The Emergence of the Nuclear Winter Theory

In 1982, atmospheric chemist Paul Crutzen and climatologist John Birks co-authored a paper in which they described the anticipated effects of a nuclear war on vast forests covering an area of the size of Scandinavia.11Paul Crutzen P. and John W. Birks, “The Atmosphere after a Nuclear War: Twilight at Noon,” In J. Petersen, Nuclear War: The Aftermath, Oxford: Pergamon Press, (1982): pp. 73-96. In their vision, fires would produce a thick smoke layer drastically reducing the amount of sunlight reaching the Earth’s surface. This darkness would persist for many weeks, rendering any agricultural activity in the Northern Hemisphere virtually impossible. Although limited to the Northern Hemisphere, the effects of photochemical smog that Crutzen and Birks considered would remain visible for several months after the particulates have been deposited on the ground, an atmospheric phenomenon that had so far gone overlooked.

Crutzen and Birks offered a very detailed estimation of a nuclear war scenario; however they only provided a localized assessment over a limited time span, primarily of how nuclear war would have an impact on the atmosphere, similar to a “twilight effect.”

Two decades later, Crutzen promoted the term “Anthropocene” as a new geological epoch driven by the all-encompassing impact of humankind on Earth’s geology and ecology.22Paul Crutzen, “Geology of mankind,” Nature 415: 23 (2002); Paul Crutzen and Eugene Stoermer, “The ‘Anthropocene,’” Global Change Newsletter, 41 (2000). Together with the biologist Eugene Stoermer, he endorsed this idea in two articles, pointing out that humanity had left a noticeable trace on the Earth’s atmosphere since the Industrial Revolution. Glacial ice cores have indeed revealed a rise in concentrations of CO₂ and CH₄ that coincide with the latter part of the eighteenth century.

While he did already envision the threat that human technologies pose in how they can recast the global environment in Twilight at Noon, he missed the occasion of predating the “Eureka” moment that lightened up in his mind when he pronounced the word “Anthropocene” in 2000, during a scientific meeting in Cuernavaca.

However, further estimations of the effects of a thermonuclear war on a planetary scale were not long in coming. In March 1983 when Ronald Reagan delivered what became known as his Star Wars speech, astronomer Carl Sagan published a piece in Parade magazine in which he extended Crutzen and Birks’s analysis to a planetary dimension.33Carl Sagan, “The Nuclear Winter,” Parade (30 October 1983): 4–7; Carl Sagan, “Nuclear War and Climatic Catastrophe: Some Policy Implications,” Foreign Affairs, 62, 2 (1983): 257-292. He warned the world about the unforeseen and devastating effects of even a few hundred megatons on the global environment. Sagan’s appeal even reached television. He warned policymakers that a global nuclear arms race would produce long-term catastrophic consequences that could harm not only the two superpowers involved, the United States and the Soviet Union, but other nations and continents too.44See here: https://www.cbc.ca/player/play/689795139915

Again in 1983, Sagan and his colleagues, Richard Turco, Owen Brian Toon, Thomas Ackerman and James Pollack, who became known by the acronym TTAPS (formed from their last initials), published an article on the hypothesis of an impending global catastrophe following multiple nuclear explosions.55Richard P. Turco et al., “Nuclear Winter: Global Consequences of Multiple Nuclear Explosions,” Science, Vol. 222/4630 (1983): 1283-1292. A landmark book titled The Cold and the Dark, authored by Sagan, the notable biologist Paul Ehrlich, Donald Kennedy, and Walter Orr Roberts, also appeared as a publication from the proceedings of a conference in which United States and Soviet scientists gathered to discuss the long term world-wide biological consequences of nuclear war. Held in Washington on October 31, 1983, The World after Nuclear War, became later known as the Halloween conference. Its proceeding volume, The Cold and the Dark, discussed thus both atmospheric and biological effects of a nuclear war giving equal importance to both dimensions as closely interrelated.

The authors gave a very dramatic description of what the planet would look like following a prolonged thermonuclear conflict: even if the United States and the Soviet Union would use only a third of their nuclear arsenal (comprising a total of around 50,000 weapons) to cause an explosion of about 5,000 megatons, the Earth would plunge into darkness. Since the surface of the planet would become inaccessible to sunlight, it would rapidly cool. Major disturbances in global circulation patterns and dramatic changes in local climate and precipitation rates would follow.

