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Where does the story begin?

As I suggested at the end of the last chapter, in order to make sense of where we stand now, we first have to look back. So, where does this story begin? In this second part of the book, we will see how trying to determine the historical roots of what today is called climate engineering forces us to embark on a turbulent journey through the history of climate science to the turn of the twentieth century (and sometimes earlier to the seventeenth and eighteenth century) when human efforts to modify climatic conditions gradually emerged as a critical political project in North America and Europe.1 Exploring these historical perspectives does more than add mere context or background to the story of this book. They are essential to understanding the recent rise and status of climate engineering. On the one hand, they unpack the roots of ideas about ‘engineering’ or deliberately modifying the climate. These perspectives explain how experts came to look at global warming as an engineering issue, an issue that might be addressed by targeted techno-scientific intervention and control. On the other hand, they suggest why climate engineering did not, however, emerge as a ‘Plan A’ in the face of global warming, but instead gained traction as a daunting possibility, a ‘bad idea whose time has come’. Diving into the longer history of climate engineering thus explains how we arrived at the present and provides the grounds for staging a meaningful debate over how to move forward.

In this chapter, we will see how visions of control, deliberate intervention, modification, or ‘engineering’, came to define relations between a nascent field of climate science and politics during the first half of the twentieth century. These visions of control ‘matched’2 the scientific to political struggles of the time. They fostered political interest in climate expertise and were instrumental in establishing the institutional and material infrastructure that modern climate science now rests on.3 This chapter will provide a brief glimpse into the longer-standing history of how experts came to look at climatic change in a way that would suggest the option and potential of its targeted ‘engineering’. It traces how this particular gaze onto the issue was assembled, providing the historical roots for later notions of climate engineering.

Before we embark on this journey, it should be noted that this effort necessarily implies working with a moving target. I do not wish to suggest that these early visions of climate modification and control – indeed the very concept of what was understood as ‘climate’ – has been the same for the past hundred or so years. Climate science, as we will see, was part of meteorology for most of the twentieth century, and that means that ‘climate and weather were not just intimately connected, they were essentially identical’.4 It was not really until the 1980s that the climate emerged as a global category, understood as more than aggregated weather phenomena. But this essential interrelation between scientific insights and concepts on the one hand, and the social order on the other, is precisely part of this story. The goal of the following pages in this sense is to follow the experts’ accounts through their respective historical settings and to understand how these accounts have incrementally assembled a vision of deliberate climate modification and control that suggests climate engineering as a potential remedy against global warming. So, when I speak of ‘climate’ in the following, then this necessarily comprises a very different scientific concept than the one that emerged during the second half of the twentieth century.

The discovery of a ‘grand possibility’: Notions of climate modification before the mid-twentieth century

On 14 August 1912, an Australian newspaper featured some promising news on the prospects of climatic changes, or, more specifically, on the ‘considerable’ impact that carbon dioxide emissions may have on the Earth’s temperature:

The furnaces of the world are now burning about 2,000,000,000 tons of coal a year. When this is burned, uniting with oxygen, it adds about 7,000,000,000 tons of carbon dioxide to the atmosphere yearly. This tends to make the air a more effective blanket for the earth and to raise its temperature. The effect may be considerable in a few centuries.5

This newspaper snippet illustrates how initial observations of what today is considered one of the greatest challenges to humankind, not only motivated optimistic reactions, but seemed to promise great potential. Scientists viewed carbon emissions not as a potential problem, but as a potential solution: ‘warming seemed a good thing’.6 In fact, early observers of human impacts on the climate sensed a ‘grand possibility’ to deliberately regulate the ‘future climate of the earth’.7 In what follows, we will trace how human impacts on the climate incrementally emerged as an object of scientific observation and political interest during the turn of the twentieth century and how this fuzzy picture of climatic change fostered initial hopes of deliberate modification.

