Visualizing 6,000 Years of Environmental Change

In 2021, digital artist Tim Thomasson and I began a collaborative project that after several iterations would come to be called “Itzan,” after the archaeological site in northern Guatemala that was the focus of my doctoral work. “Itzan” converts real geochemical data into an artwork, a high-fidelity visualization representing the changing population, vegetation, and climate of the ancient Maya population over six thousand years. The lowland Maya, the focus of my thesis, adapted to their changing environment in different ways and are thought to have abandoned their cities in response to a devastating drought around 730-900 CE.

The Classic Maya are just one example of a civilization who are thought to have succumbed to the effects of climate change. Numerous ancient societies, including the Akkadians in Mesopotamia and the Khmer in Cambodia, had to reckon with environmental stresses and climate change, and now so does contemporary human society. During drought in the Levant, Ramses II, the Egyptian pharaoh, received a clay tablet from the Queen of the Hittites, bearing the message “I have no grain in my lands.”

Whereas the Akkadians could send a stone tablet with the message of the effects of climate change, current efforts to communicate the science of climate change appear to miss the mark. Ambiguities about climate science and disinformation generally make the challenge of dealing with the effects of climate change more difficult. We wanted to make environmental and demographic changes visible, for viewers of our artwork on exhibit. As these viewers watch the story of an ancient society’s adaptation, survival, and eventual collapse, they might recognize a similarity to the environmental challenges–drought and extreme weather events–our society is facing today. Perhaps by seeing with our own eyes, humans can more deeply reconcile our delicate relationship with the earth. This project moves beyond conventional data visualization to create an affective experience that enables new ways for people to understand complex patterns found in scientific data.

Turning Sediments into Stories

The artwork is composed of a computer-generated environment which visually expresses the lowland Maya population’s responses to climate change based on real geochemical data from a lake adjacent to the archaeological site of Itzan, provoking viewers to imagine distant timescales and complex patterns of human and non-human activity. The journey of these data began in the muddy, wet Maya lowlands where, plagued by insects and the blazing tropical sun, sediment cores were retrieved on a bobbing assortment of planks buoyed up by empty plastic drums.

From there, the cores, encompassing six thousand years of sediment accumulation, made their way to sleety Montréal, where they were arduously worked over to extract the organic molecules known as lipids within using different ratios of organic solvents. I extracted and quantified molecules with obscure names like stanols, polycyclic aromatic hydrocarbons, and plant wax alkanes, to reveal insights into the changing demography and environment of the area.

We then used geographic information systems (GIS), a software called Unreal Engine, and a method known as “procedural scattering,” to turn the insights revealed by the molecules into visual landscapes. The resulting representations of the real-world site take into account vegetation distribution and other environmental elements, such as amount of rainfall, of the geochemical periods being represented. From the abandoned archaeological site of Itzan, these ancient molecules have been brought to life again. Inscribed scientific data becomes a springboard to imagine the possible stories of past, present, and future.

Depicting the Baseline

The artwork begins around 5000 years before present (BP), when humans were not yet present around the lake. We the viewers can hear birds tweeting and an assortment of forest vegetation. Flora and fauna are yet uninfluenced by the human species. A single tree is seen growing and we are the only witness to it. This environment serves as a reference point for the changes to come in the following scenes. The issue of a baseline often crops up in discussions about modern environmental change. If society is to reverse the impact that humans have had on the planet, at which point in the history of a landscape do we wish to return? When does the so-called Anthropocene begin? In the Americas, for example, is this the profound transformation following European contact and colonization, or the Indigenous landscape manipulation thousands of years before then?

The Arrival of Humans

With the arrival of humans, as migratory hunter-gatherers or the first agriculturalists, to the area in 3200 years BP comes a need for space—for habitation and for agriculture. Fire is thought to have been used as a primary way of clearing forest land to satisfy this need. In the absence of tools, fire makes short work of removing vast areas of vegetation. The sounds of birds from the previous scene have been replaced by the crackling, sputtering, and sizzling of flames, which we see in the geochemical record as large concentrations of polycyclic aromatic hydrocarbons, like those found in wood burner or cigarette smoke. Is it at this point where the landscape has undergone enough change to be deemed worthy of being dubbed the beginning of an Anthropocene? This is the first point in the six-thousand-year history of the sediment record that the nearby lake was filled with environmentally persistent compounds that we now consider to be detrimental to human health.

