The Scientist as Rebel (10 page)

Roughly speaking, half of the contiguous United States, not including Alaska and Hawaii, consists of mountains and deserts and parking lots and highways and buildings, and the other half is covered with plants and topsoil. Just to see how important an unmeasurable increase of topsoil may be, let us imagine that the increased root-to-shoot ratio of plants might cause an average net increase of topsoil biomass of one tenth of an inch per year over half the area of the contiguous United States. A simple calculation shows that the amount of carbon transferred from the atmosphere to the topsoil would be five billion tons per year. This amount is considerably more than the measured four-billion-ton annual increase of carbon in carbon dioxide in the atmosphere. So the increase of carbon dioxide in the atmosphere over the entire earth could be canceled out by an increase of topsoil biomass of a tenth of an inch per year over half of the contiguous United States.

A tenth-of-an-inch-per-year increase of topsoil would be exceedingly difficult to measure. At present we do not even know whether the topsoil of the United States is increasing or decreasing. Over the rest of the world, because of large-scale deforestation and erosion, the topsoil reservoir is probably decreasing. We do not know whether intelligent land management could ensure a growth of the topsoil reservoir by four billion tons of carbon per year, the amount needed to stop the increase of carbon dioxide in the atmosphere. All that we can say for certain is that this is a theoretical possibility and ought to be seriously explored.

Another problem mentioned by Smil that has to be taken seriously is a slow rise of sea level, which could become catastrophic if it continues to accelerate. We have accurate measurements of sea level going back two hundred years. We observe a steady rise from 1800 to the present, with an acceleration during the last fifty years. It is widely believed that the recent acceleration is due to human activities, since it coincides in time with the rapid increase of carbon dioxide in the
atmosphere. But the rise from 1800 to 1900 was probably not due to human activities. The scale of industrial activities in the nineteenth century was not large enough to have had measurable global effects. A large part of the observed rise in sea level must have other causes. One possible cause is a slow readjustment of the shape of the earth to the disappearance of the northern ice sheets at the end of the ice age 12,000 years ago. Another possible cause is the large-scale melting of glaciers, which also began long before human influences on climate became significant. Once again, we have an environmental danger whose magnitude cannot be predicted until we know much more about its causes.

The most alarming possible cause of sea-level rise is the rapid disintegration of the West Antarctic ice sheet, which is the part of Antarctica where the bottom of the ice is far below sea level. Warming seas around the edge of Antarctica might erode the ice cap from below and cause it to collapse into the ocean. If the whole of West Antarctica disintegrated rapidly, sea level would rise by five meters, with disastrous effects on billions of people. However, recent measurements of the icecap show that it is not losing volume fast enough to make a significant contribution to the presently observed sea-level rise. It appears that the warming seas around Antarctica are causing an increase in snowfall over the icecap, and the increased snowfall on top roughly cancels out the decrease of ice volume caused by erosion at the edges. This is another situation in which we do not know how much of the environmental change is due to human activities and how much to long-term natural processes over which we have no control.

Another environmental danger that is even more poorly understood is the possible coming of a new ice age. A new ice age would mean the burial of half of North America and half of Europe under massive ice sheets. We know that there is a natural cycle that has been operating for the last 800,000 years. The length of the cycle is 100,000 years. In each 100,000-year period, there is an ice age that
lasts about 90,000 years and a warm interglacial period that lasts about 10,000 years. We are at present in a warm period that began 12,000 years ago, so the onset of the next ice age is overdue. If human activities were not disturbing the climate, a new ice age might begin at any time within the next couple of thousand years, or might already have begun. We do not know how to answer the most important question: Does our burning of fossil fuels make the onset of the next ice age more likely or less likely?

There are good arguments on both sides of this question. On the one side, we know that the level of carbon dioxide in the atmosphere was much lower during past ice ages than during warm periods, so it is reasonable to expect that an artificially high level of carbon dioxide might stop an ice age from beginning. On the other side, the oceanographer Wallace Broecker
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has argued that the present warm climate in Europe depends on a circulation of ocean water, with the Gulf Stream flowing north on the ocean surface and bringing warmth to Europe, while a countercurrent of cold water flows south in the deep ocean. So a new ice age could begin whenever the cold, deep countercurrent is interrupted. The countercurrent could be interrupted when the cold surface water in the Arctic becomes less salty and fails to sink, and the water could become less salty when the warming climate increases the Arctic rainfall. Thus Broecker argues that a warm climate in the Arctic may paradoxically cause an ice age to begin. Since we are confronted with two plausible arguments leading to opposite conclusions, the only rational response is to admit our ignorance. Until the causes of ice ages are understood in detail, we cannot know whether the increase of carbon dioxide in the atmosphere is increasing or decreasing the danger.

The biosphere is the most complicated of all the things we humans have to deal with. The science of planetary ecology is still young and undeveloped. It is not surprising that honest and well-informed experts can disagree about facts. But beyond the disagreements about facts, there is another deeper disagreement about values. The disagreement about values may be described in an oversimplified way as a disagreement between naturalists and humanists. Naturalists believe that nature knows best. For them the highest value is respect for the natural order of things. Any gross human disruption of the natural environment is evil. Excessive burning of fossil fuels, and the consequent increase of atmospheric carbon dioxide, are unqualified evils.

Humanists believe that humans are an essential part of nature. Through human minds the biosphere has acquired the capacity to steer its own evolution, and we are now in charge. Humans have the right to reorganize nature so that humans and biosphere can survive and prosper together. For humanists, the highest value is intelligent coexistence between humans and nature. The greatest evils are war and poverty, underdevelopment and unemployment, disease and hunger, the miseries that deprive people of opportunities and limit their freedoms. As Bertolt Brecht wrote in
The Threepenny Opera
, “Feeding comes first, morality second.” If people do not have enough to eat, we cannot expect them to put much effort into protecting the biosphere. In the long run, preservation of the biosphere will only be possible if people everywhere have a decent standard of living. The humanist ethic does not regard an increase of carbon dioxide in the atmosphere as evil, if the increase is associated with worldwide economic prosperity, and if the poorer half of humanity gets its fair share of the benefits.