Observing, charting, mapping: The rise of weather stations

The emergence of a global system of meteorological data collection spanned several centuries and varied substantially across different nations.8 In the United States, coordinated data collection emerged from scattered individual efforts, dating all the way back to the seventeenth century. In his ‘Short Bibliography of United States Climatology’ from 1918, Harvard Professor Robert Ward refers to Rev. John Campanius, ‘who, in 1644–45, at the Swedes’ Fort, near Wilmington, Del. kept what is believed to have been the first regular record of the weather on the North American continent’.9 These efforts gained political support through several of the so-called founding fathers who began charting weather and water temperatures during the eighteenth century.10

Early notions of climate modification appear here already in the context of American settler colonialism. Historian Jim Fleming recounts how the idea that the North American climate could be improved by cultivating the land was a critical theme in colonial America. ‘Colonial promoters’ suggested that by settling the land – clearing the forests and cultivating the soil – the climate would become more moderate and pleasant.11 This narrative became an integral part of the colonial project. Proponents envisioned that the so improved and cultivated climate would provide a ‘proper nursery of genius, learning, industry and the liberal arts’.12 Critical voices warned of the adverse effects of these early climate modification schemes, suggesting that deforestation was in fact leading to desertification and crop failure.13

The nineteenth century brought coordination and cooperation to this new endeavour, as interested parties attempted to standardise and broaden the scope of meteorological observations. Most of the early efforts to coordinate data collection were state funded and driven by military and regional agricultural interests.14 The first nationally coordinated data collection effort in the United States was initiated by an 1816 order from the Army’s Medical Department, which made it obligatory for every surgeon to keep a weather diary.15 This military order generated a detailed record of weather data.16 In 1849, the Smithsonian Institution initiated a ‘fairly extended system of observations’ employing as many as three hundred and fifty observers. This work was later transferred to the War Department (as were all of the Smithsonian’s meteorological initiatives). Finally, in 1870, the US government established the National Weather Service (NWS). As with previous initiatives, the work of the Weather Service was closely linked to the military. Military posts served as central meteorological observation points and the army’s Chief Signal Officer oversaw the most important tasks being conducted by the newly created institution.17 Jim Fleming suggests that the Weather Service essentially served as a ‘national surveillance force’. Weather patterns were just one of the ‘threats to the domestic order’ that were observed here, from ‘striking railroad workers, Indian uprisings on the frontier, locust outbreaks, and natural hazards to transportation, commerce, and agriculture’.18

During these early years, ‘climate research’ in the United States thus primarily consisted of a network of amateur observers, charting and mapping weather patterns and temporal variations through an infrastructure of state and private weather services. These weather services largely amounted to ‘ad hoc efforts staffed by volunteers’ and were strongly tied to practical – agricultural, security – interests.19 The relevant theoretical insights that would contribute to scientific theories of climatic change happened elsewhere.

Scientific advances and the emergence of the hothouse theory

Progress in physical theories of global climate change was not systematically tied to this emerging infrastructure of practically oriented weather services.20 Instead, it was generated as part of a series of individual efforts without a clear institutional centre, mostly scattered across Europe.21 Only in hindsight can these efforts be understood as contributing to a joint trajectory. At the time, it rather seemed like a big mess, ‘each expert championed a personal theory about the cause of climate change’ as Spencer Weart suggests.22

There are many rich histories of this ‘discovery’ of global warming and the greenhouse effect.23 What follows can hardly serve as a comprehensive summary of these important insights. I merely want to focus on some of the central insights and relevant theories as they relate to the question at hand, namely how efforts to understand were connected to efforts to deliberately modify and control the climate.

