role for government in solving the crisis-have mounted a vigorous public relations campaign: first, to try to refute the inconvenient truth of global warming; second, to question its causes; third, to minimize its consequences; and finally, to complain about the alleged costs of transitioning from fossil fuels to more sustainable and renewable energy sources.

Such dissembling and obstruction have taken their toll; over the past fifteen years, as the United States refused to play a leadership role in marshaling global efforts to combat climate change, the crisis has grown much more severe. Now we approach several global tipping points, which-if we do not address them boldly and immediately-may plague generations to come for literally thousands of years.

One such tipping point is the loss of Earth's ice, acc.u.mulated over millions of years but now melting at an alarming rate. Across the globe, glaciers that have for centuries provided agricultural and drinking water for more than a billion people are quickly disappearing. In Antarctica, ancient ice shelves-some the size of Belgium, Scotland, or France-are beginning to disintegrate, sending ma.s.sive icebergs into the Southern Ocean. Hundreds of glaciers on Greenland are slipping faster and faster into the Atlantic. And in the Arctic Ocean, where an ice sheet has capped the polar sea for not only the entire history of human civilization but for most of the last three million years, researchers have in recent years observed a fast-paced shrinking and thinning of the Arctic sea ice that will in just a decade lead to an ice-free Arctic Ocean throughout the summer months.

Some might ask-so what? Why should we care about vanishing glaciers and remote polar ice caps? Why does the disappearance of distant ice really matter to a farmer in Nebraska, an engineer in Rio de Janeiro, an investment banker in New York, a salesperson in Cincinnati, a bus driver in London, a tour guide in Tanzania, a child in Bangladesh, or a businessman in Beijing?

The answer is that, on a global scale, ice plays a critical and major role in setting the temperature of Earth's atmosphere and oceans, governing major weather patterns, regulating sea level, and dramatically impacting agriculture, transportation, commerce, and even geopolitics. Though we have been slow to recognize this, our history and future are inextricably linked to the world's ice.

If we do not act now, as individuals, as communities, as businesses, and as nations to slow and gradually halt the current meltdown, we risk destroying the very global systems that have enabled us to thrive and prosper.

In this insightful, accessible, and important new book, Dr. Henry Pollack explores the vital role that ice plays in the functioning of our planet, how it impacts human life, how we in turn are affecting ice, and why the decisions we make today, both individually and collectively, will shape the world and human society for thousands of years to come.

A World Without Ice explains complex global systems in simple terms without dumbing down the message, and explores the very real implications for people and the planet without succ.u.mbing to romanticism or hyperbole. As such, this book will help a broad range of readers understand the challenges we face and the high stakes of the climate change debate. Readers will be confronted with the fact that humans are no longer pa.s.sive players in the global climate system, but rather key drivers of many changes now becoming apparent. explains complex global systems in simple terms without dumbing down the message, and explores the very real implications for people and the planet without succ.u.mbing to romanticism or hyperbole. As such, this book will help a broad range of readers understand the challenges we face and the high stakes of the climate change debate. Readers will be confronted with the fact that humans are no longer pa.s.sive players in the global climate system, but rather key drivers of many changes now becoming apparent.

I have known Dr. Pollack and followed his research into global climate change since 1992, when I called on him to testify before the Senate, and later I sought his expertise at the White House. A geophysicist at the University of Michigan since 1960, Dr. Pollack led a global scientific consortium that reconstructed Earth's surface temperature over the past millennium, through the innovative use of borehole temperature measurements made in the rocks of Earth's crust.

He has advised the National Science Foundation, testified before National Academy of Sciences and congressional committees, and was a contributor to and member of the United Nations Intergovernmental Panel on Climate Change, which shared the 2007 n.o.bel Peace Prize.

In addition to respecting his scientific expertise, though, I have also come to know and respect Dr. Pollack as an effective communicator, a scientist with the rare ability to engage ordinary people and to translate scientific ideas into everyday terms that are easy to understand. I've watched Dr. Pollack, as one of my advisors on The Climate Project, help hundreds of people wrap their minds around the complexities and challenges of climate change, and come away not only better informed, but feeling empowered by their knowledge as well. Intuitively, he grasps the relationship between science and humanism, and bridges them with rationality and grace. He brings that same straightforward, affable approach to the pages of A World Without Ice A World Without Ice, a book that I believe will help large numbers of readers understand and meet the paramount challenge of our time.

For years now, efforts to address the growing climate crisis have been undermined by the idea that we must choose between our planet and our way of life, between our moral duty and our economic well-being. These are false choices. In fact, the solutions to the climate crisis are the very same solutions essential to redressing our economic and national security crises.

Though daunted by the crisis at hand, I am by nature an optimist. I have seen people's capacity, when informed and inspired, to bring about necessary change. I am hopeful that A World Without Ice A World Without Ice, in illuminating the challenge of climate change through the prism of ice, will help spark people to engage their friends and families, their communities, congregations, companies, and countries, in the battle to save the natural environment that has nurtured us. We live on an unlikely, infinitesimal island of possibility in the endless sea of s.p.a.ce, and we must all work to save our home before it's too late.

-AL GORE February 11, 2009

PREFACE.

This is a book about ice and people on Earth-the impact ice has had on our planet, its climate, and its human residents, and the reciprocal impact that people are now having on ice and the climate of the future. Ice has been on Earth much longer than people have-we are relative newcomers to the terrestrial menagerie. Humans have called Earth home for only some three million years, whereas ice has been a part of Earth's landscape for billions of years.

