The White Planet: The Evolution and Future of Our Frozen World

In the eighteenth century, the way in which an educated man perceived our white planet was quite different from that which has just been presented. Of course, people knew about the existence of mountain glaciers and eternal snows that covered the highest peaks, but no geographer imagined that the amount of snow could fluctuate over time. The Arctic—at least its peripheral regions—was not a completely virgin land since native peoples lived there, but no chronicle mentions anyone reaching the North Pole or traveling across all of Greenland. As for Antarctica, that continent was terra incognita. On January 17, 1773, James Cook became the first person to cross the polar circle, declaring upon his return from what was then his second expedition: “I went around the austral hemisphere, following a high latitude, and ran along it in order to irrefutably prove that no continent exists, unless it [the continent] is close to the pole and out of reach of the sailors.”

Certain zones in the center of Antarctica remain largely unexplored to this day, but our knowledge of these polar regions has increased enormously in recent times. Their geography and topography keep very few secrets in this era of satellites, but progress has also reached more intimate aspects of the evolution of various components of the white planet: the flow and mass balance of mountain glaciers, polar ice caps, and ice sheets; the conditions prevailing at their base; the thickness and processes of formation of the ice shelf and permafrost; and so forth. We cannot resist the pleasure of including a few anecdotes about (and mentioning some names among those who became known through) the discovery then the exploration of these extreme regions. However, it is above all the scientific aspects of the explorations, the methods of observation used by researchers, and a few notable results that should be emphasized. We will leave aside for the moment one of the questions that quite naturally comes to mind: Does the recent evolution of the

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