The planet’s biogeochemical cycles would be severely altered, not just as a result from the interruption of plant photosynthesis but also because of the distribution of radioactive debris from nuclear fallout. In other words, biological systems were doomed too. The extinction of a large section of animals, plants, and microorganisms on Earth seemed possible, an extinction event which would be as severe as that at the close of the Cretaceous, when the dinosaurs and many other species died out.66Sagan, “Nuclear War,” p. 274. Any war survivors would suffer from starvation and be exposed to near-lethal doses of radiation. The size of the Homo sapiens population would be reduced to prehistoric levels or below, and its extinction could not be excluded.77Carl Sagan et al., The Cold and the Dark: The World After Nuclear War, New York: W. W. Norton & Company, 1984. As a consequence, the appearance and characteristics of the Earth after a prolonged nuclear conflict would be so different that the Nuclear Winter could trigger a transition towards a new stage in Earth history. This stage would be marked by the changing parameters of the oceanic and atmospheric circulation patterns due to the smoke lofted in the stratosphere, and a massive soot injection disrupting the Earth’s biogeochemical cycles that would to some extent impede a complete recovery of the biosphere.

Not surprisingly, the catastrophic scenario for the planet portended by nuclear power and atomic bombs struck a chord in popular culture and imagination. Perhaps the most iconic example, the image of the mushroom cloud became the epitome of the sublime power of self-annihilation technologies, featuring in many artistic and photographic exhibitions between 1982 and 1986. During these years, an aesthetic of destruction stands out in science fiction novels, visuals, and movies which relies on the sense of fear and euphoria that images of planetary collapse triggered in the spectators. Setting a record as the highest-rated TV film in film history, Nicholas Meyer’s The Day After (1983) is perhaps the most symbolic depiction of the influence that a fictional nuclear conflict plot had on the American popular culture. It was also shown on the other side of the Iron Curtain despite the fact that the Soviets had their own apocalyptic counterparts. The best-known Soviet nuclear-war narrative is Konstantin Lopushansky’s Letters from a Dead Man (1986), which was widely screened throughout the USSR and abroad, including in the US.

The Soviets enter the Nuclear Winter debate

In their study the impact of the Nuclear Winter on the Earth’s global cycles, Sagan and TTAPS greatly benefited from international collaboration. Ėgle Rindzevičiūtė has recently shown how this kind of collaborative research emerged from the US/Soviet coproduction of modeling strategies that began in the 1970s in the framework of research on global circulation models (GCMs).88Ėgle Rindzevičiūtė, The Power of System: How Policy Science Opened Up the Cold War World, Ithaca: Cornell University Press, 2016: 151-152. In this respect, the Soviets played an important role in stretching these investigations to a planetary dimension.

Working in part independently from members of TTAPS, Soviet scientists, in particular atmospheric physicists Vladimir Aleksandrov and Georgy Golytsin,99Golytsin’s research on Mars’s dust storm and how it affected the planet’s temperature had already attracted Sagan’s attention, who invited Golystin to deepen his understanding and assessment of this phenomenon with the intention of applying the Mars case study to the Earth’s global atmosphere. Other Soviet scientists involved in this modeling effort were the mathematician Georgiy Stenchikov, biologist Iury Svirezhev, and mathematician Alexander Tarko. studied the effects on nuclear weapons on the biosphere. These scientists were close collaborators of the polymath mathematician Nikita N. Moiseev, Director of the Dorodnitsyn Computer Center of the Soviet Academy of Science, a representative of both UNESCO and the Scientific Committee on the Problems of the Environment (SCOPE). Moiseev played a leading role in fostering research efforts in the Soviet Union that addressed anthropogenic signatures as the main drivers of massive environmental changes pertaining to the whole biosphere.

Together with his collaborators Svirezhev and Aleksandrov, Moiseev had established two laboratories: one examining the cycling of biotic factors in ecosystems, and the other dealing with the dynamics of the ocean-atmosphere circulation. Both laboratories promoted a comprehensive research program whose findings could be used not only to monitor the biosphere’s processes in relation to anthropogenic determinants, but also for much broader purposes. With this scope, they had to indicate possible alternatives in the future development of humanity, and with it, propose new directions for scientific and technological advancements.1010Nikita Moiseev, Kak daleko do zavtrashnego dnia. Svobodnye razmyshleniia 1917-1993 (How Far is Tomorrow. Free Reflections) Moscow: Taideks Ko, 1995. To this end, Moiseev and his collaborators lined up regular meetings which concerned not only the effects of nuclear warfare, but primarily a more comprehensive study on the effects of anthropogenic activities on the cycling of elements between the geosphere and the biosphere, and the drivers behind the rising CO₂ level.1111Indeed, the United States/Soviet Union cooperation was of particular importance to the US National Climate Program and its different working groups.