Throughout most of Earth's history, ice has been an indomitable force of nature. The creep of ice over the continents during past glacial epochs has profoundly shaped Earth's surface. The sharp Alpine peaks of Europe, the vast Great Lakes of North America, the majestic valleys of California's Yosemite National Park, and the deeply incised fjords of Norway-all are products of earlier glacial erosion. Today they grace Earth's landscape as gifts from ice to humanity. Minute by comparison, people stand awestruck at the immense scale of nature's handiwork.

But ice is much more than just a landscape sculptor and earth mover-it is a major player in Earth's climate system. Of the sunshine falling onto Earth, about 30 percent of it is reflected back into s.p.a.ce, mostly by white clouds in the atmosphere and white ice at the surface. The polar ice caps, covering virtually all of Antarctica, the Arctic Ocean, and Greenland, make up less than one tenth of Earth's surface, but account for much of the sunshine reflected from the surface. Polar ice also generates huge wind streams that spill ferociously off the ice caps and flow far beyond the ice perimeter to shape weather systems that influence the entire globe.

Geologists have translated the book of rocks, layer by layer, and discovered that there have been many times in Earth's history when the climate was different from that of today-episodes when ice blanketed half the globe, and times when the polar regions were free of ice. It is almost incredible to think that just twenty thousand years ago, at the places where New York, Detroit, and Chicago are today home to millions of people, the landscape was monochrome white, a ma.s.sive sheet of ice a half mile thick. And there were no people in all of North America to see it, to marvel at it, or to cope with it. The Western Hemisphere had yet to welcome its first human immigrants.

Over the span of only the last three centuries, however, the rapid growth of the human population and the rise of industrial society have brought the relationship between ice and humankind to a precarious tipping point. Gone are the days when ice was unfazed by the few people living on its fringes. Today human activities are having a profound effect on Earth's climate and destabilizing the world's ice. Climate scientists warn that in the not-too-distant future we may see a world without ice.

It is difficult to envision a world without ice-it requires a stretch of the imagination no less than envisioning a world without trees, or flowers, or animals. The loss of ice will have dramatic consequences for planet and people alike. The drinking water and agricultural water for almost one quarter of Earth's population-a number that exceeds the population of the entire Western Hemisphere-come directly from mountain glaciers. An even greater number of people depend on the seasonal replenishment of water from the melting of winter snow to nourish crops at the outset of the growing season. The dramatic shrinking of Arctic sea ice over the past few decades has already triggered international posturing over oil and minerals that perhaps will be discovered on the ocean floor. And the likely disappearance of summer sea ice later in this century will set the stage for exploitation of the Arctic's fisheries, and will open maritime trade routes such as the fabled Northwest Pa.s.sage between Europe and East Asia.

In the starkest terms, however, the melting of the ice now on the continents means adding more water to the oceans, and rising sea levels. The ensuing flooding will affect low-lying regions of all nations with a seacoast-more than a hundred countries. The loss of property and agricultural land, the damage to coastal infrastructure, and the pollution of fresh groundwater aquifers with salty seawater are all significant consequences with grave economic implications. But the most severe consequence will be the displacement of many millions of people who live near the sea. A sea level rise of only three feet would transform more than one hundred million coastal residents into climate refugees. Such a population displacement, a number equivalent to a third of the population of the United States, would be unprecedented in human history.

What can be done to forestall such consequences? One must recognize that some changes accompanying a warming world are unavoidable, because of the earlier inadvertent changes to the climate system that have already occurred and will continue to play out throughout this century. And it is equally clear that if no mitigation measures are taken, a broad spectrum of serious consequences will appear sooner, many within this century, and will grow larger with time. But there are a number of middle paths, some timid, some bold, that are being readied for the nations and peoples of the world to consider and perhaps embrace. The creativity of people has the potential to slow and even reverse the changes in global climate now taking place. However, the willingness of nations to take the difficult but necessary steps to do so has yet to be convincingly demonstrated.

CHAPTER 1.

DISCOVERING ICE.

The ice was here, the ice was there, The ice was all around; It cracked and growled, and roared and howled, Like noises in a swound!

-SAMUEL TAYLOR COLERIDGE The Rime of the Ancient Mariner

In late May of 1768, Lieutenant James Cook, a young officer in the Royal Navy of King George III of England, received an unusual a.s.signment from the British Admiralty. He was to sail to the South Pacific on HMS Endeavour Endeavour to make astronomical observations of the planet Venus as it pa.s.sed directly between the Sun and Earth, an orbital event that would take place in early June of the following year. Such a pa.s.sage, known as a transit of Venus, eclipses a very small circular area on the face of the Sun that appears like a shadow moving across the solar disk. This astronomical phenomenon offered a method of estimating the distance between the Sun and Earth, by simultaneous observations of the moving dark spot from different points on Earth. Cook was to make his observations on the island of Tahiti in the Pacific Ocean, on the opposite side of the globe from England. The ostensible motivation for this undertaking lay in the suggestion that an accurate determination of the Earth-Sun distance was important for reliable navigation at sea. to make astronomical observations of the planet Venus as it pa.s.sed directly between the Sun and Earth, an orbital event that would take place in early June of the following year. Such a pa.s.sage, known as a transit of Venus, eclipses a very small circular area on the face of the Sun that appears like a shadow moving across the solar disk. This astronomical phenomenon offered a method of estimating the distance between the Sun and Earth, by simultaneous observations of the moving dark spot from different points on Earth. Cook was to make his observations on the island of Tahiti in the Pacific Ocean, on the opposite side of the globe from England. The ostensible motivation for this undertaking lay in the suggestion that an accurate determination of the Earth-Sun distance was important for reliable navigation at sea.

The complexities of the motions of Earth and Venus about the Sun make transits relatively rare events, coming in pairs separated by eight years, but with more than a century separating one pair from the next. After the 1761/1769 pair, the next chances to observe a transit would come in 1874/1882 and 2004/2012. Cook had been selected for this scientific undertaking because of his skills in surveying and charting, honed a decade earlier on the St. Lawrence River, during the Seven Years' War between Britain and France for control of the territory that would become Canada.