Vernadsky, as Smil portrays him, was a humanist. He foresaw the gradual transformation of the biosphere into a noosphere. The word “noosphere,” a sphere of mind, means a planetary ecology designed and maintained by human intelligence. He recognized that, as the
noosphere comes into existence, “the aerial envelope of the land as well as all its natural waters are changed both physically and chemically.” He understood that the maintenance of a noosphere places heavy responsibilities on human shoulders. But he had faith in the ability of humans to rise to the challenge. The main conclusion of Vernadsky’s thinking, and the main conclusion of Smil’s book, is that life is complicated and any theory that attempts to describe its behavior in simple terms is likely to be wrong.

After this review appeared, Vaclav Smil published another book,
Energy at the Crossroads: Global Perspectives and Uncertainties
(
MIT
Press, 2003), dealing directly with the practical issues of energy supply and demand. The new book makes a good complement to
The Earth’s Biosphere
, which describes the larger framework of ecology within which practical policies must fit. I am grateful to Smil for sending me the new book, and sorry that I had not seen it when I wrote the review.

THOMAS LEVENSON IS
a filmmaker who produces documentary films for public television. He has a sharp eye for the dramatic events and personal details that bring history to life. His book
Einstein in Berlin
¹
is a social history of Germany covering the twenty years from 1914 to 1933, the years when Albert Einstein lived in Berlin. The picture of the city’s troubles comes into a clearer focus when it is viewed through Einstein’s eyes. Einstein was a good witness, observing the life of the city in which he played an active role but remained always emotionally detached. He wrote frequent letters to his old friends in Switzerland and his new friends in Germany, recording events as they happened and describing his hopes and fears. His daily life and activities come intermittently into the narrative but are not the main theme. The main theme is the tragedy of World War I, a tragedy that began in 1914 but did not end in 1918. This tragedy continued to torment the citizens of Berlin through the years from 1918 to 1933 and led them finally to put their fate in the hands of Hitler. Hitler was able to gain his power over them because he promised to erase the tragedy and bring them back to the happy days of the empire when Germany was prosperous and united.

Every aspect of Einstein’s life, the personal, the political, the
scientific, and the philosophical, has been described in detail and analyzed in depth by his various biographers. The world does not need another Einstein biography. Fortunately, Levenson’s book is not a biography. He has borrowed everything he needs from the published correspondence and the existing biographies of Einstein, with full acknowledgments and an excellent bibliography. The new and original aspect of this book is the context in which Einstein is placed. The context is a study in depth of the social pathology that gripped Berlin from the day Einstein arrived there in 1914 to the day he left in 1932.

The tragedy is a play in two acts, the first act being the years of war and the second act the years of the Weimar Republic. The most remarkable feature of the first act was the general belief among Einstein’s friends in Berlin that the war was winnable. The war was widely welcomed as an opportunity for Germany to achieve its proper status as a great power. Einstein observed that his academic friends and colleagues were even more deluded with patriotic dreams of grandeur than the ordinary citizens that he met in the street. In a conversation with his Swiss friend Romain Rolland in 1915, he described how Berlin had gone to war. “The masses were immensely submissive, domesticated,” he said. “The elites were worse. They were hungry, driven by their urge for power, their love of force, and the dream of conquest.” As late as the summer of 1918, after the failure of the final German offensive on the western front, many of the leading German academics were still confident of victory.

The state of mind of the mandarins in Berlin was very different from the state of mind of their enemies in Paris and London. In Paris the war was seen as a desperate struggle for survival. The guns on the western front were close enough so that everyone in Paris could hear them. In Britain the war was seen as a tragedy that had done irreparable harm to Britain and to European civilization, no matter who won it. When the war came to an end in November 1918, the British public looked back on it as an unspeakable horror that should never under any circumstances be allowed to happen again. But a large part
of the German public looked back on it differently, as a test of strength that they could have won if they had not been stabbed in the back by traitors at home. This book explains how that fatal German sense of betrayal came into being.

The second act of the tragedy is the story of the slow collapse of the Weimar Republic and the rapid rise of Hitler. Einstein was a firm supporter of the republic, but he saw which way the wind was blowing. One episode in the tragedy epitomizes the whole story. Erich Remarque’s book
Im Westen Nichts Neues
was published in 1929 and immediately became an international best seller. It is the finest of all fictional accounts of World War I, seen through the eyes of a group of young Germans who die pointlessly in the carnage of the western front. In 1930 it was made into a Hollywood film,
All Quiet on the Western Front
. The film was shown all over the world, except in Germany. When the distributors of the film tried to show it in Berlin, Hitler’s friend Joseph Goebbels organized a riot in the theater. Further Nazi demonstrations and violent protests against the film followed. And then the Weimar government banned the film throughout Germany. The Weimar authorities did not allow the German public to see the film because the Nazis considered it unpatriotic. This episode explains a mystery in my own family. One of my relatives is a lady, now ninety-four years old, who lived in Germany all her life and grew up in the Weimar years. Many years ago, I gave her Remarque’s book to read and she found it very moving. “This book is wonderful,” she said. “Why didn’t they let us read it when it was published? That was before the Hitler time, but we were told that it was disgusting and shameful and respectable people should not read it.” So the respectable Germans of her generation, even those who were not Nazis, did not read Remarque. I always wondered why, and now I know.
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