Most importantly, the Soviets’ work facilitated a step forward in Nuclear Winter modeling. TTAPS had produced a 1-dimensional simulation of the possible effects of a nuclear war in 1982. This model neglected local and seasonal atmospheric variations and could only analyze the simulated dynamics of atmospheric changes during the first month after the nuclear attack.  Soviet scientists produced a 3-dimensional model of global circulation which was presented for the first time at a symposium on the co-evolution of Man and the Biosphere in Helsinki in September 1983. Not only did the Soviet model offer a picture for the first year post-attack, it was also a two-part climate model: the first part was a two-level atmospheric model of global circulation, and the second a thermodynamic model of the upper ocean which described the oceanic and atmospheric interaction with the propagation of pollutants—dust and soot—in the atmosphere by horizontal winds and vertical motion.

TTAPS had a far more refined model of atmospheric dynamics than the Soviets, but it was not coupled with a model of ocean dynamics and thus did not reflect global circulation patterns. According to Moieseev, a model that lacked the hydrosphere could never simulate the effects of Nuclear Winter, as it would barely account for the atmospheric dynamics, let alone ecological and biological processes or the alteration in nutrient cycling. The Soviets thus focused their efforts on modeling ecological processes and nutrient exchange through global cycles, an attempt that was recognized on the other side of the Iron Curtain by Mark A. Harwell, a professor at Cornell University and one of the editors of the twenty-eighth SCOPE report on the consequences of nuclear war for ecology, agriculture, and human health. And within the USSR, the article published in 1983 in the Soviet journal Priroda titled “Nuclear Winter puts at doubt the existence of humankind as a biological species” makes explicit their effort to disseminate concern over biosphere devastation within the Soviet scientific community, stressing that humanity is now on the verge of a great environmental, biological, economic, and medical disaster.

From the atmosphere to the Earth System

When the Pentagon became alerted about the ongoing US/Soviet collaboration that was beginning to reveal Nuclear Winter to be a plausible phenomenon, US government officials’ initial reactions reveal a clear anxiety. Under pressure from Sagan and Aleksandrov in particular, Republican Congressmen William S. Cohen and Jim Leach and Democrat Congressman Timothy Wirth introduced an amendment calling for study of Nuclear Winter.1212William Cohen, “Cohen Seeks Study of ‘Nuclear Winter’”, Press Release, 1984. They ordered the secretary of defense under the Reagan administration, Casper Weinberger, to prepare a public report on the scientific and policy implications of the Nuclear Winter scenario.1313Caspar W. Weinberger, The Potential Effects of Nuclear War on the Climate: A Report to the US Congress 131, 99th Cong., 1st sess., 1985: S2579-85. The report was required to include all “atmospheric, climatic, environmental, and biological consequences” of nuclear war.1414Jacob Scherr, “Coming to Grips with Nuclear Winter,” Law, Environment: Science and Policy for Sustainable Development, 27, 8, (1985): 4-40. But instead, the Pentagon took the report as an opportunity to isolate the controversy over climatic consequences, and “to trivialize” other potential effects” of nuclear conflict.1515Ibid. (1985, p. 5). Thus Weinberger did not fulfill the specific requests made by Cohen et al., who insisted on a broader environmental assessment of the atomic explosions,1616“Transcript of interview with President on a range of issues,” The New York Times, February 12, 1985. Ibidem, https://www.nytimes.com/1985/02/12/world/transcript-of-interview-with-president-on-a-range-of-issues.html eventually allowing the Department of Defense (DoD) to minimize the unprecedented consequences of nuclear explosions in the biological and ecological realm—but still support the hypothesis that climatic consequences would follow a possible nuclear conflict.