Endeavour was a small ship, just a little longer than a modern railway coach, but home to eighty-five seamen and another dozen officers and accompanying naturalists, plus their equipment, water, provisions, and grog. The voyage from England to Tahiti followed a route south through the Atlantic, around Cape Horn at the tip of South America, and thence west into the Pacific to Tahiti. The full journey totaled roughly twelve thousand miles, equivalent to about half the distance around the globe. Under sail it took almost exactly eight months to reach Tahiti, including provisioning stops in Madeira and Rio de Janeiro, and some specimen collecting in Tierra del Fuego. was a small ship, just a little longer than a modern railway coach, but home to eighty-five seamen and another dozen officers and accompanying naturalists, plus their equipment, water, provisions, and grog. The voyage from England to Tahiti followed a route south through the Atlantic, around Cape Horn at the tip of South America, and thence west into the Pacific to Tahiti. The full journey totaled roughly twelve thousand miles, equivalent to about half the distance around the globe. Under sail it took almost exactly eight months to reach Tahiti, including provisioning stops in Madeira and Rio de Janeiro, and some specimen collecting in Tierra del Fuego.

Cook was meticulous about the health of his crew, as the scourge of scurvy was already well known on long voyages. He knew that diet was important to health, and he carried an ample supply of sauerkraut to ward off scurvy. The crew, had they known of it, would have lobbied hard for the anti-s...o...b..tant that Dutch sailors preferred: white wine. It is not clear whether Cook was aware of the prophylactic powers of wine, but he clearly knew the perils of having alcohol-incapacitated seamen. Christmas Day of 1768, celebrated off the coast of Patagonia, was marked not by religious services, but by a crew pursuing total inebriation. One of the naturalists remarked that they were lucky the Christmas winds were light.

Endeavour arrived in Tahiti in mid-April of 1769, in ample time to prepare for the astronomical observations. Cook selected a place to conduct the measurements-on a sandy beach not far from the present-day city of Papeete. He called the place Point Venus. When I visited Papeete a few years ago I was keen to see this famous scientific spot, but I worried that in the more than two centuries since Cook was there, the place might have lapsed into nothingness. I asked a taxi driver if he had ever heard of Point Venus. Yes, he replied, he knew it well. Skeptical that it would be so easy to find this historic place, I queried him further. Yes, yes, he knew the spot. So I asked him to take me there, and fifteen minutes later we arrived. It was Point Venus all right-but today well known as a popular nudist beach! Incidentally, there is also a small monument to Captain Cook's 1769 visit. arrived in Tahiti in mid-April of 1769, in ample time to prepare for the astronomical observations. Cook selected a place to conduct the measurements-on a sandy beach not far from the present-day city of Papeete. He called the place Point Venus. When I visited Papeete a few years ago I was keen to see this famous scientific spot, but I worried that in the more than two centuries since Cook was there, the place might have lapsed into nothingness. I asked a taxi driver if he had ever heard of Point Venus. Yes, he replied, he knew it well. Skeptical that it would be so easy to find this historic place, I queried him further. Yes, yes, he knew the spot. So I asked him to take me there, and fifteen minutes later we arrived. It was Point Venus all right-but today well known as a popular nudist beach! Incidentally, there is also a small monument to Captain Cook's 1769 visit.

WHILE THE TRANSIT of Venus was the announced scientific rationale for this voyage, Cook's sailing orders from the Admiralty had another component, designated as secret and not to be opened by Cook until he was at sea. These orders addressed Endeavour Endeavour's a.s.signment after the astronomical observations had been completed. They revealed that Cook was to search for Terra Australis Incognita, a hypothetical southern continent that had supposedly been dimly sighted in high southern lat.i.tudes by earlier mariners.

The notion of a southern continent had been promoted through philosophical and aesthetic arguments by Aristotle and later Ptolemy two millennia before the Age of Exploration. They believed that symmetry and balance were inherent characteristics of the natural world, and that Earth, as a natural object, must surely display these qualities. Such beliefs required the existence of landma.s.ses in the Southern Hemisphere to balance the extensive landma.s.ses of the Northern Hemisphere.

Not long after the transit was over-only six hours after it began-Cook took Endeavour Endeavour southward in search of a southern continent. Sailing south in the peak of the Southern Hemisphere winter quickly led to cold encounters with widespread sea ice, and it did not take long for Cook to realize that it was not the right season for a course into high lat.i.tudes. In September he headed west and encountered today's New Zealand. He proceeded to circ.u.mnavigate and chart the coastlines of both the North and South Islands, demonstrating that they were not a large southern continent, as had been surmised by earlier explorers. The return to England was by way of Australia, where southward in search of a southern continent. Sailing south in the peak of the Southern Hemisphere winter quickly led to cold encounters with widespread sea ice, and it did not take long for Cook to realize that it was not the right season for a course into high lat.i.tudes. In September he headed west and encountered today's New Zealand. He proceeded to circ.u.mnavigate and chart the coastlines of both the North and South Islands, demonstrating that they were not a large southern continent, as had been surmised by earlier explorers. The return to England was by way of Australia, where Endeavour Endeavour narrowly avoided disaster on the Great Barrier Reef, then onward to the East Indies, where several crew contracted malaria, and around Africa to the Atlantic, before heading north on the last long leg home. In the Atlantic he encountered some American whalers, and stopped to get news of the last three years-he learned that Europe was, for a change, at peace. Cook arrived in England in the summer of 1771, with no sighting of Terra Australis Incognita to report. narrowly avoided disaster on the Great Barrier Reef, then onward to the East Indies, where several crew contracted malaria, and around Africa to the Atlantic, before heading north on the last long leg home. In the Atlantic he encountered some American whalers, and stopped to get news of the last three years-he learned that Europe was, for a change, at peace. Cook arrived in England in the summer of 1771, with no sighting of Terra Australis Incognita to report.

