Authors: Simon Winchester
We know the sea is in trouble. We know that man plays at least some part in the wreaking of that trouble. Examples abound, most recently in the Gulf of Mexico—officially defined by the seers of Monaco as part of the Atlantic, even if it doesn’t look as though it should be—which in the early summer of 2010 was being catastrophically polluted by a drilling rig that exploded and sank in waters a few miles from New Orleans, a city that was itself still recovering from the trials of Hurricane Katrina five years earlier. A volcanic torrent of oil from a ruptured seabed pipe a mile below the Deepwater Horizon platform spread to coastlines from Texas to Florida, despoiling and polluting and killing. Eleven men died in the explosion itself.
The event—which was both predictable and preventable—promptly confounded the growing lobby of those one time skeptics who were starting to think that undersea oil exploration was safe, or at least safe enough. But to those others who recalled other great tragedies in the Atlantic—the 1988 loss of the Piper Alpha North Sea platform, with its appalling casualties, being the most egregious—it was a catastrophe that simply served to confirm another belief, that oil drilling at sea was a business inevitably and ultimately harmful to sea and man alike.
However, there was a third group—and a very large one. These were people who were quite beyond persuasion, and who believed that the world’s modern industrial needs must in any case trump such petty concerns. To this group the loss of the rig and the pollution it caused, though tragic, were of rather less consequence. They were something that, as environmentalists shudder to hear, just
went with the territory
.
The melancholy events in the Gulf serve to pose the question one further time: what is the truth? Are the legions of troubles of the sea truly the result of the mischief of man? And further: could it be that when giant hurricanes like Katrina are spawned, or when the polders of Holland are indundated or the beaches of Africa are clawed away and villages founder beneath the waves—could it be that the sea is showing signs (at least to those who like to anthropomorphize it) of somehow
striking back
? Or are all the ocean’s troubles entirely cyclical and natural-born, are the storms and sea-level rises parts of cycles, too, and is the ocean more than likely just to remain ponderously aloof to man’s fleabites of bad behavior?
This is where complication and controversy begin to appear. I recognize all too well that it would nicely serve this book’s purpose to be able to show that man is fully or even wholly responsible for the ocean’s ills, and I would clearly like to be able to do so. But I also know that there is a vast body of competing claims on the topic—with people of great distinction and good faith arguing that of course man is responsible, while others of equally stellar reputation and good faith claim that to suppose such a thing is the height of arrogance, and that man is far too puny and crabbed to be of any importance at all to an entity as vast as the Atlantic Ocean. Ever since 1995, when the Intergovernmental Panel on Climate Change uttered its historic declaration that it saw “a discernible human influence on the global climate,” the debate has assumed totemic importance, its adherents and opponents battling for hearts and minds as though hierarchs of some newfangled religion. Politics, somewhat unhelpfully, is now a party to the argument, too, muddying the issues still further, adding new and louder voices to what is already a cacophony.
That all being said, there are now a handful of proven verities, certain hard truths about the present situation of the seas that even the most ardent deniers of change have generally come to accept.
The first is at once the most simple and the most profound: the world is getting warmer, and the temperature of the oceans, and especially the temperature of the Atlantic Ocean, is currently rising at a sudden and an alarming rate. And this is going to have consequences for many of those who live on or near the sea and derive their sustenance from it. Whether these consequences are temporary or permanent matters little: the importance is that they are going to affect everyone, and not just the narwhal hunters of Ittoqqortoormiit.
The specific central facts of the argument appear to be these, with three sets of observed data seeming to be unassailable (which does not mean they pass unassailed, as we shall see). First, it is measurably clear that during the last quarter century, the average temperature of the atmosphere at the world’s surface has been increasing, and has risen by an average of 0.19 degrees centigrade during each decade. Second, observations from ships, aircraft, satellites, and scientists on the ground have led to the conclusion that the ice sheets and ice caps in the Arctic Ocean, on Greenland, and on the continent of Antarctica are all losing mass; and that since 1990 the glaciers and ice caps elsewhere that have been slowly shrinking for half a century have suddenly started melting very rapidly. And third, according to satellite observations, the world’s sea level has been rising at the rate of 3.4 millimeters every year for the last fifteen years, and the rate of rise is increasing.
