Would anyone be interested in reading a book about a volcanic eruption? In the case of Tambora, there is good reason to believe they would. This book is less about geology than about the societal reactions to an event that affected the climate worldwide – the largest volcanic eruption in human history. The explosions of April 1815 were so powerful that they could be heard thousands of kilometres away. The lava and pyroclastic flow devastated the immediate surroundings, and cyclones, tsunamis, ash fall and acid rain the adjacent region. The explosion cloud reached a height of 45 km. Large parts of Asia suffered for months under a ‘dry fog’ that obscured the sun. Upper winds distributed the gas and suspended particles around the world. The aerosols reduced solar radiation and led to a global cooling. The winter of 1815/16 was one of the coldest of the millennium. Glaciers expanded. Torrential rains caused flooding in China and India. In Europe and North America, 1816 became the ‘year without a summer’.¹ In many parts of the world, 1817 became the ‘year of famine’.²

The years that followed were devoted to coping with the results of the crisis. Epidemics paralysed entire regions; mass migration shifted social problems to other corners of the globe; and mass demonstrations, uprisings and suicide attacks generated a pre-revolutionary mood. The eruption of Tambora served as a great experiment in fields where we normally cannot conduct experiments: the economy, culture and politics. The question is, how do different countries, legal systems and religions respond to a sudden worsening of living conditions imposed by external forces? To changes in nature, failed harvests, inflation, famine, epidemics and social unrest? As the Indian historian Dipesh Chakrabarty has noted, climatic events are uniquely suited to being viewed from a global perspective.³

Throughout the world, the volcanic eruption forced the affected societies to confront a current problem using their own specific mechanisms for coping with an unexpected change in the climate that – whether through cold, drought or constant rain – challenged their usual means of supplying the population with basic necessities. Nearly all societies in the world had to demonstrate virtually simultaneously how capable they were of managing such a subsistence crisis, which almost always coincided with a spiritual crisis. Some of them seemed to do so effortlessly.⁴ The Tambora Crisis caused others to slide into a protracted decline.⁵ The sudden and simultaneous appearance of acute problems worldwide has the character of an experiment whose design we cannot determine, but can reconstruct. From the distance of two centuries, this allows us to analyse the vulnerability and resilience of the societies of the time when faced with sudden climatic turmoil.⁶

That is the topic of the present volume, which is interested not in the volcanic eruption as such, but in its cultural consequences as well as the capacities of societies at the time to respond to sudden climate change. The time period of this study is 1815 to 1820, dates that are familiar from political history as well. In 1815, participants in the Congress of Vienna resolved to reorganise the world, and in 1820, the Final Act of the Viennese Ministerial Conference integrated the intervening experiences of crisis into a set of regulations. The future US Secretary of State Henry Kissinger (b. 1923) wrote his doctoral thesis about this period, in which an excess of wars and crises led, through diplomatic negotiations, to a political order that assured peace and stability for a generation.⁷ The European post-war politician Robert Marjolin (1911–1986) also wrote a study of this period, one devoted specifically to the unrest and revolts unleashed by famine in France.⁸ The struggle for political stability took place in domestic politics as well, without some knowledge of which one cannot truly understand the foreign policy of the time. The domestic policy of these years was coloured by the climate crisis.

The period from 1815 to 1820 will be treated here as a coherent period of crisis – I call it the Tambora Crisis, to define it by its triggering factor. When the literature refers repeatedly to a crisis in the wake of the ‘European wars’,⁹ it reveals more than the authors’ refusal to meet the challenge of a worldwide crisis that was precisely not rooted in the political or military processes so familiar to them. It is almost touching to watch the same historian trying over and over again to attribute the same crisis to a different cause in every European country.¹⁰ After all, this crisis had no logical cause. The volcanic eruption could just as easily have occurred a few years earlier or later, and it could happen again today or tomorrow. It was an event ‘external’ to human society. This presents historians and sociologists with a methodological problem. The universal ‘rule of sociological method’ that it is ‘in the nature of society itself that we must seek the explanation of social life’¹¹ does not apply here. Emile Durkheim’s ‘social facts’ are abrogated when the conditions are set not by Napoleon or the bourgeoisie but by a volcano.