The return of Endeavour Endeavour was celebrated and acclaimed widely, but the focus was not on Cook, the modest master of the vessel. In the limelight was the young patrician naturalist Joseph Banks, well versed in manipulating the press to his advantage. Within just a few weeks, Banks had worked up a frenzy of public adulation in the press that culminated in his announcement that there would soon be a second voyage of exploration and scientific discovery, under his leadership. Incidentally, Banks would insist that Cook undertake the maritime duties, and there was little Cook could do to decline. Within a month of his returning home after an absence of three years, Cook was already planning the next sailing. His wife, Elizabeth, was not too pleased. was celebrated and acclaimed widely, but the focus was not on Cook, the modest master of the vessel. In the limelight was the young patrician naturalist Joseph Banks, well versed in manipulating the press to his advantage. Within just a few weeks, Banks had worked up a frenzy of public adulation in the press that culminated in his announcement that there would soon be a second voyage of exploration and scientific discovery, under his leadership. Incidentally, Banks would insist that Cook undertake the maritime duties, and there was little Cook could do to decline. Within a month of his returning home after an absence of three years, Cook was already planning the next sailing. His wife, Elizabeth, was not too pleased.

In 1772, by then promoted to captain, the rank by which he is best remembered, Cook sailed again for the Southern Ocean aboard a new ship, HMS Resolution Resolution, once again in search of Terra Australis Incognita. On this voyage he headed toward the Pacific by turning east around Africa into the Indian Ocean, and pushing to ever higher southern lat.i.tudes as ice conditions would permit. In 1773 he crossed the Antarctic Circle1 three times, at longitudes 40 east, 140 west, and 105 west; each time he encountered impenetrable ice, and came away without sighting a southern continent. three times, at longitudes 40 east, 140 west, and 105 west; each time he encountered impenetrable ice, and came away without sighting a southern continent.

His eastward course across the South Pacific, never far from the ice, brought him to the southern tip of South America just as 1774 ended. Early in the new year, he sailed eastward into the South Atlantic, and discovered South Georgia Island, a banana-shaped glacier-striped island that, at first sighting, he thought might be the long-sought southern continent. But when the distal tip of the banana came into view, he knew it was just an island. He named it Isle of Georgia, in honor of King George III. Continuing eastward, Cook reached the cape of southern Africa, intersecting his path around Africa three years earlier. He had now circ.u.mnavigated the globe in the southern high lat.i.tudes, seldom very far from the edge of the ice. Cook noted in his journal2: I had now made the circuit of the Southern Ocean in a high lat.i.tude and traversed in such manner as to leave not the least room for the possibility of there being a continent, unless near the pole and out of reach of navigation. . . . The greatest part of this Southern Continent (supposing there is one) must lie within the Polar Circle where the sea is so pestered with ice that the land is thereby inaccessible. . . . I can be bold to say that no man will ever venture farther than I have done, and that the lands which may lie to the south will never be explored. Thick fogs, snowstorms, intense cold and every other thing that can render navigation dangerous one has to encounter, and these difficulties are greatly heightened by the inexpressible horrid aspect of . . . a country doomed by nature never once to feel the warmth of the sun's rays, but to lie for ever buried under everlasting snow and ice.

Cook had clearly disproved the hemispheric "balance" of landma.s.ses postulated by Aristotle, but he demonstrated symmetry of a different type, symmetry not of land but of ice. He had shown that there was a daunting ice barrier in the high lat.i.tudes of the Southern Hemisphere, similar to that encountered in the Arctic. His predictions about the inaccessibility of the polar lat.i.tudes in the South, however, did not stand. In the early nineteenth century several sailing ships did indeed sight the Antarctic continent.

In 1838, just a little more than a half century after the founding of the nation, the United States sent an expedition to the South Pacific and Antarctic, formally called the United States Exploring Expedition of 1838-43, but colloquially known as the "U.S. Ex Ex." The expedition was commanded by Lieutenant Charles Wilkes, a naval officer, but was well staffed with scientists, the best known of which was the noted biologist and geologist James Dwight Dana. In early 1840 the expedition reached the icy barrier along the coast of Antarctica just at the Antarctic Circle, two thousand miles south of Australia. Wilkes traced the coastline for more than fifteen hundred miles, equivalent to the distance from Boston to Miami. Proof that this extensive terrain was indeed a continent would come later, but clearly the U.S. Ex Ex had encountered a big and continuous landma.s.s.

THE SEVENTH CONTINENT.

The symmetry of ice in both the northern and southern high lat.i.tudes sometimes conveys a false impression that Earth's polar regions are really quite similar. The presence of ice, however, actually masks more fundamental differences between the north and south polar regions. The Arctic and Antarctic have been described as being "poles apart," of course geographically, but also in many other characteristics. The South Pole lies well within the continent of Antarctica, some 850 miles inland from, and 10,000 feet above, the nearest coastline. The North Pole, by contrast, is located in the Arctic Ocean, with the seafloor 14,000 feet below and the closest coast some 450 miles away. Both poles are set in ice, but the thickness of the ice is very different. Beneath the South Pole lies more than 10,000 feet of ice, whereas the North Pole sits on a thin 10- to 20-foot sheet of frozen ocean water, give or take a few feet. The ice in both settings is on the move, but at very different speeds-at the South Pole the ice slips slowly over the pole at a glacial pace of about 30 to 40 feet per year, whereas the sea ice of the Arctic is swept along by wind and currents at an average speed of about 3 to 4 miles per day.