As Scherr pointed out in his 1985 article on the politics of Nuclear Winter, the DoD report on the climatic effects of nuclear war “makes clear the failure of the secretary of defense to meet his legal obligation. In fact, the introduction stated that the Pentagon had chosen to consider only the climatic signatures of a nuclear war. It does not, contrary to the explicit direction of Congress, deal with the full-range disruption of global circulation patterns that would in turn generate a cascade of effects on biological, ecological and environmental systems, especially caused by the blast, fire, radiation.”1717The budget allocated to the research effort to study the Nuclear Winter was cut to half of the initial promised sum (50 million dollars for a 5-year plan). Reagan even stated that a Nuclear Winter could be avoided if the nuclear attack was aimed at specific targets. See Scherr, “Coming to grips with nuclear winter,” 1985, p. 5. The assessment of these causes was particularly important, as the long-term circulation of nuclear debris in the atmosphere would not only alter the climate system as simulations were showing. The short- and long-term effects of fire, radiation, and fallout would also interfere with the function of the whole Earth System and the cycling of chemical elements. As perverse as this research scenario was, according to Harwell it was analogous to that found in many centers throughout the world that favored atmospheric assessments over the study of biological and ecological effects. Even though soot and radiation affect agriculture and threaten human livelihood, he notes, and current Nuclear Winter research should thus prioritize biological effects, the Pentagon’s strategy of “delaying biological assessments until physical uncertainties are resolved, then, is [to] never do them.”1818Mark A. Harwell, “Nuclear Winter – Why Study the Biological Effects of Nuclear War?,” Nuclear Winter, The Newsletter of the Centre on the Consequences of Nuclear War, Summer (1985): 3.

Downplaying the cascade of ecological effects that a Nuclear Winter might trigger was a move to safeguard the United States deterrence policy. At the same time, recognizing the importance of the temporal atmospheric effects that the explosions would produce was a neat concession to Nuclear Winter scientists, who could still engage with the endless uncertainties of the very complex and unpredictable atmospheric system. Further research into global climatology was a desideratum for the US government, which had supported weather and climate modification projects, for example, for military purposes. In the 1980s, modeling climate change was nearly impossible due to the continuous revisions that models were subject to, which made very difficult to work with data sets.1919Paul Edwards, A Vast Machine. Computer Models, Climate Data and the Politics of Global Warming, Cambridge Mass, London: The MIT Press, 2010: 253. Ultimately these uncertainties could be strategically used to cast doubts on Nuclear Winter analysis. According to Harwell, the explicit focus on the atmospheric processes served to stall research on the most pressing issues and avoid taking biological effects seriously.

If minimizing the threat of Nuclear Winter was to some extent a tactical move to secure strategic defense, keeping it alive was also useful to international security and for keeping pace with both international research and global environmentalism. Likewise, funding scientific collaboration on Nuclear Winter made it possible for the US government to control and orient research on some aspects rather than others. For example, many theoretical disputes focused on the acute phase of a quick temperature drop. But in the long run, the biological and ecological effects of even a small decrease in temperature could affect regional precipitation patterns with major, long-term consequences, much worse, in some regions, than those of the total loss of sunlight for a limited time period. Moreover, studying the biological effects of nuclear war was essential because they feed back directly into physical processes and affect the climate. Therefore, while politically expedient, studying the biosphere in isolation from the atmosphere system is obsolete and misconstrued way of proceeding, as all these consequences affect the Earth system.2020Harwell, “Nuclear Winter”, 1985.

A big hoax fabricated by the Soviets

Now that the Nuclear Winter theory had been downgraded in the US scientific community, the main concern of the Pentagon was what to expect from the Soviet side of cooperation. Were the Soviets working on more detailed examinations of the Nuclear Winter hypothesis, extending their investigations to include global ecological studies? Whereas US authorities were refraining from pushing the Nuclear Winter into the public debate, Soviet officials apparently widely endorsed the Nuclear Winter theory. The Computer Centre of the Academy of Sciences directed by Moiseev already had biosphere research and global ecological modeling as top priorities, but aptly reoriented these lines of inquiry towards the study and modeling of the biosphere under a nuclear attack. Contrary to the Americans, the Soviets wanted to include “secondary and tertiary effects” in the model, such as disruption of food chains and ecosystem responses to post-conflict biogeochemical changes.2121Lawrence Badash, A Nuclear Winter’s Tale. Science and Politics in the 1980s, Cambridge MA: MIT Press, 2009: 223. In fact, as Moiseev had already pointed out in 1972 in relation to the work of Jay Forrester, Donella and Dennis Meadows, and Jørgen Randers in The Limits to Growth, to simulate the functioning of the entire biosphere in relation to human impact required a far more complex model.