From the standpoint of global history, it is easy to see that the traditional explanations do not work everywhere anyway. Why should there be famines in China and South Africa or a cholera outbreak in India because Napoleon lost a war, the British Army demobilised its troops or more machines were used in European industry? Even in Europe, one would be hard-pressed to find documents showing that anyone connected the constant rain, floods and failed harvests or the unrest that followed with the wars and their end, or with nascent industrialisation. Historians who nonetheless make this claim have used the simple facts of chronology to draw a causal connection, along the lines of the post hoc fallacy, which psychologists call a logical fallacy.¹²

The dimensions of the Tambora Crisis were so extraordinary because its roots lay in nature, in processes of geology, atmospheric physics and meteorology. These forces of nature respect no borders. Their effects are not merely global, but also on a very particular scale. Without knowing anything about Tambora, contemporaries recognised the unusual character of this crisis by comparing it to earlier ones. According to the Swiss professor of theology and writer on poor relief Peter Scheitlin (1779–1848), ‘In 1760 people in the country earned handsomely and all foodstuffs were extremely cheap – in 1771 they earned handsomely and all foodstuffs were very dear – in 1817 they earned nearly nothing but the inflation was terrible – in 1819 they earned nearly nothing but everything was very cheap. What a strange diversity! What an interesting distribution of all the possible cases in a period of 50–60 years, that is within a human lifetime!’¹³ As we shall see, ‘famine year’ does not mean that there was no food available, but merely that it was unaffordable for the many people who, as described by the Indian economist Amartya Sen, had no access to it.¹⁴

The theme of climate and history has gained in influence ever since the world’s scientists agreed that we are living in an age of global warming.¹⁵ When climate change was put on the international agenda there were still fears of an immediately impending ice age, but by the time the international summits on climate change became established the broad consensus was that the problem for coming generations would be warming, not cooling. Since 1990, reports from the Intergovernmental Panel on Climate Change (IPCC) have regularly informed the public about the state of research in the field.¹⁶

In the 1960s, when the idea of studying the climate systematically emerged in the United Nations, a series of long, severe winters left an impression on western societies. In connection with the eruption of the Gunung Agung volcano on Bali, data was gathered for the first time from an airplane that proved that its emissions changed the composition of the air as high up as the stratosphere.¹⁷ These were important additions to the first global study of a volcanic eruption in the wake of the eruption of Krakatoa in 1883.¹⁸ One hundred years previously, following the eruption of the Icelandic volcano Laki, Benjamin Franklin (1706–1790) had already observed that the same weather phenomena occurred in Europe and North America.¹⁹ However, the obvious hypothesis that Gunung Tambora had been the catalyst for worldwide climatic phenomena was not proven until 1913, in a study by the American atmospheric physicist William Jackson Humphrey (1862–1949).²⁰

The research on volcanoes and their eruptions has progressed in the meantime. One of the principles of climate science is that violent volcanic eruptions can change the composition of the atmosphere through their emissions of ash, gases and fine particles, which can affect the climate worldwide.²¹ The number of volcanoes was determined, and, based on ice cores,²² tree rings²³ and sediment analyses, a chronology of volcanic eruptions over a period of several hundred million years was established.²⁴ Using the Volcanic Explosivity Index (VEI), the strength of volcanic eruptions was classified in seven stages, measured by the amount of matter emitted and the height of emissions.²⁵ The scale was calibrated according to the oldest precisely described larger volcanic eruption, that of Vesuvius in 79 CE (= VEI 5).²⁶ Even larger volcanic eruptions are described as ‘ultra-Plinian’ events. Their influence can be enormous. The eruption of the volcano of Thera/Santorini (= VEI 6) more than 2,650 years ago probably led to the extinction of the Minoan culture.²⁷ The eruption of Toba (= VEI 8) in present-day Indonesia some 70,000 years ago nearly led to the extinction of humankind.²⁸ The eruptions of supervolcanoes, for instance those under Yellowstone National Park or the Phlegraean Fields near Naples, surpass any scale. They could lead to a ‘volcanic winter’, a global cooling, which due to feedback effects could last for decades or even centuries.²⁹