Beyond these three facts, a number of other less certain—or more contentious—assertions and predictions are made, and by an overwhelming number of climate scientists. First, the global sea level is estimated to keep on rising, and by 2100 it will have risen by more than one meter, perhaps by as much as two. Second, this rise in global sea level is linked to the melting of the ice caps. Third, a series of so-called tipping points are now fast being approached, and if the observed warming trend continues (which is itself by no means a certainty), then changes to all manner of the world’s features and phenomena—rain forests, monsoons, hurricane frequency, desertification—will occur and may become irreversible.
The fourth point, made by many and now believed by most, is that all of these developments are occurring at the same time as a dramatic rise in the tonnage of carbon dioxide and other so-called greenhouse gases—which in essence sit in the upper atmosphere and prevent the escape of heat from the planet—that are being spewed out by the chimneys and exhaust pipes of industrial mankind. These emissions, which have all stemmed, one way or another, from the burning of fossil fuels, have increased by no less than 40 percent since 1990.
The fifth point, made by most but disbelieved by many, links all of the unassailable facts about warming, melting, and rising to this last well-known fact: that the increase in mankind’s carbon emissions is not merely coincident with the increase in global temperature, but is the ultimate cause of it. And at this point the two lobbies part ways, decisively, noisily, and with often passionate discourtesy. The one lobby insists that this is so; the other casts all manner of doubt and claims that the world’s money—vast quantities of which are being earmarked to pay for a lowering of mankind’s carbon emissions to decelerate the rate of warming—could and should be far better spent elsewhere. Population, most of these climate skeptics say, is the major problem (although recent data have shown that population may be beginning to peak, and maybe shrink back) and other vast troubles—diseases, lack of water, poverty—need to be addressed first, long before attention is given to what they say is the utterly unprovable linkage between carbon emissions and global warming.
3. UP SHE RISES
There are many predicted consequences of the warming of the world. Some of them are restricted to the land, as with the increase in droughts and the expansion of deserts. Most, however, are bound up with the future of the seas, and of them two are becoming paramount: the rise in the level of the sea and a slew of possible changes in the world’s weather.
The rise in sea level is perhaps of the greatest immediate interest, not least because the millions who live beside the sea are often vividly aware of when and if it is happening. There are two causes for the phenomenon, which is a very real and (at least in human terms) rather long-term trend: since 1870, when data used to be collected from mechanical tide gauges, rather than by today’s satellites, the world’s seas have risen by some eight inches.
The first cause of this rise stems from a simple law of physics: that as the ambient temperature increases, water expands. The warming sea, in other words, is becoming not so much taller as more
bloated
.
Though this thermal expansion is expected to contribute about 40 percent of the global sea-level rise—perhaps more than half of it, say some—it is a rather difficult concept to conjure with. Some argue that the basins that hold the seas will grow bigger in hotter weather and thus keep the level the same. Physicists who support the bloating idea counter by explaining that water expands more than rock, and so their assertion is correct. One has to take the word of science in matters such as these.
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It is much easier to grasp the other reason for sea-level change, one calculated to be responsible for the other 60 percent of the rise, and which concerns the physical form of water that has much of the high-latitude and high-altitude world in its grip: ice. As long as the world’s land-based ice—its glaciers, ice caps, permanent snowfields—remains frozen, then all will be well, or at least all will be stable. But if a large proportion of this ice melts, as it has been doing for at least the past twenty years, and if the melting continues to accelerate, as it has started to do in recent years, and if all the locked-in water becomes unlocked and flows down into the seas, then there will be trouble—or at least there will be instability. That’s because the world’s seas will become fuller, and their levels will go up and up, and they will do so for perhaps a very long while, and possibly unstoppably.
Since ice is the key to the stability of the seas, the Atlantic Ocean is the key ocean to watch. Of the world’s three great oceans, the Atlantic sports by far the largest amount of ice. A glance at a map shows why the Atlantic is such a catchment area for polar cast-off ice and why the other two oceans are less so.