Size-wise, Antarctica is a typical continent-smaller than Asia, Africa, North America, and South America, but larger than Europe and Australia. And it shares many geological characteristics with the other continents. The large-scale architecture of all continents is similar to that of icebergs-continents are composed of rocks, such as granite, that are less dense than the rocks that make up the floors of the surrounding ocean basins. Just as ice floats in water, with some ice above but most below the water's surface, continental rocks "float" in rocks of greater density, and stand a bit higher than the rocks in which they are immersed. The average elevation of the continental surface is some three miles above the ocean floor, but the low-density rocks of the continents extend more than twenty miles into the Earth, a continental "root" not unlike the submerged portion of an iceberg in the ocean.

As in the other continents, the Antarctic rocks show the telltale characteristics of a long and complex geologic history-a wide range of ages, from ancient Precambrian crystalline rocks to very young unconsolidated glacial deposits. The rock types include the common rock categories-igneous, sedimentary, and metamorphic-and in typical proportions. The Antarctic continent has mountain ranges such as the Antarctic Peninsula, which is really just an extension of the Andes of South America, and the Transantarctic Mountains, which snake across the continent from the Weddell Sea to the Ross Sea. Antarctica almost certainly has its share of mineral deposits, although none is exploitable, at least for now, because of the extreme environment. Antarctica is, however, unique in one important characteristic-its location astride the South Pole. Virtually all of Antarctica lies within the Antarctic Circle, and more than three quarters of its area lies at lat.i.tudes greater than 70 south.

How and when did Antarctica come to the South Pole? One might be tempted to ask, "Hasn't it always been there?" but there is ample geologic evidence to indicate that it has not. Sedimentary rocks of Mesozoic age along the Antarctic Peninsula show beautiful fossilized tropical ferns, and Paleozoic-age coal seams in the Transantarctic Mountains reveal well-preserved low-lat.i.tude vegetation. No, Antarctica was not always at the South Pole-it came there from somewhere else, and fairly recently, geologically speaking.

At the beginning of the Jura.s.sic period, some two hundred million years ago, the terrain that was to become Antarctica was part of a super-continental a.s.semblage called Gondwa.n.a.land, an enormous landma.s.s that also comprised the eventual continents of South America, Africa, and Australia, as well as smaller fragments including Madagascar, New Zealand, and India. Gondwa.n.a.land itself had been a.s.sembled only one hundred million years earlier, during the closing stages of the Paleozoic era. Following its a.s.sembly from predecessor continental terrains from around the globe, this composite landma.s.s received deposits of a unique and remarkably widespread sequence of rock formations, and saw the evolution of a cosmopolitan fauna and flora. Geologists and paleontologists eventually recognized this rock sequence with its contained fossils as the Gondwa.n.a.land signature-the key to recognizing the full extent of Gondwa.n.a.land.

About 170 million years ago, the forces of plate tectonics began to dismember Gondwa.n.a.land and disperse the pieces. Just as sea ice glides slowly over the surface of the high-lat.i.tude oceans, so also do large segments of Earth's rocky outer sh.e.l.l drift slowly over the globe, mobilized by forces from within the planetary interior.

The continental dispersal created a new geography in the Southern Hemisphere. Within Gondwa.n.a.land, Antarctica was originally situated at about 40 south, and governed by a temperate climate very similar to that characteristic of the continental United States today-neither polar nor tropical. Widespread forests and marshes of the time were eventually compressed into the coal beds found today in the Transantarctic Mountains.

The separation of Antarctica, Madagascar, India, and Australia from Africa, and from one another, created a gap that became the modern Indian Ocean. A little later, the departure of South America from Africa created the South Atlantic Ocean. India went its separate way northward across the equator, eventually to collide with southern Asia to create the Himalaya mountain range. Australia and Antarctica were carried southward.

The defining tectonic events for Antarctica, the events that make it unique, came around thirty to forty million years ago. Australia parted company with Antarctica and headed north, leaving Antarctica to enjoy the pole alone. And as Antarctica slipped farther south, the Andean link between South America and the Antarctic Peninsula was stretched and then broken, opening a six hundred-mile-wide oceanic chute known today as the Drake Pa.s.sage. Antarctica was then totally surrounded by the Southern Ocean, a ring of water around the globe at 60 south. The prevailing wind at that lat.i.tude blows from west to east, and it sets up an ocean current, the Antarctic Circ.u.mpolar Current, that circles Antarctica relentlessly.

THE ISOLATION OF ANTARCTICA.

The climatological impact of the west-to-east circ.u.mpolar current has been profound. With virtually no flow in a north-south direction, the current inhibits mixing of the cold Southern Ocean with warmer waters of the Atlantic, Pacific, and Indian oceans. Unlike the Arctic region, which receives tropical warmth via the northward-flowing Gulf Stream of the Atlantic Ocean, the Antarctic is climatologically isolated by this circulatory girdle. In the Arctic, the port of Murmansk, in Russia, remains ice-free throughout the year, even though it is located well north of the Arctic Circle. By contrast, in the Antarctic there is not a single place south of the Antarctic Circle that is free of winter sea ice.