The eruption of Tambora (= VEI 7) in 1815 was the largest eruption in human history – with history traditionally defined here as the period from which we have written sources, that is, approximately the last 5,000 years. This eruption brought summer snowfalls in many areas, but there was no danger of a ‘volcanic winter’.³⁰ The characterisation of the year as ‘eighteen hundred and froze to death’ is found just once in an undated poem from the USA.³¹ It reads

The designation ‘year without a summer’ is an exaggeration, although it has gained a certain currency.³³ Today, with the help of land weather reports and ships’ log books, we can reconstruct historical weather maps globally.³⁴ They show a varied range of weather anomalies for 1816. In some areas it was much too wet (e.g. western Europe and China), in others too dry (USA, India, South Africa), in most too cold, but in some also warm (e.g. Russia). These years appeared to be ‘unnatural’ in the eyes of contemporaries and anomalous in the analyses of modern climate scientists.³⁵

The eruption of Tambora and its effects were only studied in greater detail in the 1980s. The research was strongly influenced by Anglo-American scientists: Henry Stommel (1929–1992) was an oceanographer at the Massachusetts Institute of Technology,³⁶ Charles Richard Harrington (b. 1933) was a zoologist at the Canadian Museum of Nature,³⁷ Clive Oppenheimer (b. 1964) is a volcanologist at the University of Cambridge,³⁸ and the American Nicholas P. Klingaman is a meteorologist at the University of Reading.³⁹ The recent study by Gillen D’Arcy Wood, a professor of English literature at the University of Illinois, is the first to include selected international cultural aspects, for example the emergence of vampire literature.⁴⁰ Alongside this there exist a number of very good studies that explore the crisis of 1816/17 on a local or regional level.⁴¹ There is no lack of work on individual aspects such as the origins of the global cholera outbreak.⁴² Many events such as the fall of governments, the discussions surrounding constitutions for newly founded states, political murders, pogroms and planned coups have not thus far been viewed in connection with the Tambora Crisis. And yet, as I shall argue here, they are virtually impossible to understand without this context.

The Tambora Crisis – and the present volume profits from this – occurred in a more modern media environment than any previous climate or subsistence crisis. In the early nineteenth century, when European expansion had reached its height, newspapers and periodicals already existed all over the world. Everywhere we find well-trained, curious and sometimes very opinionated government officials who wrote highly competent reports on all manner of subjects or events. To name but one example, the British governor of Java, Sir Thomas Stamford Raffles (1781–1826), undertook a survey with a standardised questionnaire among all the British residents of the Indonesian archipelago to explore the causes and consequences of the explosion of Mount Tambora. Many economists, ‘political scientists’ and also theologians wrote expert testimonies or detailed accounts and analyses of the famine. Scientists from the emerging disciplines of geology, physics and chemistry sought explanations for the extraordinary natural phenomena. Agronomists and technicians, but also nutritionists, architects and town planners, looked for ways of mitigating the effects of the crisis and preventing future suffering. They presented their ideas for discussion in specialist journals. The correspondence, diaries, travel accounts and memoirs of politicians, artists and scholars afford profound insights into their thinking. Frequently, these commentaries came from well-known personalities such as the Russian Tsar Alexander I, the English poet Lord Byron, the Prussian diplomat Karl August Varnhagen von Ense and his wife Rahel, née Levin, or the Weimar minister of state Johann Wolfgang von Goethe.

The task of the present volume is to construct a new synthesis, based on the rich contemporary sources, out of the many individual aspects. The aim is to redefine the Tambora Crisis as a part of world history, an event with a rightful place not just in natural history, but also in cultural and social history. Until now, regional or national histories have cultivated their own modes of dealing with this crisis because scholars have not been thinking outside the box. Often, it has also been swept aside because it apparently does not fit into our historical narrative of human progress from servitude to liberty. Readers need to leave such ideas behind if they are to dive into the complexities of the years 1815–1820.

The eruption of Mount Tambora was the beginning of an experiment in which all of humanity became involuntary participants. The reactions to the crisis offer an example of how societies and individuals respond to climate change, what risks emerge and what opportunities may be associated with it. This book shows how the climate crisis of the early nineteenth century was overcome. Anyone who is interested in the problems of current and future climate change should know about the historical example of the Tambora Crisis.