A World Without Ice - Softcover

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Henry Pollack, PhD, and his colleagues on the Intergovernmental Panel on Climate Change shared the 2007 Nobel Peace Prize with former Vice President Al Core. Pollack has been a professor of geophysics at the University of Michigan for more than forty years and now serves as a science adviser to Al Gore's Climate Project training programs. Also the author of Uncertain Science…Uncertain World, he lives in Ann Arbor.

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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 theRoyal Navy of King George III of England, received an unusual assignmentfrom the British Admiralty. He was to sail to the South Pacific onHMS Endeavour to make astronomical observations of the planet Venusas it passed directly between the Sun and Earth, an orbital event thatwould take place in early June of the following year. Such a passage,known as a transit of Venus, eclipses a very small circular area on theface of the Sun that appears like a shadow moving across the solar disk.This astronomical phenomenon offered a method of estimating the distancebetween the Sun and Earth, by simultaneous observations of themoving dark spot from different points on Earth. Cook was to make his observations on the island of Tahiti in the Pacific Ocean, on the oppositeside of the globe from England. The ostensible motivation for thisundertaking lay in the suggestion that an accurate determination of theEarth- Sun distance was important for reliable navigation at sea.The complexities of the motions of Earth and Venus about the Sunmake transits relatively rare events, coming in pairs separated by eightyears, 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 comein 1874/1882 and 2004/2012. Cook had been selected for this scientificundertaking because of his skills in surveying and charting, honed a decadeearlier on the St. Lawrence River, during the Seven Years’ War betweenBritain and France for control of the territory that would become Canada.Endeavour was a small ship, just a little longer than a modern railwaycoach, but home to eighty- five seamen and another dozen officers andaccompanying naturalists, plus their equipment, water, provisions, andgrog. The voyage from England to Tahiti followed a route south throughthe Atlantic, around Cape Horn at the tip of South America, and thencewest into the Pacific to Tahiti. The full journey totaled roughly twelvethousand miles, equivalent to about half the distance around the globe.Under sail it took almost exactly eight months to reach Tahiti, includingprovisioning stops in Madeira and Rio de Janeiro, and some specimencollecting in Tierra del Fuego.

Cook was meticulous about the health of his crew, as the scourge ofscurvy was already well known on long voyages. He knew that diet wasimportant to health, and he carried an ample supply of sauerkraut to wardoff scurvy. The crew, had they known of it, would have lobbied hard forthe anti- scorbutant that Dutch sailors preferred: white wine. It is not clearwhether Cook was aware of the prophylactic powers of wine, but he clearlyknew the perils of having alcohol- incapacitated seamen. Christmas Dayof 1768, celebrated off the coast of Patagonia, was marked not by religiousservices, but by a crew pursuing total inebriation. One of the naturalistsremarked that they were lucky the Christmas winds were light.

Endeavour arrived in Tahiti in mid- April of 1769, in ample time toprepare for the astronomical observations. Cook selected a place to conductthe measurements— on a sandy beach not far from the present- daycity of Papeete. He called the place Point Venus. When I visited Papeetea few years ago I was keen to see this famous scientific spot, but I worriedthat in the more than two centuries since Cook was there, the placemight have lapsed into nothingness. I asked a taxi driver if he had everheard of Point Venus. Yes, he replied, he knew it well. Skeptical that itwould 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 minuteslater we arrived. It was Point Venus all right— but today well knownas a popular nudist beach! Incidentally, there is also a small monumentto Captain Cook’s 1769 visit.

WHILE THE TRANSIT of Venus was the announced scientificrationale for this voyage, Cook’s sailing orders from the Admiraltyhad another component, designated as secret and not to beopened by Cook until he was at sea. These orders addressed Endeavour’sassignment after the astronomical observations had been completed.They revealed that Cook was to search for Terra Australis Incognita, ahypothetical southern continent that had supposedly been dimly sightedin high southern latitudes by earlier mariners.The notion of a southern continent had been promoted through philosophicaland aesthetic arguments by Aristotle and later Ptolemy twomillennia before the Age of Exploration. They believed that symmetryand balance were inherent characteristics of the natural world, and thatEarth, as a natural object, must surely display these qualities. Such beliefsrequired the existence of landmasses in the Southern Hemisphere to balancethe extensive landmasses of the Northern Hemisphere.Not long after the transit was over— only six hours after it began—Cook took Endeavour southward in search of a southern continent.

Sailing south in the peak of the Southern Hemisphere winter quicklyled to cold encounters with widespread sea ice, and it did not take longfor Cook to realize that it was not the right season for a course into highlatitudes. In September he headed west and encountered today’s NewZealand. He proceeded to circumnavigate and chart the coastlines ofboth the North and South Islands, demonstrating that they were not alarge southern continent, as had been surmised by earlier explorers. Thereturn to England was by way of Australia, where Endeavour narrowlyavoided disaster on the Great Barrier Reef, then onward to the EastIndies, where several crew contracted malaria, and around Africa to theAtlantic, before heading north on the last long leg home. In the Atlantiche encountered some American whalers, and stopped to get news of thelast three years— he learned that Europe was, for a change, at peace.Cook arrived in England in the summer of 1771, with no sighting ofTerra Australis Incognita to report.

The return of Endeavour was celebrated and acclaimed widely, butthe focus was not on Cook, the modest master of the vessel. In thelimelight was the young patrician naturalist Joseph Banks, well versed inmanipulating the press to his advantage. Within just a few weeks, Bankshad worked up a frenzy of public adulation in the press that culminatedin his announcement that there would soon be a second voyage of explorationand scientific discovery, under his leadership. Incidentally, Bankswould insist that Cook undertake the maritime duties, and there waslittle Cook could do to decline. Within a month of his returning homeafter 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 bestremembered, Cook sailed again for the Southern Ocean aboard a newship, HMS Resolution, once again in search of Terra Australis Incognita.On this voyage he headed toward the Pacific by turning east aroundAfrica into the Indian Ocean, and pushing to ever higher southern latitudesas ice conditions would permit. In 1773 he crossed the Antarctic Circle1 three times, at longitudes 40º east, 140º west, and 105º west;each time he encountered impenetrable ice, and came away withoutsighting 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, anddiscovered South Georgia Island, a banana- shaped glacier-...