There are many definitions for the boundary of Antarctica. The continental coast defines the geographic boundary, the margin of the Antarctic tectonic plate delimits the geological boundary, and the 60 parallel of south lat.i.tude marks the political boundary governed by the Antarctic Treaty. But the climatological boundary, the boundary that makes Antarctica unique, is defined by the abrupt north-to-south transition from warmer temperate-zone water to frigid polar water within the Antarctic Circ.u.mpolar Current. It is not unlike the "marriage of the waters" in Brazil, at the confluence of the Rio Negro and the Amazon. There the dark water of the Rio Negro flows side by side with the tan, muddy waters of the Amazon, but after a few miles of getting acquainted, they mix together and become one. In the Antarctic, however, the winds and currents maintain the large temperature differences, and prevent a mixing of the waters. They flow side by side in a courtship never consummated-a marriage (surely not the first) thwarted by frigidity. This climatologic boundary is known as the Antarctic Convergence.

The crossing of the Convergence is marked by a drop in the temperature of the seawater of nearly ten Fahrenheit degrees, and the air temperature chills accordingly. Fog is an occasional visible marker, and the appearance of icebergs, first a few and later many, raises the navigational ante as ships penetrate farther south. The radar on a ship's bridge slowly becomes speckled with reflections from the bits and pieces of ice. Soon thereafter, large floating "islands" of ice appear. The continent is not yet visible, but it is very clear that you have arrived in the Antarctic.

When you finally reach the continent, your feelings are overtaken by the pristineness and simplicity of the landscape. Mountains rise from the sea, draped entirely in white. Large serpentine glaciers a mile across wind through the landscape, apparently static, but in reality slithering slowly downward from the heights-giant conveyor belts delivering huge blocks of ice to the sea. The seas surrounding the continent are clogged with t.i.tanic icebergs, of extraordinary size and architecture. The vista is powerful, yet quietly serene. Aboard Nimrod Nimrod in early 1908, Ernest Shackleton described his arrival: in early 1908, Ernest Shackleton described his arrival: As far as the eye could see . . . the great white wall-sided bergs stretched east, west, and south, making a striking contrast with lanes of blue-black water between them. A stillness, weird and uncanny, seemed to have fallen upon everything when we entered the silent water streets of this vast unpeopled white city.3 The landscape is vast but also deceptive-it is without most of the visual cues that attach scale, distance, and dimension to the natural world elsewhere. Indeed, the simplicity emerges from what the landscape is free of. There are no people; no buildings or construction cranes; no telephone poles or microwave towers; no roads, cars, trucks, or snowplows; no cultivated fields or irrigation circles; no airplanes overhead; no billboards, junkyards, or trash mounds. And the natural world is also limited-no bushes, hedges, trees, or forests; no tulips, sunflowers, lupines, or forsythia; and no wolves, deer, moose, or caribou.

The aural "landscape" is also very different. There are no industrial sounds; no deep rumble of diesel engines; no hissing, humming, whining, or thumping; no blaring music; no honking horns or sirens. The ubiquitous sounds of the Antarctic are those of wind, water, and ice. Winds whistle at fifty, sixty miles an hour, and waves crash with great thuds on beaches of volcanic rock, or against rocky or icy cliffs. Glaciers creak and crack as they inch their way through rocky valleys. And superposed on the inanimate sounds are those of the wildlife-whales spouting, seals belching, penguins calling. Petrels, gulls, and albatross ride the wind in almost total silence. This is truly "the world without us,"4 a frozen part of the Garden of Eden that has been off limits to us for most of human history. a frozen part of the Garden of Eden that has been off limits to us for most of human history.

The colors of the Antarctic are unlike colors elsewhere. Whereas green is the signature color of well-watered vegetation everywhere, and reds, yellows, and tans paint Earth's deserts, Antarctica specializes in black, white, and blue. The rock is mostly black and the snow white. Glacial ice is white at the surface, but deep brilliant blue where creva.s.ses and fissures reveal the interior. On a cloudy day, the deep sea is dark, and when the Sun shines brightly, the ocean appears a very deep blue. In brilliant sunshine the sky is a perfect sky blue, and when clouded over, it is a blank sheet of low-hanging gray. In deep fog a three-dimensional gray shroud settles in, completely disrupting one's sense of orientation and distance.

The Sun in the Antarctic summer is never far above or far below the horizon-it simply rides around the horizon, offering an ever-changing azimuth of illumination that casts pink hues and slowly changing long shadows that sweep across the landscape. The polar circle cuts through the Antarctic Peninsula about halfway through its lineal extent. South of the circle are long stretches of summer, when the Sun never sets, and north of that line the Sun dips just below the horizon for an hour or two, creating a very long "sunset" of delicate pinks, before returning to view and offering direct illumination once again.

Wind is erratic. A transition from total calm to gale-force winds can occur unexpectedly, the result of very cold and dense air suddenly spilling off highlands and roaring through valleys. These winds, called katabatic winds, are the atmospheric equivalent of a flash flood. They come without announcement, bl.u.s.ter through with abandon, and are gone within minutes. They can drive inattentive ships into rocks and flatten humans caught unaware.

But nothing quite matches the special experience of getting up close and personal with big icebergs. Conveying the scale of bergs requires reference to something you can envision, so let's start with a ship of the type that has brought me to the Antarctic several times-an oceangoing vessel more than four hundred feet long and almost one hundred feet high. When such a ship positions itself in the lee of a middling iceberg, the vessel is dwarfed, silhouetted against a floating ice island that easily exceeds the ship in both length and height. The ship becomes a miniature, not in a bottle, but in a vast field of icebergs. A ship that would fill a football stadium does not quite measure up.

Icebergs generally come either from a glacier discharging great chunks of ice into the sea, or from the margins of a floating ice shelf. The distinction is artificial, however, because the ice shelves themselves are fed by glaciers. But the shelves tend to lose the irregularity of the glacial ice that feeds them, eventually to exhibit a flat upper surface like a tabletop. When a shelf launches an iceberg through breakup or break-off, the berg retains the flat top (at least for a while), and accordingly is identified as a tabular berg. The chunks that calve from the snout of a valley glacier are much more irregular, depending on the extent of creva.s.sing that develops in the glacier as it creeps through its valley toward the sea.