Enter Maize Agriculture

Some people believe that the lowland Maya engaged in swidden, or slash-and-burn, agriculture. This involves cutting down or setting fire to trees to clear them and planting crops in the nutrient-rich ashes left behind. Of the crops the lowland Maya cultivated, maize has a special significance. In this scene, the birds and their song have returned in the absence of fire. We see a different composition of plants and trees, including neat rows of maize necessary to feed a growing population, and perhaps for trade.

This period of the geochemical record suggests large numbers of people moving in and out of the area and engaging in agriculture to different extents. Switching between modes of production in different parts of this world was referred to as ‘play farming’ by anthropologist David Graeber and archaeologist David Wengrow. Through experimentation, earlier societies could determine which strategies worked and which did not. Similarly, the lowland Maya appeared to have learned from failures in water conservation strategies and addressed those failures in later management approaches. We can gather this information from the six or seven sharp peaks in the geochemical record. These conservation tactics point to the human qualities of ingenuity, persistence, and trial-and-error. This sets the scene for the presence of large human populations about 1000 years later. Perhaps it is the profound transformation of landscapes for agriculture and food production that define the Plantationocene.

Climate Change

The lowland Maya dealt with the challenges of cultivating crops in an environment with highly seasonal rainfall through various innovations: the construction of reservoirs, canals, terraces. Changing water availability over time meant conserving it where possible. Some periods of Itzan history were wetter than others, and during some of these wet periods we see evidence for more extensive maize agriculture. Population growth—and consequently city expansion—during these times was likely fed by an abundance of maize, for food and for trading. In the scene above, the city has expanded, and the landscape further manipulated. The structures are now mostly stone, but we can see some remaining roofs made of overlapping palm leaves. In some parts of the lowlands, an excess of water—not a scarcity—was the problem, and entire cities were built to divert rainwater to avoid catastrophic flooding.

Adaptation and the Future

The lowland Maya adapted to these mounting environmental changes, such as climate variation, in different ways and are thought to have abandoned their cities in response to a devastating drought around 730-900 CE. Our future artwork will illustrate more scenes that represent the growth and abandonment in response to this drought event. One such scene will include depictions of dry scrubland and smoke, and the degeneration of the state of the monumental buildings at Itzan. The Maya did initially adapt to dwindling water resources with the construction of reservoirs and other water management strategies, like those recommended by the Intergovernmental Panel on Climate Change, but they were ultimately unable to keep up with the pace of environmental change. There are many theories as to how lowland Maya society restructured itself or underwent “collapse.” But this process may have involved increased social tension between neighboring polities because of water scarcity and competition for resources. The abandonment of the city and movement to other areas is an ancient example of climate migration, the same climate adaptation that is taking place today. Maya people continue to inhabit modern-day Mexico, Guatemala, Honduras, El Salvador and Belize, areas where water stress is exacerbated by anthropogenic climate change.

Because of its vast timescale and carefully crafted imagery, this project moves beyond a simple didactic representation of data toward something more obscure—where spectators are left to contemplate their relationship to the broader histories and possibilities of a past, present, and future earth, where climate change cannot go ignored. Here, our artwork begins to fill the imaginative gaps, exploring the possibilities of narrative that stretch deep into that past. The possibilities afforded by computer graphics technology enable viewers to experience a timescale which exists outside an individual’s biological time. Gazing into geological time, one might glimpse flickers of possible futures on the horizon.

---

Featured Image: Tikal, long ago an urban center of the Maya lowlands, stands above the forest in the Petén region of Guatemala. Photo by Daniel Mennerich, 2021.

The artwork in this piece was exhibited at the ACM SIGGRAPH Digital Arts Community “The Earth, Our Home” exhibition in 2021 and at the Athens Digital Arts Festival in 2022. The film version of the work debuts at the Earth Futures Festival, the Sardinia Film Festival, and the China International Conference of Science and Education Producers this fall 2022.

Benjamin Keenan is an interdisciplinary biogeochemist interested in using insights from the past to inform responses to contemporary issues such as anthropogenic climate change. Contact.

Tim Thomasson is a digital artist who works primarily with computer animation, and utilizes real-time computer graphics technologies to create continually generative environments and systems.