In this essay, we approach the method of cross-contextualization as both an actors’ category and as an analytic approach for historians interested in the construction of long-term or large-scale environmental knowledge. While we both use cross-contextualization as it was originally conceived as a method to tell global histories of science by reading together sources not obviously in conversation, we also deal with actors who themselves are doing historical work by historicizing global climates across different contexts. To do so, these actors, too, have learned to read sources at a distance from their obvious audiences, thereby expanding what it is possible to say about the broad and nebulous category of global environment. We think through two areas of research: the construction of climate knowledge in nineteenth-century Egypt, from Anna, and the use of climate proxies in the twentieth-century technoscience, from Amelia.
Anna Simon-Stickley
Throughout the nineteenth century, a colourful cast of actors negotiated Egyptian geo-history by reading human history in light of natural history and vice versa: Egyptian scholars, engineers, and journalists, European archaeologists and botanists and geologists, British colonial administrators and irrigation experts – to name just a few. This already hints at the two ways in which I will be talking about cross-contextualizing sources today: once as an analytic approach and then as an actor’s category.
As an analytic approach, cross-contextualization is part of my evolving toolbox for writing more global and less Eurocentric histories of science that include Egyptian voices.Footnote 1 The most intuitive and widely used model to write less Eurocentric and elitist global histories of science is probably circulation and the figure of the go-between.Footnote 2 In my research, many such go-betweens make appearances, from the astronomer Mahmud El-falaki and scholar Ali Mubarak who were in conversation with the geologists and climatologists of the survey department, to Tanus Botrus Jabur, field work assistant to a German naturalist. Applying this model reveals how much scientists relied on non-Western and non-elite participants whose roles were subsequently effaced. The problem with this model, though, is that it can only grasp reciprocal influence – influence often narrowly understood as a, however indirect, contribution to the Western canon of accumulating new knowledge, as if the only audience for ideas of the natural, material world consisted of Western scientists. In late nineteenth-century Egypt, many people were talking about Egyptian geo-history, but not always with each other or with the Western scientific community.
Cross-contextualizing has helped me get beyond this seeming conundrum. By reading together Egyptian discourse in newspapers, scientific journals with scientific publications and archival sources, as well as the scholarship built on these respective archives, we see not only how many people were interested in Egyptian natural history but also the political stakes of doing so. Beyond merely juxtaposing sources, though, it is important to ask why actors engaged with science or ideas of the past. The circulation model answers this question through influence, arriving at the global spread of scientific ideas. To get beyond diffusionism, or mere juxtaposition, it is useful to ask what social processes Egyptian actors were responding to by invoking scientific concepts. What new lifeworlds could be better understood through geo-histories? Many late nineteenth-century Egyptians, for example, drew on the laws of evolution and geological timescales to make plausible societal development, economic progress, and Egypt’s place in a world in which nations competed in an increasingly capitalist and imperialist world order.Footnote 3
But as I said in the beginning, cross-contextualization as an approach works for writing global history but also helps us understand what is going on in Egyptian geo-history, where very diverse sources had to be read in light of each other in order to serve as proxies of natural processes. The question whether the North African climate had got drier was one that drew together many kinds of sources, from physical traces to ancient religious texts.
One particularly pertinent source for inquiring into shifting climates was the height of the Nile flood, which had been registered since the earliest dynasties, some such markings suggesting remarkably higher floods.Footnote 4 Such ancient measurements could be found on cliff walls and Nilometers, but could also be inferred from ancient statues or tombs enveloped by the river or sand dunes. In the 1880s, the scholar and education minister Ali Mubarak compiled all known flood records from the 650s onwards, which were in turn drawn on by the colonial geologist Henry Lyons who had access to the new Nile measurements at the Aswan dam. Lyons read these measurements against evidence found in and on various ancient temples in an attempt to enlist Egyptian climate history into Eduard Brückner’s recently published theory of periodic climate changes – thus extending the scale he was working with not just temporally but spatially to get from the local to the global. To do so, he had to scale temporal data and make commensurable these disparate sources by correlating calendars and invoking both natural and human factors to account for differences in the date: accumulating sediment, bursting cataracts, as well as intentionally falsified markings or the marking of an excessive not normal flood.
Vehemently against the theory of climatic decline was the naturalist Georg Schweinfurth, who, together with Jabur, conducted studies on ancient plant remains from pyramids. He combined this data with contemporary plant imagery, vestiges from mosque gardens, as well as plant names extracted from Egyptian peasants, whom many considered as living fossils of a pharaonic race. The work of making these disparate sources commensurable, Schweinfurth cautioned, required not only knowledge of ancient Egyptian culture and art history, but also a form of source critique he likened to the work of the historian. This held especially for the climate question. Had previous botanists known Egyptian history, they would have realized that the ancients cultivated and imported many plants, and their disappearance was down to cultural, not climatic, decline.