The Pacific’s connection with the Arctic, for instance, is pinched off by the sixty-mile-wide Bering Strait; and though the Bering Sea has plenty of winter floe ice, the glaciers of Alaska and Kamchatka and far northern Russia produce relatively little new ice as their gift to their local ocean. The South American Andes spill some icebergs into the South Pacific by way of Chile—though most of them melt into high-level lakes, from which rivers course principally through Argentina and into the Atlantic. The South Pacific then (technically, at least, though an atlas might suggest otherwise) barely connects to the Antarctic icefields at all—the frozen continent lies hundreds of miles to the south of where the delineators at the International Hydrographic Organization in Monaco declare the South Pacific to end. And the Indian Ocean, which is mostly a Southern Hemisphere ocean, has no physical connection to the Arctic either. It has a southern boundary that, just like the Pacific’s, ends many hundreds of miles shy of the Antarctic coastline.
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The South Pacific and the Indian Ocean seldom if ever see icebergs and seldom if ever sport ice floes, though of course the presence or absence of ice floes makes no difference, other than seasonally, to the level of the seas.
The Atlantic Ocean, by contrast, is powerfully and intimately linked to bitterly cold polar waters, as well as to lands that breed icebergs in huge numbers. Both in its far north and its far south, the Atlantic gets more than its fair share of solid and spectacular ice.
In winter the open waters of the North Atlantic are littered with icebergs, borne on the currents to the waters well to the south of Greenland—as the
Titanic
so disastrously came to know. The North Atlantic also becomes choked with ice around Iceland—as any Fleetwood fishing trawler that is sent out for cod in wintertime well knows, too. And there is an unbroken passage of wide sea north of Iceland that drives directly to the North Pole, unchecked by any land at all, allowing pack ice—with occasional trapped bergs from Arctic-bound glaciers—to drift into the ocean proper, there to be joined by thousands of Greenland icebergs.
But Greenland—the biggest noncontinental island in the world, currently home to fifty-seven thousand people and almost three million cubic kilometers (700,000 cubic miles) of ice—is the real key. All of its ice is currently melting or ablating, at varying rates, and hundreds of well-lubricated glaciers slither off the ice cap either directly down into the Atlantic from the island’s east coast or else indirectly, by way of the Davis Strait and the Labrador Sea, from the huge glaciers on its west.
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Greenland feeds new meltwater into the ocean without cease: it has become like a gigantic faucet turned on full blast, with the bath filling fast and no one on hand to turn the water off.
The Atlantic’s attraction for new ice is not a northern phenomenon alone: its southern waters are similarly specked with icebergs—thanks mainly to a peculiar accident of tectonics. A sunken mountain range known as the Antarctic Peninsula juts northward from that continent directly into the heart of the southern Atlantic—it almost reaches up the southern tip of South America. Then by a quirk of its geology, it swivels, as South America does also, until both headlands end up facing the east. Here the two sets of cliffs, with Cape Horn in Chile to the north, and the British possessions around Elephant Island to the south, help create the infamously lethal body of water known as the Drake Passage. On maps it resembles an iron-plate exit wound from an eastbound bullet: on the Pacific side the entry is smooth, but in the Atlantic the walls are bent upward untidily, looking like an immense and ragged-ended funnel in the sea apparently purpose-built for hosing materials into the deep ocean.
And hose them it surely does. Through the passage storms a cocktail of fierce westerly winds, immense currents of ice-cold water, and melting icebergs in prodigious quantities. These great citadels of ice are swept at impressive speeds directly into the southern Atlantic, making their way south of the Falkland Islands and close to the island groups of South Georgia and South Sandwich. Icebergs in the waters of the southern Atlantic are a danger that the few vessels steaming here regard with endless wariness. But more than that: from the moment they enter the water, they increase the level of the ocean. And if thousands, millions of them are poured into the sea from the land, the level of the sea would begin to notch up to accommodate them, millimeter by dangerous millimeter.