Once an iceberg is in the sea, wind and water take over its destiny. Afloat, a berg will bob up and down like a giant cork, rising, falling, swaying, and tilting in slow motion. Sometimes a floating berg will break in two, and for a few minutes each offspring berg will slowly rock and roll in the sea, seeking a new equilibrium that places its center of gravity in a stable position below the surface. Sometimes this process leads to a complete overturning that brings the formerly submerged portion of the berg to the surface. If a berg is blown into shallower water, it may run aground and await a high tide for relaunching. Or it may sit there for years, slowly being diminished by the pounding of waves. Wave erosion creates a "waterline," where the ice and the sea surface meet; some bergs display many waterlines at different elevations and intersecting angles, telling a history of grounding and refloating, and of re-equilibration following a breakup.

The sculpting of icebergs by the elements has always fascinated observers, and opened their imaginations to interpreting the myriad shapes. Icebergs are to the polar imagination what cloud forms are to people elsewhere. Frank Worsley, the captain of Sir Ernest Shackleton's ship Endurance Endurance, offered this description of a field of Antarctic icebergs: Great fragments and hummocks of very old floes, worn, broken down, and melted into all sorts of grotesque and wondrous shapes, were heaving, bowing, curtseying, and jostling on the long westerly swell. . . . Castles, towers, and churches swayed unsteadily around us. Small pieces gathered and rattled against the boat. Swans of weird shape pecked at our planks, a gondola steered by a giraffe ran foul of us, which amused a duck sitting on a crocodile's head. Just then a bear, leaning over the top of a mosque, nearly clawed our sail. An elephant, about to spring from a Swiss chalet on to a battleship's deck, took no notice at all; but a hyena, pulling a lion's teeth, laughed so much that he fell into the sea, whereupon a sea boot and three real penguins sailed lazily through a lovely archway to see what was to do, by the sh.o.r.es of a floe littered with the ruins of a beautiful white city and surrounded by huge mushrooms with thick stalks. All the strange, fantastic shapes rose and fell in stately cadence, with a rustling, whispering sound and hollow echoes to the thudding seas, clear green at the water line, shading to a deep dark blue far below, all snowy purity and cool blue shadows above.5 WHAT LURED PEOPLE into the polar ice? Fame, glory, adventure, and career advancement were important motivations for explorers and naval officers, but fortune, territory, and geopolitical power were what the commercial and national sponsors of exploring expeditions generally hoped for. By early in the twentieth century all the land surrounding the Arctic Ocean was politically attached to either Russia, the United States, Canada, Denmark, or Norway, and the ocean itself, mostly covered with year-round sea ice, was at that time not a sufficiently attractive commercial target to promote international tensions. However, the situation in the Antarctic was different.

SLICING THE ANTARCTIC PIE.

Although at the end of the nineteenth century neither the North nor South Pole had been reached, the route to the South Pole was over land, and in that heyday of imperialism, "vacant" land invited territorial claims. The Berlin Conference of 1884 had part.i.tioned Africa for the benefit of the European powers; France, Germany, Belgium, Portugal, Great Britain, Italy, and Spain imposed colonial governments on more than 95 percent of the African territory.

Antarctica was unclaimed land. Although it was not an inviting place to establish colonies of settlers, nor seen as a great opportunity to enrich national treasuries and privileged royalty, it nevertheless offered the prestige factor of adding more pink or lavender or green to imperial world maps. And it had some strategic military value in terms of control of the Drake Pa.s.sage connecting the Atlantic and Pacific, a value that was diminished after the opening of the Panama Ca.n.a.l in 1914.

By the end of the first decade of the twentieth century, most of the European nations that had set up colonial regimes in Africa were active in exploring and exploiting the coast of Antarctica, but they were joined by Norway, Sweden, and the Southern Hemisphere nations of Australia, New Zealand, Chile, and Argentina. Both Norway and Great Britain had penetrated the interior of Antarctica as well, reaching the South Pole in December 1911 and January 1912, respectively. Britain initiated the claiming of Antarctic territory in 1908, even before reaching the pole. World War I intervened briefly while the European powers fought with one another for imperial supremacy, but over the next twenty-five years, Australia, New Zealand, France, Norway, Chile, and Argentina announced Antarctic territorial claims. These claims were typically drawn as "pie slices," with the center of the pie at the South Pole. The claims of Chile, Argentina, and Great Britain, however, inconveniently overlapped with one another, and as World War II came to a close in the Northern Hemisphere-the seeds of conflict had been planted in the territorial claims in Antarctica.

The end of World War II also saw the emergence of a new global power structure, the preeminence of the United States and the Soviet Union, and the nascent cold war between them. The United States had been active in Antarctica-from the U.S. Ex Ex presence in 1840 to the geological explorations and 1929 flight over the South Pole by Commander Richard Byrd from his Little America base on the Ross Ice Shelf. After World War II the United States returned to Little America to conduct Operation High Jump, a military exercise of 4,700 troops, 12 ships, and 9 planes.

The Soviet Union, however, was a newcomer to the Southern Hemisphere. Imperial Russia had sponsored Fabian Gottlieb von Bellings hausen's 1819-21 circ.u.mnavigation of the globe, which included a sighting of Antarctica in 1820, but nothing thereafter. The decade following World War II saw the cold war take full form-the Berlin Airlift, the Korean War, and the nuclear weapons race. The Soviets were a.s.serting themselves everywhere, and soon, perhaps not surprisingly, the cold war came to the cold continent. The Soviet Union rejected the notion of national territories in Antarctica, and in 1950 made its position very clear when it stated that it would not recognize as lawful any decisions taken on Antarctica without its partic.i.p.ation. The growl of the Red Bear echoed across the white continent.