In the 1850s and 60s, Irishman John Tyndall, a professor of natural philosophy at the Royal Institute of Great Britain, experimented with the radiative potential of various gases in the atmosphere, including carbon dioxide, ozone, and water vapour.24 By 1861, Tyndall had concluded that these gases were responsible for ‘all the mutations of climate which the research of geologists reveal. […] They constitute true causes, the extent alone of the operation remaining doubtful’.25 Tyndall eventually demonstrated that trace atmospheric constituents effectively retained heat radiation, attesting to what was then called the ‘hot-house theory’.26 Building on this research, as well as the work of the French physicist Joseph Fourier, and others, Swedish physicist Svante Arrhenius and meteorologist Nils Gustav Ekholm studied the impact of carbon dioxide on the Earth’s temperature.27 Earlier scientific findings on the connection between carbon dioxide and the climate had focused primarily on geophysical variations in the carbon cycle due to volcanic eruptions, vegetation, and other natural factors.28 Arrhenius extended these insights by developing a model that could predict the onset of Ice Ages29 – an issue that motivated much climate research at the end of the nineteenth century.30

Although scientists initially believed that anthropogenic carbon emissions played a rather negligible role in climate processes, this understanding shifted dramatically shortly thereafter.31 About a decade after Arrhenius had presented his prominent paper, ‘On the Influence of Carbonic Acid in the Air upon the Temperature on the Ground’,32 to the Stockholm Physical Society, he began to recognise the ‘noticeable degree’ to which the percentage of atmospheric carbon dioxide had changed in response to ‘the advances of industry […] in the course of a few centuries’.33 By slowly detecting the societal impact on the geologic processes of the climate system, Arrhenius and Ekholm incrementally united human agency and the natural climate system at the dawn of the twentieth century.34

This early theoretical advancement of climatological knowledge, however, did not include prophetic concerns about a global warming trend.35 In fact, the initial problematisation of climatic change inverted today’s problematisation of the issue: well into the twentieth century, the assumption was that humankind would soon experience a new Ice Age.36 Emerging insights into the possible human impact on the climate via the burning of fossil fuels thus sparked hope, namely, the hope of being able to avert the daunting crisis of a freezing planet.37

In effect, these insights prompted early visions of control, suggesting the potential to deliberately modify the climate. Writing in 1901, Ekholm was amazed by the sheer potential and prospect of human impacts on the climate. His observations seemed to promise the possibility

[…] that Man [sic] will be able efficaciously to regulate the future climate of the earth and consequently prevent the arrival of a new Ice Age. […]. It is too early to judge of how far Man might be capable of thus regulating the future climate. But already the view of such a possibility seems to me so grand that I cannot help thinking that it will afford to Mankind hitherto unforeseen means of evolution.38

Fleming therefore described Ekholm as an ‘early and eager spokesman for anthropogenic climate control’.39 Observations such as the one by Ekholm or the Australian newspaper from the beginning of this chapter, illustrate just how differently climatic change and deliberate climate intervention were related in this historical setting compared to today. The prospect of anthropogenic climate change appears here as an ‘unforeseen means of evolution’, hardly comparable to the daunting prospect of dangerous global warming that we are confronted with today. This begins to suggest just how deeply embedded scientific insights are in their respective historical times.

We must fast forward several decades from Ekholm’s observations to see how empirical evidence of a warming trend that could be confirmed by detailed meteorological records pushed the carbon dioxide theory of climatic change back into the scientific limelight.40 In 1938, Guy Stewart Callendar, a British engineer, re-established the scientific validity of the carbon dioxide theory of climate change41 when he presented a data set that clearly demonstrated a warming trend. Although he was not a professionally trained meteorologist, he ‘had the audacity to stand before the Royal Meteorological Society in London’42 and formulate the carbon dioxide theory in its ‘recognizably modern form’.43 To be sure, weather researchers continued to view anthropogenic warming as unproblematic. In the context of continued fear of the coming Ice Age, Callendar, too, believed that his findings ensured the indefinite delay of the ‘return of the deadly glaciers’.44