This brings up the matter of the politics of various climate histories. Anxiety over the possible desiccation of Egypt was mapped onto and shaped by orientalist notions of the East as fallen and stagnating.Footnote 5 Figures like Lyons needed to know whether decreasing rainfall had brought down the ancient Egyptians, as it cast doubt on the British occupation in the present. Meanwhile, Schweinfurth obsessed over the supposed eternality of climate, and thus race, in Egypt and saw ongoing modernization – the expansion of education, railways, and especially of cash crop cotton production through perennial irrigation – as entirely out of sync with the supposedly unchanging Egyptian geo-history. Others were more amenable to change. The Egyptian agronomist Kamal Gali, for instance, argued that great changes in Egyptian geology forecast the great changes that the country would still have to undergo – a subtle call for modernization as a sovereign nation. For him, Egyptian geo-history held important lessons for its political future. He not only argued that the Nile river proved the ancient connection between Egypt and Sudan at a time when Egyptian nationalists and British colonialists were pushing for its annexation, but also suggested that socialism was more ‘natural’ as the yearly rhythm of the flood made collective work and thus communal land ownership necessary.Footnote 6
In all of these cases, Egyptian geo-history was read in light of and projected onto Egyptian politics – or we could say, human history was cross-contextualized with natural history. In fact, I would argue that the making commensurable of human and natural sources or climate proxies is part of a larger, global history of scaling between the natural world and human societies at a time when these categories were increasingly questioned and in flux.Footnote 7
Coming back to our role as global historians, what can we learn from the cross-contextualizing efforts of these historical actors? Firstly, it seems that commensuration or scaling is an important first step in bringing different kinds of sources together. Just as Egyptian and European thinkers worked to convert human and natural flood markings into a common metric, historians need to find a thematic common ground between diverse texts, written for quite different reasons and audiences. In the cases outlined above, this meant broadening the framework from a narrow focus on scientific work on deep time to asking who cared about and used deep time for which political goals. Secondly, it is important to keep in mind that making things commensurable also flattens differences. Schweinfurth, for instance, enlisted peasant vocabulary based on racial prejudice that negated historical change. In cross-contextualizing, it is therefore important to be mindful of differences and of vernacular contexts.
Amelia Urry
Just as cross-contextualization has proven to be a useful tool in building broader histories of climate, I have found it to be a source of important insight both as a method to approach under-documented histories and as a way of understanding how my historical actors – climatologists and glaciologists – brought together different kinds of evidence into a condensed narrative of Earth history.
As an actors’ category, cross-contextualization works as a lens for understanding the work of climate scientists and glaciologists in the twentieth century, particularly when examining how new or controversial research approaches were put into practice in the face of apparent dead ends. The twentieth century saw the emergence of new molecular techniques in climatology and paleoclimatology that allowed scientists to read past climates from physical traces left in ice, sediment, and fossilized remains of long-lived organisms such as trees and coral. These high-tech 'climate proxies' raise the same question that cross-contextualizing does for historians, or that geo-history raised for historical climatologists: what sources can be counted on to provide legitimate knowledge about the past?
With mass spectrometry and radiocarbon-dating, materials like ice and mud can be mined for insight into past precipitation, temperatures, and atmospheric conditions. But for evidence of climate changes as they occur on the timescales relevant to human life, human history itself continued to offer other kinds of proxies even in the face of these new approaches. Sources more traditionally left to historians, such as diaries and logbooks, became rich territory for unearthing climate data from the past decades and centuries. For these sources, different techniques are necessary to make these artefacts serve as reliable witnesses to climate history. For example, in a 2007 study of paintings made across the eighteenth and nineteenth centuries, techniques of spectral analysis and statistics were applied to turn these artistic objects into scientific data, particularly surrounding the 1815 eruption of Tambora and the resulting ‘year without a summer’.Footnote 8 These paintings have since been cited as offering ‘independent proxy evidence’ about the climate, in the same language commonly applied to a fossil or isotope.Footnote 9 Historical climatologists are, quite simply, cross-contextualizing data from a wide range of sources.
As an analytical tool, of course, cross-contextualization offers much to the historian of climate knowledge. Climate histories are, perhaps obviously, also global histories, but their telling does not always reflect this fact. Large-scale institutional climate science has largely been carried out by American and European institutions, staffed by scientists and administrators often with disciplinary backgrounds in certain fields (physics, meteorology, etc.) which have historically not been open to wide representation in matters of class, race, and gender. And yet, the sciences of climate modelling and forecasting purport to speak for the globe, from a universal point of view. Therefore it is important to think about how we historians might construct histories of climate science that do not reduplicate the asymmetries inherent in these fields. One promising avenue, for me, has been in looking to narrative as a site of cross-contextualization.
