Free Frozen Earth: The Once and Future Story of Ice Ages by Doug Macdougall Page B

important ice is in shaping the landscape, Agassiz also introduced the idea that drastic climate change had occurred in the Earth’s history, and that the cold of the ice age had strongly affected life on Earth.Each of these was a new idea, and each was controversial.
    Today, Agassiz’s logic seems unassailable, and no one doubts the reality of ice ages.To present-day scientists, as to Agassiz, the conclusion that there were great sheets of ice covering the northern continents is a straightforward outcome of the observations.However, at the time it was a radical concept.By the time Agassiz’s book was published, many scientists had come to accept that the Alpine glaciers had oncebeen somewhat more extensive than they were in the 1830s—after all, there were historical accounts as proof.Europe was just then emerging from a period of several hundred years of cool temperatures that would later come to be known as the “Little Ice Age.”The slightly larger Alpine glaciers described in historical accounts could explain some of the geological observations in valleys now free of ice.But an ice age that was global in extent—that was a different matter altogether.
    Agassiz’s interest in glaciation may have been stimulated in part by his biological interests.Through his work on fossil fish, he was well aware of the paleontological evidence for periods of massive extinction in the Earth’s past.The ice age theory provided a way to understand at least one of these events, and the frozen mammoths confirmed the extreme biological impact.In a passage from his book that is quite poetic, he describes the ice age landscape and the effects he believed the frigid climate must have had on living things:
The development of these huge ice sheets must have led to the destruction of all organic life at the Earth’s surface. The land of Europe, previously covered with tropical vegetation and inhabited by herds of great elephants, enormous hippopotami, and gigantic carnivora, was suddenly buried under a vast expanse of ice, covering plains, lakes, seas, and plateaus alike. The movement of a powerful creation was supplanted by the silence of death. Springs dried up, streams ceased to flow, and the rays of the sun, rising over this frozen shore (if they reached it at all) were greeted only by the whistling of the northern wind and the rumbling of crevasses opening up across the surface of the huge ocean of ice.
    Like many of his contemporaries, Agassiz equated life with “a powerful creation.”Religion still had a strong influence on thinking about the origin and history of life, even if observation and reasoning had gradually overturned the teachings of the religious authorities on matters such as astronomy and even the Earth’s history.It was to be a topic that dogged Agassiz throughout his career.In spite of his contributions to paleontology and the evolution of fish, he would never accept Darwin’s ideas on evolution.

    Agassiz’s lecture at the Neuchâtel meeting and publication of Études sur les glaciers were the first major parries in the debate about continental-scale glaciation.Throughout, Agassiz never flagged in his efforts to convince others about the reality of an ice age.The debate raged on for much longer than he, or for that matter anyone else, could have predicted.He continued to spend summers studying Alpine ice, and in 1840, he and his colleagues set up a permanent camp and observatory on one of the major alpine glaciers in order to make continuous observations of temperature, ice movement, the nature of the rocky moraines that characterize glaciers, and many other features of these “rivers of ice.”The little scientific encampment quickly became a magnet for visiting geologists and inquisitive travelers.As always, Agassiz needed money for his venture.His friend and patron from Paris days, Alexander von Humboldt, suggested to the king of Prussia that Agassiz’s glacier research was a worthy cause, and funds soon