At the turn of the twentieth century, the relationship between scientific progress in climatology (as a subfield of meteorology) and the state was thus defined by a notable divide. On the one hand, there was scientific progress and disciplinary advancements scattered across many individual projects of scientific curiosity, and on the other, there was the dominant system of state-supported weather services that employed most ‘meteorologists’ of the time. This divide was particularly substantial in the United States, as we have seen, where climate research was mostly restricted to the Weather Bureau and strongly tied to military and practical agricultural interests.45 Through the first half of the twentieth century, most professionals at the Bureau ‘lacked any college degree’.46 Indeed, the first meteorological university department in the United States was not established until 1928 (at the Massachusetts Institute of Technology).47 According to Spencer Weart, the predominant assumption during this time was that ‘a canny amateur with no academic credentials could predict rain as successfully as a Ph.D. meteorologist’.48 The divide between academic research and pragmatic weather services was somewhat less dramatic in other countries. In Europe, for example, meteorology was considered equally prestigious as astronomy and theoretical research in the field was conducted in academic institutions in Norway, Sweden, England, and Germany.49 But ‘everywhere’, as Edwards suggests, it was national weather services and not universities or other academic institutions that employed the vast majority of meteorologists. Climate research, in other words, mainly boiled down to charting and forecasting the weather during the time and was seen ‘as a form of practical work, rather than a research science’.50 There was no political interest in advancing scientific theoretical work in the field.

The geopolitical challenges of the twentieth century: Calculating, predicting, and controlling the climate

The beginning of World War II changed this outlook substantially. Political (and especially military) interest in expanding techno-scientific control over climatic conditions ‘matched’ scientific interests. This lead to the setup of a massive infrastructure of climatological expertise and effectively advanced the emergence of climatology as a bounded discipline.51 As we will see later, this infrastructure eventually ‘discovered’ anthropogenic climate change as an issue of environmental safeguarding, effectively questioning the hopes of techno-scientific intervention that had driven the very setup of this infrastructure. Put differently, the infrastructure that was devised to make the Earth’s climate politically legible and controllable would later put the very prospect of control into question.

Linking political and scientific agendas around climatological expertise

The geopolitical challenges of the mid-twentieth century transformed meteorology and oceanography, into what Zeke Baker refers to as a political ‘high-stakes issue’.52 Baker recounts how in the United States especially, climate research became a well-established scientific discipline in the face of these challenges. The urgent military need for progress in meteorological and oceanographic expertise pushed scientific boundaries, uniting the formerly disparate state-funded and scientific efforts in climate research, and – in Baker’s terms – directly ‘matched’ political and scientific challenges.

World War II generated a boom in both meteorological personnel and observational infrastructure. At the beginning of the war, US meteorologists remained institutionally bound to the Weather Bureau and isolated from academic networks. As indicated earlier, this marked a stark contrast from Europe. Thus, when major US universities began developing academic programs in the early 1940s, almost all were directed by Scandinavians who taught Bergen school theories and methods.53 The so-called Bergen school, named after their Norwegian location, was a group of researchers linked to the Norwegian meteorologist Vilhelm Bjerknes who ‘redefined the basic concepts of weather prediction’ and provided the cornerstone for scientific meteorology.54 Bjerknes essentially conceptualised meteorology as an exact atmospheric science, providing the theoretical foundations for climate modelling. The atmosphere became understood in this context as a ‘purely mechanical and physical phenomenon’, an ‘air mass circulation engine’, as Gabriele Gramelsberger explains. This engine is driven ‘by solar radiation and gravitational forces expressed in local differences of velocity, density, air pressure, temperature, and humidity’.55 With this understanding, Bjerknes outlined the basic equations for a General Circulation Model (GCM) of the climate. The problem, however, was that they were too complex to solve with the then existing analytical methods. It would take the advent of computers to turn these equations into action and run the first numerical climate models, as we will see in a bit.

