We are living astride two epochs in geological time. The first, the Holocene, began about 11,700 years ago; the second, the Anthropocene, now defines our troubled present. In a 2002 article, the Nobel laureate Paul Crutzen and Eugene Stoermer suggested that we have entered a new era in geological time called the Anthropocene epoch. This shift to a “human-dominated, geological epoch” is significant, according to Simon Lewis and Mark Maslin, because the “impacts of human activity” will be “observable in the geological stratigraphic record for millions of years to come.”1
And yet, the Anthropocene has all too often been conceived in narrowly physical terms, such as rock layers and glacier ice. These physical records are undoubtedly crucial to understanding whether humanity has measurably affected the earth system. But deep analysis of digitized historical archives can allow us to understand how and why these changes occurred. Bridging the divide between scientific and humanistic understandings can only enrich the scientific models of this new human age.
Since the Anthropocene has been triggered by human actions, we can see a detailed record of those world-making activities in the newly accessible form of digitized archives. These were previously locked in libraries that required sleuthing, on the order of The Da Vinci Code or Stephen Greenblatt’s The Swerve, through dusty manuscripts. And even though libraries and cultural-heritage institutions have spent millions of dollars over decades to digitize their holdings, still, they have mostly been used to pursue conventional humanities questions. How can we use these digital archives to envision the contribution of humanistic work on the scale of geological time, rather than just on the scale of literary history, canons, or periodization?
As one example, our Digital History of the Anthropocene project uses recent advances in digital-humanities methods, perhaps best known for their application to language patterns in literary texts, to mine these historical digitized archives in order to better understand what people since 1610 (one of the candidate years for the start of the Anthropocene) have been thinking about, discussing, and debating—how to define the idea of the earth and man’s changing place on it.
Put another way, the Anthropocene has long been discussed in terms of hard science. Yet, if it is an age caused and created by humans, then the Anthropocene must also be examined from all human perspectives. What, then, do the humanities have to teach about the Anthropocene?
Our archives are no longer stacks of historical documents for posterity. They contain an understanding of history as a geologic record written by the human hand.
The Anthropocene has provoked a far-reaching debate among scholars from a wide range of fields spanning the sciences, social sciences, and humanities. The historian Dipesh Chakrabarty has prompted us to grapple with the sobering knowledge that human society has an effect beyond the passing of generations, or even civilizations—how can we conceptualize the collective impact of our activities within the staggering scale of geological time? How can we begin to fathom our future obsolescence by imagining our place in the fossil record alongside the dinosaurs?
For scientists, however, these existential issues have been pushed aside for more prosaic matters: In what year did this Anthropocene present start? In May 2019, the Anthropocene Working Group, composed of scientists from the International Commission on Stratigraphy, voted to approve the mid-20th century—the time range now recognized as inaugurating the atomic age and the “great acceleration” of society’s impact on the environment—as the officially recommended origin point of the Anthropocene period.
However, a backlash emerged from this dating, with scholars from a wide range of perspectives and disciplines arguing that it is far too early to set a date in stone. Although scientists are well equipped to understand if chemical forces shaping the physical and geographic record across time are present and measurable, they do not understand how and why humans caused such changes.
To understand these underlying causes, we must attend carefully to the human social and cultural record that describes, over time, how human beings have reshaped the earth. Our archives are no longer stacks of historical documents for posterity. These archives now contain an understanding of history as a geologic record written by the human hand.
Geologists and climate scientists have recently called for a broader debate, in order to define a more historically sensitive vision of the Anthropocene that engages, in the words of Erle Ellis, the “diverse array” of “material records of human alterations of Earth,”2 from records in historical and cultural archives that are as necessary to an understanding of the Anthropocene as are stratigraphic rock layers.
Digital History of the Anthropocene focused on the Renaissance, because we have a good historical understanding of this time period; 1610 was nearing the end of Shakespeare’s dramatic career, and we have an abundance of digitized records, including scanned and transcribed texts from Early English Books Online, a digital archive of up to 130,000 texts from this time, and the HathiTrust Digital Library, which contains over 17 million volumes from the medieval period to the present day.
To work through these large digital archives, we adapted a range of machine-learning algorithms for text analysis. These were originally built for search engines and for social-media-platform ranking and filtering but can be retuned to identify large-scale trends within historical archives. The algorithm’s methods all work by identifying groups of words that have a very high likelihood of coexisting near one another within the sentences, paragraphs, and whole books composing the archives. These methods help us understand words and phrases as they were actually used and as they signified “in the wild” of human culture.