One example: In 1953, the RAND Corporation and the US Atomic Energy Commission launched a covert set of studies aimed at understanding the hazards that global radioactive fallout posed to human bodies, organized under the code name Project Sunshine. This project was led by the American chemist Willard Libby, who was also a pioneer of radiocarbon-dating in paleoclimatology (he would go on to win the Nobel Prize for that in 1960). Part of Project Sunshine’s aim was to acquire human specimens, particularly cadavers of young children and infants, in order to examine how byproducts of nuclear detonations might already be migrating into human tissues, and to provide better forecasts to the public in the case of future nuclear attacks. Though the methods largely targeted medical and biological analyses, Project Sunshine also included consideration about global atmospheric circulation, information which was also rapidly becoming important to the developing field of climate modelling.
The same year that Project Sunshine was launched, in a desert outside Albuquerque, the Anaconda mining company broke ground in what would become the largest open-pit uranium mine in America. The Jackpile Paguate Mine was two miles wide at its largest point, several miles long, and several hundred feet deep. It was in continuous operation for nearly thirty years, during which time the state of New Mexico provided half of the total uranium of the US nuclear arsenal, before it was closed in the late 1980s. Despite the known harms of uranium and the potential dangers that contamination posed to human bodies – the express subject of Project Sunshine research – no regular medical monitoring or groundwater testing was carried out in the small community of Paguate and the reservation lands of the Pueblo Laguna people during this period or after the mine was decommissioned. The Jackpile mine has since been declared a Superfund site, and the communities in Paguate and the Pueblo reservation show elevated rates of cancer. Nevertheless, any definitive analysis of the effects of contamination has been made difficult or impossible by the lack of monitoring of the site.
By reading these two events together – the opening of the Jackpile mine and the launch of Project Sunshine – we can see the way in which nuclear anxieties of contamination and catastrophe were swirling through early considerations of atmospheric composition and climate effects, in ways that could go on to shape the science of climate modelling as it developed across the late twentieth century. And yet, the archive preserves little from the voices of those in the communities affected by these activities themselves. A third source can offer some insight into this ‘lost’ history: the writings of Leslie Marmon Silko, a Pueblo writer who grew up just outside of the reservation and wrote about Pueblo traditions and environments in her novel, Ceremony.
The novel’s protagonist is a Pueblo Laguna man of mixed descent who finds himself grappling with the relationship between his traditions and his environment, as well as the damage wrought upon his own psyche by his experiences as a soldier in the Pacific during the Second World War. Early in the story, he is tasked by a medicine man with saving his people from ‘the destroyers’. Over the course of the novel, he struggles with carrying out a ceremony that could bring the rain and restore ecological balance in the desert around him. Motifs of drought and of nuclear devastation repeat throughout his journey, and in fact, culminate in a violent showdown at the site of the Trinity nuclear test. Indeed, Silko’s ‘destroyers’ evoke Robert Oppenheimer’s quote (which he has also recontextualized from the Bhagavad Gita) upon the detonation of Trinity: ‘now I am become Death, the Destroyer of Worlds’. By reading Oppenheimer through Silko’s fiction, we can see the worlds being destroyed as simultaneously distant and quite close to home: a fable about the echoing reverberations of war, but also of the pollution and rupture between humans and their environment. We also see a concrete instantiation of the claim by Indigenous scholar Kyle Whyte that native peoples are already living through a post-apocalyptic world.Footnote 10 In turn, the Pueblo Laguna experiences that Silko documented show how global fears of apocalypse co-existed with – and were indeed enabled by – slow-motion and ongoing harms on the local level.
Conclusion
These examples of cross-contextualization, while shading back and forth in terms of the self-awareness with which the method is explored, share a common framing of the ‘global’ climate or environment. This framing has drawn both scientists and historians to read widely, confronting gaps in knowledge with unusual forms of evidence, in order to present a fuller picture.
There are, of course, limits to this approach as well. Perhaps no history or science can ever be truly or comprehensively global. We can see this in computerized climate models, which sacrifice resolution for scale: it is never a matter of putting every detail into the same box and hoping the correct answer comes out the other side. Perhaps the key point is that, like the Borgesian total map of the territory, models are useful because they are incomplete. They hint at dynamics and relationships that are hidden in the full rush of detail that marks ordinary, ongoing reality. Likewise, histories may benefit from remaining, on some level, partial: the space between two distant sources may tell us as much about the world as the points where they come into contact.
In any case, it is clear to us that cross-contextualization is never a finished process, but an ongoing project of reading and rereading sources against an ever-shifting background. For our historical figures, it is a continual effort of rhetorical and mathematical argument, building up piles of evidence that must be constantly reinforced and readjusted. For us, as historians, it is the ongoing work of bringing different voices into the conversation, and leaving space for them to speak.
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