The United States also rejected all existing land claims, and to emphasize the point it set up a research station at the South Pole. By "occupying" the South Pole, at the center of the continental pie, the United States could then symbolically claim control in all directions, over the full 360 of azimuth radiating outward from the pole. But it was only symbolism to make a point; the nominally non-imperial policy of the United States had long been to eschew claims of territory in the Antarctic.

In the face of the contentious overlapping claims of Argentina, Chile, and Britain on the Antarctic Peninsula, Chile in 1948 proposed a five-year suspension of sovereignty issues, and urged instead tripart.i.te scientific collaboration. In the following year, the three nations signed a treaty barring military vessels south of lat.i.tude 60. But by 1952, Argentina had built a base at Hope Bay on the peninsula, only a few hundred yards away from a British base that had partially burned a few years earlier. When later that year the British returned to rebuild their base, the Argentines fired warning shots over the heads of the British reconstruction crew. These were the first shots fired in hostility in Antarctic history, and did not augur well for a peaceful future in Antarctica. Britain brought in the Royal Marines to protect the reconstruction.

The deteriorating political situation in Antarctica invited a more sober alternative, one that would defuse the incendiary incident at Hope Bay and perhaps prevent what was apparently looming near-an inevitable conflict of national interests throughout the continent. Interested nations discussed ways to make Antarctica a continent for science, and a continent for peace. Thus was born the concept of what would become known as the International Geophysical Year of 1957-58.

INTERNATIONAL POLAR YEARS.

The idea for an international scientific year focusing on the high lat.i.tudes was not altogether new. The first International Polar Year (IPY) occurred in 1882-83, just before the imperial knife was readied for carving up Africa.6 This multinational cooperative research venture at lat.i.tudes beyond the polar circles was a recognition that much of atmospheric circulation and accompanying meteorology were affected strongly by the polar regions, and that navigation by magnetic compa.s.s would benefit greatly from investigations near the magnetic poles. Moreover, as was well known to all, working in the polar regions was difficult, dangerous, and costly, and therefore nations were willing to undertake cooperative ventures to share both risks and costs, and to keep a geopolitical eye on one another. Most of the research expeditions of this first IPY were to the Arctic, but three went to Antarctica. The second IPY took place a half century later, during the Great Depression, again focusing princ.i.p.ally on the Arctic. A third IPY had deployments occurring throughout 2007-9. This multinational cooperative research venture at lat.i.tudes beyond the polar circles was a recognition that much of atmospheric circulation and accompanying meteorology were affected strongly by the polar regions, and that navigation by magnetic compa.s.s would benefit greatly from investigations near the magnetic poles. Moreover, as was well known to all, working in the polar regions was difficult, dangerous, and costly, and therefore nations were willing to undertake cooperative ventures to share both risks and costs, and to keep a geopolitical eye on one another. Most of the research expeditions of this first IPY were to the Arctic, but three went to Antarctica. The second IPY took place a half century later, during the Great Depression, again focusing princ.i.p.ally on the Arctic. A third IPY had deployments occurring throughout 2007-9.

THE INTERNATIONAL GEOPHYSICAL YEAR AND THE ANTARCTIC TREATY.

The International Geophysical Year (IGY) of 1957-58 was an extraordinary scientific and geopolitical success. Perhaps it was because of the urgency at that time to find a way to avoid repeating the many geopolitical mistakes of the past. Or perhaps it was simply that there was a great deal of scientific interest in the polar regions, and new logistical capabilities and new scientific technologies made 1957-58 a perfect window of opportunity. Nothing symbolized the new technology more than the launching of the first artificial satellites to orbit Earth-the Soviet Sputnik 1 Sputnik 1, in October 1957, and the United States' Explorer 1 Explorer 1, four months later. And nothing characterized the spirit of scientific cooperation better than the establishment of an international data center, where observations from all the national expeditions were to be archived and shared.

Most nations that partic.i.p.ated in the IGY were delighted with its outcome, and wanted to perpetuate the science and cooperation model of activity in Antarctica. The principles of the IGY were translated into a diplomatic doc.u.ment known as the Antarctic Treaty, first adopted in 1959 and ratified in 1961 by the United States, the USSR, the United Kingdom, and nine other nations with active research programs on the white continent.

The treaty addressed many issues, but a few stand out clearly. The first article declared Antarctica a continent for peace, and laid out provisions to ensure that the continent would remain a demilitarized region. The second article declared Antarctica a continent for science, free and open everywhere for scientific investigation and cooperation. The treaty defused the conflicting territorial claims simply by saying that maps could be drawn however nations might wish, but no enforcement of claims or restrictions on travel would be allowed. Important wildlife conservation protocols were later adopted, as was a moratorium on exploration and exploitation of mineral resources that extends to the year 2043.

The treaty, reaffirmed in 1991 and today with more than forty signatories, has shown how shared governance by mutual consent has shaped a new style of international relations. That Antarctica stands alone as a continent for peace, multinational cooperation, scientific research, and non-exploitation is a remarkable outcome of the IGY and the subsequent Antarctic Treaty.

"GOVERNANCE" IN THE ARCTIC As I note earlier, land claims in the Arctic never became quite the issue that they did in the Antarctic. The countries surrounding the Arctic Ocean had more or less well-defined boundaries, and "ownership" of the few islands situated beyond obvious national affiliations was adjudicated through treaties. The question of how far national sovereignty extended into the adjacent Arctic Ocean was essentially moot because of the great difficulties the perennial sea ice imposed on resource exploitation. The relevant international law on this subject is embodied in the United Nations Convention on the Law of the Sea, to which the United States is not a signatory.