We used these methods to ask questions of the scientific rationale and the underlying historical assumptions for the different dates previous geological and chemical studies have proposed. Did Renaissance culture naively raze the natural world for the sake of inexorable technological and economic progress, as some origin narratives of the modern world and climate change begin? Like Dr. Seuss’s Once-ler character, who gained a self-conscious awareness of the error of his ways far too late to restore his ecosystem, can we, today, perceive man’s effect on the earth in a way that previous generations could not? Is this self-awareness of our ability to change the earth, which we now call the Anthropocene, a feature of our modern, technologically enriched and scientifically advanced era?
The Renaissance understanding of latitude, sunlight, and time was the original definition of “climate.”
What we found, in response to these questions, was more complex than what we had expected. We unearthed a fundamentally different Renaissance worldview and a bizarrely unexpected definition of life as it inhabits the earth. These ideas reshaped our understanding of the historical conditions at the beginnings of the Anthropocene epoch.
Our models persistently clustered words such as latitude, climate, zones, tropics, poles, complexion, and equinoctial in books from a wide, and seemingly unrelated, group of genres. As we examined these results, we saw that the common thread linking all of these words, phrases, and texts was a commonly assumed Renaissance earth system.
This system defined life across the globe in terms of the latitude bands dividing the globe into navigable global space. A latitude defines the amount of sunlight per day an area receives from the sun, with each degree of latitude representing increments of daylight. This system of latitude, sunlight, and time was the original definition of “climate.”
Rather than the long-term weather patterns we describe today, climate—in the Renaissance—was the spatial organization of the earth’s surface into latitude zones with a measurable amount of sunlight. This organization, in turn, dictated the environmental conditions of locations situated along that degree, including temperature, humidity, and precipitation. Most importantly, such an organization demonstrated—to the Renaissance mind—what plants and animals could survive and thrive in these places.
Strikingly, our models also repeatedly linked places and texts about a jumble of locations that seemed to have no relationship, and which we feared were spurious results. Books and passages about Virginia, Portugal, Spain, India, and China were grouped together in our models. This indicated that these locations shared similar word and phrase patterns, and that these texts used similar descriptive language for all of these places.
Unlike now, when our organization of the globe is by continents, or by hemispheric divisions such as “east/west” or “old world / new world,” in 1610 the world was organized by degrees of latitude. Locations along a latitude band would conceivably share more in common than locations at different latitudes on the same continent, or in adjacent nations. And so, in geographical explorations of the nascent Virginia colonies, Englishmen leaned on a comparative worldview that made sense of the new world in terms of other places at the same latitude. Such globalized thinking led to speculation that silk could grow profitably in Jamestown, because it shared the same climate as China.
This strange vitalist vision was able to closely affiliate two places 10s of thousands of miles apart, and it forced early-modern humans to define humanity and society in a fundamental relationship to the earth and its climate.
This may sound akin to an Edenic innocence, in which people were more attuned to the rhythms of the natural world. This interpretation, however, was not what we found in our models, which often contained results that were far darker.
The Renaissance definition—climate as a basis for biology at a global scale—was the principle upon which England built its idea of empire, by setting the parameters for how flora and fauna could be moved and transplanted across the earth in order to establish stable colonies. Climate was the spatial blueprint upon which England built colonial trade and its outposts—purposefully, along latitude bands, where living things could be easily exchanged.
Based on our experiments mining the digitized archives of the Renaissance, poring over texts—both famous and obscure—we found that the Anthropocene era and the global movement of life that triggered a global drop in carbon dioxide identified by scientists at the time was not a byproduct of colonialism. It was the motivation for colonialism itself.
Apart from exploring digitized historical archives from the Renaissance era, we are also expanding our research to examine literary and historical archives from the 20th century to understand the discourse around the mid-20th-century dating of the Anthropocene, as a more contemporary correlate to the historical analysis we have conducted for the 1610 dating. And we are using these methods on government environmental and weather data, as well as plant archives, to understand whether or not we can extract useful information from archival datasets to assess chemical and physical changes in the earth system.
We have designed our project as an example of the digital humanities whose primary goal is not to produce new readings of literary texts—many scholars already do this well. Rather, these methods scour our text archives for patterns of meaning and worldviews and debates that we have lost today, which challenge our assumptions about humans and their role in shaping the planet.
This article was commissioned by Richard Jean So.