The Bergen school scientists ‘worked diligently’ to make their insights known internationally.56 In the end, Fleming suggests that it was a graduate student, Anne Louise Beck, who drew the attention of the US Weather Bureau to the Bergen school methods for the very first time. After a year of working alongside Bjerknes, Beck published her thesis in the Monthly Weather Review making it visible across the Atlantic. In addition, the military challenges of an air-based war directly matched the scientific challenges of understanding, observing and bringing new perspectives to atmospheric circulation dynamics.57 As a result, the war facilitated the development of critical observational and computational infrastructure, including radar, satellites, and the electronic computer.58 In a matter of years, tens of thousands of Americans were trained as meteorologists and technicians. Some observers of the era have estimated a 1500% growth in professional personnel during the war years.59 Established only eight years earlier, the army’s Air Weather Service (AWS), for example, employed 19,000 people by 1945.60 This military connection persisted as we will see. Long after the war had ended, most American meteorologists were still linked to the military.61

By the end of the war, basic scientific advancement in climate science had become a national strategy as part of the escalating conflict with the Soviet Union. Within this context, climate science emerged as a bounded scientific field based on its capacity to ‘shape the national security state’,62 and it thrived because it was directly linked to the continuing geopolitical challenges of the time. This distinct science-politics configuration facilitated substantial advances in the problematisation of both climate change and climate control.

The International Geophysical Year (IGY), a set of projects spanning 1957 and 1958, as well as the first computer model experiments, were both essential developments in the problematisation of climate change as a societal challenge. The IGY was a response to the increasingly intolerable disciplinary fragmentation of climate-related research in the middle of the twentieth century. Researchers from a plethora of distinct, highly specialised subfields were struggling to collaborate across disciplinary and geographical borders. The IGY addressed this challenge by invoking political hopes for military applications of the resulting knowledge:63 ‘[N]ational security and scientific internationalism coalesced around a broad program of rational mastery […]’.64 The resulting project offered opportunities for international scientists from different disciplines to work together on ‘interdisciplinary research projects grander than any attempted before’.65 As part of the IGY projects, Charles David Keeling commenced measurements of carbon dioxide (CO₂) on top of the active Mauna Loa volcano in Hawaii.66 Keeling’s measurements resulted in the infamous Keeling Curve, an ‘icon’ of anthropogenic climate change today.67 His insights were able ‘put a capstone’ on the earlier work by Tyndall, Arrhenius, Callendar, and others.68

The 1950s and 1960s also witnessed the computation of the earliest climate models. As we saw earlier, Vilhelm Bjerknes and Felix Exner had identified the basic equations of atmospheric dynamics in the early twentieth century. Starting in the 1940s, an increasing focus on numerical weather prediction linked scientific challenges related to the representation of atmospheric dynamics to military strategic challenges, such as aviation safety.69 The subsequent advent of the first calculating machines – and eventually the electronic computer – meant that Bjerknes and Exner’s equations could be mathematically solved and computed.70 What follows is a rush of events, driven both by US American and Scandinavian scientists.71 In the US, Jule Charney and others successfully computed several prognoses on the Electronic Numerical Integrator and Computer (ENIAC).72 Gabriele Gramelsberger and Johann Feichter recount how, beginning already in 1948, Charney and his colleagues ‘developed the very first computer model for weather forecasting, a simple barotropic model with geostrophic wind for the area of the United States of America’.73 In 1950, the scientists then ran ‘the first numerical experiment ever conducted in meteorology’.74 And in the spring of 1953, Swedish scientists generated what would be the very first real-time weather prediction on the Swedish Binary Electronic Sequence Calculator (BESK).75 The scientists were successful at ‘beating the actual weather by some ninety minutes’.76 These developments incrementally transformed meteorology from a strictly descriptive field of rather practical ambitions into an increasingly theory- and model-based science.77

The rise of deliberate climate modification …

After the war ended, the boom in numerical weather prediction was sustained by the growing political interest in modifying atmospheric processes.78 Global climate models provided a critical link between the advancement of political and scientific infrastructures, securing financial and organisational resources for both sides. The newly established infrastructure of meteorological expertise enabled observations at higher resolutions and thus generated visions of prediction and control in relation to the climate.

The work of Harry Wexler, one of the most renowned meteorologists of the mid-twentieth century, is a case in point.79 In Wexler’s career, many of the institutions, concepts, and infrastructures that had been shaping the establishment of climate expertise at the interface of science and politics coalesced. Wexler became an internationally recognised figure pushing the boundaries of new technologies. He pioneered the use of electronic computers for climate modelling purposes and was centrally involved in the management of US atmospheric observations via satellites and rockets. Wexler worked for the US Weather Bureau throughout his career and in 1961 was appointed to represent the United States in negotiations with the Soviet Union on the joint use of meteorological satellites.