For the Soviets, Nuclear Winter research appeared as an opportunity to assess more broadly the state of the Earth under human influence. Moiseev insisted on the importance of preventing a nuclear war to assure humanity’s further co-evolution with the biosphere, and mentioned the Noosphere concept put forward by the Russian geochemist Vladimir Vernadsky in the early twentieth century.2222Nikita Moiseev, “Coevolution: Some propositions,” in International Seminar on Nuclear War. 4^th session: The Nuclear Winter and the New Defense Systems: Problems and Perspectives ed. Stanislao Stipcich and W. S Newman (1992): 457. The visible and catastrophic scenario of a planet wrapped up in dust, cold, and darkness prompted the Soviets’ effort to model human-induced Earth system changes, but they claimed that the disruptions of heat exchange processes between the atmosphere and the ocean may result from many different anthropogenic activities, not only nuclear war. Moiseev and Aleksandrov stressed the urgency of studying the biosphere processes as co-evolving with human agency in a comprehensive way, one that would include the socio-economic sphere and the evolution of economic factors. The ecological situation of our planet was in a grim condition as a result of the depletion of natural resources which caused unprecedented environmental degradation. A systemic perspective where the Earth’s spheres interact with the human dimension—the anthroposphere—informed an understanding of the nuclear conflict as a cataclysm that would extend to all parts of the Earth system, offering a vivid simulation of a new planetary transition. Moreover, these studies would turn out to be decisive in offering new insights toward further and alternative developments of human societies.2323Moiseev, “Coevolution”, 1992: 46; Ėgle Rindzevičiūtė, “Soviet Policy Sciences and Earth System Governmentality,” Modern Intellectual History, Vol. 17, (2018): 179-208. Moiseev and Aleksandrov seemed to bind Nuclear Winter research to global environmental research and to the transition from the biosphere to the noosphere, prefiguring a catastrophe caused by humanity and at the same time offering a means to understanding the planetary crisis as a multileveled phenomenon of the Earth system.

The full and open support of Nuclear Winter research from the Soviet side, however, may have cast doubts about the honesty of their intentions. By extending the effects of Nuclear Winter well beyond its impact on the atmosphere, and trying to depict a catastrophic transition with ecological and demographic repercussions on a planetary scale, the US accused the Soviets of instigating pacifist movements in the United States which put its national security strategies at risk. These arguments ignored the long-standing environmental sensibility in the history of Russian natural sciences which certainly informed research on the biosphere’s functioning in the years preceding Nuclear Winter research and collaboration. Most absurdly, these accusations openly disregarded the fact that, at least since the Halloween conference, American and European scientists such as Harwell, Harold A. Mooney, and Paul Ehrlich actively encouraged the study of the global environmental consequences of nuclear war with an equal emphasis as their Soviet colleagues. Nevertheless, in 1985 the Pentagon published a document written by Leon Gouré, a Russian-born analyst and defense advisor for the RAND Corporation, titled An Update of Soviet Research on and Exploitation of Nuclear Winter: 1984–1986.2424Leon Gouré, An Update of Soviet Research on and Exploitation of Nuclear Winter, 1984-1986. Prepared for Defence Nuclear Agency, Washington, 1986. Gouré’s report argued that the Soviets used the Nuclear Winter theory strategically as a means of propaganda. Pentagon scientists, therefore, decided to ignore the effects of blasts on the biosphere and as well on the secondary and tertiary effects of fire on ecosystems.

In October 1986, around the same time the Pentagon released Gouré’s report, the SCOPE report no. 28, Environmental Consequences of the Nuclear War, was published. The editors had decided not to use the term Nuclear Winter: “Although it is a convenient metaphor for use in describing the generic consequences, we have chosen to avoid use of the term ‘nuclear winter’ in this study because it does not, in a strict scientific sense, properly portray the range, complexity and dependencies of the potential global scale environmental consequences of a nuclear war. By this choice, we are not suggesting that the environmental effects of a major nuclear exchange would be inconsequential; to the contrary, we find that they would be substantial and significant.”2525Barrie Pittock et al., Environmental Consequences of Nuclear War, Physical and Atmospheric Effects, SCOPE 28 Vol I. in Mark Harwell and T.C Hutchinson ed Environmental Consequences of Nuclear War, Ecological and Agricultural Effects. SCOPE 28 Volume II. Chichester, New York, Brisbane, Toronto, Singapore: John Wiley and Sons (1986): XI.