In the 1950s, Wexler began to dedicate Bureau resources to the critical exploration of climate control.80 Somewhat ironically, Wexler’s appraisal of climate intervention options was an important step in the further advancement of this research. As a well-established and renowned scientist, Wexler was able to supply this line of inquiry with professional legitimacy, despite his critical attitude towards these measures.81 This ambiguous engagement with the outlook of climate control is thus notable as it parallels the stance of much of the scientific exploration of climate engineering today. In other words, Wexler’s pioneering engagement with climate control seems driven by a somewhat sceptical scientific curiosity, a curiosity that, on the one hand, effectively advanced the debate, drawing attention to not only the possibility and outlook of such an endeavour, but also to some of the technical intricacies. Meanwhile, on the other hand, it was guided by concern and distress for what this might imply.

In 1958, Wexler criticised the ‘tempting’ possibility of modifying basic atmospheric radiation, particularly by altering the Earth’s reflectivity.82 Wexler concluded that

when serious proposals for large-scale weather modification are advanced, as they inevitably will be, the full resources of general-circulation knowledge and computational meteorology must be brought to bear in predicting the results so as to avoid the unhappy situation of the cure being worse than the ailment.83

Four years later, he pursued his sceptical fascination with anthropogenic climate control in a lecture entitled, ‘On the Possibilities of Climate Control’, which was addressed to technical audiences across the country.84 Wexler was explicitly concerned here not with the prospect of local weather modification schemes – such as precipitation control or ‘rain-making’ – but with planetary-scale modifications that would result in ‘large-scale effects on general circulation patterns in short or longer periods, even approaching that of climatic change’.85 Notably, this concern included both deliberate as well as unwanted, inadvertent modifications of the climate, a distinction which emerged as essential during these years as we will see later.

In his lectures, Wexler presented a ‘purely hypothetical’ taxonomy of different kinds of climate modification schemes which ‘man might attempt deliberately to exert and also which he may now be performing or will soon be performing in ignorance of its consequences’.86 This taxonomy of deliberate as well as inadvertent climate modification schemes included approaches to both heat and cool the planet. He suggested (a) increasing the global temperature ‘by injecting a cloud of ice crystals into the polar atmosphere by detonating 10 H-bombs on the Arctic sea ice; (b) decreasing the global temperature by installing a global sun shield, by launching ‘a ring of dust particles into equatorial orbit to shade the Earth’; (c) suggesting that we ‘warm the lower atmosphere and cool the stratosphere by injecting ice, water, or other substances into space’; and finally (d) ‘destroy[ing] all stratospheric ozone, raise the tropopause, and cool the stratosphere by up to 80°C [144 °F] by an injection of catalytic de-ozonizer such as chlorine or bromine’.87

In that same year, 1962, after witnessing how substantial progress in climatological research further fuelled scientists’ interest in climate modification, Wexler warned a United Nations panel of the ‘inherent risks’ of this endeavour.88 Only a few years later, however, many national research organisations and scientific advisory bodies, such as the National Science Foundation (NSF), the President’s Science Advisory Committee (PSAC), the RAND Corporation, and the National Academy of Sciences (NAS), began to embrace the idea that increasingly better understanding of climatological processes would eventually lead to the option of their deliberate modification and ‘engineering’.89

In some respects, the debate that emerged over climate control during these years is thus strikingly comparable to discussions over climate engineering today.90 David Keith suggests that ‘the case for continuity’ between the emerging interest in deliberate climate modification during the 1960s and the debate over climate engineering today primarily ‘rests on the similarity of proposed technical methods, the continuity of citations to earlier work’, as well as ‘a similarity of debate about legal and political problems’ with the discussed measures.91 The technical concepts that were being discussed during the 1960s bear ‘a strong similarity’ in particular to what is now labelled as solar radiation management.92 Not only Wexler’s work, but also many of the above-mentioned assessments of climate control explored the potential of modifying the Earth’s reflectivity (albedo) in order to bring about deliberate changes in the global temperature. Technologies to remove CO₂ from the atmosphere, in contrast, were not yet discussed, despite the fact that carbon dioxide emissions were increasingly recognised as a problem, leading to ‘inadvertent modification of atmospheric processes’.93