A missed occasion

Returning from this historical digression on the story of Nuclear Winter at the heights of Cold War history, we find ourselves in a world where the threat of a nuclear conflict has not faded away—we see it resurface in the context of the Russian invasion of Ukraine. Some voices shout about the “End of the World,” claiming that Vladimir Putin has already threatened to bring upon us a decade-long Nuclear Winter which will obliterate many locations in the world. But as one can easily learn from the many newspaper articles attempting to explain the madness that has hit the world in the first months of 2022, this time around, the consequences of a nuclear war are also underestimated if not completely disregarded. Foreign policy experts maintain that a nuclear winter is a less likely scenario than a more targeted conflict using “tactical” atomic weapons—using nuclear weapons might be again acceptable as its effects won’t affect society at large. The Nuclear Winter story could have taught us more forcefully that, one way or another, if a (nuclear) conflict starts, what happens next is uncertain—nobody knows whether and in which way the conflict will escalate. In this respect, almost 40 years later we are still where we started when Crutzen and Birks published “Twilight at Noon.”

Nuclear Winter also lets us understand a great deal more of Crutzen’s recent theorization of the Anthropocene: nuclear twilight is a clear antecedent form of his later thinking on earthly and environmental catastrophe, which in some way absorbed the planetary focus of the Nuclear Winter debates. In this light, the selection of the radiogenic fallout as a marker of the Anthropocene acquires a particular relevance. The idea that the byproducts of science and technology provide evidence that humanity has a geological agency is nothing new. However, nuclear agency is an exceptional angle from which to study Anthropocene-related phenomena that goes well beyond the “nuclear,” concerning the development of scientific practices, theories, models, and even disputes through which the Anthropocene became a “visualizable” threat.

The Anthropocene theory goes back to 2000 when Crutzen and Stoermer proposed to use the term to distinguish the current geological epoch from the Holocene based on the visible global impact of humankind on Earth’s geology and ecology. Since then, the “Anthropocene” has grown into a buzzword, snuck in and out of the fieldwork and laboratories where the image and prototype of a GSSP Golden Spike is being “manufactured” to enter disparate venues, and reached an increasingly wider audience of experts and publics. Over the last 20 years, a timid word grew into a field of study at the intersection of the sciences and the humanities aiming at understanding the manifold meaning of the anthropogenic changes in the Earth System. The global environmental crisis we are experiencing today reveals the urgency to recognize and formalize the Anthropocene. Yet there is a long way ahead of us and there is still strong reluctance in accepting it, even within the community of earth scientists and climatologists.

The Nuclear Winter offered the occasion to anticipate the process of scientific and cultural recognition of the Anthropocene as a new geological epoch, and the parallels its history provides to today’s term can serve as a warning. Nuclear Winter showed vividly, already in the 80s, what a different stage of the Earth might look like. Different types of media showed people that a nuclear war could reshuffle the elements of our planet, and the problem of modeling a Nuclear Winter scenario showed scientists that such models would need to simulate the functioning of the Earth system in its entirety by factoring in an anthroposphere that has developed the tools to annihilate itself and its habitat. It also offered a self-apparent technoscientific and socio-political context for interpreting the markers of the Anthropocene that fall under the category of combustion particles, which otherwise are not even perceivable from the air we breathe and yet are responsible for global environmental degradation. Nuclear Winter became controversial in the policy world precisely when scientists’ collaboration resulted in the collective attempt to extend the study of its effects beyond atmospheric processes to include the whole spectrum of the Earth system, and the occasion to register all these signals was missed. The Nuclear Winter story is perhaps the clearest example of what a path opposite to a recognition of the Anthropocene would look like—one where it is buried instead. As studies on the all-encompassing effects of the Nuclear Winter on shifting dynamics in ecological, biological and anthropogenic dimensions were hampered, the pace of Earth system modeling, especially those efforts resulting from collaboration between Western and Soviet sciences, was slowed to a halt. Paradoxically, these projects could have created knowledge that would be precious in advancing our current understanding, elaboration, and assessment of the current geological epoch.

Giulia Rispoli is an Assistant Professor in History of Science at Ca’ Foscari University of Venice, and a Visiting Scholar at the Max Planck Institute for the History of Science in Berlin (MPIWG).

Please cite as: Rispoli, G (2022) The Moment We Visualized the Anthropocene. Nuclear Winter and Other Disasters. In: Rosol C and Rispoli G (eds) Anthropogenic Markers: Stratigraphy and Context, Anthropocene Curriculum. Berlin: Max Planck Institute for the History of Science. DOI: 10.58049/0563-zh20