A relevant difference between the debate in the 1960s and today concerns the motivation behind efforts to deliberately modify the climate. Keith suggests that during the 1960s, the focus rested on an ‘improvement of the natural state or mitigation of natural hazards, whereas the aim of recent geoengineering proposals is the mitigation of anthropogenic hazards’.94 The problematisation of deliberate climate modification as a potential political tool, as a response measure, or device of societal transformation, in other words, must be understood in the particular context of its time. Anthropogenic climate change as the defining reference problem for the current debate over climate engineering was only beginning to appear as an issue of global political significance during these years.

… And the rise of inadvertent climate modification

The rising interest in the potential of climate modification during the 1950s and 1960s not only pushed hopes for techno-scientific control over the atmosphere further into the science-policy limelight, but it also foreshadowed an imminent turning point in debates about such measures. Towards the latter half of the 1960s, environmental concerns appeared as increasingly prominent reference points in explorations of climate modification. Assessments of a grand possibility incrementally converged with the incremental discovery of a potential problem. Military interests had dominated efforts in weather control, particularly precipitation control during the Cold War. Cloud seeding discoveries at the General Electric Corporation after the war, for example, significantly advanced both commercial and military interest in these options.95 During the 1960s, scores of deliberate weather and climate modification programs operated in the United States96, as well as in the Soviet Union. Climate modification efforts continued to be largely motivated by the depiction of technological power as central to national strategic interests.97

Towards the end of the 1960s, this military exploration of climate modification was punctuated by the recognition of unwanted side effects. For the first time, ‘inadvertent climate modification’ started to appear relatively consistently as a topic. This ‘inadvertent modification’ was not yet problematised as a societal issue with global political consequences, but rather as an involuntary consequence of ‘the technological evolution of man’.98 Assessment bodies, such as the National Academies remained largely enthusiastic about the ‘exciting’ prospect of ‘man’s … power to modify his atmospheric environment’. Yet, incrementally, this power now seemed to provide both ‘challenge and opportunity:’

The challenge and opportunity presented to the world by the prospect of man’s achieving the power to modify his atmospheric environment is one of the most exciting of the long-range aspects of the subject. We are dealing with the possible consequences of a new and perhaps enormous power to influence the conditions of human life. Its potentialities for beneficial application are vast.99

In these expert observations, climatological research not only promised a great prospect – namely to deliberately modify the global climate – but it also began to foster a cautious sense of humility in the face of this ‘enormous power’.100 What would a couple of years later be discussed as problem and response, emerged here as two sides of a single equation: deliberate or ‘conscious’ modification was juxtaposed with ‘inadvertent human intervention’.101

This chapter has provided just a brief glimpse into the entangled histories of climate science and climate modification schemes. While scientific research and state interests have initially evolved separately in the United States, the geopolitical challenges of early and mid-twentieth century forged strong alliances between the two. Notions of modification and control were critical drivers of these alliances and thus figured prominently in the material and institutional establishment of climatology during this time. A dive into the early history of climate science has suggested that before human impacts on the climate were considered as a problem of global societal significance, they were seen as a major new opportunity, an exciting potential of the ‘enormous power of man’.

From this perspective, we might thus expect that the impending politicisation of anthropogenic climate change during the 1980s would lend renewed political attention to deliberate modification schemes. We might expect, in other words, that what is referred to today as ‘climate engineering’ would gain unprecedented steam in the face of the discovery of this new ‘grand societal challenge’. As we will see in the next chapter, however, the years that followed – especially the late 1960s to the 1990s – would tell a different story.